Abstract: Objective To evaluate the clinical efficacy effects of flap surgery in combination with minocycline hydrochloride in treatment of chronic periodontitis.Methods Fifteen patients with chronic periodontitis were recruited into this study, with a total of 16 teeth in which probing depth of two sites was over 5 mm. The subjects were randomized into two groups. After scaling and root planning in three months, the experimental group received flap surgery in combination with minocycline hydrochloride, while the control group received flap surgery only. For both groups, the following indexes were recorded at the time of baseline (before root planning), 1 month and 3 months after the treatment: probing depth (PD), clinical attachment loss (CAL), plaque index (PLI) and sulcus bleeding index (SBI).Results At the time of baseline, there was no significant difference in the indexes between the two groups. At the time of 1 and 3 months after the treatment, both groups showed significant improvement in their examined indexes. The experiment group showed a greater gain in PD and CAL compared with the control group at 1 and 3 months, though there were no significantly difference in PD and CAL between the two groups at the time 1 and 3 months (P>0.05). However, There was significant difference in PLI and SBI between the two groups at the time 1 and 3 months (P<0.05).Conclusion Following both therapeutic modalities, there were marked clinical improvements for the chronic periodontitis at the time of both 1 and 3 months compared with baseline. And flap surgery in combination with minocycline hydrochloride is more effective.

Key words: chronic periodontitis, minocycline hydrochloride, flap surgery