不同浓度单宁酸在不同酸蚀模式下对通用型粘接剂粘接强度的影响

目的研究不同浓度单宁酸在全酸蚀与自酸蚀条件对通用型粘接剂在牙本质表面粘接强度的影响。 方法将60颗无龋离体人磨牙置于存储盒中随机盲取分成2组（全酸蚀A组与自酸蚀B组，n = 30），再将每组随机分为5个亚组（n = 6）。在使用通用型粘接剂Single Bond Universal（SBU）前，在牙本质面分别涂抹浓度为0%（对照组）、25%、50%、75%和100%的单宁酸3 min并冲洗吹干。实验试件在37 ℃水中保存24 h后进行微拉伸强度测试（μTBSt）。使用Two-Way ANOVA与Games-Howell对数据进行统计学分析。用体式显微镜观察断裂面模式并在扫描电镜（SEM）下观察微拉伸试件的牙本质断端。 结果在全酸蚀模式下，75%单宁酸组粘接强度[（34.51 ± 8.43）MPa]与100%单宁酸组粘接强度[（36.16 ± 5.20）MPa]显著高于其他各组（F = 32.301，P<0.001）；在自酸蚀模式下，25%单宁酸[（31.06 ± 3.41）MPa]可显著提升SBU与牙本质粘接强度（F = 23.570，P<0.001）。双因素分析结果证实，单宁酸浓度（F = 23.134，P<0.001）与酸蚀模式（F = 4.465，P = 0.036）对粘接强度具有显著影响且两要素间显著相关（F = 28.231，P<0.001）。断裂模式分析与电镜观察结果表明，在牙本质表面不同酸蚀模式与不同浓度单宁酸所形成的界面形态差异显著。 结论在不同酸蚀模式下，不同浓度的单宁酸均可显著改善SBU与牙本质的粘接强度。

Effect of tannic acid with different concentrations on bond strength under different etching modes

ObjectiveTo evaluate the effect of tannic acid with various concentrations on the bond strength between dentin and universal adhesive under the total and self-etching modes. MethodsSixty human molars without caries were randomly divided into two groups (group A: total-etching mode; group B: self-etching mode, n = 30) with five subgroups (n = 6) from the box blindly. After exposing its dentine, tannic acid with different concentrations of 0% (control group) , 25%, 50%, 75% and 100% was applied on dentin surface for 3 minutes with rinsing and air-blowing before Single Bond Universal (SBU) was used. Micro-tensile Bond Strength test (μTBSt) was carried out after 37 ℃ water-storage for 24 h. The data were analyzed by Two-Way ANOVA and Games-Howell test (α = 0.05) . Failure mode analysis and fracture surface observation on dentin side were done by stereomicroscope and electron scanning microscope (SEM) , respectively. ResultsIn the total-etching mode, the bond strength of 75% and 100% concentration groups was significantly higher than that of the other groups (P<0.05) . In the self-etching mode, significantly higher bond strength than the rest was achieved by 25% concentration (P<0.05) . Two-Way ANOVA revealed a significant effect of tannic acid concentration (F = 23.134, P<0.001) and etching mode (F = 4.465, P = 0.036) on bond strength, while the interaction between two variables was also significant (F = 28.231, P<0.001) . The results of failure mode analysis and SEM observation indicated that the interfacial morphology on dentin created by both etching modes and different concentrations of tannic acid was significantly different. ConclusionThe bond strength between dentin and SBU could be significantly improved by tannic acid with different concentrations in both total and self-etching modes.