Resin-bonded bridges

Question 1

What is an RRB?

Answer 1

A fixed prosthesis that’s bonded to one or more unprepared (or minimally prepared) natural teeth.

Question 2

What are the advantages of an RRB?

Answer 2

\+ fixed
\+ conservative
\+ no LA required
\+ short clinical time
\+ relatively inexpensive
\+ reversible/diagnostic

Question 3

What are the disadvantages of an RRB?

Answer 3

• aesthetic issues (greying of abutment tooth, metal showing over incisal edge)
• if a try-in bridge is used it’s difficult
• temporising is difficult
• risk of debond and failure higher than in conventional bridgework (92% failure related to debond, 4% to metal fatigue, 2% to caries)
• technique sensitive

Question 4

Indications for RRB?

Answer 4

• ideally single tooth replacement
• unrestored abutment teeth or minimally restored
• sufficient good quality enamel for bonding
• intermediate prior to implant placement in young patients

Question 5

Contraindications for RRB?

Answer 5

• heavily restored abutment tooth
• teeth that lack sufficient good quality enamel
• poor OH and isolation
• translucent incisal edge
• excessive occlusal loading/bruxism

Question 6

What are the different designs?

Answer 6

• cantilever (best option if only replacing single tooth)
• fixed-fixed (can provide period splinting, oath retention, can restore multiple missing teeth, when replacing anything other than anterior or premolar, differential movement of abutment teeth can cause a debond)
• hybrid (one side conventional abutment and other side RRB, a movable joint between the pontic and conventional fixed retainer can be used to join the two retainers)

Question 7

What’s the survival time of RRB’s?

Answer 7

According to King 2015, 80.4% RRB’s lasted 10 years.

Question 8

How could you create space for the retainer?

Answer 8

• reduce the abutment tooth
• reduce the opposing tooth
• ortho
• ‘Dahl’ approach

Question 9

What is the Dahl approach?

Answer 9

The Dahl Concept refers to the relative axial tooth movement that is observed when a localised appliance or localised restorations are placed in supra-occlusion and the occlusion re-establishes full arch contacts over a period of time.

Question 10

How can the Dahl approach be used with RRB’s?

Answer 10

If there’s not enough space, the RRB can be cemented high with little or no tooth prep. The occlusion should re-establish via intrusion of abutment teeth and eruption of other teeth. This is the preferred option if there’s not enough space, unless the pt has perio or is occlusally aware.