Endodontics Flashcards
What is the definition of endodontics?
The prevention diagnosis and treatment of the dental pulp and their sequelae
What is involved during endodontic treatment
Preserving all/parts of the pulp in health
Removing all of the pulp in irreversible disease
Carrying out further treatment to preserve teeth which have failed to respond to nonsurgical endodontics or developed new lesions: root canal retreatment or periradicular surgery
What are the reasons to perform endodontics?
Pain relief
Prevent adverse signs or symptoms
remove root canal contents
Promote healing and repair of periradicular tissues
What is the mantra behind endodontics?
Apical periodontitis is caused primarily by bacteria in Root canal systems If bacteria in canal systems are reduced to levels that are not detected by culturing, then high success rates are observed • Best documented results for canal disinfection are chemo‐mechanical debridement with Ca(OH)2 for at least 1 week • Mechanical instrumentation alone reduces bacteria by 100‐1,000 fold. But only 20‐ 43% of cases show complete elimination • Do mechanical instrumentation and add 0.5% NaOCl produces complete disinfection in 40‐60% of cases • Do mechanical instrumentation with 0.5% NaOCl and add one week Ca(OH)2: get complete disinfection in 90‐100% of cases
What is the evidence behind endodontic treatment diagnosis?
Koch’s postulates cannot be applied to establishing a bacterial origin of AP
• Mantra misses host response contributions (eg; Stashenko’s P or E‐selectin knockout
showed increased AP due to bacteria (thus, phagocytic leukocytes help to minimize AP via protection
against microorganisms; implies host defenses regulate the development of AP)
• What is the clinical significance of a “non‐cultivable” root canal sample when organisms can reproduce
in <12h?
• Implication: the “mantra” is focused on what the clinician can accomplish with current methods (eg.,
reduction‐disruption of a bacterial ecosystem). It only provides general guidance for developing better
therapeutic methods, and it cannot predict clinical success in cases where immunocompetence is
altered.
• Given a polymicrobial aetiology and a disease‐modifying host capacity, it is overly simplistic
to correlate one bug with given signs or symptoms. [Recall Sundqvist (1992) used odds ratio analysis &
concluded that bacterial pairings in infected root canal systems are not random, but appear to be due
to forces such as ecological commensalism. Since pairings can occur, correlational analysis between
bugs and signs ‐symptoms may be confounded if one bug is more easily cultivable than another]
Explain the 5 stage process of endodontic diagnosis?
- The patient tells the clinician the reasons for seeking advice.
- The clinician questions the patient about the symptoms and history
that led to the visit. - The clinician performs objective clinical tests.
- The clinician correlates the objective findings with the subjective
details and creates a tentative list of differential diagnoses. - The clinician formulates a definitive diagnosis.
What key symptoms will the patient complain of that may suggest pulp involvement?
Pain Swelling No sleep Broken tooth Discomfort from hot or cold Tooth colour change
What questions should the clinician ask the patient about symptoms and history?
SOCRATES Site: quadrant Onset: when it started and does it get better/worse Character: describe the pain? Radiation: pain to other parts of body? Association: other signs and symptoms Timing: when pain worst? Exacerbate: what sets of the pain? does anything help reduce the pain? Severity: 0-10 scale
Differential diagnosis for pulpal pain - referred pain?
Referred pain:
muscle trigger point referred to tooth and mimicked endo involvement
Sinusitis
Acute dental pain can be referred to opposite arc in same side
Name the 4 differential diagnoses for pulpal pain?
Referred pain
Neuropathic pain
Cancer
Other
Differential diagnosis for pulpal pain - neuropathic pain?
MS Trigeminal sensory neuropathy Trigeminal neuralgia Herpes Atypical odontalgia Atypical facial pain Phantom tooth pain
Differential diagnosis for pulpal pain - cancer?
Numbness of lower lip - common feature of metastatic CA
Metastatic breast cancer from mandibular pain
Malignant mediastinal lymphoma as mandibular pain
Metastatic carcinoma as PARL on mandibular molar (later paresthesia)
Necrosis: metastasis occluding BF
Differential diagnosis for pulpal pain - Other?
Eagle’s syndrome
Alveolar cavitational osteopathies
Neuralgia inducing cavitational osteonecrosis
Munchausen’s syndrome
Name the 3 causes for pulpitis?
Physical irritations from extensive decay
Trauma
Anachoresis (retrograde infections)
Name 5 key symptoms for pulpitis?
Pain on biting Pain when chewing Sensitivity with hot or cold Facial swelling Discolored tooth
What difficulties arise for pulpitis localisation?
Referred pain & the lack of proprioceptors in the pulp
localising the problem to the correct tooth can often be a
considerable diagnostic challenge
• Also of significance is the difficulty in relating the clinical status of a
tooth to histopathology of the pulp in concern
• Unfortunately, no reliable symptoms or tests consistently correlate
the two.
Name the 7 classifications for pulpal disease?
1) Healthy pulp.
2) Reversible Pulpitis.
3) Symptomatic Irreversible
4) Asymptomatic Irreversible
5) Pulp Necrosis
6) Previously Treated
7) Previously Initiated Therapy
Name the 6 classifications for periapical disease?
1) Normal Apical Tissues
2) Symptomatic Apical Periodontitis
3) Asymptomatic Apical Periodontitis
4) Chronic Apical Abscess
5) Acute Apical Abscess
6) Condensing Osteitis
What to do if the tooth is not restorable or periodontally unsavable?
EXTRACTION
Name 4 types of special investigations for pulpitis?
Tap the tooth – percussion test
• Feel the surrounding hard tissue – palpation test
• Testing movement of the tooth – mobility test
• Shine a light through the tooth ‐ transillumination
Name and describe the categories for percussion?
None (-): tap on incisal edge of tooth with end of mirror causes no discomfort
Mild (+): tap on incisal edge of tooth with end of mirror causes little discomfort
Moderate (++): tap on incisal edge of tooth with end of mirror causes noticeable discomfort
(painful)
Severe (+++): tap on incisal edge of tooth with end of mirror causes definitive
discomfort
(very painful)
Name and describe the categories for palpation?
None (-): feeling buccal and lingual gingiva apical to a tooth with the oad of the finger causes no discomfort at all
Mild (+): feeling buccal and lingual gingiva apical to a tooth with the oad of the finger causes little discomfort
Moderate (++): feeling buccal and lingual gingiva apical to a tooth with the oad of the finger causes noticeable discomfort (painful)
Severe (+++): feeling buccal and lingual gingiva apical to a tooth with the oad of the finger causes definitive discomfort (very painful)
Name and describe the categories for mobility?
Grade 0 – no apparent mobility
• Grade 1 ‐ mobility less than 1mm buccolingually
• Grade 2 ‐ mobility between 1 – 2 mm buccolingually
• Grade 3 ‐ mobility greater than 2 mm buccolingually AND apical
movement greater than 1 mm
What is the definition of sensibility testing?
e help to determine the pulpal status…alive or dead
What are the limitations for a sensibility test?
Can't differentiate between: “alive & healthy” “alive and diseased” “alive but just about to snuff it” or “in the process of dying
What is the definition of vitality, sensibility and sensitivity testing?
Vitality: blood supply present in tissue
Sensibility: ability to respond to a stimuli
Sensitivity: responsiveness to a stimuli
What is the true determinant for pulp vitality?
Vitality
Explain how the laser doppler flowmetry works?
Measures BF
Uses He neon laser beam directed onto tooth
Light contacts a moving object, is Doppler shifted
and a signal is produced.
As red blood cells are the majority of moving
objects, signal measures flow rate of blood
Explain how the vitality test works?
The pulse oximeter sensor consists of two light‐emitting diodes,
one to transmit red light (640 nm) and the other
to transmit infrared light (940 nm) and
a photodetector on the opposite side of the vascular bed.
The light‐emitting diode transmits red infrared light
through a vascular bed such as the finger or ear.
Oxygenated hemoglobin and deoxygenated hemoglobin
absorb different amounts of red infrared light. The
pulsatile change in the blood volume causes periodic
changes in the amount of red infrared light absorbed by
the vascular bed before reaching the photodetector.
The relationship between the pulsatile change in the
absorption of red light and the pulsatile change in the
absorption of infrared light is analyzed by the pulse oximeter to determine the saturation of
arterial blood.
Explain how the sensibility test works?
Thermal and electrical tests assess whether the pulp nerve fibres can
respond to a stimulus when applied to the tooth, hence they are
sensibility tests
Explain how the sensitivity test works?
Thermal and electric pulp tests are NOT sensitivity tests, although
they can be used to test the sensitivity of a tooth
Name the 8 ideal characteristics for an ideal sensitivity pulp test?
Simple Objective Standardised Reproducible Inexpensive Non‐painful Non‐injurious Accurate
Why can pulpitis diagnosis be wrong sometimes?
Diagnosing pulpal and periradicular symptoms is extremely difficult
because the histopathological condition of the pulp cannot be
determined by clinical means
How can special investigations help with diagnosis?
Sensibility tests are used to try and reproduce the pain the
patient is having & so confirm the source and reason for the
pain
Tooth localisation
How do nerve fibres reach the pulp and innervate the teeth?
Hundreds of sensory trigeminal afferent axons enter
through the apical foramen & branch through the
pulp following the distribution of the pulpal blood
supply.
Ultimately reaching coronal dentine where the plexus
of Rashkow is formed
Here they terminate as free nerve endings that
synapse onto and into the odontoblast cell layer
Explain how the sensibility test works physiologically?
aim to stimulate the A‐delta (Aδ) +/‐ C fibres
Due to the location of the C fibres & their stimulation
threshold, it is easier to stimulate the A‐delta fibres
Explain the Brännströms hydrodynamic theory?
Proposed pulpal pain results when A‐delta nociceptors are
activated by fluid movement within patent dentine tubules
Hence, for this to elicit pain, odontoblasts must be intact –
i.e. pulp is alive
Gives indirect information on the pulp status a positive
response does not guarantee a healthy pulp
It only tests if A‐δ nerves can respond to a stimulus
What should be included during a sensibility test to look out for?
Use control teeth
Use the information from the history, clinical examination
and findings, other special tests/investigations
When is a sensibility test useful or indicated?
When a patient has unlocalised or referred dental pain
To aid in diagnosis between odontogenic and non‐odontogenic pain
To confirm apparent radiographic periradicular pathology in the absence of any clinical signs/symptoms
To confirm pulpal status when there are clinical signs/symptoms but no apparent radiographic changes
periradicularly
To discern between a periodontal abscess and an endodontic abscess & help confirm when a perio‐endo
lesion is suspected
To assess the pulpal status of a tooth prior to crowning.
Monitoring the success of pulp caps/ pulpotomies (ensuring that the pulp has not become necrotic)
Monitoring traumatised teeth/ revascularization cases
(usually over several months).
Monitoring teeth following orthognathic surgery/ OS procedures/ facial fractures/ tooth transplantation
To confirm profound pulpal anaesthesia.
When is a sensibility test not indicated?
Electric pulp testers DO NOT interfere with pacemakers
Name 2 types of sensibility tests?
Thermal
Electrical
Name and explain 5 types of cold sensibility tests?
Ice sticks (not could enough) Ethyl Chloride EndoIce (TFE) EndoFrost (PBM) Dry Ice (very rapid sensory response)
What are the pros and cons for a cold sensibility test?
Superior to Hot test
Colder the test more reliable
Cold stim causes a rapid outward flow of dentinal fluid:
- test a delta fibres, respond to fluid movement, info extrapolated to consider pulp is vital
Name and explain 5 types of hot sensibility tests?
Warm Gutta percha (place vaseline first)
Warmed instrument
Electrical heat sources
Rubber prophy cup (frictional heat)
What are the pros and cons for a hot sensibility test?
Less useful than cold Initially stims A delta fibres Prolonged heat stims C fibres Excessive heat can cause pulpal damage An exaggerated and linegring response to heat is indicative of pulpitis
Explain how the electric pulp tester works?
A battery operated device passes a small electrical current along the enamel prisms & dentinal tubules
to pulp tissue
Current causes an ionic shift across the neural membrane inciting an action potential at the nodes of Ranvier
in myelinated nerves
This stimulates the A‐delta fibres
EPTs have a rheostat showing the relative amount of current applied on various scales
How to explain and complete the cold test procedure on a patient?
Explain test and why it's necessary Patient will feel cold Isolate and dry tooth Find a control tooth Tweezers and cotton wool Spray cold stim onto wool and place onto tooth
Where should you place the cold sensibility test stimuli on the tooth?
On sound tooth structure Incisal edge or incisal 1/3 anteriors Mid third buccal surface premolars Mesio‐buccal cusp tip molars Hold pellet in place until the patient feels the stimuli or for a few seconds if no response
Describe a normal pulpal reaction to a cold stimuli?
A sharp, sharp cold/pain sensation which
immediately ceases when the stimuli removed
Describe a pulpitis reaction to a cold stimuli?
A severe, prolonged, exaggerated response to cold
Describe a non-responsive reaction to a cold stimulus?
Pulp necrosis
Previous pulpotomy or previous pulpectomy
False negative
How to explain and complete the electric pulp test on a patient?
Explain procedure and why it is necessary
Patient may feel tinge or warm sensation
Dry and isolate tooth + control tooth
Place interprox celluloid strip where required
Place conducting interface medium on tooth
Place tip of EPT on conducting medium and patient completes circuit by earling the lip clip or touching the probe
Increase current slowly
Let patient respond at pre-pain sensation
Where should you place the electric pulp tester on the tooth?
On sound tooth structure
Incisal edge or incisal 1/3 anteriors
Mid third buccal surface premolars
Mesio‐buccal cusp tip molars
Describe a normal pulpal reaction to an electric pulp tester?
Sharp warm/hot/tingle or throbbing sensation which immediately ceases when stimulus removed
Describe a pulpitis pulpal reaction to an electric pulp tester?
A severe prolonged exaggerated response
Describe a non-responsive pulpal reaction to an electric pulp tester?
Pulp necrosis
Previous pulpotomy or previous pulpectomy
False negative
What are the 2 reasons for a false +ve result for a sensibility test?
Anxious or young patient
Multirooted tooth
What are the 8 reasons for a false -ve result for a sensibility test?
Incomplete root development Traumatised tooth Orthodontic tooth movement Heavily restored Pulpal obliteration Periodontal disease (decreased intensity of pain response to cold) Pre-medications Psychosis
Name 1 reason for a false -ve electric pulp test result?
Improper use/technique
Name 5 reason for a false +ve electric pulp test result?
Improper use/technique Pus in canal, as it can conduct to periapical tissues Metal splints Bridges Ortho arch wires
What is the definition of sensitivity?
Proportion of positives correctly identified
What is the definition of specificity?
Proportion of negatives correctly identified
What is the definition of a periradicular lesion?
Develop near the tips of root (where canal communicates with periodontium via apical foramen)
Where is a inflammatory periodontal lesion usually found?
Emerge at other anatomical or iatrogenic openings:
- lateral aspects of root
- furcations of multirooted teeth
How does apical periodontitis develop?
Following pulp tissue breakdown and the emergence of root canal infection
Can be symptomatic or asymptomatic
Bone resorption part of process
Explain how an RCT can be used to treat apical periodontitis?
Eliminate bacteria via RCT:
- active inflammatory lesion subsides
- bone regeneration takes place
What are the active immunocomponents found in the histopathology of a periradicular pathology?
Macrophages: - HLA-DR+ cells - CD14+ Dendritic: - HLA-DR+ - CD83+
What is the role of a mature dendritic cell in a periradicular lesion?
Regulate specific immune responses
- initial phases of apical periodontitis
Explain the activation phase for a periradicular lesion?
Antigen specific T cells are cloned in regional lymph nodes
- travel to lesion site
- become dominant in lesion
More CD4 cells than CD8 cells
Explain the established chronic phase for a periradicular lesion?
More CD8 than CD4
Suggests that CD4 are active during the expansion of the inflamm process
Involved with bone-resorptive process by activating macrophages producing bone resorbing mediators
Name 3 microscopic level different structural frame-works of apical periodontitis?
Apical granuloma
Apical abscess
Apical cyst
Clinically and radiographically these histopathological entities cannot be
distinguished from each other or recognized
What is the definition of an apical granuloma?
Consists of an inflammatory lesion dominated by:
- Lymphocytes,
- Macrophages and
- Plasma cells
Numerous fibroblasts and connective tissue fibres usually present
- + many capillaries.
Around the edge an encapsulation attempt may often be found
The epithelium originates from the epithelial cell rests of Malassez
Influenced by cytokines & growth factors released in the inflammatory process
the normally resting cells divide and migrate.
- They may form more or less continuous
- Random course
- May also become attached to the root surface
Polymorphonuclear leukocytes are found in varying numbers
Abscess formation can be a transient or persistent event within an
existing apical granuloma
What is the definition of an apical abscess?
Pus within the lesion
Abscess formation = cellular dynamics within apical granuloma or direct outcome of an acute primary infection
High influx of PMNs (with high phagocytic activity of PMNs)
PMNs die and release tissue-destructive elements
CT are degraded
Tissue in centre of lesion liquefied
COntinuum exists between apical abscesses and apical granulomas
What is the definition of an apical cyst?
Epithelium-lined cavity Contains fluid or semi-solid material Surrounded by CT: - infiltrated by mononuclear leukocytes and PMNs - cavity lined with stratified squamous epithelium - originates from epithelial rest of Malassez - can be lined with ciliary epithelium Lining can be be: - continuous - disrupted - completely missing Some cysts never become steady (consume bone or slowly expand)
Name the 2 types of apical cysts?
Pocket and True
What is the definition of a true apical cyst?
Located within the periapical granuloma
No apparent connection between
their cavity and that of the root canal space.
What is the definition of a pocket cyst?
An apical inflammatory cyst
Contains a sac‐like, epithelium‐lined cavity
Open to and continuous with the root canal space.
How is an oblong needle-like crystal formed?
The crystals are thought to derive from disintegrating red blood cells in stagnant vessels of the lesion.
But could be from inflammatory cells and/or circulating plasma lipids
Explain the nutritional deficiency theory for apical cyst formation?
Assumes that epithelial proliferation
results in an epithelial mass that is too large for nutrients to reach its core,
resulting in necrosis and liquefaction of the cells in the center. PMNs are
attracted by the necrotic material, which, together with tissue exudate,
result in microcavities that eventually coalesce to form the cystic cavity
Explain the abscess theory for apical cyst formation?
Assumes that tissue liquefaction occurs first, at the
central part of an abscess. The peripheral aspect of the cavity is later lined by proliferating epithelium, owing to the inherent nature of epithelial cells to cover exposed connective tissue surfaces
Why do the size of radicular cysts slowly increase?
Increased osmosis leading to passage of fluid from the surrounding
tissue into the cyst lumen is likely to occur owing to breakdown of
epithelial and inflammatory cells
Release of bone‐
resorbing factors from mononuclear leukocytes present in the cyst wall,
including interleukins, mast cell tryptase and prostaglandins.
What are the causes for apical periodontitis?
Most AP is due to microorganisms within the RC. Other occasional
causes include trauma, occlusal trauma, foreign body reaction
Bacteria in infected necrotic pulps predominately obligate anaerobes.
Different microorganisms display differing ability
to survive in the root canal system
More likely that
a community of microbes exists
Biofilms form in RCs. Biofilms protect bacteria from being destroyed
Name 6 microbial causes of primary apical periodontitis?
Carious lesions Cracks Traumatic exposure Accessory canals Exposed dentinal tubules Periodontal pockets to the apical foramen
Name 3 factors of selective pressures for microbial invasion of apical periodontitis?
Nutrition
Oxygen
Microbial interactions
Name 6 types of bacteria present in primary root canal infections?
- Spirochetes • Fusobacteria • Actinobacteria • Firmicutes • Proteobacteria • Bacteriodetes No more than 10 per canal and more are negative and are mostly anaerobic
What is a reason for persistent Apical periodontitis?
Microbes remaining within the canal system
What are the survivability characteristics for E. faecalis?
Possesses a “proton pump” which allows it to survive in high pH (i.e. can survive calcium hydroxide)
• Can survive in mono‐infection
• can survive long periods of low/no nutrition
Name 3 forms of non-microbial causes for apical periodontitis?
Periapical cysts – 15% of lesions (Nair 1996)
• Serial sectioning indicates two types – true cysts and pocket cysts
• Foreign Body Reactions
• Cholesterol Clefts
Name 8 non-specific mediators of inflammatory reactions?
neuropeptides, • fibrinolytic peptides, • kinins, • complement fragments, • vasoactive amines, • lysosomal enzymes, • arachidonic acid metabolites, • and various cytokines
Explain the root canal response to canal instrumentation cutting BVs in the PDL or bone?
This activates intrinsic and extrinsic coagulation pathways.
• Contact between the Hageman factor and:
• collagen of basement membranes,
• enzymes such as kallikrein or plasmin,
• endotoxins from inflamed root canals
can activate the clotting cascade and the fibrinolytic system.
• Fibrinogen molecules and fibrin degradation products are released during fibrin proteolysis by plasmin
these release fibrinopeptides
• Trauma to the periapical tissues during RCT can also activate the kinin system
• This will then activate the complement system.
• C3 complement fragments found in periradicular lesions.
• Products released from the activated systems contribute to the inflammatory process and cause
swelling, pain, and tissue destruction.
How do mast cells play their part in apical periodontitis?
Mast cells are normal components of connective tissues
• present in a normal PDL.
• also found within periradicular lesions.
• (Physical or chemical) injury causes the release of vasoactive amines
• e.g. histamine,
which are chemotactic for leukocytes and macrophages.
• In addition, lysosomal enzymes cause cleavage of C5 and generation of C5a, a potent chemotactic
component, and liberation of active bradykinin from plasma kininogen
• Periradicular lesions show increased levels of lysosomal hydrolytic arylsulfatase A and B compared to
normal tissues.
• Significant levels of PGE2 and leukotriene B4 are also present in these lesions.
What can you stain with immunohistochemical staining for an apical periodontitis?
PGE2, prostaglandin F2a
(PGF2a), and 6‐keto‐PGF1a
Explain the process of formation of a periapical granuloma?
Bacterial antigens come from the infected root canal
• taken by antigen presenting cells (APC),
• processed and
• presented to the T‐lymphocytes (T).
• A dual signal of antigen presentation with IL‐1 activates the T‐lymphocytes.
• Cytokines produced by these activated cells include
• (a) IL‐4, IL‐5 and IL‐6, which induce proliferation and maturation of a specific clone of B‐lymphocytes (B) that
were exposed to this specific antigen, to result in plasma cells producing IgG specific to this antigen;
• (b) INFγ which serves to activate macrophages which in turn will produce the IL‐1 essential for local
recruitment of circulating PMNs and IL‐8 which activates these PMNs.
Bacterial endotoxin derived from Gram‐negative bacteria, activates macrophages.
• All the above is aimed to allow effective specific phagocytosis by the PMNs of any
bacterium emerging from the apical foramen.
• Bone resorption is a side‐effect of the defensive process, mediated by TNFβ,
produced by the activated T‐lymphocytes and IL‐1β, produced by the activated
macrophages. Both activate osteoclastic bone resorption
Name the 2 agents responsible for bone resorbing activity?
IL‐1β (mainly produced by activated macrophages) and
• TNFβ(mainly produced by activated T‐lymphocytes
Describe the bacteria confined to the root canal space?
Rarely be able to survive and establish themselves in the apical lesion
• In the process of pulpal breakdown, eg after carious exposure, bacteria will gradually
gain terrain and move their front line towards the apex, depending on how effective the
host response is in limiting further bacterial colonization in the pulp tissue.
• The host tissue–bacterial front will be established in the vicinity of or at the exit of the
apical foramen.
• exact position of the bacterial front is unpredictable.
• Can often be well inside the apical foramen,
• PMNs engaged in phagocytic activities prevent dispersion of bacterial elements from the
root canal biofilm.
• Yet, PMNs have a hard time dealing with those organisms attached in a biofilm structure.
• this means that there is a constant battle between the spreading organisms and the host
defense
wHAT ARE THE 2 TYPES OF EXTRARADICULAR INFECTIONS?
Bacteria in chronic abscesses
Bacterial cluster formation?
What is the definition of bacteria in chronic abscesses?
with a persistent sinus tract.
• Viable bacteria can usually be isolated from the exudate
• The source may be bacteria that emerged from the root canal space
What is the definition of bacteria in cluster formation
Actinomyces israeli
• Propionibacterium propionicum can grow in clumps and thereby prevail
• Such aggregations may become too large for phagocytosis.
• bacterial cells are out of reach for phagocytosis = chronic infection
• cannot be managed by endodontic treatment
Name the 7 factors needed for a tooth to be healthy?
comfortable to the patient • not tender to percussion or occlusal pressure • not sensitive to palpation. • Free from sinus tracts • Free from swelling • Has no painful symptoms. • Has normal pocket‐probing depths: • pocketing may also imply a sinus tract drainage along the periodontal ligament space.
Name the 5 different types of root canal infections?
asymptomatic apical periodontitis (chronic apical/periradicular periodontitis),
• symptomatic apical periodontitis (acute apical/periradicular peri‐ odontitis),
• acute apical abscess (acute periradicular abscess),
• chronic apical abscess (chronic periradicular abscess, suppurative apical/periradicular
periodontitis),
• condensing osteitis (focal sclerosing osteomyelitis, periradicular osteosclerosis, sclerosing
osteitis, sclerotic bone).
What are the radiographic findings for a normal periapical condition?
unbroken lamina dura
• distinct periodontal ligament space of normal width,
comparable to adjacent and contralateral teeth.
What is the definition of an asymptomatic apical periodontitis?
is longstanding periapical inflammatory
• Has radiographically visible periapical bone resorption
• has no clinical signs and symptoms.
• Is associated with a tooth with a non‐vital pulp (untreated or treated).
It might be suspected from a carefully taken disease history in cases when patient has
experienced a prior painful event.
What is the definition of an symptomatic apical periodontitis?
Symptomatic apical periodontitis may develop as a direct consequence of the
breakdown and infection of the pulp within a previously healthy periapical region.
• It reflects a response to an initial exposure of the periapical periodontium to bacteria
• or their products emerging from the infected root canal.
• may also appear in a tooth with previous asymptomatic apical periodontitis.
• Can be a natural shift in the balance previously established between the bacteria and
the host or occur in response to endodontic treatment (endodontic flare‐up).
• The typical symptoms include:
• pain (aching)
• may become severe or even unbearable.
• usually tender to percussion
• mucosa and bone overlying the apical area sensitive to palpation.
• premature occlusion
What is the definition of an acute apical abscess?
Characterized by:
• rapid onset,
• spontaneous pain,
• tenderness of the tooth to pressure,
• pus formation
• swelling of associated tissues.
• Initially, may be extremely painful, (pressure builds up in bone or periodontal space).
• Cortical plate may perforate and pus will accumulate under the periosteum producing a most severe painful condition.
• Only with the perforation of the periosteum will the pus be able to drain and allow pain to subside.
• Then a tender local swelling will appear.
• Sometimes, natural drainage will be established within a few days by perforation of the covering tissue.
• In other cases, the swelling will remain for some time before it gradually subsides.
• Drainage of an apical abscess will take the “path of least resistance”
• thickness of overlying bone
• Following penetration of the bone and periosteum, drainage will often be visible:
• in the oral cavity but it may also occur
• into perioral tissues or
• into the maxillary sinus.
What is the definition of an chronic apical abscess?
Typical feature = sinus tract.
• Drains into:
• mouth or
• extraorally through the skin
• A sinus tract may establish exit with drainage
• into the gingival sulcus,
• in a periodontal pocket or
• in a furcation area
• MUST be differentiated from periodontal disease and from a pocket associated with a
vertical root fracture.
• A sinus tract may also lead into the maxillary sinus and cause unilateral chronic sinusitis!
• Most commonly associated with an apical radiolucency (but not always)
• It is asymptomatic (or only slightly symptomatic)
• patient often unaware of its presence.
• This may last as long as the sinus tract is not obstructed.
What is the definition of cellulitis?
symptomatic edematous inflammation
• associated with diffuse spreading of invasive micro‐organisms through connective tissue and fascial planes.
• Its main clinical feature is diffuse swelling of facial or cervical tissues.
• Cellulitis usually follows an apical abscess that penetrated the bone,
• allows the spread of pus along paths of least resistance.
• Spreading infection may or may not be associated with systemic symptoms such as fever and malaise.
• Since cellulitis is usually a sequela of an uncontrolled apical abscess, other clinical features typical of an
apical abscess are also expected.
• Spreading of an infection into adjacent and more remote connective tissue compartments may, rarely, result
in serious or even life‐threatening complications.
• Cases of Ludwig’s angina
• orbital cellulitis
• cavernous sinus thrombosis
• and even death from a brain abscess
• originating from a spreading dental infection have been reported.
What is the definition of condensing osteitis?
diffuse radiopaque lesion
• believed to represent a localized bone reaction to a low‐ grade inflammatory
stimulus
• usually seen at an apex of a tooth (or its extraction site) in which there has been a
longstanding pulp disease.
• It is characterized by overproduction of bone in the periapical area, mostly around
the apices of mandibular molars and premolars that had long standing chronic pulpitis.
• The pulp of the involved tooth may be vital and chronically inflamed or may have
become necrotic with time, leaving the radiopaque area.
• Normally the condition does not prompt treatment
• unless the pulp necrosis.
• The radiopacity may or may not disappear after endodontic treatment or tooth
extraction
How are the periodontium and pulp connected?
Natural communications
Pathological and iatrogenic communications
As the periodontium and teeth develop, name the 3 natural avenues communication between pulp and periodontium?
Dentinal tubules
Apical foramen
Accessory canals
What can cause the dentinal tubules to become exposed?
Developmental
Disease
Periodontal surgery
Traumatic injury
Describe the 4 types of CEJ morphology?
I: cementum over enamel
II: edge edge cementum and enamel
III: gap between cementum and enamel
IV: enamel over cementum
What is the definition of the apical foramen?
Principle route of communication between pulp and periodontium
Pulpal inflamm can cause a localised inflammatory reaction
May be exposed due to severe loss of attachment
What is the definition of lateral canals?
Found apically
COntains CT and BVs
Don’t extend full width of dentine
What is the definition of a furcal canal?
All teeth with furcation involvement can potentially have exposed furcal canals
Lesions suggested radiographically may be due to infectious products from a necrotic pulp diffusing down a furcal or lateral canal
What teeth to test for exposed furcal canals?
Sensitivity test:
- Lower 46,36 (DL root)
Upper and lower premolars (1-3 roots)
Canines (2 roots)
Name the 6 bacteria present in teeth with chronic/asymptomatic PRP AND a chronic periodontitis?
Aggregatibacter actinomycetemcomitans P gingivalis Eikenella Fusobacterium P intermedia Treponema denticola
Name 5 pathological or iatrogenic pathways for communication between periodontium and the pulp?
Developmental Resorptive lesions Perforations Cracks Mucosal fenestrations
What is the definition of a developmental malformation?
Palatogingival groove
Usually maxillary lateral incisors
If epithelial attachment is breached, grooves becomes contaminated
Self-sustaining infrabony pocket develops
Loss of attachment can quickly extend to apical foramen
Difficult to treat as scaling and RSI does not work
What is a resorptive lesion and its 2 requirements for it to be one?
Injury Stimulus External inflamm resorption internal inflamm resorption Cervical inflamm resorption
What is the definition of internal inflammatory root resorption?
Associated with increased probing depths and BOP when resorptive process has perforated entirely through the root
What is the definition of an external inflammatory root resorption?
Depending on location, may be associated with increased probing depths and BOP
Late stages, can interfere with gingival sulcus and result in periodontal abscess
What is the definition of a cervical inflammatory root resorption?
Starts where the Je attaches to the root surface
Microbes in the gingival sulcus stimulate and sustain the resorptive process
Associated with increased probing depths, gingival swelling and BOP
What is the definition of perforations?
Caused pathologically by caries/resorption or iatrogenically by procedural errors
Present with perio abscess - pain, swelling, pus draining through PDL and with time infrabony pocket developing
Acute inflammatory action will occur
Closer to gingival sulcus more likelihood of apical migration of gingiva
What does the perforation prognosis depend on?
Location: - better in apical 1/3 Bad with advanced perio Time Ability to seal Chance of building new attachment Accessibility of the remaining RCs
What is the definition of a root fracture?
Horizontal:
Pocket formation may occur when fracture out with alveolar bone
Cornola 1/3 root fracture
Can present with perio abscess or sudden deepening of a perio pocket
Vertical:
Microbial colonisation of crack space = periodontal inflammation = breakdown of CT and alveolar bone leading to deep infrabony pocket
How to diagnose a vertical root fracture?
Take more than 1 x-ray
parallax increases yield
J shaped radiolucency
Can present initially with perio abscess or sudden deepening of periodontal pocket
Deep, narrow pocket, pain on biting, abscess and chronic sinus
Definitive diagnosis = surgical exploration Hopeless prognosis
What is the definition of mucosal fenestration?
Pathological condition characterised by the perforation of the alveolar bone plate and overlying the mucosa by the roots of the teeth
Asymptomatic but are PRFs
Name 6 aetiologies for mucosal fenestrations?
Root prominence Developmental Perio disease Biotype Chronic periradicular pathosis Ortho tooth movement
What is the treatment for mucosal fenestrations?
Endodontic Rx
Surgery
CT graft
Can periodontal disease affect the pulp?
Area of fibrosis
Areas of mineralisation
narrower canals
Reparative responses
If blood supply through apical foramen remains intact, pulp can withstand insult from perio disease
Pulpal necrosis only seen when perio disease advanced that microbes reach apical foramen
Can periodontal treatment affect the pulp?
RSI can remove cementum and expose dentinal tubules
Pulpal changes seen adjacent foci of inflamm +/- secondary dentine formation
How can scaling RSI and polishing affect the pulp?
Heat application to intact enamel can increase pulp temp between 5-17C causing irreversible pulpitis Frictional heat depends on: - speed - torque - amount of force Cause odontoblast death
How can endodontic pathology to affect the periodontium require?
A patent route to the periodontium
Infected root canal system
Sufficient virulent microbes to provoke a periodontal response
Do lateral canals cause infrabony defects?
Lateral canals in an infected/necrotic pulp may cause lateral periodontal lesions rarely
Can periodontal disease exert an effect on lateral canals?
Where the subgingival biofilm reached a lateral canal, the microcirculation was severed, but inflammation of the adjacent pulpal tissue was minimal
When the subgingival biofilm reached the apical foramen, the whole pulp became necrotic
Can endodontic disease affect the periodontium?
Loss of periodontal attachment directly correlated with the presence of endodontic infection
Patients have deeper pockets, increased CAL, higher freq of vertical/angular defects
Pulpal infections serve as a risk factor in patients prone to periodontitis (other papers say otherwise)
Both endo and perio disease is a microbial infection, microbes associated with a necrotic pulp are fewer than the complex biofilm in a deep periodontal pocket
Host response with be acute abscess or chronic inflamm response
How to drain an endodontic abscess?
Insert a GP cine and radiograph
Can drain through the PDL space to the sulcus
Can endodontic treatment affect the periodontium?
5-10C elevations in external root temo can produce damage to PDL Gutta percha increases flow Tip heated to 250-600C External root temp between 8.5-22.1 Ok to use with care
Name the 8 foreign body reaction in the periodontal and periradicular tissues?
Dentine and cementum chips Amalgam Root canal filling material Intracanal dressing, sealers and obturation materials Cellulose fibres Leguminous foods Calculus
Can cause acute or chronic reaction
Multinuc giant cells surround foreign body
What will influence the treatment options and prognosis?
Timing and amount of remaining perio support
What is the classification system for perio and endo lesions?
2017 World Workshop
Periodontitis associated with endodontic lesions
Explain the clinical examination for a possible endo or perio lesion?
Palpation
Percussion
pocket probing
Mobility
Sinus or pus draining through PDL
If sinus is present, palpate to see if discharging
If so, insert gutta percha cone and radiograph
Explain the diagnosis procedure for a possible endo or perio lesion?
Special tests
To differentiate between perio and endo
Sensitivity test
Higher false positives in teeth with advanced periodontitis
If perio only tooth will respond to sensitivity testing
Use 2 tests to increase reliability
Test cavities to differentiate between perio and endodontic pathosis
Both perio and endo affecting tooth form a perio-endo lesion
Characterised by CAL, bone loss and periradicular pathology
What symptoms should I suspect with a perio-endo lesion?
Hisotry of symptoms History of surgery deep pockets (average root lengths) furcation Pus exuding from deep pockets or swellings
Explain the plan of action for a perio-endo lesion?
Gather history and clinical information (endo and perio exam) 2 Sensitivity tests Radiograph periapical Make diagnosis Or further testing
What is the treatment plan for a perio-endo lesion?
Retain tooth
Extraction (vertical and horizontal bone loss)
Non-surgical endo/perio treat
Resection
Elim diseased root
Visible with fixed prosthesis (high smile line)
Buccal recession around implant
Consider condition for potential abutment teeth
Increased plaque, CAL and caries with RPDs
Explain the process of non-surgical endo and perio treatment?
Endo first and then perio
Cementum and intact PDL fibres may persist, can regenerate after perio treatment
Perio straight after endo, destroy fibres form long JE
Explain the process of root resection?
Allows functional retention of a multi-rooted tooth
Remove 1 or more roots
Use for furcated max molars
Always RCT first before resection
After treatment, cuspal coverage restoration
Important to remove any dentinal overhangs
Name the 7 indications for root resection?
Root fracture Perforation Root caries Root resorption Severe periodontal disease Grade II or III furcation Failed endodontic treatment
Name the 2 contraindications for root resection?
Medical/physical issues
Fused roots
How success are root resections?
62-100% success over 5-13 years
Resected teeth have better outcome with regular perio maintenance and Fl application
1:1 root:crown ratio is minimum acceptable
Long term tooth retention requires 50% bone support
Resected for perio better than non-perio
What is the definition of regeneration?
Aims to regenerate lost periodontal structures
Deep narrow defects favourable
endo first
Retract flap, scale, RSI, removal granulation tissue, type defect, bone graft and resorbable membrane
77.5% success over 5 years
What is the prognosis difference between single and multirooted teeth?
Better for single rooted
More success for perio than endo
Deep narrow pockets good prognosis
Name 7 factors does endo success depend on?
Reaching WL
Disinfecting full canal length
Keep all RCT material within root canals
Dense obturation with no voids within 2mm radiographic apex
Having enough dentine to achieve ferrule effect
Adequate coronal seal
Cuspal coverage
Name 7 factors does endo success depend on?
CAL Stabilisation of perio disease Reduction of perio pocket depth and lack BOP Effective perio maintenance Presence of furcation Morphology of lesion Sufficient bone
What is the definition of apical periodontitis?
Bacteria in the root canal system
Why to perform root canal treatment?
Remove/reduce the bacteria to an undetectable level
What is the best method to reduce bacteria in root canals?
C&S + NaOCl + one week later Ca(OH)2
What problems arise with our understanding of the root canal system?
Koch’s postulates (polymicrobial)
Missing the host response
Non-cultivable bacteria in root canal (immunocompetence alters response)
One bacteria can’t cause all these symptoms
Due to ecological commensalism (bacterial pairs)
What evidence supports root canal treatment to aim for the apex of the root?
Best amount of healing
Overfilled teeth have persistent inflammation
Sjorgen:
- 0-2 mm 94%
- > 2mm 68%
- overfilled 76%
Aim to fill between 0.5-2mm from the apex of the root
Where is the apex of the root found?
0.5 to 0.65 mm in elderly
0.59 mm
0.72 mm
0.8 mm
Apex changes in necrosis cases compared to normal
Changes in shape change the apex
Name the 8 cross-section shapes of a root filing tool?
K K-flex Flexofile Mwo Profile Protaper K3 Hero 642
What is the definition of a K file as a root tool?
Most common CAn be square, triangular or rhomboidal From 1.97-0.88 sharp grooves per mm 45 helical angle 21, 25 and 31mm length From 6-gauge to the 140th twisted instrument
What is the definition of a F-flex file (Kerr)?
Rhombus stem
Remove debris by increasing clearance between file and dentine wall
Sharp rhombus angle improve cut efficiency
From 6-gauge to the 80-gauge
Twisted
What is the definition of a Hedstroem file?
Drags large amounts of fabric in its traction cut
Helicoidal shape
Turned instrument
Cut in one direction only, of retraction, due to positive inclination of their groves
What motion is good for a SS file?
Bend to get round corners
What motion is good for NiTi files?
Straighten it
What gives a greater chance of separation via movement?
A CW rotation greater chance than CCW rotation
What are the pros of a tapers root file?
Better than straight
Less dentine removed
Less chance of perforation
Better debridement of apical prep
Danger zones vs safe zones?
Paper:
- Abou-Rass, Frack and Glick 1978
Explain the step-back (telescopic technique) for root filing?
Determine WL and develop apical stop to #25
Step-back by shortening 30, 35, 40 in 0.5 or 1-2mm increments
Recapitulate with #25
Coronal flare with #2 and 3 Gates-Glidden
Explain the step-down technique for root filling?
Passive use #15, 20 and 25 hedstrom in coronal 2/3 of canal system then irrigate
Coronal flare with #2 and 3 Gates-Glidden
Establish WL and prepare apical seat with standard serial filling
Step-back to blend apical and coronal segments
Recapitulate
Explain the crown-down pressureless technique for root filing?
Rotate straight file twice form larger to smaller sequence until 16mm
Coronal flare with GG
Establish provisional WL 2mm short of apex
Rotate stright file at WL
Finish apical prep at WL with file 2 sizes larger than first file to reach WL
Explain the balanced force technique for root filling?
Use FlexR files or FLexofile for non-cutting pilot tips of triangular file
Use crown-down to establish radicular access
Rotate straight file CW from 90-180 with light apical pressure to engage dentine
Shear dentine by 120 CCW rotation with apical force, flexing it to conform to canal curvature
Continue until get adequate apical enlargement at WL
Inspect file frew, do not go beyond #35 in curved canals
Explain the double-flared technique for root filling?
Passive use larger-smaller files in coronal 2/3 canal system then irrigate
Establish WL with small K file. Serial file to prepare apical stop and then step back to blend with coronal step-down flare
Circumferentially file with master K file
Explain the passive step-back technique for root filling?
Establish canal patency with small K file at WL then passive instrument with larger K files
Coronal flare with #2, 3 and possibly #4 GG in coronal 1/3
Confirm WL (typically reduced after coronal flare and curvature removal)
Increase straight line access with careful re-work with GG
Serial file to prepare apical stop and then step back to blend with coronal step-down flare
Explain the process of root filing for a Ni Ti file?
Used for crown-down sequence
Estimate working length from pre-OP radio, subtract 3mm from this length - use this new length to work to for the coronal 2/3 prep
Initial negotiation by hand using ISO files 08-20 passive
Precurve
Use lubricant
Take S1/2 to 2/3 canal length turning clockwise until snug then pull from canal and clean
If further coronal flare required or relocation orifice use SX to 2/3
Length (WL minun 3mm), turning clockwise
Determine WL with apex locator and take ISO 09-20 to WL
S1 then S2 to WL turning clockwise as above
F1 to length
Gauge the size of the apical constriction using a 20K file, if this fits snugly, the prep can be complete at this stage
However, generally the apical size needs to be at least 30 to allow irrigation into the apical 1/3
Take F2 to WL and gauge the foramen using a 25 K file
If this fits snugly, the prep can be complete
Or Take F4 to WL and gauge with 30K file, i fits snugly can be completed
Use the same sized paper points for during the canal and same sized GP cone for obturating
Why to use F3 Ni Ti files?
150mm bacteria
What is the needle nominal O.D. for a 30 gauge needle?
0.312 mm
What is the needle nominal O.D. for a 27 gauge needle?
0.413 mm
What % does NiTi superflexible show for elastic ability?
8%
How does NiTi superflexible root file become to flexible?
Martensite heated becomes Austenite and then cools and changes structure, but when deforms reverts back
Name 4 1st generation NiTi root file?
ISO standard taper (0.4 and 0.6% tapers)
Lightspeed system
GT system
Quantec
Name and describe 5 2nd generation NiTi root file?
Active cutting edges Decreased number of instruments needed Asymmetrical cross section Greater cutting efficiency ProTaper Universal K3 Mtwo Hero Shaper iRace and iRace +
Name and describe 5 3rd generation NiTi root file?
EMphasis on NiTi metallurgy Heating and cooling methods to reduce cyclic fatigue Transition point between martensite and austenite optimised M wire tech R phase tech Twisted files K3 XF files Profile Gt Series X Hyflex CM Flex Files
Name and describe 4 4th generation NiTi root file?
Canal prep more efficient with reciprocation
Reciprocation is any repetitive up and down or back and forth motion
Liberator
Wave One
Reciproc
Self-adjusting File
Name and describe 3 5th generation NiTi root file?
Centre of mass or centre of rotation is offset
Produces a mechanical wave of motion that transverses along the length of the file
Improved cutting and removal of debris by increasing cross-sectional space
Reduce engage between file and dentine
Revo S
ProTaper Next
One Shape
What is the definition of a rotary file?
Full 360
What is the definition of a reciprocating file?
Angle of rotation are asymmetrical, CCW and CW
Rotary vs Reciprocation files?
CW rotation greater than CCW rotation
CW rotation it will screw in the canal
CCW rotation, will unscrew out of the canal
CW > CCW, end result is screwing in effect and advancement of instrument
Very little pressure necessary to advance
Advantages of Rotary over Reciprocation files?
Fast Flexible Less transportation and ledging Shapes canal uniformly Reduced operator fatigue Improved efficiency
Disadvantages of Rotary over Reciprocation files?
CAn't be used in all cases Build up debris NO beyond apical foramen Fracture can occur Cost Loss tactile sensation
What is the definition of LA?
The practice of various psychological, physical and chemical approaches to the prevention and treatment of preOP, OP and postOP anxiety and pain
Name 5 methods of pain control?
Anaesthetic agents Inhalation sedation Antianxiety agents IV sedation GA
Pros and Cons for GA?
R v B
Risk death
Pros and Cons for IV sedxation?
Training
R v B
Refer necessary
Name and describe 2 form of antianxiety agents?
Oral sedation Usually Benzodiazepine Augment anaesthetics Pre-Op amnesia Drug choice depend on individual and nature of procedure Should be avoided in CNS depression, sleep apnoea and compromised airway Temazepam* Diazepam
What is the definition of a topical LA?
Numb specific site Provides temp numbing effect on nerve endings on the surface of the oral mucosa Ointment Liquid Spray
Name the 7 key characteristics for a LA?
Be non-irritating to the tissues Minimal toxicity Rapid onset Profound Anaesthesia Sufficient duration Completely reversible Sterile
Name the 4 types of LA injections?
Infiltration
Block
intraligamentary
Intraosseous
What is the defintion of short-acting?
Less than 30 mins
WHat is the definition of intermediate-acting?
Less than 60 mins
What is the definition of long acting?
Greater than 90 minutes
Indications for lidocaine?
Normal procedures
Preferable for IANB
Indications for articaine?
Profound anaesthesia infiltration
Not IANB
Indications for mepivacaine?
Short anaesthesia, periodontal treatments
Indications for prilocaine?
Pulpal anesthesia for 10 mins
Name 4 types of CCLAD LA systems?
Comfort COntrol Syringe
QuickSleeper
Anaeject
Ora Star
What is the definition of a wand/compudent system?
Accurently manipulate fingertip accuracy and deliver LA with foot control
Pen-like grasp, providing greater tactile sensation
Flow rate remains constant and can be varied
Improved experience
What is the definition of a comfort control syringe?
no foot pedal
Aids with injection and aspiration controlled directly from syringe
No more helpful than a manual syringe
What is the definition of ‘Hot Pulp’
Inflamm changes within the pulp progressively worsen as a carious lesion near the pulp
Chronic inflammation is an acute exacerbation
Influx of neutro and release inflamm mediators (glandins and IL)
Proinflamm neuropeps:
- SubP
- bradykinin
Sensitive the peripheral nociceptors within the pulp
How often does LA failure for hot pulp in the mand first molar? first premolar? lateral incisor?
17% mand first molar
11% first premolar
32% lateral incisor
Explain the lowered pH theory for LA?
Reduced pH means there is less of the base form of anaesthetic
Base form is needed to penetrate the nerve sheath and membrane
Less ionised form of LA within nerve to produce anaesthesia
What other theories are available for the failure of LA?
Nerves arise from inflamed tissue have altered resting potentials and reduced thresholds of excitability
Not able to prevent the transmission of nerve impulses because of the lowered excitability thresholds of inflamed nerve
Presence of anaesthetic resistant Na chs and up reg of Na chls in pulp with irreversible pulpitis
How successful are supplement PDL LA injections?
Endodontic: 50-96%
Irreversible pulpitis: 74-96%
What is the definition of intraosseous LA injection?
Need 27 gauge making through bone with slow speed
Immediate onset
Distal to tooth as thinnest bone
What is the definition of intrapulpal injection?
Must be given under pressure
V painful
Is pre-emptive pharmacy useful for root canal treatment?
71-76% painless treatment vs 46% in placebo
What are the advantages for a rubber dam during a root canal treatment?
Aids visualisation
Prevents ingestion or aspiration of instruments
What is the armamentarium for a rubber dam?
Rubber dam Punch Forceps Frame Scissors Floss Flat plastic Clamps
Name the 8 treatment options for odontogenic pain?
Anxiety management Emergency pulpotomy incision and drainage Extraction Pharmacological pain management Analgesics Antimicrobials
What is the definition of an endodontic emergency?
As pain and/or swelling, caused by various stages of inflammation or infection of the pulpal and/or periapical tissues
Patients who present with pulpal pain, what are the differential diagnoses?
Pulpal pain: - irreversible - reversible pulpitis Periradicular pain: - symptomatic radicular periodontitis - acute periapical abscess Cracked/fractured tooth Pain from current endodontic treatment: - NaOCl accident Iatrogenic damage Recent restorations Highly filled teeth Overfilled RC system Root fracture
What is the definition of non-odontogenic pain?
No aetiology No caries, trauma, fractures or failing restorations Pain not relieved by La Bilateral or multiple tooth pain Long standing Unresponsive to treatment
Name the 3 non-odontogenic pain discriminative symptoms?
Burning or electrical pain
Pain increases during different emotional states
Name 4 types of non-odontogenic pain?
Migraine
Cluster headache
Paroxysmal hemicrania
SUNCT
What is the pain severity, type, location and triggers for non-odontogenic pain caused by migraines?
Mod to severe
Pulsating
Frontotemporal
Stress, foods, sleep pattern changes, and hormonal changes
What is the pain severity, type, location and triggers for non-odontogenic pain caused by cluster headaches?
Very Severe
Boring
Orbital
Alcohol and nitrates
What is the pain severity, type, location and triggers for non-odontogenic pain caused by paroxysmal hemicrania?
V severe
Boring
Orbital
Mechanical
What is the pain severity, type, location and triggers for non-odontogenic pain caused by SUNCT?
V severe
Electric like
Orbital
Cutaneous
How can anxiety affect the quality and effect of the LA and treatment success?
Pain strong clinical emotional quality and must be managed
Understanding, sympathy, behaviour tech and pharma if necessary
Hypnosis can be useful
Greater anxiety = higher painful sensation and decreased pain threshold
What is the definition of an emergency pupotomy?
Effective for symptomatic irreversible pulpitis
Returns for pulpectomy/prep
Less challenging that pulpectomy
Explain the procedure for an emergency pulpotomy?
LA
Rubber dam
Open pulp chamber and irrigate with NaOCl
Amputate coronal stump with slow speed or spoon excavator
Don’t enter canals yet
Irrigate with NaOcl
Dry with dampened cotton
Seal CaOH into pulp chamber
Cover with some cotton covered by Cavit + GIC/RMGIC
Give advice
Return for RCT
What is the evidence for the success of emergency of pulpotomy?
Results in significant reduction in pain within 24hrs in 90% patients
How does a pulpotomy relieve pain?
ALters pulp haemodynamic and interstitial tissue pressure, deceases local tissue pressure and decreases inflammatory mediators, severs terminal endings of nociceptors
What are the indications for a pulpectomy?
Non-vital tooth
symptomatic PRP
Acute periapical abscess
Pulpotomy will not relive sufficient pain
What is the definition of pulpectomy?
Complete pulpal extirpation and debridement of the RCS
How does a pulpectomy relieve pain?
Reduces bacterial products in the apical 1/3 of the canals
Decreases the nociceptive activity in the periradicular tissue
Substantial decrease in pain between 24-36 hrs
What is the definition of an acute apical abscess?
Develop from a symptomatic or asymptomatic PRP or a chronic apical abscess
How does an acute apical abscess form?
Bacteria that egress infected RCS and invade periradicular tissues to establish an extraradicular infection and evoke purulent inflammation
Dom by anaerobic bacteria
12-18 bacteria compared to 7-12 in root canals
What are the clinical symptoms for an acute apical abscess?
Pain TTP Tender to palpate buccal sulci \+/i mobility, local swelling and facial space involvement Systemic manifestations: - fever, headache and nausea Radiographically: - possible widened periodontal ligament space Sensibility testing Periapical abscess = non-vital tooth Periodontal abscess = vital tooth
Where does the exudate form an acute periapical abscess exit?
Through the path of least resistance
Result in local swelling where it exists through the alveolar bone, discharged via the PDL or spread into tissue spaces
What are the treatment options for an acute periapical abscess?
Remove source of infection or relieve Pa through drainage
Extract
Pulpectomy + drain via RCS
Incise and drain
Exudate can be removed via RCS, can relieve pain
Explain the process of a pulpectomy and drainage for an acute periapical abscess?
Access to RCS to WL, if no drain, take 08 or 10 K file through apical constriction, can enable drainage
If not irrigate and dress as usual
DO NOT leave open (can cause delayed healing and later flare ups
Can become heavily infected
Persistent drain - allow patient to wait 30 mins
Dress with CaOH and seal access
How can acute apical abscess form fascial space infections?
Bacteria from RCS enter periradicular tissue and the immune system is unable to suppress invasion, they will eventually show symptoms
Can be found in vestibule or into fascial space
What is the definition of a fascial space infection?
Spread into the fascial spaces from the periradicular area of a tooth
Spread of purulent exudate
What is the definition of fascial spaces?
Potential anatomic areas that exist between the fascia and the underlying organs and other tissues
What are the requirements of an abscess to allow incision and drainage?
Swelling is fluctuant and in soft tissue
Explain the LA technique for an acute apical abscess using the incise and drain technique?
Needs LA
Mandible: IANB injection and long buccal injection
Maxilla: infiltrate both sides of facial swelling
Palatal: infiltrate over the greater palatine foramen or nasopalatine foramen
If abscess over foramen, infiltrate on either side
Why should you not inject directly into an abscess?
SPread infection
Painful
Increased BF, removes drug quicker
What is the definition of the fascial infection submandibular space?
Potential space between the mylohyoid muscle superior and platysma inferiorly
Molar tooth
What fascial spaces give a Ludwig’s angina?
Submental
Sublingual
Submandibular
Can advance into pharyngeal and cervical spaces
What is the definition of fascial infection mental space?
Potential bilateral anatomic area of the chin that lies between the mentalis muscle superior and platysma inferior
Anterior tooth
What is the definition of fascial infection sublingual space?
Anatomic area between the buccal cortical plate, overlying the alveolar mucosa and the buccinator muscle (post) or the mentalis muscle (ant)
Mand posterior or anterior tooth
What is the definition of fascial infection submental space?
Potential anatomic area between mylohyoid muscle superior and platysma inferior
Anterior tooth
What is the definition of fascial infection mand buccal vestibule?
Anatomic area between the buccal cortical plate, overlying mucosa, and the buccinator (post) or mentalis (ant)
Mand post or ant tooth
What is the definition of fascial infection buccal vestibular space?
Area between the buccal cortical plate, overlying mucosa and buccinator
Max posterior
What is the definition of fascial infection buccal space?
Between lateral surface of buccinator and medial surface of skin of cheek
Posterior mandibular or Maxillary tooth
What is the definition of fascial infection pterygomandibular space?
Space between the lateral surface of the medial pterygoid and the medial surface of the ramus
Mand second or third molar
What is the definition of fascial infection canine and infraorbital space?
Space between levator anguli inferior and levator labii superior
Max canine or first premolar
Midface infection can cause cavernous sinus thrombosis
What is the definition of fascial infection lower lip?
Max central incisor
What is the definition of fascial infection palate?
Max teeth
Lateral incisors
What is the definition of Ludwig’s angina?
Life threatening cellulitis advance into pharyngeal and cervical spaces resulting in airway obstruction
What are the treatment options for Ludwig’s angina?
Antibiotics + endodontic treatment Aggressive incision for drainage Relieve Pa Extraction RCT Incision/drainage
How to provide pathway for drainage to prevent spread for Ludwig’s angina?
Decompression of increased pressure associated with oedema
Pain relief
Improves circulation to area, allowing better delivery
Extraoral drain may be required
Explain how an RCT will treat Ludwig’s angina?
Phago kill bacteria
Leukocytes influx stop
Neutrophilic leuko die of apoptosis
Macro clean up mess
How do NSAIDs help with pulpal pain control?
As pulpal pain is due to inflammation, they are good anti-inflammatories
Explain how NSAIDs work?
Affect prostaglandin synthesis
Inhibit inflamm mediators
Suppress release of mediators at site of noxious stim
Decrease peripheral nociceptor sensitisation
What are the disadvantages of NSAIDs?
Ceiling to their analgesic effect Ulcers Asthma Liver dysfunction Diabetes Gout Influenza (Reyes syndrome)
How does paracetamol help with pulpal pain control?
Contra for NSAIDs
Post-endo pain
Analgesic and Antipyretic
What are the disadvantages of paracetamol?
Overdose
Acute liver failure
How do NSAIDs and Paracetamol combinations aid pain control?
Enhances the analgesic effect
Paracetamol appear to selectively converted within the brain into another drug which block PG synthesis in the brain having an analgesic effect on the CNS and NSAIDs act on PNS
How effective are systemic microbials at reducing endodontic pain?
No difference in pain control compared to placebo:
- post-OP pain
- swelling
- flare up
- analgesic consumption
When can you prescribe antibiotics for an dental infection?
Pulpal necrosis: plus - diffuse swelling - drainage can't be achieved - systemic involvement - fever, malaise, trismus or lymphadenopathy Needed for RCT with post
What are the post-OP advice for endodontic treatment?
Check for sharp bites and normal biting feel Usual LA advise Injection site may be tender Gingiva sore or bleeding Tooth to be tender
How can NaOCl accident occur during endodontic treatment?
Extrusion of irrigant into periradicular tissue Occur when: - needle wedges in canal - tooth wide open foramen - immature apex - resorbed apex
What are the symptoms of NaOCl accident?
Sudden, prolonged sharp pain Rapid and diffuse swelling Hemorrhagic reaction Oedema Bruising Tissue necrosis
What is the definition of a perforation?
Iatrogenic by error
Blood seen during RCT
Acute inflammatory reaction will occur
Present with perio abscess (pain, swelling and pus draining via PDL)
What is the definition of a ‘flare-up’?
Acute exacerbation Significant increase in pain and swelling Sudden exacerbation of a previously symptomless periradicular lesion Need emergency appointment Low occurrence Need active treatment Irrigate canals Drain Pre-emptive analgesia can be successful
Name 5 causes for abscess flare-ups?
Apical debris extrusion Incomplete instrumentation Secondary intracanal infection Lost provisional restorations Non-microbial causes
Name 5 risk factors for flare-ups?
Gender Systemic disease Diabetes Pre-Op pain Tooth type (5,6,7) Necrotic teeth
Name 5 ways to prevent flare-ups?
Pre-emptive analgesia Rubber dam Crown down sequence Achieve WL and irrigate passively Clear post-OP instructions
Explain the process to treat flare-ups?
Analgesics Check canals Ensure correct WL Irrigate to apical 1/3 Drainage via RCS SWelling present, consider incision and drainage Irrigate a lot Redress with CaOH + GIC Check occlusion
Name 5 causes of pain immediately after obturation?
Over-instrument Overfill Irritated periradicular tissue Perforation Root fractures Cold lateral compaction Restoration in supraocclusion Poor occlusion
GS treatment for reversible pulpitis?
Remove cause:
- defective filling
- caries
GS treatment for symptomatic irreversible pulpitis?
Emergency pulpotomy
Pulpectomy
extraction
GS treatment for necrotic pulp and symptomatic periradicular periodontitis?
Pulpectomy
Extraction
GS treatment for acute apical abscess?
Pulpectomy and drainage via RCS
Incision and drain via ST
Extraction
Antibiotics if systemic
What requirements for a tooth are needed for an RCT?
Patient wants to keep the tooth but only if its restorable
Tooth restorable
Prevent denture
Pulp in the abutment for a bridge has irreversible damaged or non-vital
Why should you routinely remove existing restoration prior to RCT?
TO check for:
- routes of microbial ingress (caries, cracks and defective margins)
- quality and quantity of dentine remaining
- investigate the tooth
How to proceed with an RCT if the tooth is thought to be resorbale?
Remove all caries and defective restorations
Restore
Radiographs:
- needs 2-3mm of periradicular tissue
Remember to consider the status of adjacent and opposing teeth
What factors to consider when thinking whether a tooth is restorable?
Perio status
General factors
Prosthodontic prognosis (seal)
Endodontic prognosis
How can medical condition impact the effectiveness of endodontic treatment?
Cooperation
Anxiety
Staying still
Name 5 medical conditions that are -ve affected by endodontic procedures?
RA Diabetes Coronary Heart DIsease Radiotherapy HIV
What is the clinical relevance to endodontics for a diabetes sufferer?
Higher prevalence of periradicular periodontitis
Slower healing
2 x risk for flare ups
Outcome for treatment worse
What clinical relevance to endodontics do allergy sufferers have?
Rubber dam Chlorhexidine NaOCl ZnOE Resins Gutta percha
What are the specific endodontic factors that may aid or reduce the success of a procedure?
Complexity Sinus involvement Previous RCT WL Isolation Obturation dense + requirements Coronal seal
What are the requirements of a tooth to be suitable for endodontic treatment?
Pulp chamber Root canals visible Root curvature Root length Apical closure Previous RCT Restoration Location and Position
How can size of pulp chambers affect the complexity for an endodontic treatment?
Size decreases with age and due to secondary/3rd dentine
Smaller chamber is more difficult
increased iatrogenic errors
Calcification can impede access into RCS
How can pulp obliteration affect the complexity for an endodontic treatment?
Occurs with increased age and 2nd/3rd dentine deposits
In response to trauma
Radiolucency = canal
If RCS not present, RCT not really possible
How can root curvature affect the complexity for an endodontic treatment?
Curves or SH shaped curve, increase risk of file mishaps such as breaking or perforations
How can root length affect the complexity for an endodontic treatment?
Can cause open apex
Idiopathic root resorption
Need sufficient working length
Can be longer than expected
How can tooth position affect the complexity for an endodontic treatment?
Tilted, rotated and retroclined can make access difficult
What is the definition of apical closure?
Open apex is the sequelae of an injury during root development which has caused pulpal necrosis
Root fails to form
Root resorption can occur
XLA due to deep occlusal caries
How can previous RCT affect the complexity for an endodontic treatment?
Access to apical 1/3
Difficult to tell the material
What website can aid complexity of an endodontic case?
aae.org
What are the success rate for vital pulp? irreversibly inflamed pulp? necrotic pulp? a/symptomatic PRP? re-RCT?
Best
V good
Slightly reduced
Lowest
What is the definition of success rates?
Mainly to apical healing and is the measure traditionally used by endodontists
What is the definition of survival rates?
Mainly to functionality of the tooth
What are the requirements for a RCT to be considered successful?
Lack signs and symptoms No history of pain/discomfort Not TTP Not tender No sinus or swelling Radiographic healing Functional and aesthetic
What did the Salehrabi and Rotstein meta analysis show about RCT survival of teeth?
97% functional at 8 years after initial non-surgical management
What are the contraindications for endodontic treatment?
Limited access
unrestorable tooth
Long term functionless or non-strategic tooth
Severe, progressive perio disease
Patient can’t lie supine or still for long enough
If too difficult REFER
Name 10 periodontal factors which can affect endodontic treatment?
Presence of periodontitis BOP OH Caries LoA Pockets Furcations Bone support Unusual anatomy Restoration margins (caries/fracture extending subgingivally) If tooth margin below gingiva - crown lengthening
What is the definition of biologic width?
Dentogingival attachment to the tooth Epithelium + CT = 20.4mm JE 0.97mm ACJ 1.07mm BW greater for posterior teeth Range between 0.75-4.33mm
What is the definition of a perio-endo lesion?
Exhibits 2 conditions concurrently
Marginal LoA
Periradicular periodontitis (PRP)
Name the 3 ways in which a perio-endo lesion can arise?
Tooth have noth advanced perio disease and coincidentally develop pulpal necrosis + PRP at the same time
Tooth with advanced perio disease + LoA extending the apical foramen (causing pulpal necrosis and develop PRP)
A tooth develop necrotic pulp + PRP, infection can cause perio pocket
What is the single most important factor influencing the endodontic prognosis?
Quantity and quality of remaining tooth structure
Need at least 2mm supragingival dentine around the circumference of the tooth
Remaining coronal tooth substance offers retention, resistance, a substrate to bond to and the ferrule effect
What is the definition of the Ferrule effect?
A metal ring or cap intended to embrace the tooth structure cervically to achieve root strengthening and prevent shattering the root
2mm H
1mm W
How can tooth surface loss affect the effectiveness of an endodontic treatment?
Exposed dentine offers route for microbial ingress to pulp
Can cause pulpal inflammation
If slow, tertiary dentine formed quick enough
If fast, can endanger pulp
Either through exposure or loss of vitality, pulp becomes necrotic
But don’t have complications after RCT treatment
Name the 6 occlusal/functional requirements for endodontic treatment?
Location in arch Molars/teeth involved in guidance have higher loads # of teeth present Tooth in function Parafunctional habits Repeated resto to tooth Mobility
What is the definition of a shortened dental arch?
Dentition with an intact anterior region and a reduction of occluding pairs of post teeth
Molars not replaced
What is the definition of a coronal seal?
Quality of the coronal restoration at preventing microbes from gaining access to the RCS
Seal fail = RCT fail
Filling/Crown/Bridge
Name 8 factors that make RCT hard to perform?
Resorption defects Pulp stones Calcified canals Curved canals Curved apices Restorations difficult to remove Previous RCT Procedural errors
What determines the shape and location of the access cavity?
Anatomy of the pulp chamber
Describe the 5 stage pre-OP assessment for an endodontic treatment?
- Diagnosis
- Assess restorability and study radiographs
- Plan access
- Dam
- Magnification
Describe the access cavity shape and location for a canine?
1 oval shaped canal so the outline of the access cavity is an oval
Describe the access cavity shape and location for a maxillary 1st premolar?
2 canals, may be connected by an isthmus
Gives a figure of 8 type shape
Outline form of access should reflect the figure of 8 shape
Oval like shape
Describe the access cavity shape and location for a mandibular molar??
3 canals
Outline form of access cavity reflects where you expect to find these within the pulp chamber
Rhombus like shape
Name 8 requirements for the access cavity?
Prevent coronal leakage during RCT Create reservoir for irrigation Good retention and thickness for temp resto Locate all canal entrances All seen from one view Give straight line access to apical 1/3 Remove all pulp chamber roof and coronal pulp tissues Conserve as much dentine as possible
What type of radiograph is essential for endodontics?
Parallel periapical
Name 7 factors to consider before creating the access cavity?
Remove all caries and defective restos and replace Assess restorability Consider removal of extracoronal restos Plan shape and location of access LA Magnification Dam
Name the 5 key stages for endodontic treatment?
- Remove caries
- Assess restorability
- Allow isolation for treatment
- Maintain occlusal relationship
- Maintain apperance
Explain how to proceed if the caries reaches into the pulpal space?
Place the vaseline covered spreader into pulp and restore around it then remove to create an access to the remaining pulp
What are the disadvantages of cutting through extra-coronal restorations?
Compromised visibility:
- canal location
- caries
Porcelain may fracture
What may a extra-coronal restoration hide, which hinders the treatment?
True orientation of the remaining tooth
Lead to perforations
Loss of support for the crown
Where to create the access cavity for an anterior tooth?
Lingually
To achieve straight line access whilst reducing aesthetic and restorative concerns
Where to create the access cavity for a posterior tooth?
Occasionally
To achieve straight line access whilst reducing aesthetic and restorative concerns
Why should you not use caries preparation as an access cavity?
Failure to remove all the pulpal debris from the chamber
Increases chance of perforation
What is the evidence behind using the microscope for endodontic preocedures?
of second mesiobuccal canals in max molar increased from 51-82%
What bur helps protect the floor of the pulp chamber?
Safe ended/non-cutting burs
Endo Z bur
Name the 2 burs to be used during an endodontic procedure?
Long fissure bur for initial outline form
One the root of the pulp chamber is entered
Non-cutting/safe ended tip bur
Name 2 factors affect the size of the pulp chamber?
Age
Previous trauma
Explain a technique to predict the size and location of the pulp chamber?
Always at the CEJ
In the centre of the tooth
Measure before you start on the external surface
Check depth when creating the access cavity
Bur tends to drop into pulp chamber
What to place after the pulp chamber is accessed?
Rubber dam
Cavity can be refined later
What to do immediately after placing the rubber dam for an endodontic treatment?
Ensure a seal is made
Use caulk
Then irrigate pulp chamber with NaOCl
If pulp is vital, haemorrhage will stain the dentinal tubules, if not removed immediately
What bur to use to improve access the the canal entrances?
Small, delicate adjustments
Pulp chamber is not all that deep, composite finishing burs can be used
OR endodontic ultrasonic
Confirm canal entrances using a DG16 endodontic probe
What is the next step once the canal entrances have been identified and the cavity shape is complete for endodontic procedure?
Irrigated lots with NaOCl
Remove pulpal remnants and dentine chips
Bleach floor of pulp chamber enhancing vision of the canal orifices
Name 4 errors that can occur when trying to find the canal enterances?
Wrong tooth Can't locate canals (not in correct place) Create false canals Make it harder to find actual canals May perforate
What error can occur is the access cavity is too small?
Pulpal debris is not removed
Files must bend more to get into canals
Canals not located
What error can occur in the access cavity is too large?
Sacrifices dentine weakening tooth
tooth susceptible to irretrievable fracture
Files do not slide gently into canal entrance but catch on step
How to make sure that every canal has been identified?
NaOCl will bubble over canal entrances Sharp DG16 robe to pick Use dye (methylene blue) Endodontic ultrasonic Long neck or gooseneck burs
Name the 4 aims of endodontic treatment?
Eliminate microbial infection
VIa chemomechanical preparation and disinfect of the root canal system
All root canals must be located
What is the common shape of the root?
Curved
S shaped
Describe the anatomy of the RCS?
Starts at CEJ or apical to it and extends to the apical foramen
Apical foramen is usually within 3mm of the actual root end
Lateral.accessory canals are common
RCS often ends in a delta
Describe the root apex?
Apical constriction is accepted as being 1mm short of the radiographic apex
WHat is Weine’s classification for root canal configuration (1)?
A single canal from orifice to foramen
What is Weine’s classification for root canal configuration (2 - 1)?
2 canal orifices in chamber but merge and exiting through 1 foramen
WHat is Weine’s classification for root canal configuration (2)?
2 canal orifices, 2 distinct canals and exit through foramina
WHat is Weine’s classification for root canal configuration (1 - 2)?
1 canal orifice in chamber, divides some way down root into 2 seperate canals and 2 foramina
Vertucci’s classification with Weine’s classification Type I?
1
Vertucci’s classification with Weine’s classification Type II?
2-1
Vertucci’s classification with Weine’s classification Type III?
1-2-1
Vertucci’s classification with Weine’s classification Type IV?
2
Vertucci’s classification with Weine’s classification Type V?
1-2
Vertucci’s classification with Weine’s classification Type VI?
2-1-2
Vertucci’s classification with Weine’s classification Type VII?
1-2-1-2
Vertucci’s classification with Weine’s classification Type VIII?
3
Which tooth has the most possible complicated root configuration?
Maxillary 2nd premolar
Name the 6 type of root canal cross sections?
Round Ribbon Figure of 8 Ovoid Kidney bean C shaped
Describe the pulpal anatomy of a maxillary central incisors?
RD: 10 Y 1 root 1 canal - TI Lateral/accessory canals common (found in apical 1/3) Pulp chamber: - 3 pulp horns newly erupted - 2 pulp horns mesial and distal - triangular in young - oval in older Access palatally
Describe the pulpal anatomy of a maxillary lateral incisors?
RD: 11 Y 1 root: - inclined palatally and distally - round in Xsec - flattened mesio-distal 1 canal: - apical foramen often laterally Lateral canals can occur Pulp chamber: - 0 or 2 pulp horns (mesial-incisal and distal-incisal) Oval shaped canal becoming more circular in the apical 1/3 Variations: - peg lateral - dens in dente - long tubercle in cingulum - dens invaginatus Access palatally
Describe the pulpal anatomy of a maxillary canine?
RD: 13-15 1 long root: - fenestration apically - curve labially in apical 1/3 1 long canal: - may have lateral canals in apical 1/3 - apical foramen often lateral Pulp chamber: - 1 pulp horn Xsec: - oval Access palatally
Describe the pulpal anatomy of a mandibular incisors?
RD: 9-10 Y 1 root: - flattened mesiodistally - figure of 8 Xsec - curve distally - T1 canal - can be 2-1 or 1-2-1 - apical foramen lateral Pulp chamber: - 3 pulp horns corresponding to mamelons Xsec canal: - oval coronally Find 2nd canal extend into cingulum 1 foramin Ribbon shaped Access palatally
Describe the pulpal anatomy of a maxillary canine?
RD: 12-14 Y 1 root: - TI canal - some TII (labial and lingual) - lateral canals - mostly apically - apical foramen lateral - apical delta Pulp chamber: - 1 pulp horn Xsec: - oval becoming round apically Access lingual
Average length of Upper 1
22.5mm
Average length of Upper 2
22mm
Average length of Upper 3
26.5mm
Average length of Lower 1
21mm
Average length of Lower 2
21mm
Average length of Lower 3
24mm
Number of canals for Upper 1/2/3?
1
Vertucci’s config for Upper 1/2/3?
T1
Number of canals for Lower 1?
1 (70%)
2
Number of canals for Lower 2?
1 (75%)
2
Number of canals for Lower 3?
1 (78%)
2 merge into 1
Vertucci’s config for Lower 1/2?
TI
TIII
Vertucci’s config for Lower 3?
TI
TII
TIV
What must you perform before creating the access cavity?
Diagnosis 1 parallel periapical radiograph Remove caries or defective resto and replace Plan shape and location LA Microscope Dam
If caries removal is complete and the root canal orifices are exposed, the tooth needs to be restored how?
Dam
Matrix band
Place petroleum jelly covered finger spreader in each canal orifice
Name the 5 benefits of good illumination and magnification?
See subtle changes of colour, texture and sclerotic plugs of dentine in the canal orifices
Floor of pulp chamber is always darker than walls
Identify when you have removed the roof of the pulp chamber
Locate extra, small canals
Name the 6 key characteristics if an access cavity?
Good canal vision Act as a reservoir for irrigants Have no overhangs of the pulp chamber roof Provides support for temporary fillings Aim to always have 4 intact walls Straight line access to canals
Explain the process in creating an access cavity in multirooted teeth?
Long fissure diamont to cut the outline form of the access cavity and penetrate the roof of the pulp chamber
Bur drops into chamber
Swap to an Endo Z bur and remove the rest of the pulp chamber roof
Irrigate the chamber with NaOCl and use spoon excavator to remove any pulpal debris
Identify canals using the DG16 or a small ss file (10)
Check straight line access into all canals using the DG16 and magnification
Explain how to refine the access cavity for a multirooted tooth?
Remove any dentinal shelves or bulges:
- use slow speed with care
- ENdo Z bur
- fine grit composite finishing bur
- endodontic diamond coated ultrasonic tip
What is the definition of a canal bifurcation?
The disappearance of a large canal in a premolar often
Where will the largest canal be situated for mand and max molars?
Mand - distal
Max - palatal
What is a common area when creating the access cavity?
Removing the roof of the pulp chamber
Use an Endo Z bur to remove
How to ensure straight line access?
DG16 and 08/10 K file
Flood pulp chamber with NaOCl
Place a size 10 K file passively in coronal 2/3s of canal
Help prevent SS files gouging into canal walls
Decreases stress on NiTi files which could lead to fracture
What os the definition of a furcal canal?
Accessory canal in the furcation region of permanent molars
30% of mand and max molars had accessory canals in the furcation area
Prevalent in upper and lower 6s
What is the definition of the isthmi?
COnnecting, usually narrow, part, organ or passage especially when joining structures or cavities larger than itself
Narrow, ribbon shaped communication between 2 root canals that contain pulp tissues
Occur with in any tooth with multiple canals
Why is the canal isthmus clinically significant?
mechanical cleaning and shaping of an isthmus is difficult and can lead to treatment failure if ineffective
If not identified can lead to treatment failure
Describe the RCS of the maxillary 3rd molar?
RC: 18-25 3 roots (MB/MP and P - converge) Root curves distally Short in length Variable tooth morpho Can be peg shaped Needs radiograph
Describe the RCS of the maxillary 2nd molar?
RC: 14-16 3 roots Roots coalescence (MB/DB) 3/4 canals Usually MB (MB2) DB and P Pulp chamber: - 4 horns for 4 cusps DB straight MB curved P largest round/oval and curved apically Access mesially of the occlusal surface
Describe the RCS of the maxillary 1st molar?
RC: 9-10 Y 3 roots Palatal root longest and most divergent because of max antrum Buccal root curve distally DB < MB length 4 canals: - MB MB2 DB P Cross sections: - DB round - MB flattened and most curved distally - palatal largest canal Access mesially via occlusal
Describe the RCS of the maxillary 2nd premolar?
RC: 12-14 Y 1 root (can be 2 bifurcation) 1 canal or 2 Pulp chamber: - 2 cusps = 2 horns - buccal pulp hor larger than palatal Xsec: - flattened mesiodistal - oval for 1 canal - isthmi for 2 canals Figure of 8 cross-section Access cavity: - narrow mesiodistally - oval shaped buccolingually
Describe the RCS of the maxillary 1st premolar?
RC: 12-13 2 roots (buccal and palatal) Roots curve slightly distally 2 pulp horns can have 1-3 roots Buccal root may divide into a MB and DB root Figure of 8 cross-section Access cavity: - narrow mesiodistally - oval shaped buccolingually
Describe the RCS of the mandibular 1st premolar?
RC: 12-13 1 root: - rounded in Xsec - slight distal curve - root sometimes bifurcated 1 canal Pulp chamber: - 2 pulp horns at different heights - B > L - pulp chamber roof tends to tilt lingually Xsec: - oval shaped - divide buccal and lingual half way down and then re-merges Access cavity oval buccolingually
Describe the RCS of the mandibular 2nd premolar?
RC: 13-14 Y 1 root, curves distally Root may bifurcate Pulp chamber: - 2 pulp horn and a single canal 3 cusp version has 3 horns Xsec: - oval-round Access cavity: - oval buccolingually
Describe the RCS of the mandibular 1st molar?
RC: 6-7 Y 2 roots: - mesial flat with mesial groove (figure of 8 cross section) Pulp chamber: 5 cusp - 3 buccal - 2 lingual Xsec: - distal = large oval or 8 figure - mesial root = 2 canals (B and L) connected by isthmus and tend to curve distally - mesial canal can bifurcate Variations: - extra distal root lingually Access cavity: - mesial side of the occlusal surface - if lingually inclined better to move slightly towards buccal and MB cusp
Describe the RCS of the mandibular 2nd molar?
RC: 14-15 Y 2 roots (M and D) - roots can be fused - extra root in DL 3 root canals: - ML MB and D Pulp chamber: - 4 pulp horns Xsec: - mesial: 8 figure, separate with 2 apical foramina, often have isthmus Variations: - 1 c-shaped canal - may have 2 canals Access cavity towards mesial of occlusal surface
Describe the RCS of the mandibular 3rd molar?
RC: 18-25 Y 2 roots M & D Shorter roots than other molars Roots may be fused Distal curvature of roots CAn have 3/2/1 canal Access cavity dependent on radiograph
Upper 4 - canals and length?
2
21mm
Upper 5 - canals and length?
1
21mm
Upper 6 - canals and length?
4
MB/DB 19-22
P 22-25mm
Upper 7 - canals and length?
3
MB/DB 19-22mm
P 21-23mm
Upper 8 - canals and length?
3
MB/DB 18-22 mm
P 18-23mm
Lower 4 - canals and length?
1
21mm
Lower 5 - canals and length?
1
21mm
Lower 6 - canals and length?
3
ML/BM 21mm
D 22-23mm
Lower 7 - canals and length?
3
ML/MD/D 20mm
Lower 8 - canals and length?
1/2
19mm
Give a description of a barbed broaches?
Variety of sizes
• Made by cutting barbs into metal wire blanks
• Used for removing vital pulps
• Sever the pulp at the apical constriction
• Not used so much nowadays (NiTis taken over)
• Are very useful for removing small cotton wool
pellets from within the root canal system
Explain how to remove pulp with a barbed broach?
If pulp is intact (e.g. in a vital or irreversibly
inflamed pulp), it may be possible to remove it in 1
piece
• Use a ss barbed broach with care
• Can get caught on sides of canal
• Avoid use in narrow/calcified canals as can #
• Where the pulp is necrotic, it is no longer intact
and the remaining pulpal debris will be removed
during the canal shaping and disinfecting
procedures – DO NOT need barbed broach
Name 6 instruments necessary for endodontic treatment?
Mirror – front silvered mirror so there is not a double reflection • Locking tweezers Perio probe • DG 16 • Excavator Flat plastic • Burnisher/plugger • measuring block & clean stand
Name the 2 styles of endodontic files?
K-type
Hedstrom
What is an ISO sized instrument?
The ISO size indicates that all ‘ISO‐sized’ instrument have a 2% taper.
ISO sized files (e.g. K files, Hedstroms) have a fixed taper
• i.e. all the files increase in size by the same amount relative to their tip
size.
• Over the 16mm length of the cutting flutes, they increase in diameter by
0.32mm
• This is a 0.02mm increase in diameter per mm length of the cutting
flute…
• Also known as a .02 or 2% taper
What is the definition of a taper?
the amount the file diameter increases each mm along its cutting
surface from the tip towards the file handle
Give a description of a K-type file?
Made by twisting square or triangular metal blanks….which means they
can untwist! Must check for this during use
• Horizontal cutting blades
• Non‐cutting tips
• In 21mm, 25mm, 31mm lengths
• All have a 16mm length of cutting flute
• Mainly made in ss but get niti too (e.g. niti‐flex Dentsply)
• Use ss for routine ‘guide path’ & for negotiating ledges
Files are identified according to their tip size
This file is a ‘40’ because at its tip (or D0) the diameter is 0.4mm
Explain how to use a K-type file to remove root tissue?
Use in a turning/rotation type movement
• Either ‘watch‐winding’ or balanced force
• NEVER a ‘screw‐in’ movement
• V rarely an up‐and‐down movement
• Relatively flexible…BUT as size increases,
rigidity increases
How have the K-type files been modified in the past?
Design has been modified to increase file flexibility changing cross section square to rhomboid from & using more flexible steel eg K Flexofiles • The tip has also been modified: • The tip guides the file and enlarges RCS • If an instrument has a cutting tip it can gouge into the canal walls creating a false canal • Now ‘non‐cutting’ or ‘semi‐ cutting’ tips
Explain how the H-type file removes root tissue?
Milled from round ss blanks • DO NOT rotate as can fracture • Designed to be used up and down • Aggressive instruments which can easily damage the root canal • Not recommended for routine use • Use in root canal re‐ treatment to help snag remaining bits of GP
Give a description of a Gates Glidden rotary instrument?
Rotary instruments
• In the past, used routinely for ‘coronal flare’
• BUT can only be used in straight portions of the canal
• Side cutting instruments/ non‐ end cutting tip
• Different sizes available
If not used carefully GG can remove far too much
dentine, weakening tooth and potentially perforating
- Superseded by NiTi files
Name the root anatomy after preparation?
Elbow
Zip
Ledge
Transportation of foramen
Name 7 problems during canal preparation?
Blockages • Ledges • Transportation • Elbows • Zips • Perforation • Instrument separation
Explain how a canal can be blocked?
• Caused by dentine debris getting packed
into the apical portion of the root
• Is extremely hard to remove!
• Attempts to remove it can result in a false
canal being cut and possible perforation
• Avoid by ‘recapitulating’ during canal
preparation
• Between each file, passively re‐insert an
08 or 10 K‐file to length
Explain how a ledge can cause problems?
A ledge is internal transportation of the canal
• Occurs when working short of length with straight files
• Avoid by ALWAYS precurving
• Ledges can sometimes be bypassed but difficult
What is the definition of apical transportation?
Transportation of the apical foramen changes the shape of the
foramen
• This makes it more difficult to fill/seal & also fails to provide
resistance for packing of gutta‐percha
• Can easily overfill
- Avoid crown-down sequence
What is the definition of zipping the root canal?
The outer side of the curve is over‐
enlarged & the inner side of the curve
under‐prepared
• Transports the canal
• The narrowest part of RCS where zipping
has occurred is called an ‘elbow’
• This hour‐glass shape makes satisfactory
obturation of the apical third very difficult
• Avoid by using ss files only for guide path &
then swap to niti’s
What happens when you create a perforation in the root?
Can occur where an end‐cutting file is used, or over
zealous preparation of a ‘zipped’ or blocked canal.
• A false canal is cut through the radicular dentine and
into the periradicular tissues
• If this happens during RCT, there will be bleeding
into the canal +/‐ patient c/o pain
• Radiographs using parallax shift can help identify
• Electronic apex locators help identify
• Dental operating microscope to identify & repair
• Avoid by using non‐end cutting files wherever
possible, work passively, never force a file or bur into
the RCS
How have NiTi instruments helped endodontics, but what problems do you still pose?
The use of NiTi files has reduced the clinical incidence of
blocks, ledges, transportation & perforation
• BUT they are believed to # fairly easily
• This can create a problem, as a fractured file blocking
access to an infected part of the RCS means that
necrotic debris cannot be removed and the success of treatment reduced
Name the 2 ways in which files can fracture?
Torsional fatigue
Flexural fatigue
What is the definition of torsional fatigue?
Occurs when the instrument tip is locked in the canal and the instrument above the jammed/locked portion continues to rotate.
This causes it to fracture
• This type of fracture is due to too much torque on the file
• The torque generated on a file during canal preparation depends on:
• The contact area of the file with the walls of the canal
• Using a crown‐down approach reduces torque
• Using a light pressure on the files reduces torque
What is the definition of flexural fatigue
Cyclic loading leads to metal fatigue
• As all endodontic files are single use in the UK this is unlikely to happen
Give a description of a NiTi file?
Each system tend to vary in design…e.g. tip shape/size, cross section,
taper etc
• Niti files are milled, although some recent new files twisted (Twisted
files by Sybron Endo)
Name the 7 advantages of NiTi files?
Superelasticity - Increased flexibility in larger sizes and tapers - 3 x more than ss • Increased cutting efficiency • Faster preps • Less iatrogenic damage • Stays centered in canal • Less transportation • More predictable result • BUT more expensive
What are the 2 main properties of NiTi are useful for endodontics?
Superelasticity with shape memory/recovery
• High resistance to cyclic fatigue
Name 1 commercially available NiTi system?
ProTaper
What is the definition of a ProTaper system?
Each instrument has a variable taper along its length
• Prevents screw‐in effect
• Allows increased apical tapers (Finishing Files)
• Allows excellent shaping with few instruments
• Each instrument engages a smaller zone of dentine which reduces
torsional loads, file fatigue and potential for breakage
• Varying tip diameters
• Superior flexibility, high efficiency and improved safety
• Mostly side cutting files
• Consist of a set of either 8 hand files OR 8 rotary files which can be used
interchangeably.
Name the 8 files of the ProTaper system?
3 shaping files - S files: coronal and mid third - SX - S1 - S2 5 finishing files - F files: apical third - F1 - F2 - F3 - F4 - F5
What are the tip, cross section and taper differences between finishing and shaping files?
Tip:
- Shaping files have partially cutting tips
• Finishing files safe, non‐cutting tips
Xsec:
- shaping files different from the finishing files
• Finishing file cross section allows for greater
flexibility & for debris to move coronally
Taper:
- shaping files have tapers which increase coronally
• finishing files have tapers which increase apically
Give a description of shaping file SX and how it is used?
length and tip diameter
No coloured band – is ‘gold’ shank • Length 19mm • Tip diameter 0.19mm • Taper apically 3.5% • Taper coronally19% • Can be used before or after S1 and S2 • Creates a large amount of coronal flare • Hand version use by turning clockwise • Rotary version can be used to relocate canal orifices • Use ‘brushing’ motion
Explain how to use a SX shaping file and their specific danger zones?
Rotary ProTapers can be used very effectively to flare canals using a
brushing action.
• ALWAYS use carefully to avoid over‐preparing/over‐’brushing’ in ‘danger
zones’
• Danger zones = the distal surface of mesial & MB roots & mesial surface of
distal roots etc (furcation areas)
Give a description of shaping file S1/2 and how it is used?
length and tip diameter
S1 = purple handle • S2 = white handle • Tip diameters • S1= 0.185 • S2= 0.20mm • 14mm cutting flutes • Partially active tips • to guide through debris • Tapers vary along length • increasing from a minimum of 2% at tip to 11.5% at handle‐end • Use hand files by turning clockwise • Rotaries with a ‘brushing’ motion
Give a description of the endodontic motor?
Allows excellent control of speed
• Constant low speeds protect against file fracture
• High torque control
• Warns (by beeping) if the instrument is likely to break
• Take it out, clean file, wash canal and check file intact and no plastic
deformation prior to reusing
• Can set auto reverse
Name the 5 rotary contraindications for use?
To use rotaries, need… straight line access
• Excessive bending will lead to separation
• No severe curves
• No merging/branching canals
• NOT designed for initial canal negotiation (see
later)
• NOT designed for by‐passing ledges
• Oval and ribbon shaped canals
• present difficulties for rotaries
• Use plenty irrigation!
What are the key DO’s and DONT’S of canal prep?
• ALWAYS create a guide path (to size 20 flexofile file) PRIOR to using any
rotaries in the RCS
• Canal should ALWAYS be flooded with irrigant prior to taking any files
into the canal
• Use rotaries at a CONSTANT speed of ~250 rpm with high torque
• Use files gently, NEVER push hard/force a file into a canal
• NEVER stop and start the motor with the file in the canal
• Remove files from the canal frequently & clean flutes on a sponge and
irrigate
• Be clear on the ‘movement’ the system you are using requires…e.g.
ProTaper require ‘brushing’ movements, some other systems require
‘pecking’
What are the objectives of cleaning and shaping the RC?
Remove infected soft and hard tissue
• Microorganisms, toxins, pulpal debris
• Allow irrigants access to the apical third for disinfection & removal of the
smear layer
• Create a smooth tapered shape of the RCS to allow:
• Space for medicaments
• Space for obturation to the apical constriction
• This will seal the RCS along its length and protect against microbial
re‐entry
• Aims to ‘entomb’ any remaining microbes so they cannot incite an
inflammatory response in the periradicular tissues
• Retain the integrity of the radicular structure.
Describe the steps to cleaning and shaping the RCS?
Mechanical instrumentation • (using hand or rotary files) • Disinfection • (using irrigants) (+/‐ 3. Intracanal medicaments placed between appointments)
What is the function of irrigants?
flush out debris, lubricate the path
of instruments for the mechanical shaping, destroy micro‐ organisms &
organic matter
Name the 11 desired irrigant actions?
Broad antimicrobial spectrum
• Highly effective against anaerobic & facultative micro organisms
organised in biofilms
• Dissolves necrotic pulp remnants
• Remain active in the presence of blood, serum & protein derivatives of
tissue
• Does not stain tooth structure
• Inactivate endotoxin
• Prevent formation of a smear layer – or dissolve it if it forms
• Not affect dentine deleteriously
• Retain its effectiveness when mixed with other irrigants
• Non toxic & hypoallergenic
• Inexpensive
What chemicals used in irrigants kill microbes?
sodium hypochlorite
• (Chlorhexidine gluconate)
• Iodine compounds
What chemicals used in irrigants remove the smear layer?
EDTA
• Citric acid
What are the advantages of using NaOCl?
Antibacterial
• Broad antimicrobial spectrum
• Kills bacteria, yeasts & some viruses
• In water NaOCl ionises
• Forms hypochlorous acid which releases chlorine
• Disrupts cell membranes & interferes with DNA synthesis
• Dissolves pulpal remnants & collagen – NO OTHER IRRIGANT OFFERS
THIS HUGE ADVANTAGE
What are the disadvantages of NaOCl?
Occasionally allergies are reported
• When used in high concentrations:
• has greater cytotoxicity if extruded into the apical tissue
• appears to have deleterious effects on dentine
• Reducing flexural strength
• Reducing the modulus of elasticity
• Lots of1‐2% NaOCl gives benefits of disinfection without the
disadvantages above.
• Doesn’t remove dentinal debris/smear layer
• need to use it with a chelating agent
• If stored diluted before use degrades & ineffective
How to use NaOCl via GS?
Use lots for as long as possible
• Needs time to work
• Need to continually refresh
• Get it into the apical 1/3!!
• measure and bend the needle so you know it’s to length
• Increase the temperature of a low concentration solution
• Improves the tissue dissolving capacity
• Ultrasonically activate it
• Acoustic streaming
• And heating
• REMEMBER never to wedge it in the canal, always make sure the tip is
free by jiggling it as you irrigate
What are the advantages of Chlorhexidine gluconate?
A broad‐spectrum antimicrobial agent
• Effective against gram ‐ & gram + & yeasts
• Bactericidal & bacteriostatic
• Substantivity
• Continues antimicrobial effect for up to 12 weeks
• Few reports of allergy
What are the disadvantages of chlorhexidine gluconate?
Not been shown to be more effective than NaOCl
• Does not dissolve pulpal tissue remnants
• NaOCl & CHX if used together react forming an insoluble precipitate
• May be useful as final irrigant due to substantivity but MUST
completely dry the canal first
• CHX also interacts with EDTA and forms a white salt precipitate
What are the advantages of Potassium Iodide?
Excellent antibacterial properties • Acts as an oxidising agent • Kills a wide range of micro‐organisms • Bacteria – E.faecalis, fungi, TB, viruses, spores • Low cytotoxicity
What are the disadvantages of Potassium Iodide?
stains dentine (must follow with NaOCl)
• Works by vapour release
• Unpredictable disinfection of the root canal system
• Potent allergen
What is the definition of the smear layer?
Dentine shavings • Cell debris • Pulp remnants • Smear layer reduces the ability of antimicrobial irrigants to enter dentinal tubules • May slow the antimicrobial effects of interappointment dressings also
Why should we remove the smear layer?
It harbours microorganisms
• prevents irrigants penetrating dentinal tubules
• gives better microbial‐tight seal of RCS if removed
• It can be removed with acids
What are the characteristics of EDTA?
Is a decalcifying calcium chelating agent
• Removes dentinal debris formed on walls of RCS
Removing the smear layer opens dentinal tubules and allows
penetration of NaOCl
• Use at 17% for 1 minute
• Self limiting decalcifying action
• Can penetrate 50µm into dentine
• Strongest effect when used synergistically with NaOCl
What are the characteristics of Citric acid?
Weak acid
• As potent, maybe more so than EDTA
• Cheaper
• Effectively removes the mineralised portion of the smear layer
Explain how to irrigate correctly?
Use a 27 gauge (yellow) Luer Lock syringe
with a side venting needle
• Measure it so you know it is in the apical 1/3
of the canal!
• Will need adequate coronal flare for this
• Irrigation only goes ~1mm beyond needle tip
• Use copious irrigation
• Between EVERY instrument
• MINIMUM 20mls/canal
• You cant use too much, but can easily use too
little
What can irrigant do to the soft tissues and how to treat this trauma?
Sudden severe pain,
• swelling, bruising
•Treat by irrigating canal with saline until
stops draining & dress, reassure, analgesics &
review
Explain the crown-down technique for endodontic procedures?
Coronal portion of canal prepared BEFORE WL verified
Irrigation introduced early
• Removes bulk of microbes early
• Better tactile sensation
• Less changes in WL
• Reduces torsional loads on files reducing risk of
instrument fracture
What are the disadvantages of coronal flaring?
Excessive flaring weakens the tooth as it removes dentine
• Leaves tooth more susceptible to fracture
• Could cause a strip perforation
Explain the process of crown-down technique?
Involves preparing the canal in 3 stages: • Creating a guide path • Prepare coronal 2/3 • Measure EWL from radiograph – subtract 3‐4mm. Set stoppers at this new length. • (find out the true/correct WL) • Prepare apical 1/3
How to estimate the working length from a pre-OP radiograph?
On R4 measure the digital radiograph by clicking on the ‘ruler’ symbol and then clicking on the radiographic apex and the incisal edge. Then subtract 3‐4mm from this length This gives the length to prepare the coronal 2/3 to.
Why is the guide path essential for endodontic treatment?
Ensures canal is patent (not blocked) • Creates a path large enough for the NiTi file tips • Prevents tip binding & instrument fracture Watchwind/twiddle a precurved 10, 15, 20 K file in a wet canal +/‐ lubricant paste to the coronal 2/3 measurement
How to create the guide path?
With stainless steel files you are ready to start with the niti ProTaper files • Set the silicone stops on the S1 & S2 files to the coronal 2/3 measurement (EWL minus 3mm)
What is the definition of the working length?
The working length is the distance from a coronal
reference point to the point at which the canal
preparation & obturation should terminate.
• The estimated working length is usually considered
as the distance in mm’s from a coronal reference
point (eg incisal edge) to the radiographic apex
minus 1mm
Explain using R4 how to estimate the working length of a RC?
Open the pre‐op periapical & select the ‘ruler’ symbol Click on the incisal reference point & around 1mm short of the radiographic apex. The PC will display the length of this in mm’s. This is the EWL If the canal appears curved, click on the curved point too to try and get a reasonably accurate EWL
What options can be used to establish an accurate WL?
- Radiographs
• Electronic Apex Locator
• Tactile sensation
• Paper points
Explain how to use radiographs to find an accurate WL?
Use a size 15 ISO
• Flexible K file
• Use a sound, reproducible reference point
• Usually the incisal edge or a cusp tip
• Use paralleling technique with film holder
• Ideally, the file tip should be 1‐2mm from the radiographic apex
Ideally the file is not right at the radiographic apex as this is probably too
long
• Radiographs are not accurate for identifying the apical constriction….we
“guesstimate” the apical constriction is around 1‐2mm away from the
radiographic apex
Despite their limitations radiographs are far more accurate than using
paper points or tactile sensation
• Ideally use electronic apex locator +/‐ radiographic WL
How to separate canals in a multi-rooted tooth?
Buccal object rule: - When a radiograph is taken from a mesial angle the buccal object is displaced distally • lingual/palatal objects displaced mesially. • PAL, SLOB etc • Your PAL always moves with you (i.e object is palatal/lingual) • Same Lingual Opposite Buccal = SLOB
Explain how to use an electronic apex locator to accurately find the WL?
When the file makes contact with the periapical tissues an audible signal
is triggered.
• Due to a fall in impedance
But must dry pulp chamber.
• Often useful to add Glyde paste to end of file to get a contact and use
with a precurved file.
Will hear signal early if there is a perforation
What are the advantages for using a small <30 finishing file for apical third of the root?
Minimal risk of canal
transportation, extrusion of
irrigants or filling materials
What are the disadvantages for using a small <30 finishing file for apical third of the root?
Little removal of infected dentine Irrigation may not get to the apical third Interappointment dressings may not get into apical third May make obturation difficult
What are the advantages for using a large >30 finishing file for apical third of the root?
Removal of infected dentine & debris from the apical third Access for irrigants and interappointment dressings into the apical third
What are the disadvantages for using a large >30 finishing file for apical third of the root?
Risk of preparation errors & extrusion of irrigants and filling materials If obturating with heated techniques, likely to get an overfill
What is the general rule when preparing the apical 1/3 of the root?
As a general rule, unless the apical 1/3 is prepared to a 30(F3),it will not
be possible to get irrigation into the apical l/3
• Try to prepare all canals to a MINIMUM size of F3
Explain the step by step process of preparing the apical 1/3 of the root?
Prepare to WL using Finishing File 1
• Place 20 Flexofile to gauge apical size
• Prepare to WL using Finishing File 2
• Place 25 Flexofile to gauge apical size
• Prepare to WL using a Finishing file 3
• Place a 30 Flexofile to gauge the apical size
• If the 30 Flexofile is loose, repeat with Finishing Files F4 & F5 until correct
apical size has been determined
What to do if the root canal WL is > than a F5 file?
If a canal is prep’d to F5 at working length:
• Insert a 50 Flexofile to WL
• Does it feel loose in canal?
• If so, it is unlikely that gutta percha will
satisfactorily seal the canal.
• This needs treated as an ‘open apex’
• Mineral trioxide aggregate will need to be
placed to form an ‘apical stop’
• Refer for completion of treatment with a
specialist
• Dress meantime in usual way
How should you irrigate the >F5 canal?
×1 syringe sodium hypochlorite
×1 syringe citric acid & leave in canal for 60 seconds
×1 syringe sodium hypochlorite
Dry canal using absorbent paper points matched size
What to comment in the notes for a >F5 canal?
Make sure you have recorded the following in the patient’s notes:
• The working length(s) (& what you have used to verify it)
• The reference point(s) used for measurements
• The size of the apical preparation i.e the final finishing file used
• Eg. Canal prep’d to F4 at WL of 23mm (using EAL) from incisal edge mid‐
point
What Post-OP instructions to give to an endodontic patient?
The tooth, injection site & gum (from RD clamp) may be tender for 2‐3
days might require analgesics
• ibuprofen or paracetamol or both
• A temporary dressing is in place and the patient should be mindful of this
• May be numb for some mins/hours more,
• take care not to traumatise soft tissues
Explain why endodontic files are single use only?
Scotland 2004 endodontic instruments designated high‐risk &
disposal after single use was deemed necessary
• research showed endo files could not be cleaned effectively
•a risk of residual contamination with nerve tissue and potential
prions
• BUT England is different….
• Following a review in 2010, now acceptable to re‐use same files
on same patient
• Stipulations for any re‐processing and traceability must be strictly
adhered to.
• & the rest of the world is different!!
What is the objective of obturation?
To achieve a complete apical, lateral and coronal seal of the root canal
system
• To entomb the remaining bacteria in the permanently filled root canal
space
• Remaining organisms deprived of nutrition
• Sealer kills organisms when in unset state
Why to obturate? why not just leave the canals empty?
- To prevent microleakage & exudate from entering into the canal
(Transient Bactereamia)
• 2. Prevention of coronal leakage
• 3. To create a favourable environment for healing
Name 2 types f seals?
Hermetic
Fluid tight or bacteria tight
What is the definition of a hermetic seal?
Sealed against the escape or entry of air
What is the definition of a bacteria tight seal?
A more appropriate term as root canals are evaluated for leakage of fluid
What are the prerequisites necessary before obturating the root canals?
Biomechanical preparation
• Thorough cleaning and correct shaping of root canal
• Creation of the ideal ‘deep shape’
Creation of ideal shape between middle and apical thirds
Describe an ideal tooth to be obturated during a single visit?
No significant symptoms
• No significant clinical signs
• The tooth must not be Tender to Percussion, TTP
• Canal must be clean and dry ‐ no blood, exudate or pus
• Appointment time must be of sufficient length
Name 3 characteristics which seem like contraindications for single visit obturation but in fact are not?
The presence of :
• A necrotic pulp
• A draining sinus tract
• A periradicular radiolucency on radiograph
Name 5 contraindications for single visit obturation?
Presence of acute signs or symptoms • Persistent exudate in root canal • Anatomical difficulties • Technical difficulties • Patient or dentist is tired or has lost patience
What are the advantages of obturating the root canals?
Allows medication with an antibacterial dressing
• Calcium hydroxide paste will reduce the number of bacteria remaining
following cleaning and shaping
Name 9 properties of an ideal obturating material?
No shrinkage • No solubility in tissue fluids • Good adhesion/adaption to dentine • No water absorption • No tooth discoloration Handling • Radiopaque require > 3mm aluminum • Setting in an adequate time • Easy to apply and remove using heat, solvents or mechanical instrumentation
Name 4 types of obturating materials?
Gutta‐percha
• Silver points
• Pastes
• Resins
Name the 4 constituents of Gutta Percha?
Gutta Percha 20%
• Zinc Oxide Eugenol 60%
• Metal Sulphates 15%
• Waxes / Resins 5%
Name the 7 advantages of using Gutta-Perch as an obturating material?
Has withstood the test of time
• Introduced as an obturating material 160 yrs ago
• Plastic – adapts well with compaction to canals
• Easy to manage
• Easy to remove
• Low toxicity
• Does not support bacterial growth
What are the 2 disadvantages of using Gutta-Percha as an obturating material?
Allergic reactions to GP • Very rare Sealability: • Does not seal without the use of a sealer • Does not adhere to dentine • Warmed GP shrinks on cooling
Name the 2 formulations of Gutta-Percha?
Standardised, (cold compaction)
Non‐standardised, (warm compaction)
What are the sizes and taper size for standardised GP?
Sizes 15‐140, taper 0.02
• Accessory cones for lateral compaction
What are the sizes and taper size for non-standardised GP?
Sizes correspond to taper of files, eg 0.04 –0.12
• Also pellets for injectable thermoplastic techniques
GuttaFlow
GuttaPercha Points
GuttaPercha Obturator
What are accessory cones?
- Size B accessory cones
* Use with Size B finger spreader
Name the disadvantages for silver points?
Poor success rate
• Are not adaptable to canal, limited seal
• Produce toxic products due to corrosion
• Difficult to remove from canal
• Silver cones should not be used as an obturating material
Name the 2 types of obturating pastes?
Zinc‐oxide and eugenol with the addition of toxic materials such as
formaldehyde
Plastics
When are plastic pastes useful for obturation?
Resin based
• Useful if patient has a diagnosed latex allergy
When should you not use Zinc oxide eugenol as an obturating paste?
Do not use – paranesthesia if overfill reaches ID canal
Name the advantage of using pastes as obturating materials?
Fast and easy to use – lentulo spiral filler
Name the 3 disadvantages for using pastes as obturating materials
Difficult to avoid overfilling the canal
• Formaldehyde containing pastes can cause paraesthesia
• Sealing ability is unpredictable
What is the definition of a resin used for an obturating material?
A polycaprolactone core and sealer filling
system
• Components were developed to bond with
each other and with canal wall to produce a
bacteria tight seal with reinforcement of the
root
What are the advantages of using resin as an obturating material?
Fast and fairly easy to use
What are the disadvantages of using resin as an obturating material?
Difficult to avoid overfilling the canal
• Sealing ability is predictable but technique sensitive
Why must a sealer be used with Gutta Percha?
Gutta percha in itself, no matter how well adapted to the canal walls,
will not create a seal
• A sealer must be used to fill the spaces between the GP cones and
between GP and canal wall to ensure a fluid tight seal
• Aim for maximum GP and minimum sealer
Name the 8 ideal properties for an endodontic sealer?
Provide a fluid‐tight seal • No shrinkage with setting • Slow setting time • Fill canal irregularities, lateral and accessory canals • Bacteriostatic • Act as a lubricant • Adhere to dentine • Radiopacity
Name the 7 types of endodontic sealers?
Zinc‐oxide eugenol • Calcium Hydroxide • Epoxy resin • Glass ionomer • Polyketone • Calcium silicate • Calcium trisilicate
Name 2 commercially avaliable silicon based sealers?
RoekoSeal
Gutta Flow
Name 1 commercially avaliable polyketone endodontic sealer?
Diaket
• Contains vinyl polymers mixed with zinc oxide and bismuth phosphat
Name 4 commercially available Calcium silicate endodontic sealers?
Endo‐CPM‐Sealer
• MTA Obtura
• proRoot Endo Sealer
• MTA fillapex
Name 1 commercially available Calcium trisilicate endodontic sealer?
Bioroot
Biodentine
Name 3 types of obturation techniques?
Cold lateral compaction
02 Taper point
ProTaper points
Name the 9 armamentarium for cold lateral compaction?
Local anaesthetic, topical • Irrigants • RCT kit • Paper points • Finger spreader (Size B) • GP master apical cone, (MAC) and accessory points (Size B) • Sealer • Flame • Resin modified glass-ionomer (Vitrebond 3M ESPE, Fuji)
Explain the initial process for cold lateral compaction for obturation?
Place rubber dam • Swab tooth with chlorhexidine or NaOCl • Remove dressing and cotton wool • Irrigate with citric acid first to remove calcium hydroxide, then sodium hypochlorite Canals are filled with • Gutta-percha master apical cone (02 taper MAC or Protaper MAC) • Sealer • Accessory cones SIZE B FINGER SPREADER • Size B accessory cone
What is the follow up procedure for obturation?
Recall 6-12 months • Ensure clinical and radiographic healing • No clinical signs • Evidence of bone healing in progress • Radiolucency decreasing in size • Continue follow up for 4 years
Explain the main cold lateral compaction obturation technique?
Select a Master Apical Cone, (MAC) the same apical size as
Master Apical File, (MAF)
• Measure cone to WL and place slowly into wet canal- to correct working length
• Aim to achieve a frictional fit apically
• There should be a definite stop when cone fits into place
Master cones lack uniformity and can vary in tip size
• Useful to take a cone-fit radiograph
Dry canal with correct size of paper points measured to WL
• Mix sealer and have spreader ready
Coat MAC lightly in sealer
• Insert into canal to correct WL
• Use a slow pumping action to allow back-flow of sealer
Remember that except for apical 2-3mm, the root canal will be much more tapered than the master gutta-percha cone
• This space is fill by compaction of accessory cones that have
been lightly coated in sealer
Insert spreader with stopper:
• 1-2mm short of WL with firm apical pressure (or as
far as possible when using (Protaper MAC)
• Leave in place 10-15secs with light lateral pressure
Remove spreader with
a slight rotation, and
place accessory cone,
lightly coated in sealer
quickly into channel
Repeat this process until no further accessory cones can be fitted
• Take an obturation verification radiograph
at this stage
• Removal and reobturation is easier if over/underfill
Cut off excess GP cones with a heated instrument (be careful not
to touch patient’s lip) and compact the coronal GP firmly in a vertical direction using an endodontic plugger
What to do if the MAC is not within 1mm of prepared length?
Refining canal is required
• Using a smaller MAC
What to do if the MAC extends beyond apical foramen?
Lack of apical stop
• Use a larger cone
What are the top tips for cold lateral compaction?
Remove ALL sealer and GP from access cavity to amelo-cemental
junction to prevent discolouration of crown
• Use cotton wool pledged soaked in alcohol (watch flame!!!)
Seal entrance to root canal(s) and floor of pulp chamber with a
resin modified glass ionomer cement
What restorations to place for the anterior teeth after obturation?
Light coloured composite resin in access cavity
What restorations to place for the posterior teeth after obturation?
Restoration depends on definitive restoration – crown / onlay
• Seal access with amalgam or glass ionomer to prevent coronal leakage
• Remove rubber dam
• Check occlusion
• Final radiograph
When should the definitive restoration be placed?
There is no need to wait for radiographic evidence of healing (6 mnth) before
placing definitive restoration, providing RCT is a high standard
How to gauge the apex of a root canal?
Gauge the size of the apical constriction using a 20K file, if this fits snugly, the prep can be complete at this stage
However, generally the apical size needs to be at least 30 to allow irrigation into the apical 1/3
Take F2 to WL and gauge the foramen using a 25 K file
If this fits snugly, the prep can be complete
Or Take F4 to WL and gauge with 30K file, i fits snugly can be completed
Use the same sized paper points for during the canal and same sized GP cone for obturating
How to gauge the apex of a root canal?
Gauge the size of the apical constriction using a 20K file, if this fits snugly, the prep can be complete at this stage
However, generally the apical size needs to be at least 30 to allow irrigation into the apical 1/3
Take F2 to WL and gauge the foramen using a 25 K file
If this fits snugly, the prep can be complete
Or Take F4 to WL and gauge with 30K file, i fits snugly can be completed
Use the same sized paper points for during the canal and same sized GP cone for obturating
