Discussion - References.
Geminated and fused teeth are generally symptom-free. Owing to the abnormal morphology of the crown and the internal complexity of the root canal system, restorative, endodontic, periodontic and orthodontic treatment protocols require special attention (Friedman et al . 1984, Grover & Lorton 1985, Chaudhry et al . 1997, HÃ¼lsmann et al . 1997).
In the present case both clinical crowns of the affected tooth were caries-free with no restoration and no traumatic history. The aetiology of the pulp infection was initially thought to be the deep lingual and buccal radicular grooves, leading to retrograde pulp infection from the periodontal pockets. This kind of bacterial invasion is often encountered with other developmental anomalies, for example, dens invaginatus (dens in dente), dens evaginatus and palatogingival groove, and can lead to pulp inflammation, necrosis and even loss of the tooth loss (Rotstein et al . 1987, Chen et al . 1990, HÃ¼lsmann et al . 1997). But, since the periodontal pockets did not reach the apical area, this theory was challenged. The later review of this case revealed that the aetiology of the pulp infection could have been due to the presence of an undetected crack along the gemination groove with pulpal involvement. This theory was further supported by the subsequent vertical fracture of the tooth. An excessive access preparation due to the complex internal morphology and the search for an extra canal probably contributed to the propagation of the crack and to the complete fracture.
The long-term prognosis of the present case will depend on the success of the root filling and on the periodontal management of the residual mesial defect. Indeed, continued periodontal treatment comprising instruction in oral hygiene and regular periodontal supportive care, as well as acceptable patient plaque control, will be required to maintain healthy periodontal conditions. Periodic clinical examinations (probing depth, probing attachment levels) and radiographic monitoring must be also planned to assess soft and hard tissues healing.
In this case the conservative endodontic and periodontal treatments were initially considered to be adequate and extraction avoidable. However, subsequent vertical fracture and an area of radiolucency between the fractured surfaces left no other alternative but the extraction of the mesial segment.
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