Effects of High Insertion Torques (≥75 Ncm) on Secondary Stability of Implants Placed According to the “All-on-Four Concept”: A 2-Year Clinical Prospective Controlled Case Series Study

Background/Objectives: Primary stability is an important factor for dental implant success, and a high insertion torque (IT) is recommended in cases where an immediate load is required or desired. At the same time, some authors have claimed that it can interfere with bone-to-implant healing. This study aimed to compare the survival rates of implants inserted with different torques in full-arch cases, with or without immediate load, with up to 2-year follow-up. Methods: This study included subjects who required full-arch rehabilitation with implants. All cases were planned for the placement of four implants on each arch and were divided into groups according to the IT and had implant stability quotient (ISQ) measurements taken periodically for up to 2 years. Results: No implant was lost during this period, and no significant differences in peri-implant bone loss were observed. The paired t-test was performed to determine the association between ISQ and IT. Conclusions: The results suggest that initial torques higher than 75 Ncm may not be harmful to the stability of implants placed for full-arch rehabilitation, at least during the study period. Further clinical studies with longer follow-up periods are necessary to confirm these results.