Complicated crown-root fracture is among the most difficult dental injuries to manage because of limited accessibility and difficulty in isolation. This case report describes the interdisciplinary management of a patient with complicated crown root fractures. After performing root canal therapy, orthodontic extrusion was done using elastics followed by gingivectomy procedure. Porcelain fused to metal crowns were then fabricated after cementation of cast metal post and core.
Trauma kills more than 3 million people in the world every year and millions of people are injured. Although the oral region comprises 1% of the total body area, the oral injuries account for as much as 5% of all body injuries with an even higher proportion of oral injuries among children. Teeth are injured in more than nine of ten patients presenting with oral injuries.1 Complicated and uncomplicated crown-root fractures pose the greatest difficulty for the dentists to establish adequate treatment plans because these fractures require multidisciplinary knowledge and approach for a correct case planning and prognosis.2
When there is a subgingival fracture of a tooth various problems are encountered. Achieving perfect seal during restoration of the tooth becomes difficult. Hence coronal leakage persists, jeopardizing outcome of treatment. Also maintenance of good oral hygiene is impeded. Thus when a tooth fractures below the gingival attachment or crest of the alveolar bone, it becomes imperative to bring the subgingival margins supragingivally.3
There are several treatment options available for restoration of complicated crown-root fractures after removal of coronal fragment:
Orthodontic extrusion of apical fragment
Gingivectomy / ostectomy to expose apical fragment
Surgical extrusion of apical fragment.
Choice of treatment depends on the site and type of fracture, as also on cost and complexity of treatment. After any of the above technique is used, further, a post and core along with full crown is given.4
This clinical report describes the multidisciplinary management of maxillary central and lateral incisor with complicated crown-root fracture.
A nineteen-year-old youth was referred to us with obliquely fractured crowns of left maxillary central and lateral incisor. There was a history of fall from the bicycle five days before. The local dentist who referred him to us had prescribed antibiotics and analgesics. Although there was no pain, the patient's chief concern was the mobile tooth fragments. Intraoral examination revealed that teeth 21 and 22 had complicated crown-root fractures with the fracture line visible in the cervical third on buccal aspect and infragingival on the palatal aspect. (Figure1.)The coronal fragments of both the teeth were mobile and slightly tender to touch. Baseline vitality testing was done for all maxillary anterior teeth using cold and electric tests. Teeth 21 and teeth 22 showed delayed response while tooth 11 showed no response. Preoperative Intraoral Periapical Radiograph confirmed the diagnosis. (Figure 2)
Figure 1: Oblique crown-root fracture with 21 and 22
Figure 3: Emergency stabilization of coronal fragments
Figure 4: Extrusion initiated using J-hook, elastics and composite wire splint.
Emergency treatment involved stabilization of the coronal fragments with composite (buccal) and composite resin splint (palatal) to adjacent teeth. (Figure 3) As teeth 21 and 22 had their pulp exposed for more than 24 hours and considering restorative needs, patient was scheduled for endodontic treatment with the same. However for tooth 11, vitality testing was evaluated again after 2 weeks. At 1 month the tooth began to show vital response. Further, radiographs taken during the course of treatment (21 and 22) showed no periapical changes with tooth 11. Hence, no further treatment was done for the said tooth.
Figure 5: Cast metal posts cemented with 21 and 22
Figure 6: Intraoral Periapical Radiograph after cementation of Cast metal posts with 21 and 22
Figure 7: Porcelain fused to metal crowns cemented for 21 and 22
Figure 8: Intraoral Periapical Radiograph at three year recall
After endodontic treatment with teeth 21 and 22 was completed under rubber dam, the coronal fragment of tooth 21 was removed. Since the palatal extent of the fracture was infra alveolar, a J-shaped hook was cemented in the root canal to facilitate forced orthodontic extrusion. Using composite wire splint and elastics (Figure 4) tooth 21 was extruded for about 2.5mm in 4 weeks. Consequently coronal fragment of tooth 22 was removed and a crown lengthening procedure was done from teeth 13 to 23. Further cast metal posts (Figure 5 and Figure 6) and porcelain fused to metal full crowns were fabricated for both the teeth. (Figure 7) Recall visit after 14 months shows stable tooth and periodontal conditions. (Figure 8)
The most conservative and convenient treatment modality for any fracture is the reattachment of the fragment if it has been retrieved. However immediate shortcoming of this treatment alternative is the frequent refracture of the reattached fragment. Additionally, in case of a crown-root fracture where the fracture line is subgingival, isolation becomes difficult. Thus, reattachment can possibly best be described as provisional until definitive treatment can be provided.
Among the various permanent treatment alternatives available for complicated crown root fracture, forced orthodontic eruption is indicated when the root is sufficiently long, so that after extrusion a sufficient amount of tooth remains embedded in the bone. Compared to the other treatment alternatives this is time-consuming and may require multidisciplinary approach. However, it produces excellent esthetic results with good prognosis and low risk of relapse.4
Forced orthodontic extrusion of 2.5mm was done in this case for tooth 21 over a period of 4 weeks followed by a retention period of 4 weeks. Further a crown lengthening gingivectomy procedure done from 13 to 23 resulted in adequate ferrule for both 21 and 22. Also, the esthetic appeal of the smile was greatly improved owing to gingival contouring. Rigid metal posts were chosen because the coronal tooth structure was compromised. Rigid posts reduce micromovement at the cervical level which leads to microleakage.5 Porcelain fused to metal crowns were cemented thereafter. Recall visits conducted every three months upto 14 months showed satisfactory esthetics and function.
Thus multidisciplinary treatment of oblique crown-root fracture is a reliable method to save such teeth which otherwise would be extracted.
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