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Prosthodontics & Occlusion · patient case with 2 questions

Loose anterior bridge with an open margin

Patient: 58-year-old woman.

Chief complaint: My bridge is loose and I can see metal at the gumline.

History: Bridge placed roughly ten years ago spanning the maxillary right canine to the maxillary left lateral incisor.

Findings: Visible open margin with exposed metal on the canine retainer, described as an over-contoured and poorly finished preparation margin. Caries at the canine margin. The prosthesis moves under load.

Question 1

What is the FIRST step in management?

  1. Recement the bridge as it is
  2. Adjust the occlusion and review in six months
  3. Remove the bridge
  4. Restore the marginal caries without removing the bridge
Show answer and explanation

Correct answer: C. Remove the bridge

  • A. Recementing over active caries seals bacteria against the abutment and guarantees progression to pulpal involvement.
  • B. Occlusal adjustment addresses none of the three problems present.
  • C. CORRECT. A loose prosthesis with an open margin and caries beneath it must come off before anything can be assessed. Only with the bridge removed can the extent of caries, the remaining tooth structure, and the restorability of the abutments be judged.
  • D. The caries is subgingival at a retainer margin; it cannot be adequately accessed or sealed with the bridge in place.

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Question 2

After removal, what is the appropriate definitive treatment?

  1. Re-prepare the canine margin and recement the original bridge
  2. Restore the caries, re-prepare the margin on the canine, and fabricate a NEW bridge
  3. Place implants and discard both abutments
  4. Recement the original bridge once the caries has been excavated
Show answer and explanation

Correct answer: B. Restore the caries, re-prepare the margin on the canine, and fabricate a NEW bridge

  • A. Re-preparing the tooth changes the preparation geometry, so the old casting cannot fit it. This is the essential concept in the item.
  • B. CORRECT. Caries control and foundation restoration come first, with endodontic assessment if the excavation runs deep. Then the abutments are re-prepared to a sound, properly finished margin, a provisional is placed, and a NEW prosthesis is made. The original casting was generated from a preparation that no longer exists.
  • C. Discarding restorable abutments in favour of implants is unnecessarily destructive.
  • D. A prosthesis with a demonstrated marginal misfit will not seal on recementation regardless of caries removal.

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