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Prosthodontics & Occlusion · patient case with 1 question

Bridge that has debonded after eight years

Patient: Male, 58 years old

Chief Complaint: “My bridge came off in one piece while I was eating.”

Background: Three-unit bridge placed eight years ago. No pain. No systemic disease.

Vital Signs: BP 130/82 mmHg · HR 74 bpm

Findings: The prosthesis has debonded intact. Clinical photographs show markedly OVER-PREPARED abutments — short, heavily tapered, with the margins finishing on existing restorative material rather than on sound tooth. Both abutments are vital, caries-free and periodontally sound. Radiographs show no periapical change.

Question 1

What is the most appropriate way to address the complaint?

  1. Rebuild the abutments with a bonded core material, then re-prepare them to a correct form for a new bridge
  2. Place posts and cores in both abutments to gain retention
  3. Extract both abutments and place implants
  4. Simply re-cement the existing bridge with a stronger cement
Show answer and explanation

Correct answer: A. Rebuild the abutments with a bonded core material, then re-prepare them to a correct form for a new bridge

  • A. CORRECT. The abutments are SOUND but MIS-SHAPED. Restoring them with a bonded composite or glass ionomer core rebuilds the lost bulk, and re-preparing to a correct form — near-parallel walls, adequate occlusogingival height, and margins on SOUND TOOTH rather than on restorative material — recreates the retention and resistance form that was missing. That is the direct fix for the actual cause of failure.
  • B. Posts are for teeth that are ROOT-TREATED and have lost most of the coronal dentine. These abutments are VITAL. Cutting post space into a vital tooth to gain retention devitalises it, removes radicular dentine and invites vertical root fracture.
  • C. Extraction discards two vital, caries-free, periodontally sound teeth. It is the most destructive option available and treats a restorative problem surgically.
  • D. Re-cementing an over-tapered, short preparation reproduces the failure. Cement compensates for nothing; the geometry is what retains a restoration.

Note: What this item adds is what to DO about it. Note the specific finding that margins sat on RESTORATION rather than tooth — a margin on old restorative material has no reliable seal and no bonding substrate, and it is an independent and often-missed cause of recurrent failure.

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