Endodontics · single question
Same case (tooth 20, no thermal response, mobile, wide PDL). What is the best next step for tooth 20?
Show answer and explanation
Correct answer: B. Root canal treatment
Tooth 20 has a wide PDL space (indicating increased stress/inflammation), grade 1 mobility, and NO RESPONSE to thermal testing = PULPAL NECROSIS. A necrotic tooth with a widened PDL requires ROOT CANAL TREATMENT to eliminate the pulpal infection, reduce periapical inflammation, and allow PDL healing. Without RCT, the infection will progress. Since the tooth is restorable and will serve as an RPD abutment, RCT is the appropriate treatment before RPD fabrication.
- A. INCORRECT. Extraction would eliminate a potentially valuable abutment tooth. If the tooth is restorable with adequate bone support, RCT is preferred before extraction.
- B. CORRECT. The tooth is non-responsive to thermal tests = pulpal necrosis. The wide PDL indicates periapical involvement. Root canal treatment is indicated to eliminate the infection and stabilize the tooth, especially since it will serve as an important RPD abutment.
- C. INCORRECT. Monitoring a necrotic tooth with periapical involvement (widened PDL) allows the infection to progress — intervention is needed.