Histological study of bone quality in the implant sites prepared by the drilling and expansion techniques

Introduction: Bone drilling and expansion techniques have been used for implant site preparation. However, histological studies comparing these two techniques are limited. This study aimed to histologically assess the bone quality in the implant sites prepared by the bone drilling and expansion techniques in a sheep model. Materials and Methods: This experimental animal study was conducted on three sheep and four sites were chosen in their mandibles. Implant holes were created by bone drilling and expansion techniques in an alternate fashion. The first sheep underwent vital perfusion immediately after surgery and its mandible was fixed. The second and the third sheep were subjected to vital perfusion 19 and 26 days after surgery, respectively. The collected samples were stained with hematoxylin and eosin and the percentage of osteogenesis, the amount of ossification and sequester area, were measured by computer assisted histomorphometric analysis system. The amount of inflammation was estimated for each sample, considering the frequency of inflammatory cells infiltration, in terms of degree of inflammation as zero, less than 10% and more than 10%, under x400 magnification. Results: No significant difference was noted between the drilling and expansion techniques for implant site preparation in terms of degree of inflammation or rate of osteogenesis. The amount of sequesters was different between the two groups in the first days after surgery but no significant difference was noted in this regard between the two groups after 3 weeks. Conclusion: according to the histological evaluation, the method of implant sites preparation does not effect of quality of bone regeneration.