Análise Histomorfométrica da Cicatrização de Implantes Transalveolares Imediatos Instalados em Mandíbulas de Cães

Abstract

The osseointegrated implants were developed seeking to the rehabilitation of edentulous patients, and the initial protocol commended the placement of the implants on the healed alveolar bone. The healing of extraction socket was considered, therefore, one of the basic requirements for the establishment of the osseointegration. However, recently, studies have been demonstrating that the implants can be placed into sockets immediately after tooth extraction, presenting success rate similar to implants placed in healed bone. The purpose of this study was to evaluate the bone healing around implants placed into fresh extraction sockets, comparing the perceptual of bone-to-implant contact of cervical third with middle third of implants. In the present study 26 implants of IMZ™ system were placed into extraction sockets of the 3° e 4° premolars in mandibles of 4 dogs, without defined race. For histomorphometric analyses, accomplished 3 months after placement of the implants, each implant was divided in three parts (cervical, middle and apical thirds). The middle third was considered as control, since in this region, the implants presented in contact with bone on surgery moment. The cervical third was considered as the experimental area, because many times, did not exist bone-toimplant contact in this region, by the fact the coronal part of socket normally have a bigger diameter than implant. The apical third was discarded of the analyses, because great part of implants was placed into mandibular canal, without or with minimum bone contact. The osseointegration perceptual obtained in the middle third of implants was 33.39%, while in the experimental area this perceptual was 11.13%, and this difference was statistically significant. The present study demonstrated that, despite of clinically the spaces between coronal portion of implants and bone walls of socket presented clinically healing, the histomorphometric analyses revealed a smaller osseointegration perceptual at cervical third comparing with middle one, after 3 months to healing.