Prosthodontics & Occlusion · patient case question
What is the MAIN PURPOSE of an intracoronal attachment?
Patient case: Intracoronal attachment prosthesis in a patient on denosumab
Patient: Female, 72 years old
Chief complaint: “Something feels loose on this side and the tooth has changed colour.”
History: Osteoporosis treated with denosumab, six-monthly injections for the past four years. No other systemic disease.
Findings: Intracoronal (precision) attachment retaining a removable partial denture. The abutment tooth shows extensive vertical bone loss, greater than the radiograph shown suggests. The tooth does not respond to pulp testing.
Show answer and explanation
Correct answer: A. Retention of the removable prosthesis
- A. CORRECT. A precision attachment is fundamentally a RETENTIVE element. It consists of a matrix housed within the abutment crown and a patrix on the partial denture, and the friction or mechanical lock between them resists dislodging forces along the path of insertion — which is precisely the definition of retention.
- B. Bracing against horizontal force is the job of rigid reciprocal components — proximal plates, guiding planes and minor connectors. An attachment contributes some stability but that is not its purpose.
- C. Support, meaning resistance to vertical seating forces, is provided by the rests and by the denture-bearing mucosa, not by the attachment.
- D. Attachments make fabrication considerably MORE demanding, not less. They require precise parallelism, adequate abutment reduction and greater laboratory expertise, and they are costly to maintain.
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