3. DEFINITION
A prosthesis that is luted to tooth structure,
primarily enamel , which has been etched to
provide mechanical retention for the
composite resin.
4. INTRODUCTION
These are prosthesis that requires minimal removal of
tooth structure , particularly for abutment teeth that are
intact and caries free.
The primary goal of the resin bonded FPD is the
replacement of missing teeth and maximum
conservation of tooth structure.
5. INDICATIONS
1. For abutment with sufficient enamel to etch for retention.
2. For splinting of periodontally compromised teeth.
3. Stabilizing of dentition after orthodontic treatment.
4. Medically compromised & adolescent patients.
5. Prolonged placement of certain prosthesis for correction of craniofacial
abnormalities.
6. CONTRAINDICATIONS
1. Patients with sensitivity to base metal alloys.
2. When abutment requires facial esthetics.
3. Abraded teeth.
4. Inadequate enamel surface to etch.
7. ADVANTAGES
1. Non invasive to dentin
2. Conservative
3. Decreased tissue irritation.
4. Less chairside time.
5. Reduced cost.
8. DISADVANTAGES
1. Demanding technique and tooth preparation.
2. Even minor laboratory errors cannot be corrected easily.
3. Plaque accumulation.
4. Intolerable bulky contour.
5. Not ideal for replacing more than one tooth.
6. The resultant aesthetic is not good.
10. ROCHETTE Bridge
It was the 1st resin prosthesis to be
developed.
Developed by:- Rochette in 1973
He used a wing-like retainer with
funnel shaped perforation with the
base towards the tooth surface.
11. ROCHETTE Bridge
The diameter of the funnel was greater towards the outside by 0.5mm.
Diameter towards outside- 1.5mm
Diameter towards tooth surface- 1mm
He also used silane-coupling agents for additional retention.
The major disadvantage of this design is external stress, abrasion &
marginal leakage.
12. MARYLAND Bridge
Developed by:- Livaditis & Thompson in 1981
He used electrolytic etching to provide micro-
mechanical retention to the non-perforated
base metal retainers which were bonded by
resin cement.
Micro-porosities were created by etching the
tissue surface of the retainer which provides
mechanical retention.
13. MARYLAND Bridge
In this method, of electrolytic etching the etchant used was 3.5% solution of nitric acid.
A current of 250mA/cm2 is supplied for 5 minutes.
This is followed by immersion of retainer in 18% HCL in an ultrasonic cleanser for 10mins.
Note: Before the etching is done, retainer is coated with paraffin wax in those areas that are not
to be etched.
Advantage:- It has good retention as compared to perforated ones.
Disadvantage:- Expensive & technique sensitive.
14. VIRGINIA Bridge
Developed by:- Moon & Hudgins in 1983
These are resin bonded fixed partial dentures which use particle roughened
retainers.
The retainer wax patterns are fabricated using resin.
Advantages:-
1. Even noble metal alloys can be used.
2. Surface treatment of retainer is not necessary.
15. VIRGINIA Bridge
Lost salt technique;
150-250 µm salt crystals are sprinkled on the cast prior to resin
fabrication.
The salt crystals get incorporated onto the tissue surface of the resin
pattern.
The salt crystals are dissolved by keeping pattern in ultrasonic cleanser.
The resin pattern is invested and cast.
Dissolved crystals will produce voids in the resin pattern.
These voids are reproduced in the cast metal retainer and they help in
mechanical retention.
16. CAST MESH FPD
A nylon mesh is placed over the
tissue surface of the retainer
wax pattern.
17. CAST MESH FPD
The mesh is placed on the cast before fabricating the wax pattern.
Now, the fabrication of the pattern is done at the mesh.
The mesh becomes incorporated and as casting is done it provides retention for
resin to metal.
Disadvantages:-
1. Nylon mesh may not adapt well to the cast during pattern fabrication.
2. The wax may not flow between the mesh locking all the undercuts.
18. ADHESIVE Bridge
Bonding of resin cement to metal is done.
Advantages:- High bond strength, fracture toughness & good clinical success.
Materials used for chemical bonding:-
1. Modified Bis GMA cement
2. Superbond
3. Rocatec system
Chemical bonding between the resin and the metal retainer can be produced by chemical
etching or tin-plating or using chemical adhesives.
19. ADHESIVE Bridge
Chemical etching;
A gel consisting of Nitric and Hydrochloric acids is applied to the internal surface of
the metal framework for approximately 25 minutes.
Tin plating;
Tin has the ability to form organic complexes with several specific adhesive resins
resulting in significantly greater bond strengths. Precious alloys can be plated with tin
and used as frameworks for resin retained fixed partial denture.
Composite resins play an important role in the bonding of the metal framework to
etched enamel.
20. POST INSERTION MANAGEMENT
All resin-bonded restorations should receive
significant attention after insertion.
Hence, frequent recall appointments should be
followed to ensure the success of the prosthesis.
21. CAUSES OF FAILURE
Inappropriate patient selection
1. Mal-alignment of tooth
2. Insufficient vertical length of abutment tooth
3. Inadequate enamel for bonding
4. History of metal sensitivity
5. Decreased labio- lingual dimensions of abutments
22. CAUSES OF FAILURE
Incomplete tooth preparation
1. Insufficient proximal and lingual surface reduction
2. Incomplete extension of retainer (less than 180°)
3. Lack of accommodation to mandibular protrusion
Bonding failure
1. Contamination
2. Prolonged mixing
3. Inappropriate luting agent
