Case Selection: 

Patient expectations
History
Examination:
General

Occlusion and parafunction
Special tests:
Vitality
Radiographs
Study casts

 

Patient factors:

 

Tooth factors:

  1. Missing teeth, position and number
  2. Condition of abutment teeth: Traumatized abutment teeth appear to carry a higher risk of a debond, probably due to loss of enamel and a greater area of dentine for bonding.

Fixed-Fixed design:

fixed–fixed design’s higher failure rate is thought to be due to differential abutment movement resulting in debond of one retainer. The high stresses involved place great demands on the rigidity of the framework, which is considered important for longevity of
resin-bonded retainers.

Debond has the potential to lead to caries, when the patient is unaware that debonding has occured.
Occlusion:

Studies:

Djemal et al 1999.

Median survival of fixed–fixed designs has been given as 7.8 years, which is significantly shorter than the 9.8 years quoted for the cantilever design.

King et al 2015.
Pijuterssen et al. 2008

Interocclusal space creation:

  1. abutment tooth preparation;  (confined to enamel, space maintained by comp or gic)
  2. opposing tooth preparation; (at cementation)
  3. Dahl concept;
  4. orthodontic tooth movement with fixed appliances;
  5. in eccentric movement, addition of composite or metal to abutment or to
    other teeth.

Tooth preparation:

Enamel only.

If needed chamfer prep, guide plane preps. to remove undercuts and therefore increase  retention

maximum coverage, as close to incisal areas as possible in anteriors and maximum occlusal coverage in posteriors.
It is thought that this increased coverage will increase not only the bonding area but also the rigidity of the metal framework

contraindicate the use of RBBs:
– anterior diastemas
– long spans
– the presence of heavily restored abutment teeth