Primary mineralization in the interface between bone and methyl methacrylate implants in rat mandibles. A correlative light and scanning and transmission electron microscope study.

Self curing polymethylmethacrylate implants were administered into rat mandibular bone. Tissue reaction was studied after different periods with light microscopy and transmission and scanning electron microscopy. Formation of fibrous tissue in the interface between implant and bone was associated with initial bone resorption and followed by the occurrence of primary calcification in a collagen rich matrix after 4-8 weeks. The features of primary mineralization comprised appearance of hydroxyapatite crystals within matrix vesicles and formation of calcospheritic structures. The occurrence of calcifying fronts after the intraosseous administration of polymethylmethacrylate suggests a favourable relationship between bone and the implant material.