Dr. Praveen Srikantachary
12.05.2015
•A fixed dental prosthesis that is luted to tooth
structures, primarily enamel, which has been etched
to provide mechanical retention for the resin
cement (GPT-8)
Primary goal of resin retained FPD is the
replacement of missing teeth and maximum
conservation of tooth structure.
Introduction :
Acid etch bridge is an alternative procedure to conventional
fixed partial denture.
Acid etch fixed partial denture lead to ultraconservative
replacement of missing tooth.
History :
Introduction of acid etch technique was done by Buonocore in
1955.
Bowen in 1962 developed BIS-GMA composite resin which
can adhere to etched enamel.
 Alain L. Rochette in 1973 first time combined mechanical
retention with silane coupling agent to produce adhesion to
metal.
 He developed a bridge called Rochette bridge in which he used
wing like retainer with funnel shaped perforations through
them to enhance resin retention.
 Virginia bridge was described by Moon and Hudgins where
they produced a rough retainer by incorporating salt crystals
into retainer pattern.
 Maryland bridge was given by Livaditis and Thompson where
they used a 3.5% solution of nitric acid with a current of 250
mA /cm2 for 5 minutes followed by immersion in 18%
hydrochloric acid solution in an ultrasonic cleanser for 10
minutes.
Rochette resin-bonded fixed
denture
Maryland resin-bonded fixed partial
denture
 To etch internal surface of solid base metal retainer for resin
bonded fixed partial dentures. This type of etched metal
prosthesis frequently called maryland bridge.
Synonyms :
1) Adhesive bridge
2) Rochette bridge
3) Maryland bridge
4) Resin bonded retainer
5) Acid etched bridge
EVOLUTION OF RESIN BONDED PROSTHESIS
Resin bonded prosthesis
Clinical direct
Natural tooth
Laboratory indirect
Resin tooth
Acrylic
Orthodontic
pads
Composite
Accessory retention
-Undercuts
-Pins
-Mesh
-Wire
Rochette Retention Combined
bead
pitted/reten
tion bead
Mesh
Pitted
Macromechanical
Cast
porcelain
Cast
framework
Lingual
attachment
Electrolyticall
y etched
Proximal
attachment
Tin plated
Chemical
etch
Micromechanical
Sandblast
Porous
metal
copings
Sandblast
oxidized
Silane
coupling
Chemical
Micromechanical
• Indications,
• Replacement of missing anterior teeth in
children and adolescents.
• Short span.
• Unrestored abutments.
• Single posterior teeth.
• Significant crown length.
• Excellent moisture control.
• Contraindications,
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Parafunctional habits.
Long edentulous span.
Restored or damaged abutments.
Compromised abutments.
Significant pontic width discrepancy.
Deep vertical overlap.
Nickel allergy.
• Advantages,
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Minimal removal of tooth structure.
Minimal potential for pulp trauma.
Anesthesia not usually required.
Supragingival preparation.
Easy impression making.
Provisional not usually required.
Reduced chair time.
Reduced patient expense.
Rebond possible.
• Disadvantages,
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Reduced restoration longevity
Enamel modifications are required.
Space correction is difficult.
Good alignment of abutment teeth is required.
Esthetics is compromised in posterior teeth.
• Types,
• Cast perforated resin retained FPDs.
(mechanical retention – Rochette bridge).
• Etched cast Resin-retained FPDs.
(Micromechanical retention- “MARYLAND
BRIDGE”).
• Macroscopic Mechanical retention resin retained
FPDs (“Virginia bridge”).
• Chemical bonding resin retained FPDs (Adhesion
bridges).
• Cast perforated resin retained FPDs,
• Introduced by Rochette in 1973.
• Replacement of posterior teeth by Livaditis.
• Perforated retainers were used to increase resistance
and retention.
• Limitations,
• Weakening of the metal retainer by the
perforations.
• Exposure to wear of the resins at the
perforations.
• Limitation adhesion of the metal provided by the
perforations.
• Etched cast resin retained FPDs,
• Thompson and Livaditis at the at the university
of Maryland.
• Developed a technique for the electrolytic
etching of Ni-Cr and Cr-Co alloys.
• Advantages,
• Retention improved because the resin-to-etched
metal bond can be substantially stronger than
the resin-to-etched enamel. The retainer can be
thinner and still resist flexing.
• The oral surface of the cast retainers is highly
polished and resists plaque accumulation.
• Macroscopic Mechanical Retention Resin
Retained FPDs,
• Developed at the Virginia Commonwealth University
School of Dentistry.
• Involves a “lost salt crystal” technique.
• An alternative technique for the macroscopic retention is
the use of a cast mesh pattern on the internal surface of
the retainers.
• Fiber-Reinforced Composite Fixed
Prostheses,
• The restoration consists of a fiber reinforced
composite (FRC) substructure veneered with a
particulate composite material.
• Indications,
• Optimal esthetic result.
• Need to decrease wear of the opposite
dentition.
• Conservative abutment preparation.
• Desire for a metal free, nonporcelain
prostheses.
• Potential for bonding the prosthesis retainer
to the abutment teeth.
• Contraindications,
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Inability to maintain good fluid control.
Long span.
Parafunctional habits.
Patients with unglazed opposing porcelain.
Patients who abuse alcoholic substances.
Occlusal marking
articulation paper
Occlusal clearance
small wheel diamond
Lingual reduction
small wheel diamond
Countersinks : flatend tapered diamond
Proximal reduction :
flat-end tapered
diamond
Proximal reduction :
flat-end tapered
diamond
Lingual axial reduction
: round-end tapered
diamond
Cingulum groove :
short needle diamond
Proximal groove :
short needle diamond
Single path of insertion and
removal of prosthesis
Basic concept of wrap around
design
Practical example of wrap
around design concept