Restorative Dentistry and Endodontics
This domain tests pulpal and apical diagnosis, adhesive dentistry and the technical sequence of root canal treatment, including how you would defend each step if challenged.
Diagnosis before drilling
- Pulpal diagnoses: normal, reversible pulpitis, irreversible pulpitis, necrosis. Apical diagnoses: symptomatic or asymptomatic apical periodontitis, acute or chronic apical abscess, condensing osteitis.
- A cold test producing a prolonged, lingering response after stimulus removal indicates irreversible pulpitis. A normal response excludes necrosis; a negative response in a tooth with a radiolucency supports it. Thermal tests are not used alone.
Adhesion
- Phosphoric acid 30 to 40 percent for 15 seconds on enamel and dentin in etch-and-rinse; self-etch systems are less technique sensitive but bond enamel less reliably.
- Shrinkage stress relates to configuration factor and volume: use incremental layering, soft-start curing, or low-stress bulk-fill materials.
- Two percent chlorhexidine after etching inhibits matrix metalloproteinases. Never mix sodium hypochlorite with chlorhexidine; a brown precipitate forms.
Endodontics
- Working length from an electronic apex locator plus a radiograph, with the file at the minor constriction, roughly 0.5 to 1 mm short of the radiographic apex.
- Sodium hypochlorite 1 to 5.25 percent dissolves tissue and disinfects; EDTA 17 percent removes the smear layer; sequence the final rinse deliberately.
- A second mesiobuccal canal is present in the majority of maxillary first molars; trough under the mesiobuccal cusp groove.
Worked example
A 40-year-old reports severe lingering pain to cold on the mandibular first molar, with no periapical radiolucency and no percussion tenderness. Diagnosis: symptomatic irreversible pulpitis with normal apical tissues. Treatment is rubber dam isolation, complete pulpectomy, shaping and obturation, not indirect pulp capping.
Traps
- Working without rubber dam.
- Obturating short or extruding sealer.
- Leaving less than 1.5 mm circumferential ferrule on a crown.