title: Mechanical and biological properties of bioactive bone cement containing silica glass powder.
abstract: Silica glass powder (SG-P) made by a fusing-quenching method was added as a second filler to a bioactive bone cement consisting of MgO-CaO-SiO2-P2O5-CaF2 apatite and wollastonite containing glass-ceramic powder (AW-P) and bisphenol-a-glycidyl methacrylate (Bis-GMA)-based resin, to achieve a higher mechanical strength and better handling properties in use. Five types of cement were used, containing different weight ratios of AW-P/SG-P (Group 1 = 100/0; Group 2 = 75/25; Group 3 = 50/50; Group 4 = 25/75; and Group 5 = 0/100) as filler, to evaluate the effect of SG-P content on the biological, mechanical, and handling properties. The total proportion of filler added to the cements was 85% w/w. The compressive, bending, and tensile strengths and fracture toughness of the cements increased with SG-P content. The viscosity of cements also increased with SG-P content, and every cement could be handled manually. The cements were evaluated in vivo by packing the intramedullary canals of rat tibiae. An affinity index was calculated for each cement; this was the length of bone directly apposed to cement expressed as a percentage of the total length of the cement surface. Histological examination of implanted tibiae for up to 26 weeks showed that the affinity indices decreased with SG-P content and that those of all the cement groups increased with time. At 26 weeks, Groups 1 and 2 had almost identical affnity indices (79% and 75%; no significant difference) but those of the other groups remained at <50%. Group 2 had better mechanical and handling properties than Group 1, and an SG-P content in the filler of no more than 25% w/w did not interfere strongly with the bioactivity of the cement.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: J
authors.initials: J
authors.lastname: Tamura
authors.forename: H
authors.initials: H
authors.lastname: Iida
authors.forename: H
authors.initials: H
authors.lastname: Fujita
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: T
authors.initials: T
authors.lastname: Kikutani
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000737:chemistry / Q000494:pharmacology; D004577:Electron Probe Microanalysis; D005898:Glass; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011208:Powders; D051381:Rats; D017208:Rats, Wistar; D012822:Silicon Dioxide; D013977:Tibia / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D011208:Powders; D012822:Silicon Dioxide