Woven bone formation around implants and the effect of bacterial infection

Several implant materials used in dental and orthopedic surgery were placed in rat tibial bones to study their effects on mineralization. The implants consisted of bone bonding and non-bonding materials. Changes in mineraliza tion were defined by morphometric analysis of matrix vesicle distribution a t the implant interface and in normal bone healing following marrow injury. Bone-bonding materials induced an increase in matrix vesicle activity. Thi s finding was supported by study of the biochemical changes in the same mod el that manifested high correlations to the morphometrical observations wit h regard to enhancement or delay of primary mineralization. In addition, th e study of healing using nuclear methods indicated that implants alter bone healing as shown by the different uptakes of Tc-99m and P-32 in the differ ent bone compartments. Decreased P-32 uptake by the organic phase in the pr esence of bone-bonding implants suggested that cleavage of (TC)-T-99m-(MDP) -P-32 into its technetium and methylene diphosphonate moieties was inhibite d by administration of implants. Further studies on the effect of bacterial infection on the peri-implant tissues revealed a decrease in woven bone fo rmation due to infection.