Background: Evaluation and measurement of primary stability could be achieved by several methods, including the resonance frequency analysis (RFA) and implant insertion torque (IT) values. The need for a sufficient primary stability, guaranteed by an adequate insertion torque and implant stability quotient values, increased its importance mainly in one stage implants or in immediate loading protocols. The aims of this study was to find if there is a correlation between the peak insertion torque (PIT) and ISQ values of implants inserted in the jaws of different bone quality which regarded as two important clinical determinant factors for prediction of implant primary stability, and to evaluate and compare whether an experienced clinician could precisely predict the primary stability of an implant on insertion with different surgical procedures using his own tactile perception. Materials and methods: A total of (60) Iraqi adult patients, (28) males and (32) females, age ranged (22-66) years old were enrolled in this clinical prospective study. The maximum torque value recorded on implant insertion using calibrated manual torque ratchet adopting three categories: low (10 to 30 N/cm), medium (30 to 50 N/cm), and high insertion torque (50 to 70 N/cm). The oral surgeon was asked to indicate the perceived ISQs values according to his perception then Implant stability quotient were measured by Osstell ™. Bone density (type) was determined according to subjective bone resistance encountered while drilling as proposed by Lekohlm and Zarb. Results: A total of 160 implants were inserted. The mean peak IT value was 49 ± 2.61N/cm. The mean ISQ value was 71.7 ± 8.86. Statistical analysis show a significant correlation between ISQ values and PIT values (P<0.001) , between IT values and bone types and between perceived primary stability and actual primary stability (P<0.001) . Conclusions:The corresponding significant correlations between insertion torque, and ISQ values may help clinicians to predict primary stability on implant insertion, that may be associated with implant survival and success rates. A moderate reliability (correlation) between perceived ISQ values and those measured using RF analyzer(Ossttel device).
