Biocompatibility of polymethylmethacrylate as a polymer material for dental implants / 中国组织工程研究

ABSTRACT

BACKGROUND:As a kind of dental implant material, the application of titanium has certain restrictions because of its higher probability of postoperative bleeding rate, infection and gingival hyperplasia. Studies have shown that polymethylmethacrylate has been used in artificial joints and artificial bones, but rarely reported to be used as dental implant material. OBJECTIVE:To explore the biocompatibility indexes such as cytotoxicity, cel adhesion rate, relative cel proliferation rate and post-implantation inflammatory response of human osteoblasts when pure titanium and polymethylmethacrylate are used as dental implant materials, so as to provide certain reference basis for the clinical usage of polymethylmethacrylate as the dental implant material. METHODS:Human osteoblasts were cultured in vitro. Three groups were divided as folows control group (cels cultured normaly), pure titanium group (cels cultured with titanium extract) and polymethylmethacrylate group (cels cultured with polymethylmethacrylate extract). RESULTS AND CONCLUSION:Compared with the control group, the cel adhesion rate was significantly decreased after 2, 4, 8 and 16 hours of culture with pure titanium and polymethylmethacrylate extracts (P < 0.05); the cel adhesion rate in the polymethylmethacrylate group was higher than that in the pure titanium group (P < 0.05). Compared with the control group, the cels were sparse and grew slowly after 2 days of culture with pure titanium and polymethylmethacrylate extracts. Cels in the polymethylmethacrylate group grew faster with fusiform distribution and obvious drawing phenomenon. Compared with the control group, the relative cel proliferation rate was significantly decreased after 2 days of culture with pure titanium and polymethylmethacrylate extracts (P < 0.05); the relative cel proliferation rate of polymethylmethacrylate group was higher than that of the pure titanium group (P < 0.05). The expression of inflammatory factors in rat serum was significantly increased after 7 days of implantation of titanium and polymethylmethacrylate materials (P < 0.05), the expression of inflammatory factors in the polymethylmethacrylate group was less than that in the titanium group (P < 0.05). There was only one rat developing alergic reaction, but no pyrogen reaction and no death in the polymethylmethacrylate group; and three rats presented with alergic reaction, one rat present with pyrogen reaction and no death occurred in the pure titanium group. These results demonstrate that as the dental implant material, polymethylmethacrylate is superior to pure titanium in the cel toxicity, inflammatory response and biocompatibility.