羟磷灰石牙本质脱敏剂对温和型通用型粘接系统粘接性能研究

Bonding properties of mild universal adhesives to dentin pretreated with hydroxyapatite-based desensitizing agents

目的本研究旨在评估含羟磷灰石(HA)脱敏剂封闭牙本质小管的效果及其对温和型通用型粘接剂粘接性能的影响。方法收集完整的第三磨牙,制备冠中部牙本质样本,建立牙本质敏感模型。根据不同的脱敏处理方式随机分为4组,分别进行下述处理:无脱敏处理(对照组)、Biorepair牙膏处理(含HA脱敏牙膏)、Dontodent牙膏处理(含HA脱敏牙膏)和HA糊剂处理。通过扫描电镜(SEM)观察牙本质小管封闭情况,并评估牙本质小管封闭率。分别使用All-Bond Universal、Single Bond Universal和Clearfil Universal Bond以自酸蚀模式应用于脱敏处理后的牙本质。通过接触角测量评估脱敏处理后牙本质表面的润湿性和表面能(SFE)。制备树脂-牙本质粘接试样,测试微拉伸粘接强度,分析脱敏处理方式对于3种通用型粘接剂的牙本质微拉伸粘接强度的影响。结果SEM显示含HA脱敏牙膏和HA脱敏剂处理后牙本质小管均明显封闭,封闭率HA组>Biorepair组>Dontodent组(P<0.05)。接触角分析表明,含HA脱敏剂对通用型粘接剂的润湿性无显著影响(P>0.05),但脱敏处理后牙本质SFE显著增加(P<0.05)。微拉伸粘接强度测试表明,含HA脱敏牙膏会降低微拉伸粘接强度(P<0.05),而HA组与对照组的微拉伸粘接强度之间差异无统计学意义(P>0.05)。结论含HA脱敏牙膏能够形成牙本质小管封闭。在使用温和型通用型粘接剂进行后续树脂修复时,含HA脱敏牙膏降低牙本质粘接强度,而HA糊剂的脱敏处理未对粘接性能产生不利影响。

Objective The purpose of the study was to evaluate the effect of hydroxyapatite(HA)-based desensiti-zing agents and determine their influence on the bonding performance of mild universal adhesives.Methods Mid-coronal dentin samples were sectioned from human third molars and prepared for a dentin-sensitive model.According to desensitizing applications,they were randomly divided into four groups for the following treatments:no desensitizing treatment(control),Biorepair toothpaste(HA-based desensitizing toothpaste)treatment,Dontodent toothpaste(HA-based desensitizing toothpaste)treatment,and HA paste treatment.Dentin tubular occlusion and occluded area ratios were evaluated by scanning electron microscopy(SEM).Furthermore,All-Bond Universal,Single Bond Universal,and Clearfil Universal Bond were applied to the desensitized dentin in self-etch mode.The wettability and surface free energy(SFE)of desensitized dentin were evaluated by contact angle measurements.Bonded specimens were sectioned into beams and tested for micro-tensile bond strength to analyze the effect of desensitizing treatment on the bond strength to dentin of universal adhesives.Results SEM revealed that the dentin tubule was occluded by HA-based desensitizing agents,and the area ratios for the occluded dentin tubules were in the following order:HA group>Biorepair group>Dontodent group(P<0.05).Contact angle analysis demonstrated that HA-based desensitizing agents had no statistically significant influence on the wettability of the universal adhesives(P>0.05).The SFE of dentin significantly increased after treatment by HA-based desensitizing agents(P<0.05).The micro-tensile bond strength test showed that HA-based desensitizing toothpastes always decreased theμTBS values(P<0.05),whereas the HA paste group presented similar bond strength to the control group(P>0.05),irrespective of universal adhesive types.Conclusion HA-based desensitizing agents can occlude the exposed dentinal tubules on sensitive dentin.When mild and ultra-mild universal adhesives were used for subsequent resin restoration,the bond strength was reduced by HA-based desensitizing toothpastes,whereas the pure HApaste had no adverse effect on bond strength.