Insertion Torque Characteristics of the KS 3 Implant in Weak Bone, Standardized Extraction-Socket-like, and Maxillary Sinus Simulation Models: An In Vitro Comparative Study

Objective: This in vitro study evaluated the insertion torque characteristics of the KS 3 implant compared with the TSIII implant in standardized artificial bone models representing weak bone, extraction-socket-like reduced support, and maxillary sinus simulation conditions. Materials and Methods: A comparative in vitro study was performed using three models: a weak bone model, a standardized extraction-socket-like reduced-support model, and a maxillary sinus simulation model. Maximum and final insertion torque values were obtained from torque–depth curves. Torque–depth integrals were additionally calculated as exploratory secondary parameters. Statistical analyses were performed using Welch’s t-test and two-way ANOVA where appropriate, and the results were interpreted as exploratory because of the limited sample size. Results: The KS 3 implant showed higher maximum and/or final insertion torque values than the TSIII implant in the weak bone, extraction-socket-like, and maxillary sinus simulation models. In the maxillary sinus model, the torque values showed directional differences according to implant type and residual bone height under the tested fixed undersized drilling protocols for both CAS drilling and bone compaction drilling. Torque–depth integral analysis provided additional information regarding cumulative insertion resistance. Conclusions: Within the limitations of this controlled in vitro study, the KS 3 implant showed higher insertion torque values than the TSIII implant under the tested artificial bone conditions. These findings should be interpreted as in vitro insertion torque data under the tested artificial bone and drilling conditions, not as evidence of clinical superiority. In the maxillary sinus simulation model, the observed torque differences should be interpreted as the combined effect of implant macrodesign and the fixed undersized drilling protocol, rather than as an isolated macrodesign effect.