Crown lengthening surgery for the treatment of 20 cases of crownroot-fractured teeth

Objective To observe clinical efficacy of crown lengthening surgery for the treatment of crown-root-fractured teeth,subgingival fractured edge.Methods Twenty patients(23 affected teeth) with crown-root-fractured teeth caused by caries and injury were performed with crown lengthening surgery and with restoration of crown 6 weeks after the surgery and effects of broken ends of fractured teeth were observed.Results Out of 23 affected teeth(20 cases),19 teeth were treated successfully and successful ratio was 82.61%.PD of 10 teeth was 4 mm and below,depth of exposure of broken ends of 10 fractured teeth was 3-4mm. Periodontal depth was 2-3mm,and successful rate was 90%.PD of 23 teeth was over 4 mm and no more than 5 mm,exposure of broken ends of fractured teeth in 10 teeth demonstrated after 6 weeks,broken ends of fractured teeth of 3 teeth were subgingival or paralleled with gum and successful rate was 76.92%.Successful rate in patients with PD≤4mm was obviously better than patients with 4mmPD≤5mm(P0.05).Conclusion Curative effects of crown lengthening surgery for the patients characterized by PD no more than 4 mm and residual root of residual crown was 1.2 cm and above,which maintains biological breadth,is benefit for complete coronal restoration and is definitive value of clinical application.