2. • Introduction
• Introduce to minimize the main drawback of conventional
fixed partial dentures i.e destruction of sound tooth
structure.
• Development of acid etching of enamel to improve the
retention of resin led to the concept of resin bonded
FPDs.
• In these FPDs metal framework is like a wing attached to
the abutment teeth.
3. • Conventional FPDs
– Greater amount of sound
tooth destruction.
– Esthetically may not be
very pleasing
– Missing as well as
abutment teeth has to be
replaced.
• Resin bonded FPDs
– Adjacent tooth preparation
is minimal.
– Can be given in both
anterior and posterior
region because of its
pleasing esthetics.
– Only the missing tooth is
to be replaced.
5. 1. Rochette bridge
• Have funnel shaped perforations in the wings to
enhance retention.
• Combined silane coupling agent to produce adhesion to
the metal.
6. 2. Maryland bridge
• Adapted electrochemical pit corroding technique.
• 3.5 % soln of nitric acid for 5 minutes with current of 250
mA/crn^2 followed by immersion 18% hydrochloric acid
soln in a ultrasonic cleaner for 10 minutes.
• Resin-alloy bond strength of 27.3 MPa.
• Specific to nonberyllium nickel-chromium alloy.
• 2.9 times more retentive than perforated type.
7. • Technique sensitive, overetching produces electro
polished surface.
• Other surface treatment techniques are;
Nonelectrolytic technique of placing a nickel-chromium-
baryllium alloy in etching solution in a waterbath for an
hour.
Combination of etching with silane.
Air abrading metal to increase bonding strength.
8. 3. Cast mesh fixed partial denture
• Nonetching method
• A net-like nylon mesh is placed over the lingual surfaces
of abutment teeth in the cast the mesh is incorporated in
the retainer wax pattern.
• If the mesh blocked out by wax when investing retention
will be compromised.
9. 4. Virginia bridge
• Incorporation of salt crystals into retainers to produce
roughness in inner surface called as lost salt technique.
• Retainer pattern fabricated with resin with 1mm wide
crystal free zone around the outline.
• The salt is dissolved in water after the resin polymerizes,
cubic voids act as the retentive component.
• Aluminum oxide use as surface treatment to improve
bonding with resin.
10.
11. Resin cement
– First bonded restorations used unfilled resin for
retention.
– Unfilled or filled resins were used with perforated
retainers
– Thin film thickness resins were then introduced for
luting resin bonded FPDs
– Then the chemically active resin cements were
introduced they could adhere to metal surface
producing retention.
– Tin plated metal alloy had better bonding with
chemically active resins, air abrasion with aluminum
oxide particles was also employed.
12. Advantages
– No local anesthetic required because most tooth
preparation involves enamel.
– Supragingival margins.
– Minimal tooth preparation required
– Can be rebounded if the axial adhesion get loose.
13. Disadvantages
– Some amount of sound tooth structure has to be
lost.
– Questionable longevity
– No alignment correction is possible.
– A provisional prosthesis cannot be fabricated.
14. Indications
– Caries free abutment teeth
– Mandibular incisor replacement
– Maxillary incisors replacement
– Periodontally compromised abutment with
reinforcement of resistance features while preparing
the tooth.
– Single posterior tooth replacement.
16. Tooth preparation
– Axial reduction and guide plane on proximal surface
with slight extension onto the facial surface
providing faciolingual lock.
– Light chamfer finish line 1mm supragingivally.
– To enhance resistance 180 degree tooth
preparation is to be done.
17.
18. – Large surface area is involved to improve bonding.
– Occlusal clearance sometimes employed.
– Vertical stops are placed like flat countersinks on
lingual surface of incisors, cingulum rest on canine,
occlual rest seat on premolars and molars.
– Grooves are used near the facioproximal line angle
and opposite side of cingulam or lingual cusp
creating a wrap around effect.
– For mandibular premolars full coverage of lingual
cusp is done .
19. – Molars also have lingual cusp coverage
preparation, inlays can be attached to anatomical
groves on distolingual surface, axial coverage
extending through proximal contact to connect with
occlusal rests.
20. • Armentarium
– High speed hand piece
– Articulating ribbon
– Small wheel and short needle diamond bur
– Flat-end and round-end tapered diamond bur.
