Abstract: Abstract: Objective To evaluate the effect of periodontal factors on chronic apical periodontitis treated by endodontic microsurgery. Methods A total of 83 patients with chronic apical periodontitis treated in Aoxin stomatological hospital at 2012-2015 were selected in this study. Clinical data, imaging examination and periodontal attachment loss (AL) were performed before the operation. Patients were divided into smoking group (n=37) and non-smoking group (n=46) according to the smoking history. After 1 year of follow-up, the effects of AL value and smoking on the therapeutic effect were analyzed through clinical and imaging findings. Results The therapeutic effective rate decreased significantly with the increase of the mesial-distal AL (97.6% vs. 86.4% vs. 73.6%, χ2=7.994，P=0.018). There was no significant difference in the effective rate between different buccal tongue to AL patients (82.6% vs. 84.0% vs. 97.1%, χ2=4.017, P＞0.05). The effective rate was significantly higher in non-smoking group than that of smoking group (97.8% vs. 78.3%, χ2=6.137, P=0.013). Conclusion Periodontal adverse factors can reduce the therapeutic effective rate of microperiapical surgery. Before operation, we should choose the indications according to the loss of periodontal attachment and smoking or not, in order to improve the survival rate of the teeth after operation.

Key words: periapical periodontitis, smoking, periodontal attachment loss, endodontic microsurgery