Uncommon Crown-Root Fracture Treated with Adhesive Tooth Fragment Reattachment: 7 Years of Follow-up

Emergency dental care should emphasize measures to alleviate the pain and discomfort and, whenever possible, the reestablishment of esthetics. Conservative treatment alternatives, such as tooth fragment reattachment and composite resin reconstruction, may be used depending on the bone level of the fracture, type of fracture, treatment cost, and complexity.¹ If the fracture line extends along the root's long axis, extraction is indicated.¹

The definitive treatment for these injuries should consider the level of fracture line, root length and/or morphology, and esthetic needs.⁷ Several treatment strategies for esthetic and functional rehabilitation in cases of crown-root fracture are available, including mucogingival flap and adhesive reattachment of the original fragment, orthodontic/surgical extrusion followed by reconstruction of tooth crown with a composite restorative material, and prosthetic reconstructions.⁸

This article reports a case of an uncomplicated crown-root fracture in the permanent maxillary right central incisor in a young patient who received conservative treatment with adhesive reattachment of a fragment with atypical shape. This preserved the anatomic characteristics of the fractured tooth after periodontal intervention.

Case Report

A 14-year-old patient sought treatment at Araçatuba Dental School, São Paulo State University, Brazil, after he sustained a crown-root fracture in the permanent maxillary right central incisor. The patient indicated that he found the fractured coronal fragment on the floor immediately after the accident, washed it with running water, and placed it on the remaining root portion. Three days later, the fragment detached and the patient visited his dentist. The fragment was bonded but detached after 7 days, causing sensitivity upon chewing and drinking, which prompted the patient to seek treatment at the authors' clinic.

The intraoral examination showed a swollen marginal gingiva (Figure 1). The coronal fragment resembled a laminate veneer (Figure 1), and its cervical margin was slightly subgingival. Pulp vitality was checked thermally (sensitivity to cold stimulus) and confirmed with positive responses.

No alterations in the periodontal and bone tissues were observed in the radiographic examination (Figure 2). As the first clinical step, the coronal fragment and remaining root portion were cleaned with rubber cup pumice prophylaxis. There was a small area of pulpal exposure, which was partially curetted (Figure 3) and received a dressing with a commercially prepared antibiotic corticosteroid (Otosporin^®, GlaxoSmithKline, www.gsk.com) for 5 minutes followed by direct pulpal capping with calcium hydroxide p.a. and a calcium hydroxide-containing cement (Hydro C, DENTSPLY, www.dentsply.com). A full-thickness flap was elevated to provide better access to the fracture line, as well as to permit the correct placement of a rubber dam and provide a clean, dry operative field. Flap elevation revealed a fracture margin ending in a 0° angle and an adequate adaptation of the coronal fragment to the remaining root portion (Figure 4). The coronal fragment and remaining root portion were then etched with 37% phosphoric acid, rinsed thoroughly, and gently air-dried. The coronal fragment was re-attached to the root remnant using an adhesive restorative technique with an etch-and-rinse adhesive system (Prime & Bond 2-1^®, DENTSPLY) and a light-cured microhybrid composite resin (TPH^®, DENTSPLY) (Figure 5). The restoration of the fractured crown was completed at the cervical third with resin-modified glass ionomer cement (GC Fuji II LC, GC America Inc., www.gcamerica.com) (Figure 5).

All restored surfaces were finished with fine-grain diamond points and polished with fine and superfine grain polishing discs (Sof-Lex™ Pop-On, 3M ESPE, www.3MESPE.com). The flap was repositioned and sutured. Antibiotic therapy (amoxicillin 500 mg, 3 times/day) was started and maintained for 7 days. The use of 0.12% chlorhexidine oral rinse twice daily for 7 days was prescribed. After 15 days, a groove extending from the buccal to the palatal side of the tooth was prepared with a No. 1302 round diamond bur at high speed along the fracture line (Figure 6) and was restored with composite resin in order to mask the union between the fragments and improve esthetics.

Follow-up after 7 years showed good adaptation of the tooth fragment/composite resin restoration, pulpal vitality, no signs of root resorption, and no painful symptomatology (Figure 7 and Figure 8).

Discussion

Crown-root fractures are more frequent in adults due to the maturity of the periodontal ligament fibers that absorb the impact, leading to the rupture of enamel prisms, which extends to dentin and cementum. In this case, a high-intensity impact such as a fall caused a crown-root fracture because the energy generated resulted in a combination of compressive and tensile forces.^1,2,9

The fracture line in crown-root fractures usually accompanies the direction of the enamel prisms, starting on the buccal side of the crown and following obliquely and subgingivally to the palatal side.⁹ In the case presented in this article, the fragment had an atypical shape and the fracture line had an unusual presentation. This line started on the incisal portion of the palatal surface, extended obliquely to the buccal side, and was slightly subgingival. The fractured fragment resembled a laminate veneer.

The force causing the trauma to this tooth was probably unusual. In this case, a force in a buccopalatal direction or even acting on the incisal edge caused the fracture. The crown segment had no previous restoration that could have rendered it more fragile, because it is known that the extension and quality of restorations may affect tooth susceptibility to fracture.¹⁰

In cases of fracture involving anterior teeth, the treatment plan should consider that procedures such as osteotomy, gingivoplasty, and gingivectomy may compromise the esthetics of the fractured tooth and adjacent teeth.^10,11

Although adhesive fragment reattachment cannot be considered a durable procedure for the management of extensive fractures, this technique was used in the present case because it offered an effective, less complex, and conservative approach. It reduces the treatment costs, shortens the operatory time, and improves esthetics because the color, translucency, brightness, shape, and contour of the natural tooth structure are recovered. In addition, bonding of the fractured tooth fragment provides better resistance to staining and abrasion than composite reconstruction. Because the margins of the restoration are established in natural tooth structure, gingival problems are less frequent.¹² The incisal guide and function are re-established with the tooth in position, which provides the patient with a positive psychological, emotional, and social response.^2,6,8,10,11

This treatment approach was chosen because the fracture extended only slightly into the subgingival region and produced a single fragment. The use of this technique for management of multiple fractures, however, may have a less favorable esthetic outcome.¹⁰

The tooth fragment reattachment technique requires rubber dam isolation to obtain a dry, clean operative field and a high-quality bonding between the fractured and remaining tooth portions. In the present case, flap surgery was necessary to expose the fracture margin and permit an adequate isolation.⁸ Direct pulpal capping was performed to protect the dentin-pulpal complex and preserve pulpal vitality. This treatment is the preferred choice for young patients with completely formed teeth. Calcium hydroxide and mineral trioxide aggregate (MTA) (white) are suitable materials for such procedures.¹³ This procedure is even more important, considering the small dentin thickness and the need for acid etching. If too much time elapses between accident and treatment and the pulp becomes necrotic, root canal treatment is indicated to preserve the tooth. In extensive crown fractures a decision must be made whether treatment other than extraction is feasible.¹³

Adhesive tooth fragment reattachment may provide good results on a short- and medium-term basis.⁵ However, dehydration of the fragment when it remains dry after the accident is a major problem with this technique. Dentists should teach their patients about the importance of collecting fragments of teeth damaged due to traumatic injuries.

They should provide instructions on the use of an adequate wet storage medium, so that the fragments can be suitable for reattachment. In the present case, the fragment was maintained in the oral cavity since the accident, which avoided desiccation and color change.⁵ Frequently, after adhesive reattachment of a fractured tooth fragment, the line between the coronal and apical fragments is perceptible. In the present case, this problem was overcome by preparing a groove along the fracture line and filling it with composite resin to mask the defect.

Conclusion

After 7 years, the attached coronal fragment remained in position with good esthetics, and there were clinical and radiographic signs of pulpal vitality, periodontal health, and root integrity, thus indicating success. However, as with any trauma case, periodic evaluation is necessary in order to detect any evidence of pulpal necrosis and/or root resorption.

References

1. Andreasen JO, Andreasen FM, Andersson L, eds. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 4th ed. Copenhagen, Denmark: Blackwell Munksgaard; 2007.

2. Turgut MD, Gönül N, Altay N. Multiple complicated crown-root fracture of a permanent incisor. Dent Traumatol. 2004;20(5):288-292.

3. Rodd HD, Davidson LE, Livesey S, Cooke ME. Survival of intentionally retained permanent incisor roots following crown root fractures in children. Dent Traumatol. 2002;18(2):92-97.

4. Castro JC, Poi WR, Manfrin TM, Zina LG. Analysis of the crown fractures and crown-root fractures due to dental assisted by the Integrated Clinic from 1992 to 2002. Dent Traumatol. 2005;21(3):121-126.

5. Öz IA, Haytaç MC, Toroglu MS. Multidisciplinary approach to the rehabilitation of crown-root fracture with original fragment for immediate esthetics: a case repot with 4-year follow-up. Dent Traumatol. 2006;22(1):48-52.

6. Rappelli G, Massaccesi C, Putignano A. Clinical procedures for the immediate reattachment of a tooth fragment. Dent Traumatol, 2002;18(5):281-284.

7. Olsburgh S, Jacoby T, Krejci I. Crown fracture in the permanent dentition: pulpal and restorative considerations. Dent Traumatol. 2002;18(3):103-115.

8. Marchi GM, Gianinni M, Pimenta LAF, et al. Adhesive tooth fragment reattachments with intracanal reinforcement. RBO. 1996;LIII:34-37.

9. Andreasen JO, Andreasen FM. Essentials of Traumatic Injuries to the Teeth. 2nd ed. Copenhagen, Denmark: Munksgaard; 2000.

10. Baratieri LN. Restorative Dentistry–Fundamentals and Possibilities. 1st ed. São Paulo, Brazil: Livraria Santos; 2001.

11. Baratieri LN, Monteiro S Jr, Caldeira de Andrada MA. Tooth fracture reattachment: case reports. Quintessence Int. 1990;21(4):261-270.

12. Pasini S, Bardellini E, Keller E, et al. Surgical removal and immediate reattachment of coronal fragment embedded in lip. Dent Traumatol. 2006;22(3):165-168.

13. Flores MT, Andersson L, Andreasen JO, et al. Guidelines for the management of traumatic dental injuries. I. Fractures and luxations of permanent teeth. Dent Traumatol. 2007, 23(2):66-71.

About the Authors

Claudia Letícia Vendrame dos Santos, DDS, MS, PhD
Doctorate degree student
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil

Carolina Lunardelli Trevisan, MS
Master degree student
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil

Eloá Rodrigues Luvizuto, DDS, MS
Doctorate degree student
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil

Sonia Regina Panzarini, DDS, MS, PhD
Doctor Assistant Professor
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil

Wilson Roberto Poi, DDS, MS, PhD
Doctor Assistant Professor
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil

Celso Koogi Sonoda, DDS, MS, PhD
Doctor Assistant Professor
Department of Integrated Clinic and Surgery
UNESP–São Paulo State University
São Paulo, Brazil