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Reuse of existing crown after tooth fracture at the gingival margin
Reuse of’ existing crown after tooth fracture at the gingival margin Joseph J. Portera, D.M.D.,+ and Judith A. Thomson, Ph.D., D.M.D.** University
of Mississippi,
School of Dentistry,
Jackson,
P
Miss.
Complete fracture of a previously crowned tooth at the gingival margin occurs frequently. If extraction is not indicated because sufficient root structure remains, treatment may include endodontic therapy, fabrication of a cast post and core, and a new crown. Substantial chairside time and expense to the patient are required. In this presentation the existing crown was used after a cast post and core were made. The technique did not use the die of the original preparation, which may be available only to the original dentist.’
*Associate Professor, Department of Restorative Dentistry. **Assistant Professor, Department of Restorative Dentistry.
Fig. Fig. Fig. Fig.
THE JOURNAL
1. 2. 3. 4.
TECHNIQUE 1. The maxillary left central incisor was fractured at the gingival margin (Fig. 1). The ceramometal crown was intact and contained some fractured tooth substance (Fig. 2). 2. The tooth fragment was removed from the crown, and the crown was positioned on remaining tooth structure to evaluate feasibility of the proposed treatment. Endodontic therapy was both necessary and feasible. 3. Endodontic therapy was performed by means of conventional techniques with gutta-percha and lateral condensation. Post space of 7 to 8 mm was provided, and all undercuts were removed from the post space.
Remaining tooth structure after crown/tooth fracture. Crown with tooth substance inside. Trimmed plastic pin loosely placed in canal following endodontic treatment. Wax pattern of canal.
OF PROSTHETIC
DENTISTRY
195
PORTERA
AND
THOMSON
Fig. 5. Wax pattern/plastic pin before pin is prepared for pick-up with crown and Duralay. Fig. 6. Duralay of crown’s internal dimensions and hole prepared for pin and wax pick-up. Fig. 7. Crown carried into place with second mix of Duralay. Fig. 8. Wax post and core removed with Duralay inside crown. Fig. 9. Finished cast post and core after cementation. Fig. 10. Original crown after cementation. 4. A plastic toothpick was trimmed with an arbor band to fit loosely in the canal and extended within 1 to 2 mm of the gutta-percha seal (Fig. 3). 5. Sprue wax was molded around the toothpick, which was then inserted into the canal and withdrawn several times to ensure optimal adaptation (Fig. 4). The coronal portion of the toothpick was “nailheaded” with a hot instrument, leaving about 2 mm extruding from the canal (Fig. 5). 6. The crown was lubricated with petroleum jelly, and a creamy mix of Duralay (Reliance Dental Mfg. Co., Worth, Ill.) was placed inside. After the Duralay
196
had set, a cavity was prepared in the center of the Duralay to accommodate the toothpick extension from the canal (Fig. 6). 7. An additional mix of Duralay was added to the cavity in the crown, and the crown with the soft Duralay was placed over the tooth containing the post pattern. The crown was held in the original position and the excess Duralay was quickly removed (Fig. 7). After the Duralay was allowed to set, the crown with attached wax pattern was removed (Fig. 8). 8. The wax post and Duralay core were removed from the crown and invested and cast in the usual way.
AUGUST
1983
VOLUME
50
NUMBER
2
REUSE OF EXISTING
CROWN
9. The finished casting was adjusted for proper fit in the canal and cemented (Fig. 9). The crown was then cemented over the core preparation in the usual fashion (Fig. 10).
DISCUSSION The technique {describedoffers several advantages in reusing an existing crown after fracture occlusally to the gingival margin. The remaining tooth structure is strengthened with a cast post and core, and there is excellent marginal adaptation of the existing crown to the new core preparation complex. The technique reduced the mampulation and trauma to the patient, the time for completing the restoration, and additional cost had a new crown been made. This technique does
not rely on the availability of the die of the original preparation as described by Brady.’ The purpose of the double application of Duralay, in conjunction with the plastic toothpick and wax adapted inside the canal, was to reduce the amount of exothermic heat, which could have injured the tissues or melted the wax. REFERENCE 1. Brady, W. F.: Restoration of a tooth to accommodate a preexisting cast crown. J PROSTHET DENT 48~268, 1982. Refml reyuesls lo: DR. JOSEPH J. PORTERA UNIVERSITY OF MISSISSIPPI SCHWL OF DENTISTRY JACKSON, MS 39216
ARTICLES TO APPEAR IN FUTURE ISSUES Analysis of stress produced by a maxillary
mouthstick
prosthesis
J. L. Henson, D.D.S., M.S.Ed., A. A. Caputo, Ph.D., and P. K. Turley, D.D.S., M&D., M.Ed
A kinematic investigation of mandibular border movement by means of an electronic measuring system. Part I: Development of the measuring system Sumiya Hobo, D.D.S., M.S.D., and Sadanari Mochizuki, B.S., D.Sc.
Chewing pattern before and after treatment with full upper and partial lower bilateral free-end dentures Torstcn Jemt, Bjorn Hedegard, and Klas Wickberg
Anatomy of the cast gold margin David A. Kaiser, D.D.S., M.S.D.
Effects of chemical denture cleaners on the flexibility
of cast clasps
Charlie Kastner, D.D.S., Carl W. Svare, D.D.S., Ph.D., Forrest F. Scandrett, D.D.S., M.S., Paul E. Kcrber, M.A., Ph.D., Thomas D. Taylor, D.D.S., M.S.D., and H. Edwin Semler, D.D.S.
Oral findings in osteoporosis. Part I: Measurement of mandibular density
bone
Patricia J. Kribbs, D.D.S., M.S.D., Dale E. Smith, D.D.S., M.S.D., and Charles H. Chesnut III, M.D.
Superior and inferior bellies of the lateral pterygoid muscle EMG activity at base jaw positions Parker E. Mahan, D.D.S., Ph.D., Thomas M. Wilkinson, B.D.S., M.Sc., Charles H. Gibbs, Ph.D., A. Manderli, D.D.S., and L. S. Brannon, D.M.D.
THE JOURNAL
OF PROSTHETIC
DENTISTRY
197
of Mississippi,
School of Dentistry,
Jackson,
P
Miss.
Complete fracture of a previously crowned tooth at the gingival margin occurs frequently. If extraction is not indicated because sufficient root structure remains, treatment may include endodontic therapy, fabrication of a cast post and core, and a new crown. Substantial chairside time and expense to the patient are required. In this presentation the existing crown was used after a cast post and core were made. The technique did not use the die of the original preparation, which may be available only to the original dentist.’
*Associate Professor, Department of Restorative Dentistry. **Assistant Professor, Department of Restorative Dentistry.
Fig. Fig. Fig. Fig.
THE JOURNAL
1. 2. 3. 4.
TECHNIQUE 1. The maxillary left central incisor was fractured at the gingival margin (Fig. 1). The ceramometal crown was intact and contained some fractured tooth substance (Fig. 2). 2. The tooth fragment was removed from the crown, and the crown was positioned on remaining tooth structure to evaluate feasibility of the proposed treatment. Endodontic therapy was both necessary and feasible. 3. Endodontic therapy was performed by means of conventional techniques with gutta-percha and lateral condensation. Post space of 7 to 8 mm was provided, and all undercuts were removed from the post space.
Remaining tooth structure after crown/tooth fracture. Crown with tooth substance inside. Trimmed plastic pin loosely placed in canal following endodontic treatment. Wax pattern of canal.
OF PROSTHETIC
DENTISTRY
195
PORTERA
AND
THOMSON
Fig. 5. Wax pattern/plastic pin before pin is prepared for pick-up with crown and Duralay. Fig. 6. Duralay of crown’s internal dimensions and hole prepared for pin and wax pick-up. Fig. 7. Crown carried into place with second mix of Duralay. Fig. 8. Wax post and core removed with Duralay inside crown. Fig. 9. Finished cast post and core after cementation. Fig. 10. Original crown after cementation. 4. A plastic toothpick was trimmed with an arbor band to fit loosely in the canal and extended within 1 to 2 mm of the gutta-percha seal (Fig. 3). 5. Sprue wax was molded around the toothpick, which was then inserted into the canal and withdrawn several times to ensure optimal adaptation (Fig. 4). The coronal portion of the toothpick was “nailheaded” with a hot instrument, leaving about 2 mm extruding from the canal (Fig. 5). 6. The crown was lubricated with petroleum jelly, and a creamy mix of Duralay (Reliance Dental Mfg. Co., Worth, Ill.) was placed inside. After the Duralay
196
had set, a cavity was prepared in the center of the Duralay to accommodate the toothpick extension from the canal (Fig. 6). 7. An additional mix of Duralay was added to the cavity in the crown, and the crown with the soft Duralay was placed over the tooth containing the post pattern. The crown was held in the original position and the excess Duralay was quickly removed (Fig. 7). After the Duralay was allowed to set, the crown with attached wax pattern was removed (Fig. 8). 8. The wax post and Duralay core were removed from the crown and invested and cast in the usual way.
AUGUST
1983
VOLUME
50
NUMBER
2
REUSE OF EXISTING
CROWN
9. The finished casting was adjusted for proper fit in the canal and cemented (Fig. 9). The crown was then cemented over the core preparation in the usual fashion (Fig. 10).
DISCUSSION The technique {describedoffers several advantages in reusing an existing crown after fracture occlusally to the gingival margin. The remaining tooth structure is strengthened with a cast post and core, and there is excellent marginal adaptation of the existing crown to the new core preparation complex. The technique reduced the mampulation and trauma to the patient, the time for completing the restoration, and additional cost had a new crown been made. This technique does
not rely on the availability of the die of the original preparation as described by Brady.’ The purpose of the double application of Duralay, in conjunction with the plastic toothpick and wax adapted inside the canal, was to reduce the amount of exothermic heat, which could have injured the tissues or melted the wax. REFERENCE 1. Brady, W. F.: Restoration of a tooth to accommodate a preexisting cast crown. J PROSTHET DENT 48~268, 1982. Refml reyuesls lo: DR. JOSEPH J. PORTERA UNIVERSITY OF MISSISSIPPI SCHWL OF DENTISTRY JACKSON, MS 39216
ARTICLES TO APPEAR IN FUTURE ISSUES Analysis of stress produced by a maxillary
mouthstick
prosthesis
J. L. Henson, D.D.S., M.S.Ed., A. A. Caputo, Ph.D., and P. K. Turley, D.D.S., M&D., M.Ed
A kinematic investigation of mandibular border movement by means of an electronic measuring system. Part I: Development of the measuring system Sumiya Hobo, D.D.S., M.S.D., and Sadanari Mochizuki, B.S., D.Sc.
Chewing pattern before and after treatment with full upper and partial lower bilateral free-end dentures Torstcn Jemt, Bjorn Hedegard, and Klas Wickberg
Anatomy of the cast gold margin David A. Kaiser, D.D.S., M.S.D.
Effects of chemical denture cleaners on the flexibility
of cast clasps
Charlie Kastner, D.D.S., Carl W. Svare, D.D.S., Ph.D., Forrest F. Scandrett, D.D.S., M.S., Paul E. Kcrber, M.A., Ph.D., Thomas D. Taylor, D.D.S., M.S.D., and H. Edwin Semler, D.D.S.
Oral findings in osteoporosis. Part I: Measurement of mandibular density
bone
Patricia J. Kribbs, D.D.S., M.S.D., Dale E. Smith, D.D.S., M.S.D., and Charles H. Chesnut III, M.D.
Superior and inferior bellies of the lateral pterygoid muscle EMG activity at base jaw positions Parker E. Mahan, D.D.S., Ph.D., Thomas M. Wilkinson, B.D.S., M.Sc., Charles H. Gibbs, Ph.D., A. Manderli, D.D.S., and L. S. Brannon, D.M.D.
THE JOURNAL
OF PROSTHETIC
DENTISTRY
197