Fractured

Bonding of Fractured Tooth Segments: A Review of the Past Twenty Years

Dr. DiAngeles will present "Bruised, broken and bedeviled teeth: managing traumatic injuries to the dentition" at the ADA Annual Session in San Francisco on Sunday, Oct. 25, from 8:30 am - 11 am and 1 pm - 3:30 pm, in room 309 at Moscone Center.

The technology of tooth-bonding materials has developed over the past 20 years to achieve results that are quick, minimally invasive and esthetically pleasing. The following paper is an overview of the advances in tooth-bonding technology over the past 20 years.

Twenty years ago this year, two separate papers reported the reattachment of fractured tooth segments utilizing only the micro-mechanical properties of the acid-etch resin adhesive technique.1,2 Prior to this the literature described reattachment of tooth fragments utilizing conventional cements and cast posts, as well as mini pins in combination with the new light-cured resins.3,4 Over the next several years a series of case reports appeared further documenting the utility of this relatively new application of resin-bonded materials.5,6,7,8 Authors explored various tooth and fragment preparations, methods of pulpal protection and resin types.9,10,11 In the mid 1980's several authors described successful reattachment even in instances of frank coronal amputation.12,13 In 1985 Ludlow and LaTurno introduced dentinal bonding together with acid-etching advancing the short-term success of reattachment advanced one step further.12 Croll, Baratieri, and Santos in independent reports incorporated the use of glass-ionomer cements to enhance dentinal bonding in such injuries.14,15,16

While much of the literature on reattachment focused on restoring function and esthetics to anterior teeth, Santos and colleagues published a technique for rebuilding caries devastated molars using coronal tooth segments harvested from extracted third molars, glass ionomer cement and dentin-enamel bonding materials.16 Additionally, Jackson in 1993 described a conservative method of restoring fractured posterior teeth by reattaching fractured cusps coupled with adjunctive composite restorations.17

In separate articles both Croll and DiAngelis suggested that placement of direct composite veneers after reattachment of anterior tooth fragments not only enhanced esthetics in certain instances but probably strengthened the reattachment due to the increased surface area of the bond.18,19,20 The latter hypothesis however, has not been tested in either clinical or laboratory experiments.

For years reattachment was regarded with caution and viewed at best as a transitional or interim restoration. However, laboratory studies conducted by Andreasen and colleagues, altered our thinking on the longevity of such restorations.21 In a series of experiments the authors demonstrated that the placement of bonded porcelain laminate veneers over reattachments substantially strengthened their resistance to future fracture. In fact results demonstrated that previously fractured and reattached teeth which had porcelain laminate veneers placed showed the same or greater fracture strength as intact incisors.

Technique

The clinical methods for reattaching fractured tooth segments are adequately described in the previously cited literature. Essentially it consists of the following:

1. Cleaning the tooth segment and fractured tooth with pumice and water.

2. Determining the reattachment path of insertion. When the fracture is relatively clean and in one plane or if there is considerable crushing of the cavosurface enamel rods, refitting the fractured segment accurately can be a challenge. The fragment may be misaligned anteroposteriorly.

3. An internal bevel as described by Simonsen can be placed in the enamel of both the segment and remaining tooth.22 Conversely no bevels need be placed. If the fracture necessitates pulpectomy and obturation of the root with gutta percha, additional mechanical retention can be gained by creating a slight circumferential undercut in the pulp chamber of the tooth and in the chamber of the tooth fragment.

4. A suitable etchant is applied, according to the manufacturers direction, to both the segment and tooth extending 2 millimeters beyond the cavosurface margins. Rinse well.

5. A dentinal primer is applied, followed by application of an unfilled resin.

6. Ultimately, a light-cured composite diluted to a creamy consistency with unfilled resin is applied to the tooth and segment. The segment is carefully reattached, excess removed with a resin coated instrument and the restoration light cured circumferentially while being stabilized by the clinician. Alternatively, a dual cure composite resin luting agent may be used.

7. Polishing requires little more than the use of disks and strips, finishing burs or diamonds.

8. The occlusion is checked and adjusted as necessary.

Figure 1. Fractured maxillary central incisor with fracture segment available for reattachment. Figure 2. Reattached coronal segment.

In short, the procedures and materials necessary to effect reattachment are essentially the same as those utilized in restoring a Class IV fracture with a composite resin. The major difference is conservation of time. Reattachment requires a minimum of finishing and polishing as the correct texture, color and shape of the restoration exists within the tooth segment itself. Figures 1 and 2 demonstrate an uncomplicated reattachment.

Pulpal Protection

In the early evolution of reattachment, prior to the advent of dentinal bonding agents, dycal was placed over the exposed dentin and over pinpoint exposures. When light cured glass ionomer cements became available, this was incorporated into the procedure to seal over the dycal, and/or to protect the dentin. Additionally glass ionomer bonds to dentin and is capable of being etched for additional retention.23,24 When liners or bases are utilized an equivalent amount of dentin must be removed from the tooth fragment to permit proper apposition to the tooth.

At present, the total etch alternative has been advocated for pulpal protection. The ability of dentin-enamel bonding agents to seal out bacteria and achieve a well-sealed margin greatly reduces the risk of pulpal irritation.25 Kanca in a recent case report documented a three year uneventful pulpal response to acid-etching of a significant pulp exposure with subsequent resin placement during a fragment reattachment procedure.26 Management of pulpal exposures in this manner requires further study, however. Other researchers have documented good pulpal response to direct contact with composite resin as long as bacteria are excluded.27,28

In instances where there is significant pulpal exposure and incomplete root formation every effort should be made to preserve as much healthy pulp tissue as possible. In these instances a partial pulpotomy technique as first described by Cvek and subsequent authors is the treatment of choice.29,30,31 The extremely high success rate of this technique permits continued natural root development. If circumstances dictate, complete pulpotomy may be necessary.

In mature teeth with frank exposure, pulpectomy and obturation with gutta percha and sealer is recommended. This can be accomplished prior to reattachment.

More recently Andreasen and colleagues retrospectively reported on the long-term survival of reattached fractured crown segments.32 Their findings suggest that the use of dentinal bonding in conjunction with acid-etching of enamel insures greater initial strength to reattachment restorations than acid-etching alone and may also provide enhanced pulpal protection. Additionally their results underscore the observations and experiences of many clinicians and researchers that reattachment is a suitable alternative to composite for restoring function and esthetics in fractured teeth.

Case Reports:

The following case reports graphically illustrate challenges and solutions encountered in several traumatically fractured teeth.

Figure 3. Coronal factures of both maillary central incisors.

Figure 4. Fractured segments available for reattachment.

Figure 5. One year postoperative follow-up of reattached maxillary central incisors.

Figures 3 and 4 demonstrate fractures of both maxillary central incisors with concomitant pulp exposures in a 23-year-old patient who suffered a blow to the face. The fractured segment of the maxillary right central had sustained a vertical fracture as well. The fractured segments were bonded together prior to reattachment to the fractured tooth. Figure 5 demonstrates a satisfactory esthetic and functional result one year post treatment.

Figure 6. Coronal facture of maillary right central incisor.	Figure 7. Utilizing a sticky wax handle to assist in reattachment of coronal fragment.
Figure 8. Diagrammatic representation of misaligned coronal fragment.	Figure 9. Esthetic result after modifying misaligned reattachment.

Figures 6-9 demonstrate the necessity of exercising caution when using a 'handle' to aid in reapposition of the fractured segment. Several authors have recommended utilizing a sticky wax or gutta percha handle for better control of small fractured segments.18,33 A problem may arise in that use of such aids result in the loss of fine proprioception. If the fracture does not have a definite index (i.e. the segment fits only one way), misalignment may occur. While that was the case with this 17 year old, a good esthetic result was still achieved by selective enamelplasty and the addition of composite resin.


Figures 10-13 illustrate reattachment followed by a direct composite veneer and ultimately restored with bonded porcelain laminate veneers.

Figure 10. Coronal amputation of maxillary right central incisor. Reproduced by permission from August 1992 Journal of the American Dental Association	Figure 11. Appearance of maxillary right central incisor immediately after reattachment. Reproduced by permission from August 1992 Journal of the American Dental Association
Figure 12. Appearance of direct composite veneer of maxillary right central incisor four years after reattachment. Reproduced by permission from August 1992 Journal of the American Dental Association	Figure 13. Porcelain laminate veneers of maxillary anterior teeth eight years after reattachment of maxillary right central incisor. Courtesy Dr. Patrick Mascia.

In this era of conservative, esthetic dentistry, the reattachment of fractured tooth segments has established itself as a realistic treatment option in the restoration of fractured teeth. It permits rapid restoration of original tooth contours and overall esthetics with greatly reduced chair time for both the patient and operator.

References

1. Marder C. Restoration of a fractured anterior tooth. JADA 96 (1):113-115, 1978.
2. Tennery TN. The fractured tooth reunified using the acid-etch bonding technique. Texas Dent J 96 (8):16-17, 1978.
3. Chosack A, Eidelman E. Rehabilitation of a fractured incisor using the patient's natural crown - case report. J Dent Child 31-32 (1st quarter):19-21, 1964.
4. Spasser HF. Repair and restoration of a fractured, pulpally involved anterior tooth: report of a case. JADA 94 (3):519-520, 1977.
5. Simonsen RJ. Traumatic fracture restoration: an alternative use of the acid-etch technique. Quintessence Int 101(2):15-22, 1979
6. Starkey PE. Reattachment of a fractured fragment to a tooth. J Int Dent Assoc 58(5):37-38, 1979.
7. Osborne JW and Lambert RL. Reattachment of fractured incisal tooth segment. Gen Dent 33(6):516-517, 1985.
8. Amir E, Bar-Gil B et al. Restoration of fractured immature maxillary central incisors using the crown fragments. Pediatr Dent 8(4):285-288, 1986.
9. Dean JA, Avery DR et al. Attachment of anterior tooth fragments. Pediatr Dent 8(3):139-142, 1986.
10. Croll TP. Dentin adhesive bonding: New applications (I). Quintessence Int 15(10):1021-1027, 1984.
11. Andreasen FM, Rindom JL et al. Bonding of enamel-dentin fractures with Gluma and resin. Endod Dent Traumatol 2 (6):1-4, 1986.
12. Ludlow JB and LaTurno SA. Traumatic fracture - one-visit endodontic treatment and dentinal bonding reattachment of coronal fragment: report of a case. JADA 110 (3):341-343, 1985.
13. DiAngelis AJ and Jungbluth MA. Restoration of an amputated crown by the acid-etch technique. Quintessence Int 18(12):829-833, 1987.
14. Croll TP. Repair of a severe crown fracture with glass ionomer and composite resin bonding. Quintessence Int 19(9):649-654, 1988.
15. Baratieri LN, Motiero S et al. The "sandwich" technique as a base for reattachment of dental fragments. Quintessence Int 22(2):81-85, 1991.
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17. Jackson RD. A clinical technique for rebonding fractured cusps in posterior teeth. Perio Prosth and Aesth 5 (1):11-17, 1993.
18. Croll TP. Rapid reattachment of fractured crown segment: an update. J of Esthetic Dentistry 2 (1):1-5, 1990.
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20. DiAngelis AJ. Restoring traumatic coronal fractures: advantages of a reattachment technique. Dental Team 7(6):19-21, 1994.
21. Andreasen FM, Daugaard-Jensen J et al. Reinforcement of bonded crown fragments with porcelain veneers. Endod Dent Traumatol 7(2):78-83, 1991.
22. Simonsen RJ. Restoration of a fractured central incisor using original tooth fragment. JADA 105(4):646-648, 1982.
23. Hicks J et al. Secondary caries formation in vitro around glass-ionomer restorations. Quintessence Int 17 (9):527-32, 1986.
24. Wilson AD, McLean JW. Glass-ionomer cement. Chicago, Quintessence 1988.
25. Qvist V. Correlation between marginal adaptation of composite resin restorations and bacterial growth in cavities. Scand J Dent Res 88(4):296-300, 1980.
26. Kanca J. Replacement of a fractured incisor fragment over pulpal exposure: a long-term case report. Quintessence Int 27(12):829-832, 1996.
27. Cox C, Keall C. et al. Biocompatibility of surface-sealed dental materials against exposed pulps. J Prosthet Dent 57(1):1-8, 1987.
28. Tsuneda Y, Hayakawa T et al. A histological study of direct pulp capping with adhesive resins. Oper Dent 20(6):223-229, 1995.
29.Cvek M. A clinical report on partial pulpotomy and capping with calcium hydroxide in permanent incisors with complicated crown fracture. J Endod
4(8):232-7, 1978.
30. Fuks AB, Chosack A et al. Partial pulpotomy as a treatment alternative for exposed pulps in crown fractured permanent incisors. Endod Dent Traumatol 3 (3):100-102, 1987.
31. Klein H, Fuks A et al. Partial pulpotomy following complicated crown fracture in permanent incisors: a clinical and radiographical study. J Pedod 9: 142-147, 1985.
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33. Andreasen JO and Andreasen FM. Essentials of traumatic injuries to the teeth, Munksgaard, Copenhagen 1990.

To request a printed copy of this article, please contact / Anthony J. DiAngelis, D.M.D., M.P.H.,701 Park Avenue South,Minneapolis, MN 55415