Endo board review Flashcards
What is the most common cell type of the pulp
fibroblasts
what are the pulpal cell zones
-pulp proper -cell rich zone odontoblasts predentin dentin
Where are the undifferentiated mesenchymal cells and what do they do
cell rich zone replace irreversibly damaged odontoblasts
What are the three main types of dentin
Predentin secondary dentin tertiary dentin
What is predentin
unmineralized dentin
what is secondary dentin
dentin that is physiologically formed after root development is complete
what are the types of tertiary dentin
reactionary and reparative
what is reationary dentin
tertiary dentin that is produced in response to irritation by ORIGINAL odontoblasts
what is reparative dentin
tertiary denting that is produced in response to irritation by recruited undifferentiated mesenchymal cells after the original odontoblasts are destroyed
how many dentinal tubules per sq mm are at the DEJ/CEJ vs pulpal wall
10-25K vs 30-52K
What are the diameter of dentinal tubules at the DEJ/CEJ vs pulpal wall
1-2 microns v 3-4
What is dentin by Volume
45% inorganic 33% organic 22% water
Whats the hydrodynamic theory and who proposed it
Brannstrom Fluid movement inside exposed dentinal tubules caused by heat, cold, air, probing, etc stimulates the A delta fibers causing dentinal hypersensitivity
What are the afferent nerve types of the pulp
–A-δ: large, myelinated; quick, sharp, shooting pain; fully formed 3-5 yr post eruption –A-β: myelinated, but few in # –C: small, unmyelinated; delayed, dull, aching, or burning sensation
What are the efferent
–C: sympathetic fibers – vasoconstriction
What are the proprioceptive fibers of the pulp
trick question there are none
What is the pulpal response to caries
Inflammatory reaction precedes bacteria “Chronic” response –Predominant cells: lymphocytes, macrophages “Acute” response – 0.5mm Edema – localized Microabscess Pressure - localized Degeneration # bacteria vs inflammatory response
what is meant by the pathogen transition
Aerobic Anaerobic (facultative anaerobes obligate anaerobes)
What does kakehashi 65 tell us
Abiotic mice had no issues so…No bacteria … no periapical pathosis
Radiographic signs of additional canals
Sudden canal disappearance Sudden reduction in density –May represent canal division Root outline unclear –May represent additional roots Canal not centered in root
Radiographic signs of internal resorption
Enlarged canal area Canal not evident through lesion Usually symmetrical Well-defined margins Stays centered on canal with change in horizontal angulation
Radiographic signs of external resorption
Canal evident through lesion Usually asymmetrical Poorly-defined margins Shifts off canal with change in horizontal view
What is our endo diagnostic goal
Reproduce, Alter or Eliminate the Chief Complaint
What are the limitations of endo diagnosis
Diagnostic testing – imprecise Patient processing and feedback - imprecise Lack of pulpal proprioception (cannot localize) Referred pain Misdiagnosis by referring dentist
Do pulpal test evaluate nerve response or pulpal blood flow
nerve response,
What chemical do we use for cold testing
Tetrafluoroethane … -14° F
How should you properly cold test
“Educate” patient … why, how, what Use large, fluffy cotton pellet Establish controls Facial surface Directly on metal restorations OK?? Alternatives … ice, immersion
What might cause a false positive to thermal testing
–Anxiety –Gingival response –Adjacent teeth –Saliva –Periradicular response
what might cause a false negative response to thermal testing
–Calcified canals –Inadequate stimulus –Restorations –Immature tooth –Trauma
when might you use cold immersion and how?
CC not duplicated with Endo Ice Cracks, open margins, can’t localize Simulates “real-world” activity Single tooth RD isolation Establish control responses first
When and how to use hot immersion
Heat is primary factor of CC Cold test inconclusive Single tooth RD isolation Establish control responses first 150 F
What can you infer from EPT
No diagnostic value with vital pulp pathosis May defer if teeth respond to thermal test Implies only pulpal vitality or necrosis via negative nerve response A “yes or no” result … ignore the number
What may cause a false positive EPT
–Anxiety –Restorations –Gingival conduction
What may cause false negative EPT
–Inadequate contact –Immature tooth –Recent trauma
What are the different pulpal dx
Normal Reversible pulpitis Symptomatic irreversible pulpitis Asymptomatic irreversible pulpitis Pulpal necrosis Previously initiated therapy Previously treated
What are the different apical dx
Normal apical tissues Symptomatic apical periodontitis Asymptomatic apical periodontitis Acute apical abscess Chronic apical abscess Condensing osteitis
Symptomatic apical periodontitis
Pain - Yes Swelling - None Sinus tract - None Palpation – Maybe tender Biting – Maybe painful Percussion – normally painful Radiograph – with or without apical radiolucency
Asymptomatic apical periodontitis
Pain - None Swelling - None Sinus tract - None Palpation - WNL Biting - WNL Percussion - WNL Radiograph – Apical radiolucency
Acute Apical Abscess
Pain – Normally present Swelling – Present Sinus tract – None / maybe Palpation - Painful Biting - Painful Percussion - Painful Radiograph – WNL or apical pathology
Chronic apical abscess
Pain – None, maybe episodic Swelling - None Sinus tract – Present or recent Palpation – Maybe tender Biting - WNL Percussion – Maybe tender Radiograph – Apical pathology normally present
Condensing Osteitis
•A localized overproduction of apical bone •Apices of mandibular posterior teeth •Chronic pulpitis or pulp necrosis •A low-grade inflammation of the periradicular tissues
What is law of centrality
pulpal floor always located in center of tooth at level of the CEJ
Law of the CEJ
the CEJ is the most consistent, repeatable landmark for locating the position of pulp chamber
Law of concentricity
walls of pulp chamber are always concentric to external surface of tooth at level of the CEJ
Law of symmetry
except for max molars, orifices are equidistant from a line drawn in a MD direction through pulpal floor except for max molars; Orifices lie on a line perpendicular to a line drawn in a MD direction across center of pulpal floor
Who said the laws of the pulpal floor
Krasner & Rankow, JOE 2004
Law of color change
the color of the pulpchamber floor is always darker than walls
Law of orifice location
the orifices are always located at junction of walls and floor the orifices are located at angles of floor-wall junction the orifices are located at terminus of root developmental fusion lines
What are the canal configuration classifications
I single canal II 2 canals merge into 1 III two canals stay separate IV 1 canal splits into 2
How many cnals in max ant
1
Man ant incisor
1 canal 57 2 canals 43 1 foramen 99
Man canines
2 canals 22%
max 1st premolars
2 canals 85 3 canals 6% 2 roots 57
Max 2nd premolar
50/50
man 1st premolar
1 canal 75 2 canal 24 3 canal 1
man 2nd premolar
1 canal 97 2 canal 3
Max 1st molar MB root
1 canal 20 2 canal 77 3 canals 3
max 2nd molar mb root
1 canal 63 2 canal 37
Man 1st molar
2 canal 7 3 canal 64 4 canal 29
man 2nd molar
2 canals 4% 3 canals 81% 4 canals 11% C-shape 3%
advantages of straight line access
– Vision improved – Reduces curvature … facilitates instrumentation & obturation – Improves instrument control … fewer misadventures
How do you arrive at an appropriate working length?
Estimate Radiograph (0.5 – 1.0 mm) Tactile sense Electronic apex locator Paper point Patient sensation
Apical Foramen Position
92 % deviation of major foramina from radiographic apex 0.59mm deviation from radiographic apex
How does the apex locator work
“Ratio method” Simultaneously measures impedance of two different frequencies, calculates the quotient of the impedances, and expresses this quotient as a position of the file inside the root canal No calibration required
What are the objectives of cleaning and shaping
Total removal of contents of pulp space –Tissue, debris, bacteria, byproducts Develop straight line access to apical region Maintain central axis of canal Keep apical constriction small and in original position Continuously tapering, smooth, funnel-shaped preparation
Curvature complications of instrumentation
Elbow Ledge Zip (w/ or w/o perforation) Transportation Strip Perforation
Consequences of transportation
Incomplete debridement Difficult to obturate with good seal Incomplete healing Inability to adequately re-treat
Causes of transportation
Insufficient access cavity extension Poor control of file insertion length Use of end-cutting files Attempting to achieve too large a MAF size Failure to recapitulate Excessive axial (in-out) filing in a curve Insufficient irrigation Dentinal mud at apex
Balanced force technique
Neutralize restoring forces Maintaining centering of prep, avoiding transportation of original canal Safe-ended instrument required (Flex-R) Very efficient way to cut dentin
Crown-Down Philosophy
Early opening of canal for better irrigant penetration Reduce curvature, better straight-line access to apical region Reduce binding of file along full length of canal Reduce apical packing and extruding of debris
Results of Proper Access
Straight line access to canals Eliminates coronal canal curvature Provides “gutters” into canal Allows “blind” instrumentation Significantly improves speed Minimizes coronal file binding Allows localization of all orifices Minimizes canal transportation Improved Obturation
what are the fundamentals of instrumentation
Don’t force instruments / Don’t Push Files Examine files for unwinding Copious irrigation/ lubrication Recapitulate
Properties of niti
Extraordinary flexibility Due to very low elastic modulus Superior fracture resistance Due to ductility of the NiTi alloy Outstanding shape memory
disadvantages of niti
cost Altered tactile feel Requires practice to minimize problems Mandel et al IEJ 1999 Can have little or no warning prior to fracture Negotiating ledges or complicated anatomy Instrumenting abrupt curves Instrumenting canals that come together at sharp angles
Advantages of niti rotary
Enlarge canal that has been negotiated to length Create smooth continuous taper Reduce operator fatigue Reduce time of instrumentation
Types of fx
Torsional fracture Flexural fracture
Torsional fx
Torque load on file causes unwinding and twisting in the opposite direction Instrument is locked in the canal while the shaft continues to rotate Occurs in smaller files
cylic fx
Breakage occurs abruptly, with little warning No other defects visible in association with fracture Occurs more frequently in larger size files
Advantages of our K3 rotary system
Safe ended tip minimizes transportation ISO sizes through 60 similar to Profiles 3rd Radial Land (wide) stabilizes & keeps file centered in canal Smaller shank shortens overall length of files by 4 mm Variable Helical Flute Angle from tip to handle helps with debris removal Positive Rake Angle Variable Core Diameter+stronger tip
Gates glidden comparison to files size
size 1 = 50 file, 2 = 70 file
Peeso reemer size to file size
1=70, 2 = 90
Why do we need chemical shapers
All aspects of a canal system cannot be reached by files
gold standard of irrigation
8% (full strength) NaOCl is “gold standard” – Dissolves necrotic tissue – Removes the organic portion of smear layer – Germicide – Detoxifies endotoxins – Lubricant – Bleaching agent – Deodorizer
17% EDTA
– Chelating agent – Lubricant – Helps remove inorganic portion of smear layer – ethylenediaminetetracetic acid
CaOH
High pH … alters environment Antimicrobial Dissolves tissue Favors calcification (alkaline phosphatase formation) Favors osteogenesis Causes limited tissue necrosis … elicits healing response Helps dry “weeping” canals Halts or slows resorptive processes Effective for 1 week
Goals of obturation
Replicate root canal system Maintain materials inside Tight seal to fluids, bacteria, byproducts Seal in bacteria Seal out nutrients
How do you disenfect gutta percha
–6 % NaOCl immersion –60 seconds
GP composition
Zinc oxide 56 - 75 % Gutta-percha 19 - 22 % Metal sulfates 2 - 17 % Waxes & resins 1 - 4 %
Roth cement composition
Powder Zinc oxide 42 % Staybelite resin 27 % Bismuth subnitrate 15 % Barium sulfate 15 % Sodium borate anhydrous 1 % Liquid Eugenol 100%
what did ray and trope 95 say
Good restoration significantly more important then than the technical quality of the endodontic treatment for apical periodontal health.
1 vs multiple visit endo
1-visit ▪ Pt unable to return ▪ Medically impaired ▪ Vital ▪ Esthetic concerns ▪ Negative per pathosis Multi-visit ▪ Canal system infection ▪ Most retreatments ▪ Acute apical symptoms ▪ Weeping canal ▪ Difficult case ▪ Sinus tract
Perf prognosis
▪Good – Fresh – Small – Apical / Coronal ▪Poor – Old – Large – Sulcular / Crestal
which type of instrument fatigue has warning signs? What are they?
Torsional – Too much apical force – Clicking sounds – Unwinding
Management of NaOCL extrusion
– Calm patient – Augment anesthesia – Cold compress x 6 hrs – Warm compress x 2 days – Analgesics & antibiotics – Immediate referral if airway compromise – Daily recall
What form of the local diffuses through the nerve sheeth
unpolarized form
what binds internally to Na channel site to block transmission
the ionized form
what controls onset time of local
low pKa faster
what makes local ineffective
•Low pH shifts equation to less base •Dilution by blood and fluid •Rapid absorption into circulation •Tetrodotoxin Resistance •Central Sensitization •Hyperalgesia •Allodynia
whats the key to success for intrapulpal injection
Backpressure, not solution
what did okeefe 76 say about post op pain
perop pain=post op pain
what is barodontalgia
Tooth pain caused by an increase or decrease in ambient pressure Usually reported by aircraft personnel and divers Tough to diagnose … pulp testing inconclusive Affects teeth with a vital pulp – defective restoration Look for etiology of chronic pulp inflammation
whats an enamel infraction
incomplete fracture (crack) of the enamel without loss of tooth substance
Whats the difference between uncomplicated and complicated fracture
pulpal involvement
What are the ellis classifications
Ellis Class1: enamel only Ellis Class 2: Enamel plus dentin Ellis Class 3: Enamel plus dentin plus pulp
What is the most commonly cracked teeth
man molars 70%
where do vertical root fractures begin
root and move coronally
What are some clinical signs of VRF
Narrow probing defect w/sinus tract at base 2 narrow probing defects on opposite sides of root Treatment: extraction
What are the types of luxation injuries from best to worst
Concussion Subluxation Extrusive luxation Lateral luxation Intrusive luxation
what are the potential sequelae of luxation injury
-pulp survival -pulp canal obliteration -pulp necrosis -marginal bone loss -resorption
Who are the victim of 1/2 of all dental trauma
Children
What is the cause of most dental trauma for kids under 1
Fall injuries
Possible cause of dental trauma for kids under 3
Battered child syndrome
Which age has the most dental injuries
8-12 Play/athletics
Why might teens have dental injuries
Fights
What are two common reasons for all ages of dental trauma
Auto injuries and fights
Which teeth are most commonly injured
Max anteriors
What are the most common types of injuries to primary teeth
Luxations/avulsions
What is the type of injury most common to the permanent dentition
Crown fractures
Steps of pt evaluation
History and Chief Complaint
Neurologic Assessment
Extraoral to Intraoral Soft / Hard Tissue injuries
Radiologic Evaluation
What are the classification of crown fractures
Complicated (involving the pulp)and uncomplicated (no plural involvement)
What radiographs are needed.
Multiple angulations recommended
- Standard periapical
- Occlusal Periapical with lateral angulations
- Mesial & Distal
- Consider soft tissue radiograph If lip or cheek laceration To search for tooth fragments
How should percussion be tested in a traumatic case
with finger as a mirror handle is likely to much for a pt in pain
Why is vitality testing important?
To have a baseline
Emergency Management of Uncomplicated Crown Fracture
- Seal exposed dentin
- Bond tooth fragment If available
- Composite Resin
- Glass ionomer (Vitrebond)
What is the incidence of Pulp necrosis in Uncomplicated Crown Fx only in enamel
.2-1%
What is the incidence of pulp canal obliteration in uncomplicated crown fx only in enamel
.5%
What is the incidence of root resorption in uncomplicated crown fx only in enamel
.2%
What is the incidence of Pulp necrosis in Uncomplicated Crown Fx into dentin
1-6%
What is the incidence of pulp canal obliteration in uncomplicated crown fx into dentin
0
What is the incidence of root resorption in uncomplicated crown fx into dentin
0
Assessing either type of crown fx
- Assessment Radiographs
- Percussion/mobility testing
- Baseline vitality testing
- Visualize Adjacent teeth
Treatment options for complicated crown fas
- Pulp Capping
- Pulpotomy
- Pulpectomy
Whats the main factor for tx of complicated crown fracture
Stage of Root Maturation
Mature root -Pulpectomy
Immature root -Pulpotomy -Pulp capping
Pulp healing prognosis of pulp capping
71-88%
Pulp healing prognosis of partial pulpotomy
94-96%
Pulp healing prognosis of Cervical pulpotomy
72-79%
Preffered tx for an immature root
Partial pulpotomy (apexogenesis)
Average depth of inflammatory change in partial pulpotomy
less than 2 mmm
Types of crown-root fx
Uncomplicated and complicated
Emergency management of Crown to Root Fx
Radiographs
Splint fragments temporarily to alleviate pain from mastication
What determines the definitive tx of crown to root fx
Level of the fracture
Treatment modalities of uncomplicated crown to root fx
1 Fragment rem
2 restoration
Tx of complicated crown to root fx (restorable)
- Fragment removal
- Gingivectomy/ostectomy*
- Endodontic therapy Post-retained crown
*(can use orthodox extrusion/surgical extrusion instead of periodontal surgery)
Clinical presentation of Root Fractures
Tooth usually slightly extruded
Tooth frequently displaced lingually
Diagnosis entirely dependent upon radiographic examination
Radiographs for root fas
Periapical radiographs
- Standard XCP radiograph
- Increased vertical angulation
Emergency Management of root fx
- Reposition coronal fragment
- Flexible Splint
- -4 Weeks
- -If Fx near the cervical area - longer splinting time is beneficial Up to 4 months
What are the 4 types of root fx healing
- Hard tissue 2. Conenctive tissue 3. Interposition of Bone and Connective tissue 4. Interposition of granulation tissue
What is the incidence of pulpal necrosis after root fx for both segments
Coronal segment - 20 to 44%
Apical segment - 0%
What is the incidence of pulpal obliteration after root fx for both segments
69%
What is the incidence of root resorption after root fx
60%
What is the determinant of prognosis of root fracture
Fracture location
Prognosis of root fx in cervical 3rd
poorer
Prognosis of root fx in middle and apical 3rd
better
Classifications of luxation injuries
- Concussion
- Subluxation
- Extrusive Luxation
- Lateral Luxation
- Intrusive Luxation
Lunation injury complications
- Pulp necrosis
- Pulp canal obliteration
- Root resorption
- External
- Internal
- Loss of marginal bone support
Types of Ext root resorption
- Surface resorption
- Replacement resorption (Ankylosis)
- Inflammatory resorption
Surface resorption
Superficial resorption cavities
Mainly in cementum
Complete repair of PDL
Replacement resorption
Direct union of bone and root
Resorption of root - replacement with bone
Direct result of loss of vital PDL
Inflammatory resorption
Resorption of cementum and dentin
Inflammatory reaction in the periodontal ligament
Surface resorption of cementum exposing dentinal tubules
Pulp necrosis
Toxic products from the pulp provoke an inflammatory response in the PDL
Internal root resorption types
- Internal surface resorption
- Internal replacement resorption
- Internal inflammatory resorption
Internal inflammatory resorption incidence in lunated permanent teeth
2%
Concussion injury description
No abnormal loosening No displacement
Subluxation description
Abnormal Loosening No displacement
Emergency management of concussion and subluxation injuries
- Radiograph
- Baseline vitality testing
- Usually no splinting required 7-10 days for comfort
- Trauma Dx adjacent teeth Occlusal adjustment, if needed
- Recall
Pulpal necrosis incidence after concussion
3%
Pulp canal obliteration incidence after concussion
5%
Root resorption incidence after concussion
5%
Pulpal necrosis incidence after subluxation
6%
Pulp canal obliteration after subluxation
10%
Root resorption incidence after subluxation
2%
Extrusive luxation description
Partial displacement of tooth out of socket
Tooth appears elongated
Lingual deviation of crown typically
Excessively mobile
Emergency management of extrusive luxation
- Radiographs
- Baseline vitality testing
- Anesthesia
- Reposition tooth
- Flexible splint 2 weeks
- Follow-up
- 2, 4 weeks 6-8 weeks 6 months 1 year Every year for 5 years
Pulpal necrosis incidence after extrusive luxation
26%
Pulp canal obliteration incidence after extrusive luxation
45%
Root resorption incidence after extrusive luxation
9%
Lateral luxation description
Eccentric displacement of tooth
Crown usually displaced lingually
Fracture of socket wall
Tooth immobile
Percussion may have ankylotic sound
Emergency management of lateral luxation
- Radiographs
- PA
- Lateral
- CBCT
- Baseline vitality testing
- Usually negative results
- Anesthesia
- Reposition
- Flexible splint 4 weeks
- Add 3-4 weeks in case of marginal bone breakdown
- Occlusal adjustment, if needed
One week after lateral luxation
- Start endo / Ca(OH)2
- Complete within one month
- Follow-up 2 weeks 4 weeks (splint removal) 6-8 weeks 6 months 1 year Every year for 5 years
Incidence of pulp necrosis after lat luxation
58% (77 with closed apex)
Incidence of pulp canal obliteration after lat luxation
28%
Incidence of root resorption after lat luxation
27%
Incidence of loss of marginal bone support after lat luxation
5%
Intrusive luxation description
Displacement of the tooth into alveolar bone
Comminution or fracture of socket
Immobile with ankylotic percussion sound
Emergency management of Intrusive lunation
- Radiographs
- Pulp vitality tests Usually negative
- Anesthesia
- “Slightly luxate the tooth with forceps”
Emergency management of Intrusive lunation of teeth with incomplete root
- Allow eruption without intervention
- If no movement within a few weeks initiate orthodontic repositioning
- If tooth intruded >7mm reposition surgically or orthodontically
- Monitor pulp vitality -if becomes necrotic Pulp regeneration or apexification
What may happen if deciduous tooth is intruded
May damage developing permanent tooth
Emergency management of Intrusive lunation of teeth with complete root
- Allow eruption without intervention
- If tooth intruded <3mm If no movement within a few weeks initiate orthodontic repositioning
- If tooth intruded >7mm reposition surgically Pulp will be necrotic Pulpectomy 2 weeks after injury Ca(OH)2 for up to 4 weeks
If intruded tooth is repositioned surgically or orthodontically
Flexible Splint 2 weeks 4 weeks if displacement is ‘extensive
Intrusion follow up
Follow-up depends on treatment
Pulp necrosis and intrusion
complete root 100% Overall 85%
Pulp canal obliteration incidence in intrusion
10%
Root resorption incidence in intrusion
66%
Loss of marginal bone support incidence in intrusive injuries
24%
Graph of open apex luxation injury complications
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Graph of closed apex luxation injury complcations
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what makes post trauma dx difficult
Transient paresthesia in >50%
Vital pulp may not respond to thermal or EPT!
May take 2 - 10 months to respond normally
Initial positive response may revert to negative within 2 months … usually indicates pulp necrosis
Baseline findings at time of injury important
Immature root formation improves prognosis
Is RCT indicated on tooth with calcific metamorphosis
NO!
what kind of pulp is associated with internal resorption