title: Tissue response around silicon nitride implants in rabbits.
abstract: The chemical and dimensional stability associated with suitable fracture toughness and propitious tribological characteristics make silicon nitride-based ceramics potential candidates for biomedical applications, mainly as orthopedic implants. Considering this combination of properties, silicon nitride components were investigated in relation to their biocompatibility. For this study, two cylindrical implants were installed in each tibia of five rabbits and were kept in the animals for 8 weeks. During the healing time, tissue tracers were administrated in the animals so as to evaluate the bone growth around the implants. Eight weeks after the surgery, the animals were euthanized and histological analyses were performed. No adverse reactions were observed close to the implant. The osteogenesis process occurred during the entire period defined by the tracers. However, this process occurred more intensely 4 weeks after the surgery. In addition, the histological analyses showed that bone growth occurred preferentially in the cortical areas. Different kinds of tissue were identified on the implant surface, characterized by lamellar bone tissue containing osteocytes and osteons, by a noncalcified matrix containing osteoblasts, or by the presence of collagen III, which may change to collagen I or remain as a fibrous tissue. The results demonstrated that silicon nitride obtained according to the procedure proposed in this research is a biocompatible material.
authors.affiliation: Centro Tecnológico da Marinha em São Paulo, São Paulo 05508-000, Brasil. ceciliacguedes@gmail.com
authors.forename: Cecilia C
authors.initials: CC
authors.lastname: Guedes e Silva
authors.forename: Bruno
authors.initials: B
authors.lastname: König
authors.forename: Marcelo José
authors.initials: MJ
authors.lastname: Carbonari
authors.forename: Marcelo
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Sérgio
authors.initials: S
authors.lastname: Allegrini
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Bressiani
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001844:Bone Conduction / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D001842:Bone and Bones / Q000033:anatomy & histology; D004396:Coloring Agents; D005260:Female; D008422:Materials Testing; D008856:Microscopy, Fluorescence; D008859:Microscopy, Polarization; D019736:Prostheses and Implants; D011817:Rabbits; D017655:Silicon Compounds / Q000494:pharmacology*; D014048:Tolonium Chloride
chemical_list: D001672:Biocompatible Materials; D004396:Coloring Agents; D017655:Silicon Compounds; D014048:Tolonium Chloride; C032734:silicon nitride