牙种植高分子材料聚甲基丙烯酸甲酯的生物相容性

Biocompatibility of polymethylmethacrylate as a polymer material for dental implants

背景:钛作为牙种植材料,术后的出血率、发生感染和牙龈增生的概率较高,使得钛的应用受到了一定的限制;有研究表明,甲基丙烯酸甲酯已经应用于人造关节、人造骨,但用于牙种植材料的报道还很少。目的:通过探究纯钛和聚甲基丙烯酸甲酯分子材料作为牙种植材料对于人成骨细胞的细胞毒性、细胞贴壁率、相对增殖率以及种植后所引起的炎性反应等生物相容性指标,为临床上聚甲基丙烯酸甲酯作为牙种植体的广泛应用提供一定的参考依据。方法:体外培养人成骨细胞的细胞,实验分为3组:空白对照组细胞正常培养;纯钛组培养液中加入纯钛浸提液培养细胞;聚甲基丙烯酸甲酯组培养液中加入聚甲基丙烯酸甲酯浸提液培养细胞。结果与结论:与空白对照组相比,加入纯钛和聚甲基丙烯酸甲酯提取液培养细胞2,4,8,16 h后,细胞贴壁率均明显降低(P<0.05),聚甲基丙烯酸甲酯组的细胞贴壁率高于纯钛组(P<0.05);与空白对照组相比,加入纯钛和聚甲基丙烯酸甲酯提取液培养细胞2 d后,细胞稀疏,生长速度缓慢,其中聚甲基丙烯酸甲酯组细胞生长较快,呈梭形,拉丝现象不明显;与空白对照组相比,加入纯钛和聚甲基丙烯酸甲酯提取液培养细胞2 d后,细胞相对增殖率均明显降低(P<0.05),聚甲基丙烯酸甲酯组的细胞增殖率高于纯钛组(P<0.05);种植纯钛和聚甲基丙烯酸甲酯材料7 d后,大鼠血清中炎性因子表达明显增加(P<0.05),种植聚甲基丙烯酸甲酯组的炎性因子表达较纯钛组少(P<0.05);聚甲基丙烯酸甲酯组仅有1只大鼠发生过敏反应,无热原反应和死亡,而纯钛组有3只大鼠发生过敏反应,1只发生热原反应,无死亡。结果证实,聚甲基丙烯酸甲酯作为牙种植材料,在细胞毒性、种植后引发的炎症反应以及生物相容性方面均优于纯钛。

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＆nbsp;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.