The document discusses resin bonded fixed partial dentures (RBFPDs), also known as adhesive bridges. It covers the history, definitions, classifications, indications, contraindications, and various types of RBFPDs including bonded pontics, cast perforated resin-retained FPDs, etched cast resin-retained FPDs, and macro-mechanical retention resin-retained FPDs. Preparation designs for anterior and posterior teeth are described. Bonding involves cleaning, etching, priming, and using composite resin cements.

1. RESIN BONDED FPD’S (PART-I)
DR SHRIMANT RAMAN
DEPARTMENT OF PROSTHODONTICS

2. Introduction
• The need for conservation of natural tooth
structure has always been the desired but
elusive goal in dentistry.
• In fixed partial prosthodontics this goal
manifests itself with the continued interest
and development of Resin bonded fixed
partial dentures (RBFPD) or Adhesive bridge

3. Definition
“A fixeddental prosthesis thatis lutedto tooth structures,
primarily enamel, which has been etchedto provide
mechanicalretention for theresin cement.”
- GPT - 8

4. Indications
• Replacement of missing anterior teeth in children and adolescents
• Short span edentulous space & Significant crown length
• Single posterior tooth replacement
• Splinting periodontally compromised tooth
• For medically compromised patients – for whom prolonged dental
procedures are not advisable
• As an interim bridge – for eg following periodontal surgery
• As a space maintainer

5. Contraindications
• Parafunctional habits
• Long edentulous spans
• Restored or damaged abutments
• Compromised enamel
• Pontic width discrepancy
• Deep vertical overlap
• Nickel allergy
• When facial esthetics of the abutments require improvement

6. DATE CONTRIBUTION PERSONEL
1955 Bonding to enamel Buonocore
1962 Development of composite resin Bowen
1973 First bonded cast alloy framework Rochette
perforated retainer for periodontal
splinting
1976 Electrolytically etched dental alloy Dunneries Bick
1977 Improved splint for missing anterior Howe Danley
teeth
1981 Developing of etched metal bridge Gerald McLaughlin
History

7. Classification
Of Resin
Bonded FPD
Bonded Pontics
Cast perforated resin-
retained FPDs
(mechanical retention)
Maryland bridge
Etched cast resin-
retained FPDs (micro-
mechanical retention)
Virginia bridge
(Macro-mechanical
retention resin-retained
FPDs)
Adhesion bridges
(Chemical bonding resin-
retained FPDs)
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8. BONDED PONTICS
ACRYLIC RESIN
DENTURE TOOTH
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Advocated by Ibsen
(1974) and
Buonocore in (1975)

9. COMPOSITE RESIN
CROWNS
• Simonsen:1978
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10. 5/20/2022 10
Natural Tooth
Pontic
Simonsen, Davilla and Gwinnet

11. Drawbacks :
• Natural teeth and acrylic teeth used as pontics
• Composite resin connectors were brittle and
required supporting wire or a stainless steel
mesh framework
• Limited lifetime
• Limited to short anterior Spans

12. Cast Perforated Resin Retained FPD
• In 1973, Rochette introduced the concept of bonding metal to teeth using
flared perforations of the metal casting to provide mechanical retention.
• He used the technique principally for periodontal splinting but also included
pontics in his design

13. • Perforated lingual coverage
• Mechanical retention
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HOWE AND DENEHY (1977)
• Used cast –perforated metal
retainers bonded to abutment
teeth and metal ceramic pontics.
• Covered maximum area of lingual
surface but with little or no tooth
preparation.
• Bonded with composite resin.

14. • Replacement of
posterior teeth –
Livaditis
• Extension –
interproximally and onto
occlusal surfaces.
• Tooth modification
• Survival rate -3 years
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15. Drawbacks :
• Failure through the resin projections into the
perforations
• Wear of composite resin
• Weakening of alloy framework
• Thick lingual retainers
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16. Etched Cast Resin Retained FPDs
(Maryland Bridge)
• Tanaka et al (1979)
• Livaditis and Thompson
(1980)…Baltimore college of
dentistry, University of Maryland
• Study for etching conditions of non
berylium Ni-Cr alloys.
• Micromechanical retention
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17. 5/20/2022 17
Resin-alloy bond
strength:27.3 Mpa

18. Etching Apparatus
• Electrodes: 0.036 inches stainless steel
orthodontic wire or a copper wire 12-14 gauge
• Electrolytes used vary according to metal type.
Ni-Cr Be alloys: 10% sulphuric acid.
Ni-Cr/Co-Cr: 3.5% nitric acid
• D.C. power supply
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19. TWO STEP TECHNIQUE OF
ELECTROLYTIC ETCHING
Used a 3.5% solution of nitric acid with a current of
250mA/sq cm followed by immersion in an 18% hydrochloric
acid solution in an ultrasonic cleaner for 10 minutes.
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20. ONE-STEP TECHNIQUE
Combined solution of
sulfuric and
hydrochloric acids
placed in an activated
ultrasonic cleaner for
95 seconds and the
electric current is
passed (McLaughlin)
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21. DRAWBACKS
• Technique sensitive
• Lab dependent
• Varies with metal type
• Prone to contamination
• Cannot be done with noble metal alloys
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22. Chair side etching unit
The bridge is clipped to the anode
of etching unit and touched with an
absorbent point soaked in the
etching solution and connected to
cathode.
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23. Base metal alloys for resin bonded bridges:
Nickel-
chromium-
beryllium
Etched in 10%H2SO4
220-300mA/sq cm
3-6 mins
Ultrasonic cleaning in
18%HCl
Nickel-
chromium
Etched in 0.1-0.5M HNO3
250-400mA/sq cm
5 mins
Ultrasonic cleaning in
18%HCl
Cobalt-
chromium
Etched in a mixture of HCl and
HNO3
200-300mA/sq cm
7-8 mins
Ultrasonic cleaning in
18%HCl
Silver-
palladium
Etched in mixture of HNO3
NaNO3 and NaF
300mA/sq cm
1 ½ to 3 mins
Ultrasonic cleaning in
H2SO4 and H3PO4
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24. Macroscopic mechanical retention resin-
retained FPDs
Virginia bridge
Cast mesh FPD
Virginia bridge:
- Developed at the Virginia Commonwealth University
School of dentistry
- Was advocated first by Moon and Hudgins et al in 1984
- It involves the ‘lost salt technique’

25. Lost salt technique:
• On the working cast, the abutments are coated with a model
spray and a lubricant is then applied
• Within the outline of the retainers, specially sized salt crystals
(150-250m) are sprinkled over the surface in a uniform
monolayer, leaving a 0.5mm border without crystals at the
periphery of the pattern
• Followed by the application of the resin pattern

26. • When the resin has
polymerized, the patterns are
removed from the cast,
cleaned with a solvent and
then placed in water in an
ultrasonic cleaner to dissolve
the salt crystals
• This leaves cubic voids in the
surface that are reproduced in
the cast retainers

27. Cast mesh FPD:
• A net-like nylon mesh can be placed over the lingual surfaces of
the abutment teeth on the working cast
• It is then incorporated into the retainer wax pattern, with the
undersurface of the retainer becoming a mesh-like surface when
the retainer is cast

28. • Eliminates the need for etching and permits
the use of noble-metal alloys
• Disadvantages – tends to be stiff, difficult to
adapt, and the wax can block into the
undercuts

29. Chemical (Adhesive Bridges)
• Adhesion bridges
• Surface treatment of metals
• Sand blasting
• Tiller et al (1985)
• Used alumina (50 microns) for sand blasting

30. The common adhesive systems:
• The first to be developed – PMMA powder and MMA
monomer with the adhesion promoter 4-META (4-
methacryloxyethyl-trimellitic anhydride) – [Super bond]
- Has the highest initial bond strengths of any adhesive systems
- Other advantages – lower elastic modulus, higher fracture
toughness
- Less brittleness and good clinical results have been observed

31. • Panavia – Bis-GMA based composite resin modified
with adhesion promoter MDP – methocryloxydecyl
dihydrogen phosphate
• Has shown excellent adhesion to air-abraded Ni-Cr
and Co-Cr alloys
- Improved tensile bond
strength

32.  Panavia F – is a dual cure system
• Releases fluoride
• Has a self etching primer system
• Bonding to both enamel and dentin

33. • Rocatec :
 Initially particle abraded with 120m alumina
 Followed by abrasion with a special silicate
particle containing alumina
 Then silane and the composite resin are
applied.

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Preparation Of Anterior Tooth

35. 5/20/2022 35

36. Preparation of Posterior Tooth
FEATURES OF
PREPARATION IN
POSTERIOR R.B.P.
- 180 degree wrap
around.
- 1 mm deep occlusal
rests.
- Definite path of
insertion.
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37. • Conceptually anterior and posterior
preparations are similar, except that the
design and retentive features for posterior
teeth are more extensive because of tooth
morphology and the need to resist forces of
posterior occlusion

38. Rest seat
• Depth = 1mm
• B-L width = 2.5 to 3
mm
• M-D width = 1 to 1.5
mm

39. • Use a tapered diamond bur to reduce the lingual and
proximal heights of contour and establish the occluso-
gingival path of insertion.
• The lingual finishing line should be 1.0 mm above the
crest of the gingiva.
• The proximal "wings" of the casting should be
approximately 3.0 to 5.0 mm in occlusogingival length
and should never impinge on the soft tissue.

40. BONDING
• Cleaned using pumice and water
• 37% phosphoric acid for 15 seconds
• Composite resin cements
• Metal primer or silane on fitting surface of casting
followed by by application of bonding agent on enamel
surface
• Resin cement is mixed and place on internal surface of
retainer follwed by insertion of prosthesis