Fabrication Of Three Unit Fixed Partial Denture Notes

Fabrication Of Three Unit Fixed Partial Denture

Instruments And Materials

Inlay wax
Sprue former
Casting ring
Ring liner
Sprue base/investment material

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Table of Contents

Distilled water
Brush
Furnace
Crucible
Tungsten carbide bur.

Fabrication Of Three Unit Fixed Partial Denture Procedure

Tooth preparation is done and an impression is made. Die preparation is done after pouring the impression. The wax pattern is prepared on dies by an indirect technique using inlay wax (type 2). Sprue former is attached at the maximum bulk of the wax pattern or on the nonfunctional cusp.

The casting ring liner is placed in the casting ring. It should be 3 mm short at both ends of the casting ring. The ring is placed over the sprue base to which the wax pattern is attached while the height is adjusted in such a way that the wax pattern is one-fourth inch away from the open end of the ring.

Investment material is mixed with mixing liquid and is painted on the wax pattern with the help of the camel paintbrush. Sometimes dry investment material is sprinkled on it to eliminate excess water if any. The ring is filled with remaining investment from the side of the ring allowing the material to flow uniformly against earlier investment painted over wax pattern, till the ring is completely filled with investment material.

Fabrication Of Three Unit Fixed Partial Denture die preparation

Fabrication Of Three Unit Fixed Partial Denture preparation of wax pattern

Fabrication Of Three Unit Fixed Partial Denture attachment of sprue formre on wax pattern

Fabrication Of Three Unit Fixed Partial Denture casting ring liner and sprue base and ring liner 3 mm short of open end of ring

Fabrication Of Three Unit Fixed Partial Denture wax pattern should be one fourth inch away from open end of the ring

Fabrication Of Three Unit Fixed Partial Denture painting of investment material on wax pattern

After the investment has been set, the ring is placed in the furnace and gradually heated at 650°C for an hour for wax pattern burnout. Alloy is melted in a casting crucible and allowed to flow in the mold formed after the burn-out procedure.

The melted metal is flown to the casting ring to take the shape of the restoration. Once the casting ring is cooled down to room temperature, divestment is done to remove casting from the ring. Sprue is cut and casting is checked on the

Fabrication Of Three Unit Fixed Partial Denture pouring the investment material to fill the casting ring completely

Fabrication Of Three Unit Fixed Partial Denture casting ring is placed in burn out furnace

Fabrication Of Three Unit Fixed Partial Denture metal in crucible and melted metal inserted in casting ring

Fabrication Of Three Unit Fixed Partial Denture metal flown into casting moild

Fabrication Of Three Unit Fixed Partial Denture casting after cutting the sprues

tooth fitting surfaces for any irregularities which will be eliminated using tungsten carbide burs. The opaque layer is applied on the casting coping to hide the metallic color of metal alloys and to improve esthetic. After the opaque layer dentine and enamel layers of porcelain are applied and occlusal anatomy is created. Finally, glazing is done to give the final finish and luster to the prosthesis.

Fabrication Of Three Unit Fixed Partial Denture cleaning of casting removal of investment material from all surfaces

Fabrication Of Three Unit Fixed Partial Denture application of dentine and enamel layer porcelain

Fabrication Of Three Unit Fixed Partial Denture application of dentine and enamel layer of porcelain

Fabrication Of Three Unit Fixed Partial Denture threee units PFM bridge after glazing

Note: The metallic cementation surface and porcelain occlusal surface.

Fabrication Of Three Unit Fixed Partial Denture Notes