Comparison of the restorative effects of crown lengthening surgery and gingivectomy on dowel crown of deep-seated subgingival teeth fracture

Objective To compare the restorative effects of crown lengthening surgery and gingivectomy on dowel crown of deep-seated subgingival teeth fracture. Methods Fifty-eight teeth were selected and divided into the crown lengthening surgery group and gingivectomy group .We performed regular restoration of post crown after the teeth cross-section was completely exposed. Then, the clinical effects were compared by measuring the depths of gingival pocket at the time of two weeks and six months after operation, and the results were evaluated by χ2 test. Results Two weeks after operation, the effective rate in the gingivectomy group was much lower than the rate of the crown lengthening surgery group (P0.05) . Six months after operation,the occurrence rate of periodontitis in the gingivectomy group was significantly higher than that in the crown lengthening surgery group ( P0.05). Conclusion According to the biologic width principle, crown lengthening surgery can conserve these teeth with subgingivally involved defect, and has a good, long-time clinical effect.