Prosthodontics & Occlusion · single question
A distal attachment on a premolar for a removable partial denture — tooth 20 has grade 1 mobility and a wide PDL with no response to thermal testing. What type of connector is this distal attachment?
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Correct answer: A. Non-rigid attachment
A NON-RIGID ATTACHMENT (also called a stress-breaker or precision attachment connector) allows controlled movement between parts of the RPD, reducing torque on the abutment tooth. With a mobile tooth (grade 1 mobility) and a wide PDL (indicating stress), using a non-rigid connector distributes forces differently than a rigid clasp, protecting the compromised abutment from excessive torquing forces.
- A. CORRECT. A non-rigid (stress-breaking) attachment allows slight movement between the abutment and the RPD framework. This is appropriate when the abutment tooth has mobility or compromised periodontium, as it reduces torquing forces on the tooth.
- B. INCORRECT. Infrabulge refers to a clasp arm approaching from below the survey line (into the undercut) — again, clasp position terminology, not connector type.
- C. INCORRECT. Suprabulge refers to the path of a clasp arm that approaches the tooth from above the survey line — it describes clasp position, not the type of major connector.
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