The response of midfacial bone in sheep to loaded osteosynthesis screws in pretapped and nontapped implant sites.

Abstract This study compared the functional retention of pretapped and self-tapping 2-mm AO miniscrews (Stratec Medical, Waldenburg, Switzerland) in an animal experimental model. Histologic evaluation of the bone surrounding the loaded screws showed significantly more remodeling when pretapped screws were used than when self-tapping screws were used. Although the experimental situation may not be directly comparable with the clinical situation, this study does lend credibility to the assumption that pretapping is not advisable in the thin bone of the midface.