Prosthodontics & Occlusion · patient case question
What is the principal advantage of this attachment over a conventional extracoronal clasp?
Patient case: Attachment-Retained Partial Denture
Patient: 47-year-old female
Chief Complaint: “I don’t want a metal clasp showing when I smile.”
Background: Missing #18, #19, and #20 on the left with a dentate right side — a mandibular Kennedy Class II arch. Generalized moderate chronic periodontitis, currently stable after non-surgical therapy: probing depths 3–5 mm, no bleeding on probing, grade I mobility on the abutments.
Medications: None
Vital Signs: BP 118/74 mmHg · HR 70 bpm · RR 16 · T 98.6°F
Findings: An attachment-retained removable partial denture is planned, using an intracoronal (precision) attachment within a splinted crown on #21 rather than an extracoronal clasp. A radiograph of an existing prosthesis on the contralateral side shows a radiopaque box-and-key interface between a retainer and an adjacent unit.
Show answer and explanation
Correct answer: C. Improved esthetics — no visible clasp arm on the buccal surface
- A. Incorrect. Preparation is more demanding. The abutment must be prepared with enough depth to house the matrix without encroaching on the pulp, which frequently requires endodontic treatment and a full-coverage restoration.
- B. Incorrect. Repair is more difficult, not less. A fractured attachment component often requires remaking the crown or replacing proprietary parts.
- C. Correct. Retention is generated inside the crown contour, so no metal component crosses the visible buccal surface. This is the reason the technique is chosen and it directly addresses her chief complaint.
- D. Incorrect. Precision attachments are considerably more expensive, requiring specialized components and precise laboratory work.
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