Clinical Skills: Fixed Prosthodontic Options

Course Overview

  • Course: Clinical Skills B (DSUR301501)
  • Institution: School of Dentistry, Faculty of Medicine and Health, University of Leeds
  • Collaborating Institution: Leeds Teaching Hospitals NHS Trust

Objectives

  • Familiarize with key terminology:
    • Fixed bridges, components, types
  • Understand different types of bridges:
    • Conventional bridges
    • Resin retained bridges
  • Case selection, treatment planning, and prosthesis design
  • Analyze present research evidence supporting treatment decisions

Terminology

  • Fixed Dental Prosthesis: A type of dental prosthesis
    • Definition: Any dental prosthesis that is luted, screwed, or mechanically attached to natural teeth, tooth roots, and/or dental implant abutments.

Components of Fixed Dental Prostheses

  • Abutment: The structure that receives pressure; could be a natural tooth or a component of a dental implant.
    • Types:
    • Single Abutment
    • Cantilevered Fixed Bridge
    • Double Abutment Fixed-Fixed Bridge
  • Pontic: An artificial tooth that replaces a missing natural tooth.
    • Designs:
    • Modified Ridge Lap (most common)
    • Ovate (aesthetic, requires surgery)
    • Sanitary (hygienic design)
  • Retainer: The part of the bridge cemented to the abutments.
    • Forms:
    • Full crowns
    • ¾ crowns
    • Inlays/onlays
    • Metal wing (for resin-retained bridges)

Types of Conventional Bridges

  1. Fixed-Fixed Bridges: Pontic is supported by two abutments.
  2. Cantilever Bridges: Pontic retained by a single crown, inlay, or onlay.

Indications for Conventional Bridgework

  • Heavily restored abutments
  • Well-motivated patients with excellent plaque control
  • No active caries lesions
  • Stable periodontium and ability to maintain bridgework
  • Small edentulous spaces and replacement bridge work

Contraindications

  • Unrestored abutments
  • Poor motivation, active caries, and periodontitis
  • Poor manual dexterity for cleaning
  • Large edentulous spaces and contact sports involvement

Resin Retained Bridges

  • Definition: The pontic is retained by a metal retainer relying on cement.

Indications for Resin Retained Bridges

  • Sound, unrestored abutments
  • Well-motivated patients with excellent plaque control
  • No active caries lesions and stable periodontium
  • Small edentulous spaces

Contraindications

  • Heavily restored abutments, low crown height
  • Poor motivation and active caries or periodontitis
  • Poor manual dexterity and large edentulous spaces
  • Bruxism and contact sports involvement

Design Features

  • Abutment Preparation:
    • Minimal preparation for better bonding to enamel layer.
  • Maximal Surface Area Coverage: To enhance retention.
  • Use Rigid, Non-Precious Metal Wing Retainers: At least 0.7-0.8mm thickness.
  • Canines and Molars: Ideal bridge abutments.

Clinical Workflow for Bridges

Conventional Bridges

  1. Primary Impression
  2. Diagnostic wax-up on study model
  3. Abutment preparation and Master Impression (silicon)
  4. Temporisation
  5. Bridge construction and trial with cementation

Resin Retained Bridges

  • Similar steps as conventional but discuss wax-up and explain visibility of metal wing to patients.

Take Home Messages

  • Well-maintained teeth have a long lifespan.
  • Prosthodontic procedures have biological and technical consequences.
  • Planning is crucial: diagnostic wax-up and selection of occlusal scheme before starting.
  • Choose the least destructive technique and consider the Shortened Dental Arch concept for better outcomes.

Complications and Survival Rates

  • Survival Rates:
    • Conventional Cantilever: 91% at 5 years, 81.8% at 10 years.
    • Resin Retained Cantilever: 87.7% at 5 years, 65% at 10 years.
    • Conventional Fixed-Fixed: 94% at 5 years, 92% at 10 years.
  • Common Reasons for Failure:
    • Debonding, caries, endodontic issues, and fractures.

Research Findings

  • Recent evidence emphasizes the superior longevity of resin-retained bridges with minimal preparation, supporting better patient satisfaction rates.