Abstract
It is well known that implant surface characteristics (topography) affect osseointegration. Grit blasting with abrasives is one method of implant surface modification. It was reported that osteogenesis was increased more by roughening implant surface by apatite grit-blast treatment than by using alumina. This study compared the direction and arrangement of bone induction and formation in the boundary area between the implant produced by the following methods and the surrounding bone, using back-scattering image in SEM:Ti alloy rods grit-blasted with alumina abrasive (Group 1), with apatitic abrasive (Group 2), and with alumina abrasive and plasma-sprayed using hydroxyapatite source (Group 3).
Rabbits were used as the experimental animal for this study, in which a 2.8 mm hole was produced in the tibia and implantation was performed under anesthesia. The rabbits were sacrificed 1, 2, and 4 weeks after surgery under anesthesia, and part of the tibia including the implant was collected as non-decalcified tissue specimens. After vacuum evaporation of carbon, BSI of the specimens was observed using a scanning electron microscope. Although it had been difficult to differentiate the formation of new bone by conventional microscopic observation, entire images could be obtained by the use of BSI, and osteogenetic patterns were clearly observed in this study.
Although G l and G 3 showed new bone smoothly developing from the adjoining compact bone toward the implant surface, G 2 exhibited bone growth originating from the medullary cavity, showing different osteogenetic patterns.
These findings revealed that new bone formation was more marked in the early stage by the use of grit-blasted implants than by the use of apatite materials, showing bone growth patterns differing fromthose in G 1 and G 3.
Entire images could be obtained by the use of BSI in which it had been difficult to differentiate the formation of new bone by conventional microscopic observation, and osteogenetic patterns were clearly observed in this study.
