掺氮TiO_(2-x)N_x薄膜托槽生物相容性的实验研究

Biocompatibility of MBT straight wire appliance with nitrogen-doped titania TiO_(2-x)N_x film

目的制备掺氮TiO2-xNx薄膜托槽并评价薄膜托槽的生物相容性。方法采用射频磁控溅射法在直丝弓金属托槽原材料试样表面制备锐钛矿相掺氮TiO2-xNx薄膜:①将薄膜材料(薄膜托槽组)和普通托槽材料(普通托槽组)分别缝合于大鼠颊黏膜2侧,2周后肉眼观察和组织学评价薄膜的口腔黏膜刺激性;②分别用薄膜材料(薄膜托槽组)、普通托槽材料(普通托槽组)浸提液和生理盐水(生理盐水组)给小鼠灌胃1周,观察小鼠的临床毒性体征、体质量增长率和重要脏器组织学变化以评价薄膜材料的短期全身毒性作用;③薄膜材料对兔血的溶血实验评价材料的溶血性;④分组同②,各组小鼠在24 h内给予对应液灌胃2次,制备小鼠骨髓涂片评价薄膜材料可能的致畸致突变作用。结果大鼠饮食、活动如常,薄膜托槽组的口腔黏膜与普通托槽组组织学表现一致,表明薄膜托槽无明显口腔黏膜刺激作用;短期全身毒性实验中,3组小鼠体质量增长率差异无统计学意义(P>0.05),所有动物未观察到明显的临床毒性体征,病理解剖也未观察到明显异常,表明薄膜托槽无明显短期全身毒性作用;溶血实验中,薄膜托槽组溶血率<5%,未发现红细胞破象,表明薄膜试样不引起急性溶血;微核实验中生理盐水组、薄膜托槽组和普通托槽组的微核率分别为1.48‰、2.08‰和2.16‰,均低于5‰,且两两之间差异无统计学意义(P>0.05)。结论掺氮TiO2-xNx薄膜托槽无口腔黏膜刺激性、无短期全身毒性、无溶血性以及无遗传毒性,具有良好的生物相容性。

Objective To produce nitrogen-doped titania （TiO2-xNx） film on MBT straight wire appli- ance and to evaluate its biocompatibility. Methods Radio-frequency magnetron sputtering was applied to produce TiO2-xNx film on the surface of raw material of MBT straight wire appliance. Biocompatibility was evaluated as follows： （ 1 ） The film material （ raw material of MBT straight wire appliance with TiO〉xN, film） and the control material （ raw material of MBT straight wire appliance） were fixed on the surface of rat oral mucosa, which were examined macroscopically and histologically after 2 weeks. （2） Mice were given the extracted liquids of the film material and the control material and normal saline by lavage for 1 week, respectively. The clinical symptoms were observed, body weight was recorded and viscera were dissected and observed in the mice to evaluate the short-term systemic toxicity of the film material. （3） The hemolysis of the film material was evalua- ted with rabbit blood in vitro. （4） Mice were given the extracted liquids of the film material and the control ma- terial and normal saline by lavage twice in 24 h, respectively, and the bone marrow slides of the mice were pre- pared to evaluate the teratogenicity and mutagenicity of the film material. Results The appetite and movement of the rats were normal, and the histological morphology of rat oral mucosa of the film material group showed nosignificant difference from that of the control material group, which suggested the film material had no oral mu- cosa irritation response. The growth rate of mouse body weight was not significantly different between the film material group and the control material group （P 〉 0.05 ）, and neither toxic signs nor apparent abnormality of pathological examination was found, revealing that the film material had no obvious short-term systemic toxicity. The hemolytic rate was less than 5 %, and the breaking up of red blood cells was not found in the film material group, indicating that the fihn material had no hemolytic reaction. The micronuclear rates in the polychromatic erythrocytes （PCE） of the mouse bone marrow of the negative control group, the film material group and the control material group were 1.48, 2.08 and 2.16 , respectively, which were all less than 5 , but there was no significant difference between the three groups （P 〉 0.05 ）. Conclusion MBT straight wire appliance with nitrogen-doped titania TiO2-xNx film has good biocompatibility without oral mucosa irritation response, short-term systemic toxicity, hemolysis and genotoxicity.