Bone and Microvasculature around Implants Prepared Using Different Surface Treatments and under Occlusal Loading

Abstract

For the long-term functioning of an implant,it is important that the established peri-implant bone is maintained. The formation and absorption of the bone are related to the microvasculature. Therefore, we investigated the sequential changes in bone percentage and vascular percentage around rough- and smooth-surfaced implants having the same structure and under occlusal loading. We additionally elucidated the implant that showed long-term functionality.
In this study, a rough-surfaced implant produced by blasting (BI) and a smooth-surfaced implant produced by machining (MI) were used.These implants were fixed in the molar part of the mandible of three monkeys and were maintained under non-loading conditions for 14 weeks. The implants were loaded after setting up a super-structure at 14 weeks following fixation. At 14 weeks under the non-loading conditions and at 1, 4, 12, and 24 weeks under the loading conditions, bone and microvasculature specimens were prepared by the plastic injection method and were observed under a scanning electron microscope. The bone percentage and the vascular percentage in the 500-μm area surrounding each implant were calculated using image processing software.
For each week, the bone percentage of MI was higher than that of BI. The former did not change during 0-12 weeks after the loading and decreased during 12-24 weeks. The latter did not change during 0-4 weeks after the loading, increased during 4-12 weeks, and decreased remarkably during 12-24 weeks. For each week, the vascular percentage of MI was higher than that of BI. The former did not change during 0-4 weeks after the loading,increased during 4-12 weeks, and did not change during 12-24 weeks. The latter did not change during 0-4 weeks, increased during 4-12 weeks, and increased further during 12-24 weeks.
From the result that the bone percentage of MI was higher than that of BI until 24 weeks after the loading, it was suggested that the peri-implant bone of MI was maintained for a longer time than that of BI.