Operative Dentistry and Endodontics
Core concepts
Operative: cavity classification (GV Black I–VI), principles of minimal intervention, enamel/dentin bonding, amalgam vs composite indications, and matrix and wedge use. Understand caries removal, pulp protection (liners, bases), and the rationale for sealants. Endodontics: access cavity shapes per tooth, working length determination, cleaning and shaping (irrigation with NaOCl, EDTA, chlorhexidine), obturation techniques (lateral condensation, warm vertical), and management of complications (ledges, perforations, separated instruments). Know indications for pulpotomy, pulpectomy, apexification, and retreatment.
Traps
Questions test the difference between working length (apical constriction) and radiographic apex. NaOCl is tissue solvent and antimicrobial but not a chelator; EDTA chelates smear layer. Chlorhexidine cannot be mixed with NaOCl (precipitate). Composite requires moisture control and enamel etching; amalgam needs retention form and marginal seal. Beware stems asking for the FIRST step in an emergency (e.g., access and drainage for acute pulpitis/abscess).
Worked example
Rule of thumb: "Irrigation sequence: NaOCl for tissue dissolution and disinfection, EDTA to remove smear layer, final rinse; never mix NaOCl and chlorhexidine directly." For a tooth with irreversible pulpitis and no swelling, the answer is complete pulpectomy or extraction, not antibiotics alone.