Fabrication of a crown and fixed partial denture remount cast

DENTAL TECHNOLOGY SECTION

EUITOR

DANIEL

H. GEHL

Fabrication of a crown and fixed partial denture remount cast Joseph N. Tregaskes, D.M. D., M. S.,* Charles A. Kass, D. D. S., M. S.,” * Florian J. Knap, D.D.S., M.S.,*** and John E. Ward, D.D.S., M.S.D.**** Medical College of Virginia, Milwaukee, Wis.

School of Dentistry,

Richmond,

Va., and Marquette

University,

School of Dentistry,

0

ften, dental castings must be accurately reoriented on a new cast with easily removable castings. This is a useful procedure when refining a functional occlusion prior to insertion, when fabricating the framework or developing the occlusion for a precision attachment removable partial denture, when finalizing the contours of abutments for a claspretained removable partial denture, or when completing soldering procedures. Several techniques have been described for the fabrication of remount casts utilizing low fusing metal.‘-” This article describes a technique for fabricating an artificial stone cast with acrylic resin abutments from which crowns and/or fixed partial dentures can easily be removed. TECHNIQUE 1. Fit verify

the castings

their

marginal

to the abutment

teeth

and

integrity.

2. Coat the internal surfaces of the castings with a thin film of Duralay acrylic resin lubricant.? 3. Using a sable brush, paint the inside of the castings with acrylic resin monomer and Duralay polymer (Fig. 1). 4. When the surface of the acrylic resin has acquired a dull appearance, place a dowel pin into the resin, and hold in position until polymerization is complete (Fig. 2). 5. Remove the die from the casting (Fig. 3). Slight warming of the casting will facilitate removal. When the dies have been fabricated, the dowel pins can be notched for increased retention in the stone base (Fig. 4). 6. Place the castings on the abutment teeth, and make

an impression

utilizing

either

zinc-oxide

“Assistant Clinical

Professor, Department of Prosthodontics. **Assistant Professor, Department of Fixed Prosthodontics. ***Professor, Department of Fixed Prosthodontics. ****Associate Professor, Department of Prosthodontics. ?Reliance Dental Mfg. Co., Worth, IL.

334

MARCH

1981

Fig. 1. Acrylic resin monomer and polymer painted into crown.

VOLUME

45

NUMBER

3

and

Fig.

2.

Dowel pin placed into acrylic resin.

eugenol, plaster, or a polyether material. These materials are preferred because of their rigidity and accuracy. 7. Accurately orient the castings into the impression, and seat the acrylic resin dies into the castings OOZZ-3913/81/030334

+ 02$00.20/0O

1981 The

C. V. Mosby

Co.

REMOUNT

CAST

Fig. 6. Stone cast with acrylic resin dies.

Fig. 4. Dowel pins notched for increased retention. Fig. 7. Remounted stone casts. crowns may be readily removed, and the indicated procedures may be completed (Figs. 6 and 7). SUMMARY A technique has been described for fabricating an accurate working cast in which the finished crowns are easily removable. REFERENCES 1.

Fig. 5. Crowns and acrylic resin dies oriented in impression.

2. 3.

(Fig. 5). Exposed parts of crowns and interproximal surfaces may be covered with a thin layer of wax or lubricant to ensure easy removal of the crowns from the stone cast. 8. Pour the impression using a vacuum mix of improved die stone. Upon final set of the stone, the THE JOURNAL

OF PROSTHETIC

DENTISTRY

Lucia, V. 0.: Modern Gnathological Concepts. St. Louis, 1961, The C. V. Mosby Co., p 427. Lucia, V. 0.: Remounting procedure for completion of full mouth rehabilitation. J PROSTHET DENT 30:679, 1973. Schluger, S., Yuodelis, R., and Page, R.: Periodontal Disease. Philadelphia, 1977, Lea & Febiger, p 693.

Reprint requeststo: lk JOSEPH N. TREGASKES GRACE MEDICAL VILLAGE, Sm. 5700 W. GRACE ST. kxmom, VA 23226

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