Biological reactions of alveolar bone to orthodontic loading of oral implants

Enosseous oral implants have been suggested as anchorage for orthodontic ap pliances in cases where the existing dentition cannot provide sufficient st ability. Long-term studies of oral implants have suggested that excessive l oading may contribute as an etiologic factor in the pathogenesis of failing implants. The purpose of the present study was to perform a histomorphomet ric analysis of tissue reactions around implants subjected to a well-define d force system. The analysis was performed on undecalcified sections cut pe rpendicularly to the long axis of the implant. The degree of osseointegrati on, bone density at varying distances from the implant as well as the relat ive extent of resorption and formation of alveolar bone adjacent to the imp lant-bone interface were evaluated. The results were correlated with the lo cal strain of the tissue estimated by the means of a finite element analysi s. It was found that loading significantly influenced both the turnover and the density of the alveolar bone in the proximity of the implants. However , even unloaded implants tended to maintain the bone characteristics of the alveolar process. On the other hand, the degree of osseointegration appear ed to be independent of the loading of the implant.