纳米二氧化钛对正畸粘接剂抗菌性与拉伸粘接强度的影响

Effect of TiO_2 nanoparticles on the antibacterial effects and tensile bonding strength of orthodontic adhesive

目的研究纳米级二氧化钛对正畸托槽粘接剂抗菌效果及拉伸粘接强度的影响。方法在光固化托槽粘接剂(Grengloo)中加入质量分数1%、2%、3%纳米级二氧化钛。空白对照组不加入二氧化钛。将托槽粘接于离体前磨牙上,测量拉伸粘接强度与粘接剂残留量。粘接剂制成树脂圆片与菌悬液共培养48 h后,进行细菌活性与代谢测定。结果 4组粘接剂的拉伸粘接强度和粘接剂残留指数无显著差异。2%、3%组的pH值明显增加、乳酸产生量明显减少,但两组间无明显差别。加入纳米二氧化钛的三组菌落计数均明显减少,但3组间无明显差别。结论 2%纳米二氧化钛对Grengloo托槽粘接剂拉伸粘接强度无明显影响,同时提高其抗菌性。

Objective To evaluate the effect of titanium dioxide （ TiO2 ） nanoparticles on tensile bonding strength （ TBS） and anti-bacterial properties of an orthodontic adhesive. Methods Light cure orthodontic adhesive （ Grengloo） was blended with TiO2 nanopar-ticles by 1%, 2%, 3% （ mass fraction） . The control was not blended with TiO2 . Brackets were bonded to extracted premolars by these new adhesives. TBS of four groups was determined, and the adhesive remnant index （ ARI） scores were assessed. A total of 20 compos-ite discs specimen were prepared, and incubated with bacterial suspension for 48 hours and tested for antibacterial properties. Results No significant difference was found among TBS and ARI of the four groups. PH values of group 2% and 3% were significantly in-creased and lactate production was significantly reduced compared with the control group, but no significant difference was found be-tween these two groups. The colony unit counts of the three groups containing TiO2 were significantly reduced, but no significant differ-ence among these three groups was observed. Conclusion Adding 2%TiO2 to Grengloo enhances its antibacterial effects without in-creasing the tensile bonding strength.