Variables that influence the relationship between osseointegration and bone adjacent to an implant

It is often assumed that there is a direct relationship between the bone de nsity adjacent to an implant, as revealed by radiographs, and the percent h istologic osseointegration. Moreover, the lack of standardized methods for evaluation of histologic preparations makes it difficult to compare publish ed studies, especially as little is known about the variables that influenc e these measurements. In this animal study, computer-assisted lineal analys is was used to evaluate the effects of subject, tooth position, and implant surface site on measured bone density and osseointegration in a bone augme ntation experiment. Three sites-coronal lingual, apical lingual, and apical facial-were analyzed around each of 6 (3.75 X 8 mm) threaded machined tita nium implants, as well as the apical facial site of 21 other implants place d in the mandibular premolar area of 5 dogs. In all sites, a progressive de crease in bone density was observed from bone adjacent to the implant to th at at the titanium implant surface. There was an animal effect on osseointe gration, but there were no differences between the mandibular premolar loca tions (second, third, and fourth). Most importantly, there were significant measurable effects attributable to the surface site examined. The need for carefully standardized histologic evaluations is established.