Endodontics Flashcards
What are the three main reasons for RCT?
- To remove aetiological factors to allow healing to take place
- Prevent re-infection of root canal system
- Allow tooth to become a healthy functioning unit
How do you ensure prevention of re-infection during RCT?
By placing an effective coronal and apical seal
Name 5 TRUE contraindications of RCT?
- Insufficient periodontal support
- Non restorable teeth
- Vertical root fracture
- Poorly motivated patient with poor OH
- Non strategic teeth with no current or possible future function
What treatment option is most suitable for a tooth that cannot be restored to function by RCT?
Extraction
What classifies a “non-restorable tooth”?
A tooth with:
1. Extensive caries/root caries
2. Massive resorptive defects
3. Poor crown/root ratio
If a patients tooth has vertical root fracture, what is the only treatment option?
Extraction
In what situation would a third molar undergo RCT instead of extraction?
If it is a functional tooth
what age of patient tend to have immature roots with open apices ?
Young patients
how may the pulp/root canals appear in patients of older age?
Shallow pulp chambers and narrow root canals
Name 4 patient related potential contraindications
- Age
- Physical limitations
- Patient financial status
- Patient motivation and availability
Name 7 abnormal canal configurations
- Torturous canals
- Dens invaginatus
- Severely curved canals
- C-shaped canals
- Taurodontism
- Lingual developmental groove
- Aberrant extra canals
what are the most common teeth to be affected by aberrant extra canals?
- Upper premolars with 3 canals
A malformation resulting from an unfolding of the dental papillae during tooth development
Dens invaginatus
Malformation in shape of tooth where it has a long pulp chamber that divides into multiple canals in the apical third of the tooth
Taurodontism
Name 13 contraindications for RCT due to complex treatment, that may need referral.
- abnormal canal configurations
- Immature apex
- Root resorption
- Hypercalcification (canal obliteration)
- Crown/root ratio that is > 1:1
- Tooth malpositioning
- Re treatment of root canals
- Iatrogenic problems
- Traumatic injuries
- Endodontic-periodontics lesions
- Persistent signs and/or symptoms
- Approximation to vital structures
- Existing restorations making pulp chambers difficult to locate and access
What is internal root resorption?
Resorption seen on the wall of the root canal
What is external root resorption?
Resorption on external surface of the root
what is the most common cause of an obliterated root canal?
Trauma
What are the different types of endodontic-periodontic lesions?
- Primary Endo/secondary perio
- Primary perio/secondary Endo
- Combined lesion
what is the general rule for deciding whether a lesion has initiated from an endodontic point of view, or a periodontics point of view? (There are exceptions to this rule!)
- if its more perio focused, the tooth may still be VITAL
- if its more Endo focused, the tooth will probably be NON-VITAL
What anatomical structure is often in approximation to teeth that could be treated for RCT?
Maxillary sinus
What medications do you have to be particularly wary of when planning to do RCT? And why?
Anticoagulants and anti-platelets, due to the bleeding risk
What does the INR score need to be for a patient taking warfarin in order for minor dental surgical procedures to take place?
<4.0
Patients who are taking warfarin, with an INR <4, should be referred to the special care department for treatment if they have other particular conditions. What are these other particular conditions?
- Liver impairment/alcoholism
- Renal failure
- Thrombocytopenia
- Haemophilia
- If they are taking cytotoxic medications
When taking warfarin, what type of mouthwash should be avoided in routine use?
Tranexemic acid mouthwash
When a patient takes warfarin, what pain relief is appropriate/safe to take?
Paracetamol or dihydrocodeine
When a patient takes warfarin, what antibiotics are appropriate/safe to take?
Amoxicillin (provided there is no Penicillin allergy) or clindamycin
What does MRONJ stand for?
Medication-related osteonecrosis of the jaw
what is MRONJ?
Exposed, necrotic bone in the maxilla or mandible that has persisted for more than 8 weeks following surgical procedure in patients taking anti-resorptive and anti-angiogenic drugs
What is the estimated incidence of MRONJ in a cancer patient treated with anti-resorptive or anti-angiogenic drugs?
1% (1 case per 100)
What is the estimated incidence of MRONJ in osteoperosis patients treated with anti-resorptive drugs?
0.01-0.1% (1-10 cases per 10,000)
What are the three main drug types associated with MRONJ?
- Bisphosphonates
- RANKL inhibitor
- Anti-angiogenic’s
what type of drug is Alendronic acid?
Bisphosphonate
How do Bisphosphonates work?
They reduce bone resorption by inhibiting enzymes essential for the formation, recruitment and function of osteoclasts.
What drug type is linked with delayed soft tissue healing and may inhibit angiogenesis?
Bisphosphonates
how can use of Bisphosphonates lead to MRONJ?
The drug accumulates at sites with high bone turnover, e.g. maxilla and mandible (jaws), this may reduce bone turnover and bone blood supply and lead to osteonecrosis
what is osteonecrosis?
Death of bone tissue
What is RANKL? And what is its role?
Receptor activator of nuclear factors knappa-B ligand, it regulates osteoclast formation, activation and survival.
Name the most commonly used RANKL inhibitor
Denosumab
what is the function of denosumab?
A human antibody which inhibits osteoclastic function and associated bone resorption by inhibiting RANKL
what is the function of anti-angiogenics?
Used in cancer treatment to restrict tumour vascularisation
How do anti-angiogenic drugs lead to MRONJ?
They reduce vascularisation in bone which can lead to osteonecrosis
what is the risk of developing infective endocarditis in the general population?
1:10,000
When there is history of MI, how long should routine treatment and use of adrenaline containing LA be avoided for?
6 months
What is Type IV latex allergy?
Allergic contact dermatitis
How would you treat someone with type IV latex allergy?
- use latex free rubber dam
what is type 1 latex allergy?
Anaphylactic reaction
How would you plan treatment for a patient with a type I latex allergy?
- patient required to be seen in a special latex free room
- observe patient closely and be prepared to manage anaphylaxis
What is apical periodontitis?
An inflammatory disease of microbial aetiology caused by infection of the root canal system, where microorganisms produce toxins which cause an inflammatory and immunological reaction, resulting in bone resorption around the roots
How would apical periodontitis appear on a radiograph?
As a periapical lucency
A Vital pulp offers protection against infection by one of what four ways?
- Outward movement of dentinal fluid
- Tubular contents which act as a blocking mechanism
- Productive of protective tertiary dentine
- Host defence molecules within the pulpal tissue
Dentine exposure does not normally represent a significant route of infection. What are the exceptions?
- when dentine thickness is reduced
- when dentine permeability is increased
Host defences function in the necrotic pulp.
True or false?
False, host defences do not function in the necrotic pulp
What three factors can cause pulpal inflammation? (In order of most common)
- micro-organisms
- Mechanical trauma
- Chemical irritation
Necrotic pulp + microbial infection = _____________
Apical periodontitis
Does bacterial invasion of dentinal tubules occur more rapidly in necrotic pulp or vital pulp?
Necrotic pulp
At what distance does bacteria need to be from the pulp in order for the pulp to become inflamed?
0.5mm away
where is the diameter of dentinal tubules at its largest?
Closest to the pulp
what are the three main chronic inflammatory cells that can infiltrate the base of carious tubules?
Macrophages, lymphocytes and plasma cells
What are the 5 main routes (caused by mechanical injury to the pulp) which can lead to root canal infection?
- traumatic accident
- iatrogenic damage during dental procedures
- excessive orthodontic procedures which can disrupt blood supply and damage tooth
- sub-gingival scaling
- attrition/abrasion
What two types of injury can happen to a tooth crown, leading to infection of pulp and root canals?
- Impact injury (microcracks in enamel and blood flow damages)
- Fracture of crown (results in pulpal exposure)
What dental factors can cause root infection?
- crown/bridge prep
- accidental exposure
- inadequate water spray on high speed drill
- over drying exposed dentine
- inadequate isolation of teeth from saliva
- failure to adequately protect and seal tubules
What two forms of chemical irritation can cause root infection?
- Erosion
- Inappropriate use of acidic dental materials (e.g. acid etch and bonding agents)
where do microbes colonise and persist in the pulp/root?
At the site of necrosis
The pulp can remain inflamed for a long time period, undergo necrosis slowly or quickly. What are the multiple factors that this depends on?
- Bacterial virulence
- Inflammatory response
- Host resistance
- Amount of circulation
- Lymphatic drainage
what are the two responses that the host generates upon infection?
- Inflammatory response
- Immunological response
What happens in the inflammatory host response to root infection?
Inflammatory response is non-specific, involves inflammatory mediators such as histamine, bradykinin etc.
What happens during the host immunological response to root infection?
- production of immunocompetent cells, which are produced as a response to bacterial toxins which acts as potential antigens
Give 3 examples of immunocompetent cells involves in the immunological host response?
- T & B lymphocytes
- Macrophages
- Dentritic cells
Pulpal necrosis causes apical periodontitis.
True or false?
False. Pulp necrosis does not directly cause this, but because the tissue becomes unable to defend itself it will quickly become infected by bacteria. The microbes cause apical periodontitis.
Give a 5 step summary of apical lesion progression once infection has occured.
- Increased tissue pressure
- Inability of pulpal tissue to expand
- Lack of collateral circulation
- Pulpal necrosis +microbes
- Periapical periodontitis
Why does the pulp not have the ability to repair?
Because the pulp is enclosed in a rigid mineralised structure
Why type of anaerobes are found in root canal system?
Strictly anaerobic bacteria (gram-ve bacteria)
Name some common Endodontic microbes
- prevotella
- porphyramonas
- fusobacterium
- veilonella
- peptostreptococcus
- eubacterium
- Actinomyces
- lactobacillus
- streptococcus
Is the bacterial count higher in the apical or coronal region of a tooth?
Coronal
Where are most microbes located within the root canal system?
In suspension (planktonic bacteria)
Define, “a sessile multi-cellular microbial community characterised by cells that are firmly attached to a surface and enmeshed in a self-produced matrix of Extracellular polymeric substances (EPS)”
A biofilm
Define, ‘a branch of dental science concerned with the study of form, function, health of, injuries to and diseases of the dental pulp and periradicular tissues.’
Endodontology
define, ‘ the clinical discipline that deals with the prevention, diagnosis and treatment of endodontic disease.’
Endodontics
When the dental pulp of a tooth is irreversibly damaged (irreversible pulpitis or pulpal necrosis) or has periapical disease, what treatment is required?
Root canal treatment
What is elective root canal treatment and what is it required for?
Procedure that is scheduled in advance. This procedure is required for placement of post-retained crowns on broken down teeth.
What are the two diagnosis that tooth needs to receive in Endodontics?
- Pulpal diagnosis
- Periapical diagnosis
what are the 6 pulpal diagnosis that can be given?
- Clinically normal pulp
- Reversible pulpitis
- Irreversible pulpitis
- Pulpal necrosis
- Previously initiated treatment
- Previously treated
What are the characteristics of a normal pulp?
Include;
1. Symptoms
2. Response to sensibility testing
- Symptom free
- Mild response that subsides immediately when stimulus removed
What are the characteristics of reversible pulpitis?
Include;
1. Symptoms
2. Radiographic appearance
3. Causes
4. Treatment
- Short/sharp pain, not spontaneous, stimulated by cold, sweet and sometimes hot
- No significant radiographic changes apically, clear band of dentine between decay and pulp
- Caries into dentine, fractures, restorative procedures, trauma
- Conservative pulp therapy, caries removal
Reversible pulpitis should be considered a provisional diagnosis, when should the status of the pulp be reviewed again?
After 3 months
What are the two forms of irreversible pulpitis?
- Symptomatic
- Asymptomatic
What is the most common type of irreversible pulpitis?
Symptomatic
What are the characteristics of symptomatic irreversible pulpitis?
- sharp pain on thermal stimulus which lingers
- pulp allydonia
- spontaneous pain
- excruciating pain which can be relieved by cold
- referred pain
- accentuated pain by postural changes
What are the characteristics of asymptomatic irreversible pulpitis?
- no clinical symptoms
- responds normally to sensitivity testing
- trauma or deep caries
What is dental allodynia?
‘Recurrent episodes of diffuse, dull and throbbing tooth pain which develops when returning to an indoor room temperature after being exposed to a cold weather for a long period’
What postural change can accentuate IP pain?
Lying down makes pain worse
If a pulp has irreversible pulpitis, will it be TTP?
No, tooth will not be TTP as inflammation has not reached periapical tissues yet
What is pulpal necrosis?
Breakdown of the pulpal tissue allowing bacteria to colonise the root canal system
If irreversible pulpitis is left untreated, what will this progress to?
Liquefaction pulpal necrosis
What three factors can lead to pulpal necrosis?
- direct exposure of pulp
- dentinal tubules
- cracks in enamel or dentine
what is liquefactive necrosis?
‘ a type of necrosis which results in a transformation of the tissue into a liquid viscous mass’
how can trauma to a tooth cause pulpal necrosis?
Traumatic injury causes ischaemic necrosis due to disruption of blood supply
Pulpal necrosis is usually asymptomatic. When can it be symptomatic?
If inflammation has progressed to periapical tissues (there would be TTP or apical palpation)
What response does pulpal necrosis give to sensibility testing?
No response, tooth usually non-vital .
What is meant by ‘previously treated’ pulpal diagnosis?
A clinical diagnostic category indicating the tooth has been endodontically treated and the canals obturated with root canal filling material
What is meant by ‘previously initiated therapy’ pulpal diagnosis?
A clinical diagnostic category indicating that the tooth has been previously treated by partial endodontic therapy (e.g. pulpotomy, pulpectomy)
- canals may have been located, cleaned and shaped but not obturated
Radiographically, would there be signs of root canal filling in a tooth with a pulpal diagnosis of ‘previously initiated treatment’?
No, pulp not obturated
What is meant by periapical pathology?
Microbes and by-products reach the periapical tissues resulting in an inflammatory and immunological response
What are the two main characteristics of periapical pathology?
- Resorption of surrounding bone
- epithelial cells proliferate to from a granuloma or cyst
what are the 5 periapical diagnosis?
- Normal periapical tissues
- Symptomatic periapical periodontitis
- Asymptomatic periapical periodontitis
- Acute periapical abscess
- Chronic periapical abscess
What are the characteristics of a normal periapical tissues?
Include;
1. Response to special testing
2. Radiographic appearance
- Teeth non-sensitive to percussion and palpation testing
- Radiographically the tissues are normal with intact lamina dura and a uniform periodontal ligament space
What are the characteristics of symptomatic periapical periodontitis?
Include;
1. Response to special testing
2. Radiographic appearance
3. Other symptoms
4. Causes
- Sensitive to percussion, may or may not be sensitive to palpation, sensibility testing depends on whether pulp is irreversibly inflamed or necrotic
- Periapical changes present: loss of lamina dura, widening of pdl, periapical radiolucency
- Discomfort on biting or chewing
- Microbial toxins cause inflammation
What can be the cause of transient periodontitis?
- chemicals used in RCT
- occlusal trauma
- RCT over-instrumentation
What are the characteristics of an acute periapical abscess?
Include;
1. Response to special testing
2. Radiographic appearance
3. Other symptoms
4. Causes
- Tooth mobile
- PDL space may be normal, slightly widened, or may demonstrate a distinct radiolucency if an acute flare up of chronic lesion
- Rapid onset, localised pain, pus formation, systemic involvement, swelling
- Progression of bacterial invasion into periapical tissues
What is the emergency treatment for an acute apical abscess?
- Drainage (either by direct incision or through root canal)
- RCT or extraction
If a patient has systemic involvement from an acute apical abscess what treatment would be recommended?
Course of antibiotics
Why does asymptomatic periapical periodontitis occur?
Occurs when bacterial products from a necrotic or pulp-less tooth slowly ingress the periapical tissues
What are the clinical and radio-graphical signs of asymptomatic periapical periodontitis?
Clinical = no response to sensibility tests
Radiographically = radiolucency around apex of tooth
what is a chronic periapical abscess?
An inflammatory reaction to pulpal infection and necrosis characterised by gradual onset, little or no discomfort and intermittent discharge through an associated sinus tract
Where is a chronic periapical abscess sinus tract usually located?
Usually on buccal/labial sulcus. Can be palatal, lingual or extra-oral
Does a chronic periapical abscess respond to percussion, palpation or sensibility testing?
No
What is the radiographic appearance of a chronic periapical abscess?
Radiolucent area on bone
What are clinical signs of dentine hypersensitivity?
Exaggerated sharp, transient pain
what pulpal condition has the same symptoms as dentine hypersensitivity, however involves specific factors such as caries, fractures etc.?
Reversible pulpitis
what is focal sclerosing osteomyelitis (condensing osteitis)?
‘A periapical lesion that involves reactive osteogenesis evoked by chronic inflammation of dental pulp’
what is the radiographic signs of focal sclerosing osteomyelitis (condensing osteitis)?
Increased radio density and opacity around one or more roots
what is the treatment for focal sclerosing osteomyelitis (condensing osteitis)?
RCT
If cracked teeth are left undiagnosed or recognised, what could be the consequence?
- vertical root fracture and extraction of tooth
What are causes of cracked teeth?
- occlusal forces
- abnormal chewing habits
- accidental trauma
- structure fatigue
What are common symptoms of cracked teeth?
- sharp shooting pain on biting hard objects
- sensitivity to thermal changes, sweet or acidic food
- often difficult to localise
What are the 5 types of cracks? (Listed from least damaging to most damaging)
- craze lines
- fractured cusp
- cracked tooth
- split tooth
- vertical root fracture
what instrument can help to diagnose cracked teeth?
Tooth slooth
What are craze lines?
Cracks that effect only enamel, across marginal ridges, buccal and lingual surfaces
How do you diagnose craze lines?
Transillumination
What is a fractured cusp?
Complete or incomplete fracture initiated from a crown
how do you treat fractured cusp?
- remove cusps and restore
OR - RCT if crack effects pulp
what is a cracked tooth?
Incomplete fracture initiated in crown and extending subgingivally (usually mesio-distal)
What is a split tooth?
Complete fracture initiated from the crown and extending subgingivally (usually mesio-distal), more centred occlusally and extends apically
What is the treatment option for split tooth?
Extraction
What is vertical root fracture?
Complete or incomplete fracture initiated from the root at any level usually buccal-lingually
What are the symptoms of a periodontal abscess?
- rapid onset
- spontaneous pain
- TTP
- pus formation
- swelling
- deep periodontal pocket
- normal response to sensibility tests
What is rubber dam?
A means of isolating teeth during restorative and endodontic procedures
What is the purple rubber dam made from?
Nitrile
What is the green rubber dam made from?
Latex
what restorative procedures should rubber dam be used on?
- composite fillings, especially in molar teeth
- bonded restorations (e.g. cores, veneers, crowns etc.)
Rubber dam should be used for ALL endodontic procedures. True or false?
True
What are the 6 main reasons to use rubber dam?
- Protection from aspiration
- Retraction/protection of soft tissues
- Better visibility
- Reduction of delays during treatment
- Patients and dentists more relaxed
- Dentists and nurses are protected against infections which can be transmitted by patients saliva
What is the function of the rubber dam clamp?
It attaches the rubber dam sheet to the tooth and holds it in place
What is the major concern over use of latex rubber dam?
Allergies, this could lead to anaphylaxis and possibly death
What are the symptoms of anaphylaxis?
- swelling
- light headedness, dizziness
- oedema, erythema, itching
- difficulty breathing
what is the treatment for anaphylaxis?
- Assess patient and call ambulance
- Inject 0.5ml (1:1000) epinephrine (adrenaline) IM every 5 minutes if required
- 100% supplemental oxygen (10litres/min)
what are the 4 types of clamp design?
- Winged
- Wingless
- Passive
- Active
How is a winged clamp placed with rubber dam?
Placed onto rubber dam first and then they are placed together into mouth and onto tooth
How is a wingless clamp placed with rubber dam?
Placed on tooth before applying rubber dam
What is a passive clamp?
A clamp that has 4 points of contact to the crown of the tooth, it is not aggressive and suits teeth with intact crowns.
what is an active clamp?
Suitable for broken down/partially erupted/ tooth that has no undercut. It is aggressive and may traumatise gingival tissues.
When should you never use an active clamp on a tooth?
When it has a ceramic crown
What could you use to make sure patient is not in pain due to an active clamp?
Use LA on that tooth, or apply topically.
When may an anterior clamp be used on anterior teeth?
- when there is minimal coronal tooth structure
- For retraction of gingival tissues for placement of composite/GI cervically
what must you tie around a clamp before placing it in oral cavity? And why?
Floss. Because bow of clamp can break on occasion, so they are easily retrievable if floss is attached.
What are wedget cords and when are they used?
Little elastic cords that are useful when placing rubber dam when no clamp is placed, or when you have placed clamp on one side of arch and you want to stabilise rubber dam at other side.
What is used to fill small gaps that arise between tooth and hole made in rubber dam before starting procedures?
Use of rubber dam liquid seal that can be light cured (fluid tight seal)
what is the function of floss ligatures?
Keep rubber dam well below the margins that we require to work with.
where should rubber dam sit on the face and what areas would it cover?
Dam should protect the oropharynx by sitting over patients upper lip but NOT covering the nose
What is the most likely cause/s of clamps breaking?
Effect of sodium hypochlorite or autoclaving
where should the bow of the clamp always be facing when placed in the mouth?
To the back of the mouth (posteriorly)
Describe the split-dam technique in 4 stages?
- Clamps are placed on teeth mesial and distal to a broken down tooth
- 3 holes are made in dam and joined together with scissors
- Dam is stretched over three teeth
- Requires extra protection from salivary contamination (use of cotton wool rolls in sulcus and salivary ejectors)
Does rubber dam stay in place during x-rays to check RCT ?
Yes
What colour is an endodontic film holder?
Green
How many radiographs are required during RCT treatment and what are they assessing?
3 radiographs required
- one to assess working length
- one to assess trial point
- one to assess final obturation
What are the clinical tests to assess periapical status of a tooth?
- percussion
- palpation
- pulp sensibility testing
What are the clinical tests to assess periodontal status of a tooth?
- BPE
- mobility
If a patient complains of intense pain, with recent onset and no relief from analgesics, what would you be considering as a provisional diagnosis before testing?
Either:
- irreversible pulpitis
- acute apical abscess
What is the maximum dose of paracetamol than an individual (around 70kg) can take in 24 hours?
8 x 500mg tablets (4g)
In what situations would the maximum dose of paracetamol for an individual be lower than the normal 4g in 24 hours?
- if they have not eaten
- if they have drank alcohol whilst taking the drug
- if they already have liver issues
how often must a new medical history form be completed according to the GDC?
Every 2 years
What is meant by a “tentative” diagnosis?
This is a provisional diagnosis, which is not certain or fixed.
What are the three reasons for always testing control (healthy) teeth first?
- Patient knows what to expect
- Dentist can observe patients response
- Can determine if a stimulus is capable of evoking a response
What does percussion of a tooth determine?
If there is presence of periapical inflammation
What is a severe percussion response?
- sharp pain, patient withdraws
- Indicates periapical inflammation
What does palpation of a tooth determine?
- if inflammation has extended periapically
What is a ‘positive’ response to palpation of a tooth?
Periapical inflammation
What does pulp sensibility testing involve? What does it stimulate?
Sensory nerve fibres
What is the most accurate determinant of pulp vitality? Vascular supply or nerve Innervation.
Vascular supply
Describe direct dentine stimulation as a special investigation.
- cut a test cavity, if tooth is vital, patient will feel sudden, sharp pain when dentine is cut.
What is selective anaesthesia?
The process by which local anaesthetics are used to narrow down a source of pain
Name 5 special investigations in endodontics.
- Direct dentine stimulation
- Selective anaesthesia
- Transillumination
- Bite test
- Diagnostic gotta percha cone placed in sinus
What special investigations can be used to investigate a cracked or fractured tooth?
Transillumination and bite test
In a bite test, when would the patient feel pain if they have a cracked tooth?
They would feel pain on release of pressure
What technique will allow a dentist to differentiate between diseases of endodontic and periodontal origin?
Gutta percha cone placed in sinus
What are the limitations of radiographic examination for endodontic cases?
- pathological changes in the pulp are not visible
- periapical pathology is not visible in the early stages
- x-rays are 2D, therefore more than one view is often required
To be visible inflammation on a radiograph, where must the pathology have spread to?
To the cortical plates/bone
What CBCT machine is useful for implant planning?
ICAT
What type of CBCT scan is best suited for endodontic imaging?
Limited volume CBCT
When would CBCT be used for endodontic cases?
Not used routinely, for the assessment and treatment of complex cases (e.g. perforations, root resorption)
When should follow-up of RCT take place?
- Clinical and radiographic follow up at least 1 year after treatment
- Further follow up for up to 4 years if signs if healing are slow
What are 4 prognostic factors, favourable for the success of RCT?
- Pre-operative absence of periapical radiolucency
- Root canal filling with no voids
- RCF extending within 2mm of radiographic apex
- Satisfactory coronal seal
What are vital pulp treatments?
“Strategies aimed at maintaining the health of all or part of the pulp”
Clinically, what classification is used for pulpal and periapical diagnosis?
American Association of Endodontists (AAE)
What are the three categories of pulpitis or pulp status according to the AAE?
- a normal pulp which is asymptomatic
- reversible pulpitis
- symptomatic or asymptomatic irreversible pulpitis
Define this vital pulp treatment:
Application of a biomaterial onto a thin dentine barrier in a one-stage carious-tissue removal technique generally to hard dentine.
Indirect pulp capping
When is indirect pulp capping usually indicated?
In the management of deep caries with no pulp exposure
Define this vital pulp treatment:
Removal to soft or firm dentine. Immediate placement of a permanent restoration.
Selective carious-tissue removal in one-stage
Define this vital pulp treatment:
First stage involves selective carious removal to soft dentine, to an extent that facilitates proper placement of a temporary restoration, and second stage removal to firm dentine. Final placement of a permanent restoration.
Stepwise excavation
Define this vital pulp treatment:
Following the preservation of an aseptic working field, application of a biomaterial directly onto the exposed pulp, prior to immediate placement of a permanent restoration.
Direct pulp capping
What is class I direct pulp capping?
Management of pulp exposure due to a traumatic injury/iatrogenic damage to the tooth
What is class II direct pulp capping?
Management of pulp exposure judged clinically to be through a zone of bacterial contamination. This is where there is a deep carious lesion present so we expect there to be pulp exposure upon treatment of such a lesion.
What vital pulp treatment is described:
Removal of a small portion of coronal pulp tissue after exposure, followed by application if a biomaterial directly onto the remaining pulp tissue prior to placement of permanent restoration.
Partial pulpotomy
What vital pulp treatment is described:
Complete removal of the coronal pulp tissue and application if a biomaterial directly onto the pulp tissue at the level of the root canal orifice(s), prior to placement of permanent restoration.
Full pulpotomy
What vital pulp treatment is described:
Total removal of the pulp from the root canal system followed by root canal treatment, prior to a placement of a permanent restoration.
Pulpectomy
When is pulpectomy indicated?
In the management of an irreversibly damaged pulp
What are the functions of the dentine pulp complex?
- Formation and nutrition of the dentin
- Innervation and defence of the tooth
When dentine is damaged, what is its response to insult?
Releases bioactive dentine matrix components, releasing cytokines, chemokines and growth factors which orchestrate recruitment, migration, proliferation and differentiation of pulpal proginetor cells, critical for the formation of newly deposited dentine.
What pulpal cells are critical for formation of newly deposited dentine?
Pulpal progenitor cells
When there is mild stimulus, or a slowly advancing carious lesion, what type of dentinogensis will occur in response?
Reactionary dentinogenesis
what happens during reactionary dentinogenesis?
Upregulation of surviving odontoblast activity and new tubular dentine formed
When there is severe or aggressive stimulus or a rapidly advancing carious lesion, what type of dentinogenesis will take place in response?
Reparative dentinogeneiss
What happens during reparative dentinogenesis?
Death of primary odontoblast and replacement by odontoblast-like cells, low quality atubular mineralised tissue formed
What occurs in non-selective caries removal?
All caries is removed. Still staining of dentine present but this would be hard to touch with probe.
What is the indication for use of a selective caries removal technique?
This technique is used to help prevent pulp exposure
What occurs in selective caries removal?
Any carious lesion which is softer towards the pulp is left in order to seal it off with a restoration and arrest the decay.
What are the advantages to selective caries removal?
Conservative and minimally invasive
What is the stepwise technique for caries removal?
- Precede to selective caries removal
- Place temporary dressing on tooth in order for reactionary or reparative dentinogenesis to occur
- A month later, remove temporary dressing and any remaining carious lesion to restore the tooth definitively once we are sure there is formation of a dentinal bridge that would protect the pulp from any exposure.
clinically, what shade/colour of caries indicates an actively progressing lesion?
Light yellow
clinically, what shade/colour of caries indicates an slowly progressing lesion?
Light brown
clinically, what shade/colour of caries indicates an arrested lesion?
Dark brown
what are three commonly utilised biocompatible materials for pulp capping?
- calcium hydroxide
- Mineral trioxide aggregate (MTA)
- bio-dentine (calcium silicate)
what is the main advantage of using bio dentine for management of exposed pulp?
It has a fast setting time of 12 minutes. (6 minutes handling, 6 minutes setting)
What would be the management for a tooth with irreversible pulptitis, with normal apical tissues?
Partial or full pulpotomy
What are the 4 main advantages to using pulpotomy?
- To preserve pulp vitality and its functions while retaining more structural integrity of the tooth
- To simplify treatment protocol and avoid procedural errors associated with RCT
- Minimally invasive endodontic procedure, so usually less painful
- Potential for more efficient procedures reducing cost and number of appointments for patient
In a full pulpotomy technique, why would we not advocate the use of intrapulpal infiltration?
Because the action of the anaesthetic with the vasoconstrictor could be damaging to the pulp and lead to necrosis
why is there not a need to dry the pulp chamber too much, especially when using bio-dentine?
Because bio-dentine is a thixotropic material that follows moisture
How do you assess the success of vital pulp treatment?
By pulp sensibility testing (clinical assessment) and radiographic assessment (PA)
what would be the two main indicators that VPT was successful?
- absence of clinical signs and symptoms
- absence of emerging radiolucency associated with the treated tooth
What are hydraulic calcium silicate-based cements?
MTA lookalike materials, they are cements or root canal sealers that have been made based on a composition of calcium and silicate
What are the three most commonly used hydraulic calcium silicate based cement?
- Pro root
- Bio dentine
- Bio dentine XP
what are the two downsides to proroot?
- it has a long setting time (up to 24 hours) so would need to be covered with a temporary dressing
- handling is challenging as mixing must be very precise
what are the advantages of using bio dentine XP over bio dentine?
Bio dentine XP:
1. is a compule, so removes the need to handle powder and liquid components like in use of bio dentine.
2. Has a more reliable consistency for optimal result
3. Optimise delivery with gun and bendable nozzle
What is the drawback of using bio dentine XP?
The equipment for its use is expensive
What is TotalFill RRM Fast-Set Putty, and what is it used for?
It is a calcium silicate bio ceramic putty, which sets in 20 minutes, and is indicated for:
- root Endo filling
- repair of root perforations
- repair of root resorption
- apexification
- pulp capping
What is the action of non-setting calcium hydroxide as a temporary dressing at site of access cavity?
- disinfects area with its high pH 12.5 (bactericidal)
what are endodontic spacers?
These are materials placed between Endo appointments or after completion of Endo therapy, until the placement of a definitive restoration
what is coltosol?
A temporary euganol-free filling material which self cures under the action of saliva
What is meant by Obturation?
Process of filling a root canal
What materials can be used to seal perforations if they were to occur during RCT?
Calcium silicate cements, such as MTA.
when carrying out access cavity preparation, what bur should be used to cut the initial outline form of the cavity?
Small round diamond bur
when carrying out access cavity preparation, how deep into the enamel should the initial outline form of the cavity be cut?
1mm
when carrying out access cavity preparation, what bur should be used to deepen the access towards the roof of the pulp chamber and to penetrate the roof whilst avoiding perforation?
A long fissure diamond bur
If access cavity prep has to be carried out through a crown, what bur should be used to cut through a metal crown?
Tungsten carbide bur
If access cavity prep has to be carried out through a crown, what bur should be used to cut through a metal ceramic crown?
- cut porcelain part with small round diamond bur
- cut metal (once its exposed) with tungsten carbide bur
If access cavity prep has to be carried out through a crown, why do specialised burs have to be used and not round diamond bur?
Because the zirconium or lithium disilicate in the ceramic crown is very hard and would blunt the round diamond bur.
What are the three uses of a long-shanked bur?
- removal of roof of pulp chamber
- removal of palatal shelf in upper anterior teeth
- careful exploration of pulpal floor to uncover narrow canal orifices
What type of bur is used after completion of access to flare, flatten and finish axial walls?
Non-end cutting high speed bur
What are the two types of non-end cutting high speed burs?
- Diamond tapered bur
- Tungsten carbide tapered bur
What is the shape of the access cavity for a maxillary central incisor?
Triangular
What is the shape of the access cavity for a maxillary lateral incisor?
Triangular
What is the shape of the access cavity for a maxillary/mandibular canine?
Ovoid
What bur is used for enlargement of access cavity to remove dentine overhangs on dentinal walls?
Long-shanked round bur on a low-speed handpiece
what is the cutting action of a long-shanked round bur?
Cutting action is applied on the way out working on the dentinal walls with a brushing motion to remove all dentine overhangs
What shape is the access cavity for premolars?
Oval
What angle is the initial outline form of the access cavity cut in relation to the palatal/lingual surface of an anterior tooth?
45 degrees
When preparing an access cavity on anterior teeth, what is created by the change of angle of the bur from initial outline form to proceeding down the long axis of the tooth?
Creates a palate shelf which needs to be removed and smoothed out
What bur is used to remove the roof of the pulp chamber and palatal shelf to allow straight access of instruments into the pulp/root canals?
Long shanked round bur
What has to be considered regarding access cavity preparation for the mandibular first premolar?
The crown is usually tilted towards the lingual aspect, take care not to perforate. Pulp chamber is placed under buccal cusp.
Why do we clean and shape the root canal?
To achieve an environment which will promote healing of apical tissues
What does cleaning of root canal system specifically achieve?
Removal of organic pulp debris, microorganisms and toxins
What does shaping of the root canal system specifically achieve?
Controlled removal of dentine to produce a tapering shape that can be disinfected and sealed. It allows disinfectant to reach the apical areas.
What is the narrowest part of the root canal system?
The apical construction
What is the name of the endodontic exploring probe?
DG16
What sort of mirror is used for endodontics? And why?
A front surface mirror, because it will not give a double image
What is an endoblock used for?
Measuring the length of files
What material are hand files, for initial negotiation of the canal, made of?
Stainless steel
What material are rotary files, which shape the canals, made from?
Nickel titanium
What are the three main mishaps that can occur from use of conventional hand stainless steel files?
- ledges
- canal blockade
- zipping of foramen (tear)
What hand file technique can be used when a root canal is too wide (>50 (F5)) to be shaped with a pro-taper gold?
The balanced force technique
Describe the 3 steps involved in the balanced force technique to prepare root canals.
- Use clockwise and quarter turn into canal
- Then turn anti-clockwise, keeping pressure down in order to cut dentine and shape canal
- Irrigate
Give two examples of situations that may require the balanced force technique for root canal preparation?
- An open apex in an immature tooth
- A tooth with inflammatory root resorption
What are the five advantages of rotary NiTi techniques?
- less canal transportation
- less debris extrusion
- less post op pain
- faster than hand preparation
- more predictable results
What is meant by torque?
Forces that act in a rotational manner
What is more likely to cause a file to get “jammed” in a canal, use of high torque or low torque?
High torque
What is the speed and torque that rotary NiTi protaper gold files should be used at?
Speed = 300rpm
Torque = 4
What is the most common reason why a rotary NiTi instrument will fail?
Sheer fracture/torsional fracture
What causes flexural fracture/cyclical fatigue of rotary instruments?
Continuous rotation in curved canals
Name the three types of protaper shaping files?
- SX
- S1
- S2
Name the five types of protaper shaping files?
F1-5
What material are protaper shaping and finishing files made from?
Nickel titanium
What size of flexofile does an F1 file equate to?
Size 20
What size of flexofile does an F2 file equate to?
Size 25
What size of flexofile does an F3 file equate to?
Size 30
What size of flexofile does an F4 file equate to?
Size 40
What size of flexofile does an F5 file equate to?
Size 50
What is meant by estimated working length and how do you measure it?
This is tooth length, measure the length of the tooth from incisal edge to radiographic apex
What instrument/s could you use to remove “ palatal shoulder” after access cavity prep to confirm straight-line access into the canal?
Long-shanked round bur on slow speed
OR
SX file
What shaping file should be used to flare the canal orifice?
SX
What motion should be used for an SX file?
Brushing motion
What are the two components that make up glyde?
- EDTA
- Carbamide peroxide
What is the function of EDTA as an irrigant?
It chelates calcium salts
What is the function of carbamide peroxide as an irrigant?
Emulsifies pulp remnants
Wat is the narrowest part of a root canal?
Apical constriction
What do electronic Apex locators measure to determine working length?
The difference in electrical impedance between the lip and the file in the mouth
What flexofile is used in the EAL to measure working length?
Size 10 flexofile
On an EAL, where does the black lead attach to?
The file
On an EAL, where does the white lead attach to?
Metal hook and then onto lip
What is meant by “apical patency”?
The ability to pass a small flexofile passively through the apical constriction without widening it
Give two reasons as to why the glide path is so important?
- Gives information about canal morphology
- Creates or confirms a smooth reproducible path of adequate diameter before introducing rotary files
What two components can glide path be divided into?
- micro glide path
- macro glide path
How do you establish a micro glide path?
With hand files (size 08 and 10 k-files to WL)
How do you establish a macro glide path?
Enhance micro glide path with rotary instruments (proglider)
What type of file is a proglider and what is it made from?
It is a rotary file made from M wire NiTi
What speed and torque should a proglider rotary file be used at?
Speed = 300rpm
Torque = 2
What are the 6 ground riles to safe use of rotary instruments?
- Constant speed of rotation with torque control
- Irrigate before engaging file
- use light pressure and progress slowly, withdraw when resistance is felt.
- Do not stop/start file in the canal
- Clean files regularly during use
- Irrigate, recapitulate and irrigate between each rotary file
What are the 4 factors that can prevent passive movement of a file?
- insufficient glide path
- build-up of debris within canal
- build- up of debris on flutes of file
- complicated root canal anatomy
What files are used for apical gauging in canal preparation?
F1-5 files (use in sequence to determine which file fits appropriately), the gauge using corresponding flexofile.
What is meant but apical gauging?
Where you want the tip of the F file to be the same size of slightly larger than your apical constriction
Name an instrumentation technique for challenging root canal anatomy?
Crown down sequence
What tool is available to help assess the risks and difficulties of a particular case that requires non-surgical endodontic treatment?
BES case assessment tool
Using the BES case assessment tool, what would a sore of 1-12 indicate in terms of level of difficulty of treatment and who is recommended to manage the case?
Level of difficulty = low
Management = GDP
Using the BES case assessment tool, what would a sore of 17-24 indicate in terms of level of difficulty of treatment and who is recommended to manage the case?
Level four difficulty = High
Management = dentist with enhanced skill since endodontics or specialist endodontist
Using the BES case assessment tool, what would a sore of 13-16 indicate in terms of level of difficulty of treatment and who is recommended to manage the case?
Level of difficulty = Average
Management = GDP or dentist with enhanced skills in endodontics
Using the BES case assessment tool, what would a sore of >25 indicate in terms of level of difficulty of treatment and who is recommended to manage the case?
Level of difficulty = Very high
Management = specialist endodontist
What is meant but recapitulation?
A process used to ensure the root area is cleaned out thoroughly and free of debris
What files are used in the balanced forced technique for large apices in order to complete apical preparation?
Flexofiles
What solutions are used for final irrigation of root canal prior to obturation?
- 3mL sodium hypochlorite
- 3mL citric acid (removes smear layer)
What is the purpose of paper points?
They absorb residual irritant from canal (dry canal)
What is the most commonly used inter-appointment medicament?
Non-setting Calcium hydroxide
Other than calcium hydroxide, what are two other medicaments used in endodontic treatment?
- odontopaste
- Iodine
What material is the basis of odontopaste?
Zinc oxide
When is use of odontopaste indicated? And why?
In the management of irreversible pulpitis, as well as being anti-microbial, it is an ant-inflammatory which causes rapid pain relief.
For how long should odontopaste be taken to resolve inflammation related to symptomatic irreversible pulpitis?
4-6 weeks
Why should you prevent odontopaste from contacting access cavity walls?
As contact could result in discolouration of tooth
What are the contraindications of odontopaste?
- Not recommended on pregnant or breastfeeding women (potential teratogenic effects)
2.known hypersensitivity to corticoids and clindamycin - Purelent pulpitis
- Endodontic treatment of deciduous teeth
What is purulent pulpitis?
Pulpitis with pus discharge
What are contraindications of using iodine as a medicament in Endodontics?
- iodine hypersensitivity
- pregnant of breastfeeding women
What facultative anaerobe has been isolated and cultured frequently in endodontic re-treatment cases?
Enterococci faecalis
Give examples of microbes involved in primary endodontic cases?
- black pigmented bacteria (prevotella, porphyramonas)
- fusobacterium nucleatum
- veillonella parvula
- eubacterium
Give examples of microbes involved in root filled endodontic cases?
- enterococci
- streptococci
- lactobacilli
- Actinomyces
- candida
What are the commonly used root canal irrigants with antimicrobial function?
- sodium hypochlorite
- 2% chlorohexidine
What are the commonly used root canal irrigants to remove the smear layer?
- Citric acid
- EDTA
What irrigant is capable of dissolving necrotic (organic) tissue?
Sodium hypochlorite
What are the three disadvantages of sodium hypochlorite as an irrigant?
- unpleasant taste
- high toxicity
- inability to remove smear layer when used alone
What symptoms could present if irrigation of sodium hypochlorite goes beyond root apex?
- extreme pain and burning sensation
- haematoma May develop (swelling and produce haemorrhage from root canal)
- 2nd infection and tissue necrosis
- paraesthesia
What should be used to treat an NaOCl accident?
- analgesics
- external compression with cold packs and warm compresses
- antibiotics mat be required to prevent secondary infection
In a serious event of NaOCl accident, what should treatment consist of?
Referral to oral surgery for surgical intervention
What causes production of a “smear layer”?
Cleaning and shaping of canal
What are the two disadvantages of maintaining a smear layer?
- Protects microbes in the dentinal tubules from effects of disinfectants
- Prevents complete adaptation of obturation materials to the root canal surfaces
What are the 5 advantages of using non setting calcium hydroxide medicament?
- Kills bacteria and inactivates endotoxin
- Reduces inflammation
- Helps eliminate apical exudate
- Controls inflammatory root resorption
- Prevents contamination between appointments
What 3 specific effects does calcium hydroxide have on bacterial cells?
- Damages the bacterial cell cytoplasmic membrane by chemical injury
- Dentures protein
- Damages DNA
What are the commercial names for calcium hydroxide medicament?
- hypocal
- ultracal
What temporary filling material is used over calcium hydroxide interappointmnet medicament?
GI
What are the post-treatment instructions that should be given after placing inter-appointment medicament in root canal and then a temporary filling?
- treat pain with 400mg ibuprofen x4 daily after food (or paracetemol (1000mg x4 daily) if unable to take NSAIDS)
What are the three main purposes of obturation?
- Reduces coronal leakage and bacterial contamination
- Seals the apex from periapical tissue fluids
- Entombs remaining irritants in the canal
What type of seal is achieved by obturation?
Fluid tight/ bacteria tight seal
In what scenario is a single visit preferred in order to fully prepare and obturate in root canal treatment? And why?
In the case of vital pulp tissue. This is because bacterial contamination will be minimal and a single visit will prevent possible contamination via leakage between visits.
What is condensing osteitis?
Where bone becomes denser and inflamed, it results from a reaction to a dental related infection
Describe asymptomatic periapical periodontitis
“Inflammation and destruction of the apical periodontium that is of pulpal origin and appears asymptomatic”
What two tooth diagnoses resulting from necrotic pulp require one visit Endo treatment?
- asymptomatic apical periodontitis
- condensing osteitis
When should Endo treatment be delayed?
If a tooth has acute symptoms or an acute periapical abscess is present
What would be the 4 contraindications to a single visit for endodontic treatment?
- significant symptoms
- Tooth TTP
- Blood, exudate or pus in canal
- Insufficient time for appointment
What appearance on a radiograph would indicate asymptomatic periapical periodontitis?
A periapical radiolucency
When is post-operative pain more likely to occur after Endo treatment?
In cases of continual suppuration during canal preparation
What are the main advantages of a multiple visit endodontic treatment?
- allows medication with an antibacterial dressing
- calcium hydroxide paste will reduce number of bacteria remaining following cleaning and shaping
Why should inter-appointment medicaments like CMCP, or cresophene be avoided?
They are not effective and very toxic (contain phenolic and fixative agents)
Where does the apical constriction lie in comparison to the radiographic apex?
0.5-1mm from radiographic apex
What are the five different Obturation techniques? Start with the technqiue most commonly used.
- Cold lateral compaction
- Warm vertical compaction
- Continuous wave condensation
- Carrier based systems
- Single cone obturation
What is the composition of gutta percha?
- 59-75% zinc oxide
- 19-22% gutta percha
- 10% radiopacifiers
- 5% plasticisers
what size of finger spreader and accessory cones are required for cold lateral compaction?
Size B
What is the limitation if the cold lateral compaction technique?
You aren’t always able to see whether there are voids depending on the angle you view the radiograph from
What are the three main drawbacks of lateral condensation/compaction?
- The apical seal is only entrusted on the sealer as there is no heat applied to the gutta percha apically
- There can be volumetric leakage with no apical seal
- Higher risk of creating vertical root fractures due to pressure of finger spreader
What is an alternative technique to cold lateral compaction that is becoming increasingly popular?
Single cone obturation with bio ceramic sealers
What is the advantage of a single cone obturation with bio ceramic sealer?
Bioceramic sealer injected into canals ensures good distribution of sealing agent and higher chance for obturating any lateral canals
What is the drawback of a single cone obturation with bio ceramic sealer?
Higher risk of extrusion into the periapical region
What are the properties of bio ceramic cement that make it a clinically acceptable root canal cement?
- biocompatible with pulp cells
- precipitates calcium phosphate on hydration
- incites odontoblastic proliferation
- hydrophilic
- high alkilinity increases mineralisation process
- does not shrink upon setting
What two materials can be used to seal the entrance to the root canals and the floor of the pulp to prevent coronal leakage?
- Resin modified GI (vitrebond)
- Smart dentine replacement (SDR)
What is SDR? And what is its advantage?
A flowable composite bulk filler, it self levels and minimises shrinkage stress
Prior to placing coronal seal, what should you use to clean access cavity, and why?
Use alcohol to clean away all traces of sealer
In what sort of tooth should multiple radiographs be taken at different angles?
In a multi-rooted tooth, such as molars
Why is an access cavity cut prior to rubber dam placement?
To help angulation of the bur ad prevent perforation
What material are endodontic hand instruments generally made from?
Stainless steel
What taper do hand files have?
2%
What are the main disadvantages to stainless steel hand files?
- they have poor flexibility, especially in curved canals
- this can lead to many procedural errors during canal shaping
Small instruments are manufactured from square blocks, what is the benefit of this?
More resistant to torque fractures
Large instruments are manufactured from triangular blocks, what is the benefit of this?
Improves cutting efficiency
What are the different types of stainless steel files?
- barbed broaches
- K file
- flexofile
- hedstrom file
What stainless steel hand files is used for emergency pulp extrapation in the case of symptomatic irreversible pulpits ?
Barbed broaches
When would a hedstroem file be indicated for use?
In retreatment cases to help remove gutta percha or an overfilling of the root canal (cut in a coronal direction)
What type of rotary file can be placed in curved canals with little lateral force?
NiTi alloy files
What are the main characteristics of NiTi alloy?
- super-elasticity
- can be strained more than other alloys without permanent deformation
- less transportation, zipping and ledging
- centrally placed preparation
What is M-wire?
A wire that has undergone a thermo-mechanical process, as a result of this it is much more flexible and has more fatigue resistance
What are controlled memory (CM) files?
Very flexible files with virtually no memory which allows the file to adapt to root canal curvatures
What happens to martensitic NiTi after unloading out of a curved Canal?
Shaped memory effect is maintained, file stays curved
What is martensitic steel?
Contains more carbon so is harder and more brittle
What is austenitic steel?
Contains less carbon, so is soft and ductile
What is the benefit of having a larger taper on a file?
Allows more effective disinfection of the canal system
What are inter-appointment medicaments?
Antimicrobial agents that are placed in the root canal system between appointments
What is apexification?
“ a procedure whereby the root canal of an open apex tooth is filled with non-setting calcium hydroxide to stimulate the formation of a hard tissue barrier at the apical portion of the root”
Give 5 uses of calcium hydroxide
- Inter-appointment medicament
- Pulp capping
- Apexification
- During treatment of root perforations, fractures, resorption and dental trauma
- Root canal sealer
When would apexification be indicated?
- Vital radicular pulp in an immature tooth pulpotomy
- Pulpless immature tooth with or without a periapical radiolucency
What are the two types of root resorption?
Internal and external
What is internal root resorption?
Resorption which starts from the root canal and destroys surrounding tooth structure
What is external root resorption?
Initiated resorption from outside the tooth, usually follows trauma to the PDL.
What is most often the cause of internal root resorption?
Chronic pulpitis
If internal root resorption is left untreated, what will be the consequence?
It will progress to perforate root and pulp will become necrotic
How would you treat internal root resorption if there is no perforation?
- Extripate the pulp
- Dress CaOH
- Obturate with warm gutta percha
How would you treat internal root resorption if there is perforation?
Defect must be sealed either surgically or intracanal using MTA
What are the six types of external resorption?
- surface resorption
- inflammatory resorption
- replacement resorption
- pressure resorption
- systemic resorption
- idiopathic resorption
What type of external root resorption is self-limiting in nature and usually results from trauma?
Surface resorption
What type of external root resorption occurs when there has been loss of cementum due to trauma and the root canal system has become infected?
Inflammatory resorption
What type of external root resorption is a continuous process where the tooth gradually becomes replaced by bone (ankylosis), due to trauma, replantation and luxation injuries?
Replacement resorption
What type of external root resorption is non-inflammatory and usually caused by eruption of teeth, impacted teeth, orthodontic movement etc.?
Pressure resorption
What type of external root resorption is caused by conditions such as hyperparathyroidism, Paget’s disease, Turner’s syndrome etc.?
Systemic resorption
What type of external root resorption can be localised to the apical or cervical region of the tooth?
Idiopathic resorption
What are the three treatment options for non-vital immature permanent incisor teeth?
- apexification
- apical barrier
- revascularisation
What is the apical barrier method?
Method to try and seal the apical 4mm of a root canal
What is the commercial name for the most common type of MTA used?
Pro-root
What is the revascularisation method?
In the absence of infection, ingrowth of tissue from the periapical region leads to revascularisation of the reticular pulp. As root development continues the dentinal walls thicken and the apex closes.
What two crystalline forms does gutta percha exist in?
Alpha and beta
What is the beta form of gutta percha, and what is it used for?
- It is a solid mass that is compactable
- used in gutta percha points
What is the alpha form of gutta percha, and what is it used for?
- When heated, becomes soft and tacky, shrinks on cooling
- used in thermo-plastic Obturation techniques
What are the three disadvantages of gutta percha as an obturating material?
- Lack of adhesion to dentine
- When heated, shrinks on cooling
- Cannot be heat sterilised
What might cause pain in the tooth after obturation and completion of Endo treatment?
The sealer used during obturation, sealers all exhibit toxicity when freshly mixed, but this reduces on setting.
What sealer is popular for use when using heated thermoplastic obturation techniques?
Zinc oxide and euganol
What characteristic of bioceramic sealers allows them to utilise moisture within a canal to complete the setting reaction?
They are hydrophilic
Give an example of a bioceramic sealer commonly used in dentistry?
Calcium silicates (e.g. MTA)
What material is best used to form an apical plug?
MTA
What is the setting time of MTA?
3 hours
What is the advantage of an MTA sealer?
It stimulates cementogenesis and hard tissue formation by osteocalcin gene expression of osteoblasts cells
Give an example of an ideal dentine replacement material
Bio dentine
What massive advantage does bio dentine have?
Fast setting time (10-12 minutes)
What disadvantage does bio dentine have?
May cause tooth discolouration
What does pulp sensibility test?
Allows us to assess the nerve supply of the pulp by stimulating sensory nerve fibres
What is the most accurate determinant of pulp vitality?
Vascular supply
What type of fibres innervate the pulp?
- myelinated A delta and A beta fibres
- unmyelinated C fibres
What are the 4 key uses for pulp testing?
- prior to operative procedures if the pulp health is in question
- diagnosis of pain
- investigation of radiolucent areas
- post-trauma assessment
What teeth may produce an incorrect result from pulp sensibility testing?
- traumatised teeth
- immature teeth
What are the 4 pulp sensibility tests that can be carried out?
- Thermal testing
- Electric pulp test
- Test cavity preparation
- LA test
What pulp sensibility test response would you expect to occur in a vital tooth or a tooth with reversible pulpitis?
Normal response
What pulp sensibility test response would you expect to occur in a tooth with suggested irreversible pulpitis?
Intense, prolonged response
What pulp sensibility test response would you expect to occur in a tooth with a necrotic pulp?
No response
What can cause a tooth to have a false negative response to pulp sensibility testing?
- calcified canal
- immature apex
- recent trauma
In thermal testing, what would a response to cold usually indicate?
A vital pulp
In thermal testing what would a response to heat be suggestive of?
Pulpal/periapical pathology that may require endodontic intervention
During cold testing what leads to the sharp sensation felt by the patient?
Contraction of the dentinal fluid within the tubules, resulting in a rapid outward flow which results in hydrodynamic forces acting on a delta fibres leading to a sharp sensation
What can cold testing be used for?
To differentiate between reversible and irreversible pulpitis
What cold test response would you expect to get if there is suggested reversible pulpitis?
Pain subsides on removal of stimulus
What cold test response would you expect to get if there is suggested irreversible pulpitis?
Pain lingers after removal of stimulus
Describe the 4 step technique for cold testing?
- Isolate with cotton wool rolls
- Spray small piece of CW roll with Endo frost
- Place on control tooth, note reaction
- Place on test tooth, compare results
What are the two techniques used for heat activation for pulpal C-fibres?
- hot water syringed onto a tooth isolated with rubber dam
- GP stick heated in a flame
What nerve fibres does EPT stimulate?
A delta fibres
What sensation should the pateint feel upon EPT?
Warm, tingling sensation
What conducting medium tends to be used in EPT?
Prophy paste
Where should the electric pulp tester be placed on an anterior tooth?
Incisal third
Where should the electric pulp tester be placed on a posterior molar tooth? And why?
Tip of mesio-buccal cusp, highest innervation
Give 6 reasons as to why you may get a false positive response from EPT?
- electrode makes contact with gingiva or large amalgam restoration
- patient is anxious
- liquefaction necrosis
- tooth is not dry or well isolated
- partial necrosis
Why might a tooth with an acute alveolar abscess respond positively to EPT?
Because the gaseous and liquified elements within the pulp can transmit electric charges to periapical tissues
Give 5 examples of why a false negative result from EPT may occur?
- patient is premedicated
- inadequate contact of electrode with enamel
- trauma
- canal is calcified
- apex is immature
Why can trauma to a tooth cause a false negative response to EPT?
Because there will be temporary parasthesia of the nerves in the cervical area of tooth.
Why are EPT not reliable on immature teeth?
Because these teeth contain fewer A-delta fibres than mature teeth and myelinated nerves do not reach their maximal depth of penetration into the pulp until the apex completes its development.
In an EPT test, what would a positive response indicate?
Presence of A-delta nerve fibres
In an EPT test, what would a negative response indicate?
Pulpal necrosis
How often do false-positives/negatives occur in EPT?
10-20% of the time
What two tests are used as a last resort in pulp sensibility testing?
- Test cavity preparation (direct dentine stimulation)
- Local anaesthetic test
What is the technique used in test cavity preparation?
- Drill through the enamel-dentine junction of an unanaesthetised tooth under rubber dam isolation using a small round diamond bur with water coolant
- If the patient feels pain when dentine us reached the procedure is terminated and cavity restored
What is the technique for local anaesthetic test?
- Using an infiltration in the most posterior tooth in the suspected area
- If pain persists the next tooth mesial is anaesthetised (and so on until pain disappears)
What is meant by test sensitivity in general and in pulp sensibility testing?
General: The ability of a test to detect disease in patients who actually have the disease
Pulp sensibility testing: the ability to identify non-vital teeth
What is meant by test specificity in general and in pulp sensibility testing?
General: the ability of a test to detect the absence of disease
Pulp sensibility testing: the ability to identify vital teeth
What does pulpal vitality measure/assess?
Pulpal blood flow
What clinical test can be used to assess pulp vitality?
Laser Doppler flowmetry
What occurs in laser Doppler flowmetry?
A method used to enable the number and velocity of particles conveyed by a fluid to be measured (moving red blood cells within pulpal tissue)
What are the 4 indications for use of laser Doppler flowmetry?
- Pulp testing in children
- Traumatise teeth
- Monitoring re vascularisation of replanted teeth
- Differential diagnosis of periapical radiolucencies
Following trauma in an immature permanent tooth with an open apex, what sensibility test should be used to assess nerve supply?
Cold testing
Following trauma in an immature permanent tooth with pulp canal mineralisation, what sensibility test should be used to assess nerve supply?
EPT
Following trauma in an mature permanent tooth with pulp canal mineralisation, what sensibility test should be used to assess nerve supply?
EPT
Following trauma in an mature permanent tooth with patent canal space, what sensibility test/s should be used to assess nerve supply?
Cold testing
EPT
Heat testing
How many distinct patterns of accessory canals are in mandibular first molars?
3
What are the three distinct accessory canal patterns in mandibular first molars?
A- a single function canal extends from pulp chamber to intra-radicular region
B- lateral canal extends from coronal 3rd of a major root canal to the furcation region
C- both lateral and furcation canals
What material can fill accessory canals during RCT?
Sealer
What part of the tooth are majority of canals located in molar teeth?
Within the mesial aspect of the tooth
As a general rule, what is the distance from the pulpal floor to the furcation?
3mm
As a general rule, what is the pulp chamber height of a mandibular molar?
1.5mm
As a general rule, what is the pulp chamber height of a maxillary molar?
2mm
As a general rule, what is the buccal cusp to pulp chamber roof height of a mandibular and maxillary molars?
6mm
It is common for pulp chamber height and level of ACJ to be the same. True or false?
True
How many roots does a maxillary first molar have, and name them?
3 roots:
- palatal
- mesiobuccal
- distobuccal
How many canals can a maxillary first molar have?
3-4 canals
What is the general rule for locating 2nd mesiobuccal canal in maxillary first molar?
2nd mesiobuccal canal located on a line between the mesiobuccal and palatal orifices
How many roots and canals are usually present in maxillary second molars?
3 roots and 3/4 canals
How many roots does a mandibular first molar have?
2
In a mandibular first molar, which root has a two canals, buccal and lingual ?
Mesial root
What is meant by radix entomolaris? And what tooth does it effect?
An extra lingual root, usually effects the mandibular first molar
What is meant by radix paramolaris, and what tooth does it effect?
Extra buccal root, usually effects mandibular first molar
How many roots and canals do mandibular second molars have?
2 roots, usually 3 canals (sometimes 4 canals)
Which bur should be used to start creating the shape of your molar access cavity?
Diamond round bur or short fissure bur
What bur should be used to create more depth in an access cavity and achieve access through the roof of the pulp?
Long fissure bur
What bur could be used if access is required through a crown/metal ceramic crown?
Tungsten carbide bur
What shape of access cavity should be used for maxillary molars?
Blunted triangular outline
What shape of access cavity should be used for mandibular molars?
Rhomboid shape
What are the complications that can be caused by poor access preparation?
- Inadequate open in compromising cleaning/shaping for canals and instrumentation
- Coronal fracture (removal of too much tooth structure)
- Inadequate caries removal
- Labial/furcal perforation
- Entering wrong tooth
- Allowing debris to clog and block orifices or canals
What is the maximum drug dosage in a 24-hour period for:
Paracetamol
4g (2x500mg tablets up to 4x daily)
What is the maximum drug dosage in a 24-hour period for:
Ibuprofen
2.4g (2x200mg tablets up to 4x daily)
What is the maximum drug dosage in a 24-hour period for:
Diclofenac
150mg (1x50mg tablet 3x daily)
What are the three main antibiotics recommended as first-line treatment for dental infections?
- Amoxicillin
- Pen V
- Metronidazole
Define, an exaggerated response to application of a stimulus to exposed dentine regardless of location.
Dentine hypersensitivity
Why does dentine hypersensitivity occur?
Due to rapid fluid flow in exposed dentinal tubules and hydrodynamic activation of A delta fibres
What are the symptoms of reversible pulpitis?
- sharp pain to cold or sweet,salty, sour
- lasts a few seconds
What are the causes of reversible pulpitis?
- caries into dentine
- broken, worn teeth
- defective restorations
- recent dental treatment
What is the normal treatment for reversible pulpitis?
- caries removal and a restoration
What is asymptomatic irreversible pulpitis?
No symptoms but deep caries or loss of tooth structure that if left untreated will cause symptoms or the tooth to become non-vital
What are the symptoms of symptomatic irrevsrible pulpitis?
- intermittent or spontaneous pain
- last only minutes or can last for hours
- pain induced by hot and cold
Why is pain related to irrevsrible pulpitis difficult to localise in early stages?
Because inflammation is in the pulp tissue and has not yet travelled to PDL
What are the treatment options for a tooth with irreversible pulpitis?
- RCT if tooth restorable
- emergency pulpotomy and dressing with ledermix or odontopaste
- extarction
What treatment is most appropriate for a tooth with irreversible pulpitis in an emergency situation with little time?
Pulpotomy and dressing with ledermix or odontopaste until RCT can be carried out
What are the symptoms of advanced symptomatic pulpitis?
- excruciating acute pain
- cold momentarily relieves pain
- TTP
- reacts violently to heat
What feature on a radiograph would suggest advanced symptomatic pulpitis in a tooth?
Thickening of the periodontal ligament
During vital pulp therapy, what biomaterials can be used at the level of the canal orifices, prior to placing a direct restoration?
MTA or Biodentine
Odontopaste and ledermix can be used during pregnancy. True or false?
False, potential teratogenic effects.
What are the two causes of symptomatic periapical periodontitis?
- Bacteria, toxins from infected, necrotic pulp
- Procedures during RCT such as over-instrumentation that pushes debris beyond the apex
How does symptomatic periapical periodontitis present clincially?
Pain, especially tender to biting.
How does symptomatic periapical periodontitis present radiographically?
Radiolucent area around apex of tooth
What are three reasons that tissue swelling may occur in the oral region?
- acute periapical abscess
- inter appointment flare-up
- post-endodontic complication
What are the clinical signs of an acute apical abscess?
- pain
- tooth extruded from socket
- swelling
- mobility of tooth
- systemic involvement
If there is a fluctuant swelling of the head and neck region, what does this indicate about its position between tissues?
Submucosal
If there is a non-fluctuant swelling of the head and neck region, what does this indicate about its position between tissues?
Subperiosteal
Give 5 key instances where you should NOT prescribe antibiotics?
- irreversible pulpitis
- symptomatic apical periodontitis
- draining sinus tracts (chronic abscess)
- after endodontic surgery to prevent flare-ups
- after incisor and drainage of local swelling (without cellulitis, fever or lymphadenopathy)
In what circumstances should antibiotics be prescribed?
- where there is a diffuse swelling/cellulitis
- drainage cannot be achieved
- patient has systemic involvement
When prescribing pen V as an antibiotic, what is the normal prescription you would give to patients?
1 tablet four times a day for 5 days
When prescribing amoxicillin as an antibiotic, what is the prescription you would give to patients?
1x500mg capsule three times daily for 5 days
What antibiotic is moist effective at treating dental abscesses?
Amoxicillin
When prescribing metronidazole as an antibiotic, what prescription would you give to patients?
1x400mg tablets three times daily for 5 days
What anaerobes does metronidazole act upon?
Strict anaerobes (without oxygen)
What antibiotic is used as an adjunct to amoxicillin in patients with spreading infection or pyrexial?
Metronidazole
What are the three main analgesics that you would recommend for patient use?
- ibuprofen
- diclofenac
- paracetamol
When can pain arise during Endo procedure?
- failure to achieve LA
- pain during shaping and cleaning
- pain after Obturation
If the effect of inflammation in a tooth prevents LA of tissues using lidocaine or articaine, what other LA solution could be used and why?
3% mepivicaine (scandonest), because it has lower pKa values
How could the effect of inflammation on blood flow cause LA to fail?
Peripheral vasodilation induced by inflammatory mediators could reduce the concentration of LA by increasing the rate of systemic absorption.
What effect does inflammation have on nociceptors and why might this cause failure of LA?
Inflammatory mediators activate/sensitise neurons, bradykinin and prostaglandin E2, which causes nerve sprouting and increases the size of the receptive field so sodium channels are less sensitive to lidocaine
What factors might cause pain following canal preparation?
- apical extrusion of debris
- over instrumentation (enlargement for foramen)
- incomplete debridement
- undetected canal
- perforation
- restoration in supraocclusion
What are signs of sodium hypochlorite accident?
- acute pain, swelling, redness
- profuse haemorrhage
- numbness, weakness of CN VII
- secondary infection
How would you manage a hypochlorite accident?
- irrigation with saline to reduce tissue damage
- analgesics
- reassurance
- cold pack for 6 hours
- warm compresses for several days
- review in 1 day
- may require referral
What are the 4 causes of pain following canal Obturation?
- Restorations in supraocclusion
- Over-instrumentation, over-filling with GP
- Sealers slightly toxic for 24-48hours
- Root fracture
What are 4 causes of pain some months after RCT?
- Incomplete apical seal
- Tooth in traumatic occlusion
- Cracked, fracture tooth
- Poor coronal seal
What is cracked tooth syndrome? And symptoms?
Incomplete fracture of a vital posterior tooth that may or may not involve the pulp. Consistent symptoms of pain to biting and cold temperature
What are the 5 differnt description for cracks that can occur in teeth?
- Craze lines
- Fractured cusps
- Cracked tooth
- A split tooth
- Vertical root fractures
What type of crack is described?
Visible fractures that only involve enamel
Craze lines
What type of crack is described?
A crack extending from the occlusal surface of the tooth apically without separation of the two segments
Cracked tooth
What type of crack is described?
Originates in the crown, extending into dentine and terminates in cervical region, usually associated with lathe restorations causing unsupported cuspal enamel.
Fractured cusps
What type of crack is described?
Originates in the root and are generally complete
Vertical root fracture
What type of crack is described?
A crack that extends through both marginal ridges usually in a mesiodistal direction, splitting the tooth completely into two seperate segments
A split tooth
What are the symptoms of a cracked tooth?
- localised pain on chewing or biting
- unexplained sensitivity to cold
- pain on release of pressure
What are special investigations that should used if there is a suspected cracked tooth?
- transillumination
- use of magnification
- removal of existing restoration/staining
- bite test tooth slooth (pain on release)
What is the likely treatment option for cracked tooth with irreversible pulpitis/ necrotic pulp?
- RCT before restoration
What are 6 endodontic risk factors for tooth loss?
- Post-treatment disease
- Loss of substantia tooth structure
- Weakening of tooth structure through use of endodontic chemicals
- Dehydration of dentine and transformation of collagen fibre structure
- Reduction in the level of proprioception
- Delay in providing definitive restoration to the tooth
What are the 5 key considerations when carrying out an endodontic evaluation of a root filled tooth?
- Percuss the tooth to assess per-radicular inflammation
- Palpate around tooth, assessing mucoperiosteal inflammation
- Assess for sinus tract (persistent endodontic infection)
- Assess mobility
- 6-point chart tooth
Name the endodontic and/or periodontal lesions that can present in a tooth?
- Primary endodontic lesion (secondary periodontal involvement)
- Primary periodontal lesion (secondary endodontic involvement)
- True combined lesion
- The concomitant pulpal-periodontal lesion
What is an effective method to assess the source of infection of a sinus tract?
Insert GP cone into sinus, identifying source of infection through radiograph
What tool is essential to confirm diagnosis of a tooth?
Radiographic evaluation
What is the supracrestal tissue attachment?
2-3mm of gingival attachment from alveolar bone
Why is it very important to always keep crown restorations or any indirect restorations above the supracrestal tissue attachment?
If restoration encroaches on supracrestal tissue attachment this can result in:
- persistent inflammation
- loss of attachment
- pocket formation
- recession
What are the two iatrogenic reasons for root perforation?
- Endodontic perforation
- Post placement
What are the two pathological reasons for root perforation?
- internal resorption
- external resorption
What is a Ferrule?
Parallel walls of dentine extending coronally from the crown margin
What are the benefits of a ferrule during coronal restoration?
Provides a protective effect by reducing stresses within a tooth
How high should a properly executed ferrule be, especially on the palatal and buccal walls?
1.5-2mm high
Why should posts not be placed in posterior teeth?
- they have thinner curved roots so risk of perforation
- higher risk of fracture due to removal of radicular dentine
- not required for retention
What is the conservative management of anetrior teeth with risk of discolouration upon treatment?
Internal bleaching
Other than internal bleaching, what are the other two methods of management for anterior teeth with risk of discolouration upon treatment?
- veneers
- full crown coverage
What is the purpose of core system?
Replaces missing coronal tooth structure prior to restoration with an indirect restoration and helps t stabilise weakened parts of the tooth
What are 5 core materials for restoration?
- Dentine
- Composite resins
- Cast metal and ceramic
- Glass ionomer and RMGI’s
- Amalgam
What is nayyar core?
An outdated technique where the core designed to use the pulp chamber and coronal aspect of canals to create a core without post system
What the most favourable material for cores?
Composite/ resin based materials
When do gold cast posts show the best long-term results?
When there is limited/ no ferrule on a tooth
When is it appropriate to use a post for restoration?
- severe loss of coronal tooth structure
- no or minimal ferrule effect
- to allow the rebuilding of the tooth structure prior to the crown restoration
What are the main disadvantages of of metal alloy posts, commonly used historically?
- concentrated stresses in zones that are vital to the tooth root
- aesthetically, can cause discolouration of tooth
- requires multiple stages with a technician involved
What post material has biocompatible properties more comparable to dentine compared to the metal alloy posts, however has a higher risk of debonding?
Fibre-reinforced posts
In post prep, how much gutta-percha should be retained apically?
4-5mm
What feature of a post gives it better retention?
The longer it is
What are the consequences of a short post?
Poor retention and transmit lateral forces to remaining root structure compared to longer posts
Name the three main types of definitive restoration?
- direct restoration
- indirect adhesive restoration
- indirect cemented restoration
What type of restoration should be used if the tooth has intact marginal ridges?
Direct composite restoration
What type of restoration should be used if the tooth has restorations involving the marginal ridge or extensive tooth structure loss needing a cuspal coverage restoration?
Indirect restoration
How many classes are there in the classification system for the restoration of root filled teeth?
4
What classification for the restoration of root filled teeth is described:
- enough coronal tissue to increase adhesive surface area and mechanical retention (>50%)
Class 0 : no post, composite core build-up
What classification for the restoration of root filled teeth is described:
- Limited amount of coronal tissue (<50%)
- two or fewer walls present in anterior teeth and premolars
Class 1: fibre post
What classification for the restoration of root filled teeth is described:
- teeth with no ferrule effect
Class 3: gold cast post
What classification for the restoration of root filled teeth is described:
- post placement cannot compensate for total or partial ferrule loss
- delayed definitive restoration to achieve predictable aesthetic outcome
Class 2: pre-restorative procedures needed
What classification for the restoration of root filled teeth is described:
- restoration of the compromised root filled tooth too complex and time consuming with no predictable outcome
Class 4: extraction
What is an Endo crown?
Concept of an onlay that is cones to dentine of the pulp chamber for retention, and is an alternative to post placement in posterior teeth.
