title: Transmission electron microscopic study of interface between bioactive bone cement and bone: comparison of apatite and wollastonite containing glass-ceramic filler with hydroxyapatite and beta-tricalcium phosphate fillers.
abstract: We developed a bioactive bone cement that consists of apatite and wollastonite containing glass-ceramic (AW-GC) powder and bisphenol-a-glycidyl methacrylate (Bis-GMA) based resin. In this study, we made three types of cement (designated AWC, HAC, and TCPC) consisting of either AW-GC, hydroxyapatite (HA), or beta-tricalcium phosphate (beta-TCP) powder as the inorganic filler and Bis-GMA based resin as the organic matrix. These cements were implanted into rat tibiae and cured in situ. Specimens were prepared 1, 2, 4, and 8 weeks after the operation and observed using transmission electron microscopy. Each of the bone cements was in direct contact with the bone. In AWC-implanted tibiae, the uncured surface layer of Bis-GMA based resin was completely filled with newly formed bone-like tissue 2 weeks after implantation. The AW-GC particles were surrounded by bone and were in contact with bone through an apatite layer. No intervening soft tissue was seen. In HAC-implanted tibiae, it took 4 weeks for the uncured layer to completely fill with newly formed bonelike tissue. The HA particles were also in contact with bone through an apatite layer. In TCPC-implanted tibiae, it took 8 weeks for the uncured layer to fill with newly formed bone-like tissue. The new bone that formed on the TCPC was not as dense as that on the AWC or HAC, and an intervening apatite layer was not evident. Results indicated that AWC had higher bioactivity than either HAC or TCPC.
mesh_terms: D000818:Animals; D001031:Apatites; D001672:Biocompatible Materials; D001843:Bone Cements; D001846:Bone Development; D001842:Bone and Bones / Q000187:drug effects / Q000648:ultrastructure*; D017610:Calcium Compounds; D002130:Calcium Phosphates; D002516:Ceramics; D017886:Durapatite; D005109:Extracellular Matrix / Q000187:drug effects / Q000648:ultrastructure; D005898:Glass; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D017208:Rats, Wistar; D017640:Silicates; D013977:Tibia / Q000187:drug effects / Q000648:ultrastructure; D013997:Time Factors