正畸改性流动树脂的体外研究

In Vitro Study of Modified Flowable Resin for Orthodontics

目的:为了增加正畸粘接剂的抗菌性,减少正畸患者的龋白斑发生,现将季铵盐单体甲基丙烯酸十六烷基二甲胺(DMAHDM)以不同浓度梯度加入到流动树脂中作为一种正畸改性粘接剂,以期该种改性粘接剂在满足正畸临床粘接要求的前提下获得更好的抗菌效果。方法:将DMAHDM以质量分数为0%、3%、5%、7.5%加入到3M Z350XT流动树脂中分别记为A组(0%DMAHDM+3M),B组(3%DMAHDM+3M)C组(5%DMAHDM+3M)和D组(7.5%DMAHDM+3M),并在离体牙上粘接托槽。测试托槽剪切粘结强度(shear bond strength,SBS),建立变形链球菌生物膜模型,扫描电镜观察菌斑粘附量,MTT法测得生物膜代谢活性A值来评价改性粘接剂的抗菌性能。结果:抗剪切强度分析,各组间SBS值差异有统计学意义(P=0.001),A组与B组差异无统计学意义(P=0.600),A组与C组、D组差异有统计学意义(P<0.05),C组与D组差异无统计学意义(P=0.530),与A、B组相比,C、D组SBS值下降。抗菌性能的检测,各组菌斑代谢活性(A值)差异有显著性(P=0.000),B、C、D组的抗菌效果均优于A组,C组优于B组,D组优于C组。扫描电镜观察,D组粘接剂的试件表面细菌粘附量最少。结论:在3M Z350XT流动树脂中添加7.5%DMAHDM抗菌剂作为正畸改性粘接剂,但仍能够满足正畸临床粘接的要求且抗菌效果显著,具有一定的临床应用价值。

Objective:To evaluate the antibacterial activity and bond strength of flowing resin containing dimethylaminohexadecy methacrylate(DMAHDM).Methods:A modified orthodontic adhesive was prepared by adding 0%(control),3%,5%,and 7.5%(w/w)DMAHDM to 3M Z350XT flowable resin,recorded as group A,group B,group C,and group D.Enamel shear bond strength(SBS)was tested.The MTT method was used to detect the activity of the Streptococcus mutans biofilm.And bacterial adhesion was observed by scanning electron microscope.Data were analyzed with ANOVA and LSD-t statistical significance was set at the 0.05 probability level.Results:Group A showed no significant differences in the SBS compared with group B(P=0.600).However,the SBS values of group C and group D significantly decreased(P<0.05),although they could meet the orthodontic bonding requirements.The difference between DMAHDM weight concentration gradients was statistically significant(P=0.000),and group D had the best antibacterial effect.Conclusion:Mixing 7.5%DMAHDM into flowable resin improved the antibacterial properties and meet the orthodontic adhesive requirement.