Bone reactions adjacent to titanium implants subjected to static load of different duration. A study in the dog (III)

The aim of the present experiment was to study the effect of a long-standin g lateral static load on the peri-implant bone. Three beagle dogs were used . The mandibular premolars were extracted and 12 weeks later 3 titanium imp lants (ITI(R) Dental Implant System) were installed in each quadrant. Crown s were fitted to all implants 12 weeks after the installation procedure. Th e anterior and central crowns were fused and connected to the posterior cro wn by an expansion screw. In the right side of the mandible, the expansion screws were activated every 2 weeks during a 46-week period. During the las t 10 weeks of this period, an expansion force similar to that of the right side was applied in the left. The animals were sacrificed and block biopsie s of each implant site harvested and prepared for histological analysis. Si tes subjected to 10 weeks or 46 weeks of lateral load had a similar (i) dis tribution of bone markers (ii) proportion of bone density and (iii) degree of bone-to-implant contact. The proportion of fluorochromes was higher at s ites subjected to 10 weeks of loading than at sites subjected to 46 weeks o f loading.