The effect of osteotomy dimension on osseointegration to resorbable media-treated implants: a study in the sheep

The drilling technique and the surface characteristics are known to influence the healing times of oral implants. The influence of osteotomy dimension on osseointegration of microroughned implant surfaces treated with resorbable blasting media was tested in an in vivo model. Ninety-six implants (ø4.5 mm, 8 mm in length) with resorbable blasting media-treated surfaces were placed in the ileum of six sheep. The final osteotomy diameters were 4.6 mm (reamer), 4.1 mm (loose), 3.7 mm (medium), and 3.2 mm (tight). After three and six weeks of healing, the implants were biomechanically tested and histologically evaluated. Statistical analysis was performed using Page L trend test for ordered and paired sample and linear regression, with significance level at p < 0.05. An overall increase in all dependent variables was observed with the reduction of osteotomy diameter. In addition, all osseointegration scores increased over time. At three weeks, the retention was significantly higher for smaller osteotomies. The histological sections depicted intimate contact of bone with all the implant surfaces and osteoblast lines were visible in all sections. The resorbable blasting media microroughed surfaces achieved successful osseointegration for all the instrumentation procedures tested, with higher osseointegration scores for the high insertion torque group.