Effects of predrilling on the osseointegration potential of mini-implants.

Objectives: To determine a reliable method of drilling a pilot hole when using a self-tapping surface-treated mini-implant and to evaluate stability after placement.

Materials And Methods: Implant sites were predrilled in 12 rabbits with two devices: a conventional motor-driven handpiece and a newly developed hand drill. Mini-implants were then inserted in a complete random block design. Samples were divided into 1-week and 6-week groups to investigate osseointegration capacity in relation to the two time intervals. Mechanical and histomorphometric assessments were performed.

Results: Mechanical analysis revealed no difference in maximum removal torque or total removal energy between the motor-driven predrilling group and the hand-drilling group. No difference was found between the 1-week group and the 6-week group. Histomorphometric evaluation showed no difference in the bone-implant contact (BIC) ratio or the bone volume (BV) area. For the time interval, a statistically significant increase in BIC and BV area was found in the 6-week group when compared to the 1-week group.

Conclusions: The osseointegration potential of the motor-driven predrilling method was not different from that of the manual predrilling method with the newly developed hand drill. Hand drilling may be an attractive predrilling method in preference to the conventional motor-driven pilot drilling.