Untitled

Abstract

This study investigated cytotoxicity of cement fragments harvested from two prosthesis revisions by the MTT test using L929 fibroblasts and human osteoblasts. The results did not show any toxicity of the extracts prepared after 48 and 78 months implantation. We consider that no MMA monomer has been released from the cement fragments. Histological studies on undecalcified samples harvested around revising prosthesis from 11 patients were used to evaluate tissue reactions at the bone-cement interface after 2-168 months implantation. Cement and prosthesis particles (5-35 microm) either dispersed or forming a layer were observed. A fibrous tissue layer, osteolysis, and osteonecrosis areas were observed at the interface. Besides, fibroblasts, macrophages, and multinucleated giant cells were also observed. New bone formation with osteoid, osteoblasts, and endochondral ossification with fibrocartilaginous tissue has been observed. The tissue reactions seemed to decrease with time. However, osseous trabeculae fractures were observed in the samples after 19 months. Although we consider that monomer toxicity, exothermic reaction, and particles formation may cause short-term prosthesis loosening; the trabeculae fractures may be due to prosthesis and bone cement micromovements. This fractures and particles formation may cause long-term prosthesis loosening.

Customized Polymethyl Methacrylate Implants for the Reconstruction of Craniofacial Osseous Defects

“…The monomer toxicity should disappear completely within four hours [3]. No monomer fragments are released after PMMA implantation, and no PMMA toxicity occurs after 48 and 78 months following surgical reconstruction [10]. …”

Reconstruction of bony facial contour deficiencies with polymethylmethacrylate implants: case report

“…After the polymerization, usually 15 min, about 3-5% of the monomer remains, and decreases to 1-2% with time. The monomer toxicity should disappear within 4 h 12 . Lu, et al 12 (2002) did not found any toxicity of PMMA after 48 and 78 months of implantation.…”

“…The monomer toxicity should disappear within 4 h 12 . Lu, et al 12 (2002) did not found any toxicity of PMMA after 48 and 78 months of implantation. In addition, the authors reported no MMA monomer released fragments after implantation.…”

Semi-degradable poly(β-amino ester) networks with temporally controlled enhancement of mechanical properties

“…By combining them with a nondegradable, high Tg monomer, such as methyl methacrylate, the Tg of the network was increased to ambient conditions [32]. The biodegradable crosslinkers have shown previous biocompatibility in vivo , and PMMA is well known to be biocompatible [33–35]. In order for the PBAE-MMA network to have the same benefits of standard biodegradable polymers, it must elicit a favorable biological response, while also showing an increase in modulus during degradation.…”