Interdisciplinary management in the paediatric patient: restoration of a complicated crown-root fracture

Case report

A healthy 12-year-old boy attended the paediatric casualty clinic of a UK dental hospital as an emergency patient after an accident earlier that day at school. The boy had tripped and fallen in the playground sustaining trauma to his maxillary left central incisor. There was nothing significant in his past dental or medical histories. Extra-oral examination revealed nothing significant. Intra-oral clinical examination revealed that he was in the full permanent dentition with the exception of his third molars. He presented with a Class I molar and incisal relationships. He had no previous restorations, was completely caries free and oral hygiene was good (BPE score of: 0/1/1, 0/0/0). There was evidence of intra-oral bleeding from the gingivae of the traumatized tooth which also had a mobility level of grade two (Figure 1). No injuries were sustained to other parts of the body from the fall. Radiographic investigations consisted of a standard upper anterior occlusal and periapical views (Figure 2a and b). The radiographs revealed the roots of the maxillary permanent central and lateral incisors were fully formed with their apices closed. In addition, the periapical radiograph confirmed the presence of a coronal fracture of the maxillary left central incisor (Figure 2b). There were no other visible signs of injuries on the adjacent or opposing teeth. Additional examination was carried out under informed consent and local anaesthetic. Manipulation of the gingival sulcus above the traumatized central incisor revealed the involvement of pulpal tissues across the fracture line, with the fracture starting supra-gingival on the labial surface and extending palatally and eventually sub-gingival around the circumference of the tooth (Figure 3). A diagnosis of a complicated crown-root fracture in the coronal third of the maxillary left central incisor was established.

On establishing the diagnosis, discussion of all possible treatment options regarding the tooth and what was involved was considered with the patient and parents. It was decided by the parents and patient to restore the tooth and opt for attempted preservation of the tooth fragment, with associated root-filling if required. Both the patient and parents strongly opposed carrying out any flap surgery but were happy for gingival margin modifications using an electro-cautery machine. The limitation and possible failure of this technique was conveyed, and the parents were advised that the sub-gingival and infra-bony location of the palatal fracture may represent an area of weakness for the subsequent restoration if flap surgery was not carried out. The other option considered orthodontic extrusion to allow modification of the restoration margins after the initial phase of management. All parties involved were happy to go ahead with this decision.

The immediate phase of management consisted of securing the fractured tooth with a flexible splint of orthodontic brackets and 0.014” nickel-titanium archwire. The brackets and archwire spanned from the upper right lateral incisor to the upper left canine teeth. The secured tooth was then accessed through the palatal aspect of the crown and the pulp extirpated under rubber dam. The canal was irrigated with 1% sodium hypochlorite, dried and dressed with a non-setting calcium hydroxide paste, and the access cavity was sealed with a glass-ionomer cement until further treatment could commence.

At a subsequent appointment one week later, all possible treatment options discussed on day one were revisited in order to ensure that the patient and parents understood the agreed plan. The options included:

Following the biomechanical preparation of the root canal under rubber dam, a small orthograde mineral trioxide aggregate plug (MTA-Angelus, Londrina, PR, Brazil) approximately 1 mm in diameter was compacted at the root apex. This was positioned as an apical barrier to prevent any thermoplastic gutta-percha from seeping out through the neurovascular constriction of the canal into the periapical tissues. Obturation of the root canal system was achieved by backfilling of the canal with the Obtura II, warm gutta-percha delivery system (Obtura Spartan, Missouri, USA). The fractured portion of the crown was then removed from its attached tissues and placed in physiological saline to prevent drying out. A small amount of the labial and palatal gingival tissue was removed using electro-cautery around the subgingival portion of the root fragment to allow for adequate visualization and access to the retained root. Gutta-percha from the canal was then removed to a level of approximately 4 mm from the MTA plug and the canal walls were cleaned and brushed free of any debris using a wire-handled interdental brush (size 8135, Dentocare UK). A tapered and radio-opaque translucent glass fibre reinforced composite post (DT-Light Post ®; RTD, France) was measured to length, tried in and bonded into the canal (Figure 4). A minimal-sized channel was prepared in the centre (originally part of the pulp chamber) of the detached crown fragment to allow the fibre post to pass through the channel made in the crown (Figure 5). Both the fibre post and the fractured coronal portion were bonded with SealBond Ultima® (RTD, France), a fifth generation, dual-cure bonding system for translucent composites (Figure 6). A post-operative radiograph taken after cementation revealed what appeared to be some small deficiencies in the margins of the subgingival tooth-restoration interface. It was agreed that this represented a possible area which could cause failure of the restoration with time due to fracture or periodontal irritation leading to breakdown of periodontal tissues. This finding was discussed with the patient and his parents. The option of raising a mucoperiosteal flap and carrying out an osteotomy to expose the margins was offered to correct the problem. The patient and parents did not want to undergo any advanced invasive surgery and expressed a preference for a short course of orthodontic treatment to extrude the tooth and enable visual assessment for any additional restoration.

Having discussed the case with the orthodontic department at the initial presentation, the orthodontic phase of treatment was embarked upon under the guidance of a consultant orthodontist. The restored upper left central incisor was extruded using light forces applied by orthodontic brackets and 0.014” nickel-titanium archwire attached from the upper right lateral incisor to the upper left canine teeth. (Figure 7). The mechanics of this phase of treatment lasted six weeks and extruded the tooth approximately 3.5 mm before it was sufficient enough to allow access to the margin of the root fracture (Figure 8). Additional composite (Filtek Z-250, 3M ESPE) was then placed circumferentially around the abutment margin of the re-attached crown fragment and carefully contoured and polished to a smooth finish. Immediately after polishing, a new bracket was repositioned on the traumatized tooth to facilitate orthodontic intrusion for re-alignment of the natural crown fragment using the same progressive light wire forces (Figure 9). The tooth was fully aligned after four weeks and the brackets and archwire removed (Figure 10).

Discussion

This case report describes the management of a complicated crown-root fracture in the coronal third of a maxillary left central incisor using an adhesive fibre-reinforced composite post to re-attach the crown of a tooth to its original aesthetic form and function. It is anticipated that the technique described in this paper will allow the natural tooth to be maintained in the arch until maximum jaw growth has been achieved, enabling the maintained space and alveolar bone to be used for advanced restorative work, denture or dental implant if the natural tooth is eventually lost. Similar cases presented in the dental literature give examples of re-attachment of coronal fractures using tapered fibre posts and dual cure bonding resins remaining pathology and fracture free between 2–10 years in the absence of further traumatic injuries.1,6,7,8,12,17,18

Compared with some of the alternative treatment options, it could be argued that the comprehensive treatment provided in this case was extensive and prolonged for the patient. Unfortunately, some clinicians may have influenced their patients' choice of treatment, even if it did not follow what was evidence-based or best practice. That view can no longer be upheld, especially with the success of restoring fractured teeth using adhesive techniques, as patients have access to additional information which they can source from the internet. It is therefore desirable that clinicians take the time to inform patients of all treatment options available and likely outcomes, success, survival rates and complications that may be associated with them. Both the patients and the carers can then weigh up the benefits and risks and decide on their treatment. Our patient and his parents did exactly that in this case and embarked upon an option of treatment which they accepted and with which they were comfortable. In this case, the demands and the prognosis were carefully explained to the patient and parents at the outset of treatment, along with the other treatment options and their prognosis that were available at the time. What was essential from the outset was the desire to preserve the alveolar bone and the natural aesthetics and function of the tooth by trying to retain the tooth as a natural space maintainer for as long as possible. This has obvious benefits for future implications if an implant needs to be considered. Therefore, if this tooth remains an aesthetic, pathology free and functional space maintainer for a number of years, allowing jaw growth and preservation of alveolar bone, then the technique would be considered as a successful and acceptable outcome in this case.

In this case report, orthodontic extrusion and repositioning back into alignment using controlled fixed appliance therapy was the treatment of choice to gain access to the tooth-restoration interface. The option of raising a mucoperiosteal flap and minor periodontal surgery (osteotomy) may have given the tooth a better prognosis, except the patient and parents refused this procedure. It may also have had implications on the final gingival margin contour and position above the traumatized tooth. In cases of orthodontic extrusion, the final gingival margin position and contour can often be one of unpredictability and, in some circumstances, some minor recontouring to alter this may be required.14 The decision to re-intrude the tooth and allow the restoration to become subgingival, as opposed to reducing the length of the crown and recontouring with composite, was to achieve an optimal gingival emergence profile of the tooth compared to the adjacent central incisor. This also gave the benefit of maintaining the original palatal contours for occlusal purposes and the optimal mesio-distal width of the tooth (Figure 10).

It was noted, upon the completion of the patient's orthodontic treatment, that the movements of the tooth had caused some rolling of the gingival cuff at the cervical margin of the upper left central incisor (Figure 10). This was not a concern for the patient and his parents, who were happy with the outcome of his treatment at this stage. The patient and parents reported no problems or symptoms from the tooth at his 12-month follow-up appointment and clinical examination revealed only minor gingival inflammation around the labial surface of the restored upper left central incisor tooth (BPE index 0/1/0, 0/0/1). Radiographic examination at this visit revealed no peri-radicular pathology and good marginal integrity of the sub-gingival restoration (Figure 11). The patient remains free of dental caries, with good oral hygiene and is currently awaiting orthodontic assessment for his malocclusion.

In summary, we believe that the intervention described in this case report, using an alternative treatment technique, restored a traumatized permanent tooth back to function and aesthetics and is one that can be utilized by other dentists in the management of similar traumatic injuries in children.

Conclusion

This case report demonstrates an interdisciplinary approach to the management of a traumatized tooth which can maintain the benefits of function and aesthetics to patient and parents. Patients and parents should be made aware of all possible treatment options as the role of parental support is crucial to the successful management of paediatric patients.