A prosthesis that requires minimal removal of tooth structure, particularly of intact, caries free abutment teeth as compared to conventional fixed partial dentures.

It involves bonding b/w etched enamel & metal casting.

Minimal removal of tooth structure. Minimal potential for pulpal trauma. Anaesthesia not usually required. Supragingival preparation. Easy impression making. Interim prosthesis not usually required. Reduced chair time. Reduced patient expense.

Rebonding possible. removal of retainer by Monobevel chisel. Ultrasonic scalers

1955 Buonocore described acid etching of enamel.

Bonded ponticNatural or acrylic teeth were bonded to proximal and lingual surfaces of abutment teeth with composite resin.

1973 Rochette 1977 Howe & Denehy Livaditis

Drawbacks Weakening of metal retainer by

perforations. Exposure to wear of resin at perforations. Limited adhesion of metal provided by

perforations.

50% fail in 110 months

Cast perforated resin retained FPDs cont.

”Maryland bridge” Thompson & Livaditis (Univ. of Maryland) developed a technique for electrolytic

etching of Ni-Cr and Cr-Co alloy.

Advantages Retention is improved because resin to

etched metal bond is substantially stronger than resin to etched enamel. The retainers can be thinner and still resist flexing.

The oral surface of cast retainers is highly polished and resists plaque accumulation.

First generation of resin cements – Comspan was used.

by Moon in 1987 “Lost Salt Crystal “ technique, Alternative technique using Cast

Mesh Pattern

1990 Japan Super Bond (Sun Medical, Osaka, Japan)

Could not be used with noble alloys. Panavia (Kuraray co., Osaka, Japan) has sown excellent bonds to air abraded

Ni-Cr & Co-Cr alloys as well as tin plated gold &gold palladium based alloys

Roactec system

Roactec system Initially particle abrasion with 120um

alumina particles followed by abrasion with Silicate particle containing alumina.

Reduced restoration longevity. Enamel modifications are required.

Require extensive moisture control.

Space correction is difficult. Good alignment of abutment teeth is

required. Aesthetics is compromised on posterior

teeth.

Replacing missing anterior teeth in children, adolescents and medically compromised patients.

Short span. Unrestored abutments. Single posterior teeth. Periodontal splinting. Stabilizing dentitions after

orthodontics.

Para functional habits. Long edentulous spaces. Restored or damaged abutments. Compromised enamel. Significant pontic width discrepancy. Deep vertical overlap. Nickel allergy.

Basic principles The prosthesis should have a

distinct path of insertion with axial reduction and guide planes.

Resistance form by Preparation encompassing

180degress of tooth

Proximal grooves and slots. Occlusal rest seat. Occlusal clearance of 0.5 mm in

anterior teeth. Definite gingival margin.

High speed hand piece Articulating ribbon. Small wheel and short needle

diamonds. Flat end and round end tapered

diamonds.

Maxillary central incisor

Maxillary central incisor

Maxillary central incisor

Maxillary canine Maxillary first premolar

Mandibular MandibularSecond premolar First premolar

Maxillary Mandibular first First Molar Molar

Wax the framework and cast in Ni-Cr alloy.

Build up pontic in porcelain, fire it and contour it.

Evaluate the restoration clinically. Cleaning of casting is finished by

abrading it with aluminum oxide.

Abraded FPD placed in detergent in ultrasonic unit.

Tin plating Cleaning of abutments.

Etchant application.

Drying Primer liquids

Primer application Resin pastes

Applied resin. Oxyguard

application

Final restoration.