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ing forces are applied. If possible, retention should be derived from the internal contours of the defect to avoid use of irritating external retentive devices (elastic bands, adhesive tape) (Fig. 1). 3. The tissues of the defect should be observed at rest and in function to determine the maximum extensions of the dressing margins. 4. Biocompatibility of materials such as silicone rubber and poly(methylmethacrylate) suggests their use for prosthetic dressings. 5. Prosthetic dressings should be made in visual harmony with the surrounding tissues. Size, shape, and shade all contribute to this harmony. The size of a dressing should approximate the size of the contralateral orbit if the extent of the postsurgical defect is proportional. The margins should parallel the curvatures of the superior and inferior orbital rims and the medial and lateral limits of the orbital

cavity. The facial curvature of the dressing should not extend more anterior than the curvature of the intact orbit to avoid an exophthalmic appearance. 6. The custom dressing should be in harmony with the psychologic needs and desires of the patient, which may vary (Figs. 1 through 4). A basic black dressing may be indicated for daily activities but dressings of different colors and textures may be indicated for other occasions. Many dressings can be made to attach to the same orbital obturator. Reprint requests to: DR. ROBERT M. BRYGIDER FACULTY OF DENTISTRY DALHOUSIE UNIVERSITY HALIFAX, NOVA SCOTIA CANADA B 3 H 3J5

C o u n t e r a c t i n g t h e d a r k e n i n g e f f e c t o f a m e t a l f r a m e w o r k on acrylic resin denture base material John R. Ivanhoe, D.D.S.,* Eric D. Adrian, D.M.D.,** and William A. Krantz, D.D.S.*** Emory University, School of Postgraduate Dentistry, Atlanta, Ga., and Fort Gordon, Ga. Fixed-removable implant metal frameworks by necessity must be thick in order to support the cantilever design and to avoid fracture. The increased thickness of the metal

The opinions or assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of the Army. *Assistant Professor, Emory University, School of Postgraduate Dentistry. **Major, U.S. Army,DC; Assistant Chief, RemovableProsthodontic Service, U.S. Army DENTAC, Fort Gordon, Ga. ***Colonel, U.S. Army, DC; Chief, RemovableProsthodontic Service; Assistant Director, Prosthodontic Residency Program, U.S. Army DENTAC, Fort Gordon, Ga. 10/4/20560

framework often necessitates a corresponding decrease in the thickness of the acrylic resin denture base material, resulting in an unesthetic darkening of the acrylic resin denture base material. The darkening can be counteracted by opaquing that portion of the metal framework on which the denture base material is to be placed. The opaquing is done by the use of the Silicoater (Kulzer, Irvine, Calif.) system. The application of the opaque masks the darkening effect of the metal framework and returns the acrylic resin denture base material to its natural color (Fig. 1). Reprint requests to: DR. ERIC D. ADRIAN 4128 KNOLLCREST CIRCLE MARTINEZ, GA 30907

Fig. 1. Acrylic resin on right demonstrates natural color with use of opaquer. Acrylic resin on left demonstrates darkening effect of untreated framework.

THE JOURNAL OF PROSTHETIC DENTISTRY

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Counteracting the darkening effect of a metal framework on acrylic resin denture base material.

TIPS FROM OUR READERS ing forces are applied. If possible, retention should be derived from the internal contours of the defect to avoid use of irrit...
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