The Effects of High Insertion Torque Versus Low Insertion Torque on Marginal Bone Resorption and Implant Failure Rates: A Systematic Review With Meta-Analyses

OBJECTIVES: The aim was to analyze the data about the effects on marginal boneresorption and implant failure rates between implants inserted with high or lowinsertion torque values.MATERIALS AND METHODS: A systematic literature search until July 2015 wasconducted. Data were summarized qualitatively in descriptive tables andquantitatively by performing random effects meta-analyses of effect sizes (ESs)for bone resorption and bone-to-implant contact (BIC) and relative risks (RRs)for implant failures. Risk of bias assessments were performed using the Cochrane tool for human studies and the SYRCLE's tool for animal studies.RESULTS: Four studies in humans and 6 quasirandomized animal studies wereincluded. A total of 591 implants were evaluated qualitatively: 348 installedwith high insertion torque (>25 Ncm, up to 176 Ncm) and 243 implants insertedwith low torque values (<30-35 Ncm). No significant differences were detected forbone resorption (ES, 0.13; 95% confidence interval [CI], -0.12 to 0.38 in humanstudies; ES predictive interval from 35.03 to 34.50 in animal studies), implantfailure (RR, 0.39; 95% CI, 0.01-20.77 in human studies; RR, 2.05; 95% CI,0.19-21.71 in animal studies), or BIC (ES predictive interval from -3.84 to 5.13 in animal studies).CONCLUSION: The current review indicated that there is no significant difference in marginal bone resorption and implant failure rate between implants insertedwith high or low insertion torque values.