Final Revision Flashcards
What is the aim of RCT for teeth w/ vital pulp?
pulpectomy and prevention of apical periodontitis
What is the aim of RCT for teeth w/ non-vital pulp?
treatment of apical periodontitis
RCT Indication:
- root caries
- poor crown:root ratio
- periodontal disease
- restorative condition of tooth
- lesions that mimic endodontic pathoses but they are not of odontogenic origin
RCT Contraindications:
- poor periodontal prognosis -> extraction
- extensive loss of hard tissues due to caries, root fractures, cervical resorption
- restorations -> should be removed before
- teeth w/ vital pulp
- implants
- inadequate periodontal support which cannot be corrected
What are the RCT outcomes?
- successful outcome for short/long-term evaluation
- failure of post-treatment (apical periodontitis)
- uncertain outcome
Which factors play role in good prognosis of RCT?
- full working length
- no apical extrusion of foreign material
- no missed RC
- effective cleaning and shaping of PC and proper disinfection
- hermetic obturation
- good tooth restoration
RCT Procedure: good technical quality
- Access cavity prep
- Tooth isolation from oral environment
- Working length determination
- RC shaping and cleaning (chemomechanical prep of RC)
- RC disinfection
- RC obturation
- Tooth restoration without leakage
SOS
What is the role of radiograph in endo diagnosis?
- characterize root hard tissues normal structure
- recognize pathological alteration of root hard tissues
- determine root anatomy and root canal pathway
- identify pathological changes in root and periapical periodontal tissues
- locate RC and study their configuration
- determine WL of RC
- evaluate possible iatrogenic factors during treatment
- evaluate presence of calcification in RC space
- to identify new disease
- to evaluate periapical disease healing
What criteria to evaluate changes in periodontal tissues?
- LD (presence, absence, widening)
- periapical ligament space (normal, widening)
- periapical radiolucency (localized, large)
ex: apical periodontitis - periapical radiopacity
What are the techniques of periapical radiographs?
- parallel (long) cone technique
- bisecting angle technique
What are the ADV of Parallel (long) cone technique?
- min enlargement and less distortion
- sharp image
- represents true relationship w/ alveolar crest and bone
- reproductibility
What are the DISADV of Parallel (long) cone technique?
- difficulties in small mouths
- difficulties w/ tooth isolation
- requires film holders
- apices below zygomatic arch are usually not seen clearly
What are the ADV of Bisecting angle technique?
- easy use
- film placed in close proximity to tooth
What are the DISADV of Bisecting angle technique?
- distortion of tooth root structure
- no reproductibility
The access prep for RCT should be:
- locating all canals
- straight-line access of instruments to apical root part
- removal of roof pulp chamber and whole coronal pulp
- conservation of tooth structure
What are the forms of access cavity?
- outline form
- convenience form
Outline form definition:
=projection of internal tooth anatomy
Convenience form definition:
=modification of ideal outline form to facilitate manipulation after complete caries removal
SOS
Pulp chamber principle:
- always at the center of the tooth
- its floor is always darker in color than walls and grooves connecting RCs
- at level of CEJ
- same distance from crown’s external surface to pulp chamber wall
- RC orifices located at the junction of walls and floor
General principles of cavities:
- always include pulp horns removal
- must have parallel walls
- must provide instruments free entrance
- prep after complete caries removal
Why is the cavity access prep done after complete caries removal?
- it creates an aseptic environment
- it allows assessment of restorability before RCT
- it provides sound tooth structure for temporal filling
- no change in reference point for WL
SOS
Number of roots for:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: 1 maxillary I2: 1 maxillary C: 1 maxillary P1: 2 (60%) maxillary P2: - maxillary M1: 3 (91%) maxillary M2: 3 (60%)
mandibular I1: 1 (95%) mandibular I2: 1 (95%) mandibular C: 1 (95%) mandibular P1: 1 (86%) mandibular P2: 1 (86%) mandibular M1: 2 (95%) mandibular M2: 2 (95%)
Root curvatures:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: - maxillary I2: apical maxillary C: apical maxillary P1: apical maxillary P2: apical maxillary M1: apical maxillary M2: apical
mandibular I1: apical mandibular I2: apical mandibular C: apical mandibular P1: middle or apical mandibular P2: middle or apical mandibular M1: apical mandibular M2: apical
Root shape:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: triangular to round
maxillary I2: oval
maxillary C: long oval
maxillary P1: long oval coronally to round apically
maxillary P2: long oval coronally to round apically
maxillary M1: oval to long oval
maxillary M2: oval to long oval
mandibular I1: long oval
mandibular I2: long oval
mandibular C: long oval
mandibular P1: long oval coronally to round apically
mandibular P2: long oval coronally to round apically
mandibular M1: long oval
mandibular M2: long oval
Number of root canals:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: 1 maxillary I2: 1 maxillary C: 1 (70%) maxillary P1: 2 (90%) maxillary P2: 1 (53%) maxillary M1: 4 (65%) maxillary M2: 3 (65%)
mandibular I1: 1 (70%) maxillary I2: 1 (55%) mandibular C: 1 (90%) mandibular P1: 1 (70%) mandibular P2: 1 (85%) mandibular M1: 3 (70%) mandibular M2: 3 (70%)
Number of apical exists:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: 1 maxillary I2: 1 maxillary C: 1 maxillary P1: 2 (78%) maxillary P2: 1 (75%) maxillary M1: 4 (80%) maxillary M2: 3 (80%)
mandibular I1: 1 (70%) mandibular I2: 1 (55%) mandibular C: 1 (90%) mandibular P1: 1 (74%) mandibular P2: 1 (97%) mandibular M1: 3 (70%) mandibular M2: 3 (70%)
Access view:
maxillary I1: maxillary I2: maxillary C: maxillary P1: maxillary P2: maxillary M1: maxillary M2:
mandibular I1: mandibular I2: mandibular C: mandibular P1: mandibular P2: mandibular M1: mandibular M2:
maxillary I1: triangular maxillary I2: oval maxillary C: oval maxillary P1: oval maxillary P2: oval maxillary M1: oval maxillary M2: oval
mandibular I1: long oval mandibular I2: long oval mandibular C: oval mandibular P1: oval mandibular P2: oval mandibular M1: oval mandibular M2: oval
Basic instrument pack components:
mirror dental tweezers/cotton pliers dental explorer endo tweezers endo explorer DG16 periodontal probe anesthetic syringe paper points long shank spoon excavator flat plastic instrument amalgam plugger plastic/metal ruler endo stand or endo ring
Ultrasonic tips use:
- calcifications
- access cavity prep
- broken instruments removal
- intracanal posts removal
Cold lateral compaction:
Warm vertical compaction:
remove excess gutta percha
SOS
What is the objective of working length determination?
to establish the length at which canal prep and obturation are completed
Root end diameter
0.5 - 1.2 mm
Topography of apical constriction:
Traditional single constriction:
Multiconstricted:
Tapering constriction:
Parallel constriction:
Traditional single constriction: 46%
Multiconstricted: 19%
Tapering constriction: 30%
Parallel constriction: 5%
Short constriction:
Long constriction:
Short constriction: 76%
0.5 - 1 mm OR > 1 mm from radiographic apex
Long constriction: 24%
1 - 3 mm form radiographic apex
Techniques used for WL determination:
tactile method
radiographic technique
electronic technique
Tactile method:
- unreliable
- well developed fingertip tactile sense can detect when the file tip reached apical constriction
What are the 2 pints for an accurate measurement of Radiographic technique:
- reference point
- apical end of file
Radiographic technique:
- # 10 file placements in RC
- measurement made in initial x-ray, with 3 mm subtracted
- then diagnostic x-ray is made using paralleling technique (to measure WL)
- empirical technique: apical constriction estimations: 1 statistical basis
- measurement w/ endo meter
- same cusp as a reference point