Effect of Multiple Coatings of One-step Self-etching Adhesive on Microtensile Bond Strength to Primary Dentin

Objective To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin.Methods Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each.In group 1,each tooth was hemisected into two halves.One half was assigned to control subgroup 1,which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing.In group 2,the teeth were also hemisected into two halves.One half was assigned to control subgroup 2,which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer.Microtensile bond strength was immediately tested after specimen preparation.Results When the adhesive was applied three times before light curing,the bond strength of the experimental subgroup 1(n=33,57.49±11.61 MPa) was higher than that of the control subgroup 1(n=31,49.71±11.43 MPa,P<0.05).When using the technique of applying multiple layers of adhesive with light curing each successive layer,no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2(P>0.05).Conclusion Multiple coatings of one-step self-etching adhesive can increase the immediate bond strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

Multiple Coatings can Improve the Bond Durability of One-step Self-etching Adhesive to Primary Dentin

Objective To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin. Methods Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instruc- tions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaC1 containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis. Results When the adhesive was applied three times before light curing, the bond strength of the ex- perimental subgroup 1 was significantly higher than that of the control subgroup 1 （47.46__＋13.91 vs. 38.12＋11.21 MPa, P〈O.05）. When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup （39.40＋8.87 vs. 40.87-＋9.33 MPa, P〉O.05）. Conclusion Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

3M粘结剂治疗牙本质过敏症的疗效观察

目的 观察3M粘结剂治疗牙本质过敏的疗效。方法 选取2015年1月~4月我院收治的牙本质过敏症患者92例（136颗牙）,将患牙分为实验组70颗,对照组66颗,实验组应用3M粘结剂进行脱敏治疗,对照组应用75%氟化钠甘油进行脱敏治疗。观察两组在治疗即刻与治疗3个月后的疗效。结果 实验组即刻有效率为92.76%,对照组即刻有效率为53.03%,差异有统计学意义（P〈0.05）,3个月后复查结果相同。结论 3M粘结剂治疗牙本质过敏症的疗效显著,是一种较好的脱敏剂。

两种粘结剂联合复合树脂充填修复乳前牙环状龋的疗效对比分析

目的对乳前牙环状龋患儿采用不同粘结剂联合复合树脂充填修复的效果进行分析对比。方法选择2017年10月—2018年10月于本院进行治疗的乳前牙环状龋患儿70例(共167颗患牙)为研究对象,将所有患儿根据治疗方式的不同分为对照组和观察组两组,每组各35例,对照组患牙81颗,采用自酸蚀牙本质粘结剂+复合树脂进行填充修复;观察组患牙86颗,采用新型混合型两种粘结剂+复合树脂进行填充修复。对比两组在治疗后半年、一年的牙齿修复效果。结果治疗后半年、一年,观察组的修复体固位、边缘密合性以及牙髓活性均显著优于对照组,差异均具有统计学意义(P<0.05)。结论对于乳前牙环状龋患儿,将新型混合型粘结剂和复合树脂作为填充修复的材料,能够有效保证修复体固位完整,增强边缘密合性和牙髓活性,值得临床上推广运用。

2%氯己定预处理牙本质对全酸蚀粘接剂的微拉伸强度的影响

目的探讨2%氯己定(CHX)预处理牙本质对全酸蚀粘接剂的粘接强度的影响。方法取40颗离体人磨牙,磨除牙合面牙釉质至釉牙本质界下,暴露牙本质,作为粘接面。随机分为四组,取两组在酸蚀后涂粘接剂前涂布CHX为实验组,另外两组同法涂布蒸馏水处理为对照组。所有组经全酸蚀粘接剂3M ESPE Single Bond2处理后,堆积超声树脂制备成粘接模型。取一组实验组和一组对照组制备成标准试件后,直接测试微拉伸粘接强度;另外一组实验组和空白组在冷热循环5 000次后制备标准试件,并测试其微拉伸粘接强度。运用体视显微镜和扫描电镜观察断裂界面,分析断裂模式。结果 CHX处理组和空白组之间的微拉伸强度的差异具有统计学意义(P<0.05)。老化后,CHX处理组和空白组之间的微拉伸强度的差异也具有统计学意义(P<0.05)。经CHX处理的即刻组和老化组,其差异具有显著性统计学意义(P<0.01)。空白对照的即刻组和老化组间无统计学差异(P>0.05)。所有组别的断裂大多是在粘接剂内部即界面断裂,少数的混合断裂及极少数的内聚断裂。结论 2%CHX预处理能够增强牙本质全酸蚀粘接强度,老化后增强作用变得更加明显。