Abstract: OBJECTIVE: To study the effect of different Insertion torque values on implant stability and osseointegration by using the means of Resonance Frequency Analysis. MATERIAL AND METHODS: 49 patients were chosen randomly according to the following standards, with 86 screws implanted. Furthermore, the same experienced clinician finished all surgeries. All implants were divided into three groups based on the insertion torque values: Group A, Itv0~15Ncm; Group B，Itv20~40Ncm；Group C，Itv>40Ncm. The dental implant stability was measured to evaluate the osteointegration by Resonance frequency analysis when implants were placed immediately and at the time point of 8 weeks and 12 weeks after the surgeries. RESULTS: 1.Compared with the ISQ measured immediately after the surgery, all the values of ISQ at the time points of 8 weeks and 12 weeks after the surgeries were higher. 2.The ISQ at the 8 week time point of Group A showed the most obvious increase; while there was no significant difference among the three groups. 3.The ISQ values showed no significant difference between the 8-week time point and the 12-week time point in all three groups. Conclusion: The 8-week time point is a critical time for implants healing to develop a high- quality osseointegration. What is more, there was no obvious difference that has been observed of the osseointegration at the 8-week time point when ISQ changed among the groups.

Key words: osseointegration, ISQ, insert torque, Resonance Frequency Analysis, Implants