Abstract: OBJECTIVE To observe and compare the effects of flap curettage combined with guided bone regeneration and ultrasonic scaling in combination with drug therapy on treatment of peri-implant infections so as to provide guidance for treatment of dental implant infections. METHODS A total of 26 patients (28 implants) who received implant restoration and had peri-implant infections in Binzhou People's Hospital from Jan 2009 to Dec 2013 were enrolled in the study and were randomly divided into the group A with 13 cases (15 implants) and the group B with 13 cases (13 implants).The group A was treated with flap curettage combined with guided bone regeneration, while the group B was given ultrasonic scaling in combination with drug therapy.The specimens were collected for identification of pathogens; the plaque index (PLI), probing depth (PD), sulcular bleeding index (SBI), and X-ray data of the two groups of patients were recorded before the treatment and after the treatment for 1, 6, and 12 months. RESULTS Of the 312 implants, 28 had the infections, with the infection rate 8.97%.Totally 52 strains of pathogens were isolated, of which 34.62% were Prevost melaninogenica, and 23.08% were oral Streptococci. The PLI, PD, and SBI of the group A and the group B were significantly reduced after the treatment for 1, 6, and 12 months.The dental implant marginal bone heights of the group A were remarkably increased before the treatment and after the treatment for 1 and 6 months; the dental implant marginal bone heights of the group B were remarkably increased after the treatment for 6 months, as compared with those before the treatment(P＜0.05). CONCLUSION Both the flap curettage combined with guided bone regeneration and the ultrasonic scaling in combination with drug therapy can achieve significant clinical effect on treatment of the peri-implant infections; the flap curettage combined with guided bone regeneration may better promote the combination of bone and implant.