[Evaluation of the clinical effect of the teeth with subgingivally involved defect conserved by crown lengthening surgery].

PURPOSE: To evaluate the clinical effect of the teeth with subgingivally involved defect which were conserved by crown lengthening surgery. METHODS: 62 teeth, with defect subgingivally from 1.5 mm to 4 mm, mobility degree(MD)0.05), but a significant increase about MD occurred in the major defect group one year after restoration (P<0.01), and there was significant correlation between MD of each stage after operation and PD of pre-operation in anterior teeth (r=0.489, 0.526, 0.531, P<0.01). CONCLUSIONS: According to the biological width principle, crown lengthening surgery may conserve these teeth with subgingivally involved defect, and has a good, long-time clinical effect. But MD showed an increasing trend after operation and significant cor.

[Experience of repairing alveolar bone defects by collagen membrane and hydroxyapatite and its long-term result].

PURPOSE: To observe the clinical effect of using the domestic BME-10X medical collagen membrane and hydroxyapatite (HA) in guide tissue regeneration of the bone defects caused by periodontitis and periapical cyst. METHODS: 18 cases with 9 points in 9 teeth with II degree furation involvement, 16 points in 11 teeth with 2 or 3 bone bottom pockets and 6 cases with periapical cyst were chosen in our study. The defect region of alveolar bone was stuffed with HA and covered with collagen membrane. The pathological changes after over one year were observed and recorded. RESULTS: The pathological changes of alveolar bone defects were significant in 7 cases with furcation involvements (77.8%),12 cases with bone bottom pockets (75%),and 6 cases of periapical cyst (100%). CONCLUSION: The combination of collagen membrane and HA can be applied in repairing the alveolar bone defects resulting form periodontitis and periapical cysts.