Effect of insertion load on insertion torque value

Background/Purpose

This study examined the effect of insertion load on implant primary stability by evaluating the insertion torque and insertion time in various implant designs.

Materials and methods

Four implant designs were tested, including one cylindrical implant standard (S), two hybrid implants tapered effect (TE) and bone level (BL), and one conical implant bone level tapered (BLT). Polyurethane bone models of the maxillary posterior region were used. Insertion torque value (ITV) and insertion time, defined as the duration from implant placement initiation to platform alignment, were recorded under two load conditions, the minimum load and a load of 5.0 newton (N). A torque meter was used to capture torque–time curves, and the mean and standard deviation of ITV were calculated. Data were analyzed using a paired t-test (P < 0.05).

Results

The minimum insertion load varied by design: implant S required 2.5 N, implants TE and BL each required 2.0 N, and implant BLT required 1.0 N. At minimum load, insertion torque was 8.68 N cm for implant S, 6.64 N cm for implant TE, 12.29 N cm for implant BL, and 29.52 N cm for implant BLT. Under 5.0 N, the values were 8.12, 7.82, 14.89, and 30.53 N cm, respectively. Insertion time decreased by up to 12.52 % from 1.0 N to 5.0 N, with significant differences in implant BLT.

Conclusion

Hybrid implants are more sensitive to load variations. Optimizing the insertion load based on implant design can enhance clinical outcomes. The insertion load is a critical but often overlooked factor in primary implant stability.