Pontics for gold-acrylic resin fixed partial dentures

PONTICS

FOR

GOLD-ACRYLIC

RESIN

FIXED

PARTIAL

DENTURES

BEN PINE, D.D.S., A.B. New York, N. Y. RESIN PONTICS are unsatisfactory for use in contact with the gingival tissue of edentulous spaces. Removal of fixed restorations with acrylic resin pontics in contact with soft tissue almost invariably, shows reddened gingivae, and at least a slight odor emanates from the resin. Apparently the gingival tissue has less tolerance to acrylic resin than to less porous materials such as porcelain, platinum, and gold. Regardless of the material, the ideal pontic makes light, uniform contact with the edentulous ridge, and sufficient space exists between the pontic and the abutment tooth at the ridge for cleaning purposes. Narrow buccolingual tissue surface coverage by the pontic is desirable, e.g., the “bullet-shaped” pontic. Well-fitted glazed porcelain is the best-tolerated material for pontics. However, porcelain has the disadvantage of friability, and it is difficult to repair. The tissues have good tolerance for well-fitted platinum or gold. This procedure utilizes the advantages of gold or platinum and the esthetic advantages and strength of acrylic resins.

A

CRYLIC

TECHNIQUE

FOR

PLATINUM-BASE

PONTICS

A layer of 0.006 inch platinum foil is burnished over the edentulous space on the cast. A thin layer of 18K gold solder is flowed over the platinum on the side which will be away from the tissue. The solder prevents distortion of the platinum foil and also aids in the attachment of the gold that will be cast to the foil. The solder is trimmed, and the mesial, occlusal, and distal parts of the pontic are waxed to the reinforced platinum matrix. A thin layer of wax is flowed over the solder. Thus, an enclosed ring is developed which is open buccolingually and which wiI1 be filled with acrylic resin (Fig. 1). The pattern, including the platinum matrix, is removed from the cast, invested, and cast in a hard gold. The casting is polished, reseated on the articulated cast, and soldered to the other units of the restoration. TECHN.IQUE

FOR

GOLD-BASE

PONTICS

The platinum foil and solder are not necessary for gold-base pontics. A ring of wax is placed on the mesial, occlusal, distal, and tissue surfaces of the cast. The wax pattern is invested and cast in gold. In this procedure, gold rather than platinum will contact the edentulous gingivae. the

Read First

before District

the Columbia Dental society

Study Club of Advanced in New York, N. Y. 347

Dental

Science

in

New

York,

N.

Y.,

and

348

J. Pros. Den. March-April, 1962

PINE

c-

_ c - _ _ _ _ Mesial _ __ _ __ -0cclusal - Distal

abutment bevel abutment

opening ‘.\ a‘,. xc-Buccolingual -,Gingival bevel Fig. l.-The wax-up center of the ring will retention for the resin.

for the metal be filled with

part of the pontic forms a ring. The acrylic resin. The interior slope of

open space in the the ring provides

Retention for the resin is obtained similarly for either the platinum-base or gold-base pontics. The buccal and lingual surfaces underneath the occlusal metal work are beveled, and the flair in the opposite direction from the resin around the residual ridge provides adequate retention. After the assembled gold work is polished, the veneers and the buccolingual parts of the pontics are waxed with white inlay wax. The restorations are flasked, and the pontics are cured in acrylic resin. CONCLUSION

When metal-base acrylic resin pontics are removed from the mouth, they are odor-free. The gingivae under the pontics are healthy and pink even after several years of use of the pontics. 55 CENTRAL NEW YORK

PARK

WEST

23, N. Y.