Immediate loading of single implants inserted flapless with medium or high insertion torque: a 6-month follow-up of a split-mouth randomised controlled trial

Purpose: To compare the outcome of immediately loaded single implants inserted with medium (from 25 to 35 Ncm) or high insertion torques (>80 Ncm). Materials and methods: Fifty patients received two single non-adjacent implants, each randomly inserted flapless with a torque between 25 to 35 Ncm or >80 Ncm according to a split-mouth design. Non-occluding temporary crowns were immediately placed on provisional abutments and definitive crowns were delivered after 6 weeks. Patients were followed for 6 months after initial loading. Outcome measures were crown/implant failures, complications, peri-implant marginal bone level changes, postoperative pain and presence of peri-implant apical radiolucency. Results: No drop-out occurred. Seven implants inserted with a torque between 25 to 35 Ncm failed versus none of the implants inserted with a torque >35 Ncm. With the exception of crown/implant failures (exact McNemar significance P = 0.0156, difference in proportions: -0.12; 95% CI -0.21 to -0.02) there were no statistically significant differences between groups for the other outcome measures. Conclusions: It is preferable to insert single implants with a high insertion torque (>80 Ncm), to minimise early implant failures, when loading them immediately. Keywords: dental implants, immediate loading, insertion torque, success