Eliminating restorations

coronal discoloration when cementing over metal posts and cores

all-ceramic

S. FrejIich, DDS, MSD,” and Charles J. Goodacre, DDS, MSDb Antwerp, Belgium, and Indiana University, School of Dentistry, Indianapolis, Ind. All-ceramic restorations have long been recognized for their esthetic qualitiesle5 and the ease with which these qualities can be developed when compared with metal ceramics.6 Some of the natural appearance is lost when they are placed over endodontically treated teeth with metal posts and cores.7The metal grays the restoration and alters chromatic aspects. One report7 suggested the use of glass-ceramic (Dicer, Dentsply International, York, Pa.) posts and cores to eliminate the discoloration and indicated that this procedure was esthetically effective. However, laboratory studies related to the strength of all-ceramic posts and cores are lacking and long-term clinical experiences have not been reported. In addition, some posts and cores only restore a small portion of the coronal integrity, creating thin surfaces which can be difficult to cast in a glass-ceramic material. When metal posts and cores are used in conjunction with all-ceramic restorations, it is possible to eliminate the negative color effect of the metal by fusing opaque porcelain over the core.

Fig. 2. Opaque porcelain fired over cores.

CLINICAL EXAMPLE Complete coverage restorations were planned for six maxillary anterior teeth. Endodontic treatment was required on both central incisors (Fig. 1). No coronal tooth structure was remaining on the maxillary right central incisor. Sufficient coronal tooth structure was present on the

BPrivate practice, Antwerp, Belgium. bChairman, Department of Prosthodontics, Indiana University, School of Dentistry. 10/4/33974

Fig. 3. Posts and cores cemented.

Fig. 1. Preprosthodontic photograph shows condition of endodontically treated central incisors.

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Fig. 4. Incisal view of Dicer crowns.

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5. Facial view of cemented Dicer crowns.

6. Black and white photograph shows uniform Values between central incisor crowns cemented over posts and cores and anterior crowns cemented over vital teeth.

Fig.

left central incisor so that only a thin portion of the lingual and distal surfaces required core restoration. Wax patterns were developed and cast in a metal ceramic alloy. The surfaces were finished on the working cast to achieve final form and occlusal convergence. Opaque porcelain was applied over appropriate areas of the cores and fired (Fig. 2). The opaque thickness was carefully adjusted on the working cast to insure that no binding occurred between the core and remaining coronal tooth structure. The opaqued castings were cemented (Fig. 3), the preparations refined, and an impression was made. Dicer crowns were made, colored, and cemented on all six maxillary anterior teeth (Figs. 4 and 5). Although the use of metal posts and cores with a layer of opaque porcelain does not completely eliminate root discoloration, it permits more uniform Value to be developed between restorations placed over vital teeth and those placed over metal posts and cores (Fig. 6).

REFERENCES 1. Rosenstiel SF, Land MF, Fujimoto J. Contemporary fixed prosthodontics. St Louis: CV Mosby, 1988;192. 2. Shillingburg HT, Hobo S, Whitsett LD. Fundamentals of fixed prostbodontics. 2nd ed. Chicago: Quintessence Publ, I 1981;420. 3. Dykema RW, Goodacre CJ, Phihips RW. Johnston’s modern practice in fixed prosthodontics. 4th ed. Philadelphia: WR Saunders, 1936;249. 4. Soxio RR, Riley RI. The shrink-free ceramic crown. J PROSTHET DENT 1983;49:182-7.

5. GeIIer W, Kwiatkowski SJ. The Wiis Glas crown: a new solution in the dark and shadowed xones of esthetic porcelain restorations. Quintessence Dent Technol 1987;11:233-42. 6. Wohlwend A, Strub JR, Scharer P. Metal ceramic and ail-porcelain restorations: current considerations. Int J Prosthodont 1989,2:13-26. 7. Kwiatkowski SJ, GeIIer W. A preliminary consideration of the glass-ceramic dowel post and core. Int J Prosthodont 1969251-5.

SUMMARY

Reprintrequeststo:

Opaque porcelain was fused over metal posts and cores. This procedure permitted the definitive all-ceramic restorations to possessa more uniform shade between teeth restored with metal posts and cores and adjacent vital teeth.

DR. CHARLES J. G~~DACRE SCHOLL OF DENTISTRY INDL~NA UNIWRSITY 1121WEsT &tICHIGAh ST. hDIANAPOLIS, IN 46202

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Eliminating coronal discoloration when cementing all-ceramic restorations over metal posts and cores.

Opaque procelain was fused over metal posts and cores. This procedure permitted the definitive all-ceramic restorations to possess a more uniform shad...
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