Abstract：
To evaluate the effect of adhesive coats application on the enamel microtensile bond strength (µTBS) of universal adhesives, morphological etching pattern and their chemical interaction with hydroxyapatite (HA). Two universal adhesives were investigated: Scotchbond Universal (SBU, 3 M) and Prime&Bond Universal (PBU, Dentsply). The adhesives were applied in self-etching mode on bovine enamel (n = 8) in one (1L), two (2L) or three coats (3L) and light-cured as per manufacturers\' instructions. As controls adhesives were applied to etched enamel (H3PO4-37% phosphoric acid). Bonded specimens were cut into sticks that were stored in deionized water for 24 h or 6 months prior to µTBS testing. Two-way ANOVA and Tukey\'s test were used for statistical analysis of bond strength with α = 5%. For morphological SEM analysis, enamel surfaces were treated as aforementioned and immediately rinsed with acetone. The intensity of monomer-calcium salt formation from each treatment was measured via infrared spectroscopy (ATR-FTIR). All treatments presented no significant reduction on µTBS after aging (p > 0.05). However, SBU attained highest µTBS when applied in 3L. PBU showed higher µTBS when applied to H3PO4 etched enamel than 1L or 2L. Etching pattern was enhanced by 3L application, particularly with PBU. Chemical interaction was notably higher for SBU than PBU, with no relevant differences with more layers or prior H3PO4-etching. The application of three adhesive coats of universal adhesives in self-etch mode using may enhance the bonding performance and etching pattern to enamel, surpassing the H3PO4-etched enamel bond for SBU. The chemical interaction with calcium from enamel is not affected by number of coats or prior phosphoric acid etching.
摘要：
为了评估粘合剂涂层对通用粘合剂的釉质微拉伸粘合强度（µTBS）的影响，形态蚀刻模式及其与羟基磷灰石(HA)的化学相互作用。研究了两种通用粘合剂：ScotchbondUniversal(SBU，3M)和Prime&BondUniversal(PBU，Dentsply).粘合剂以自蚀刻模式应用于牛牙釉质（n=8）中的一个（1L），两层（2L）或三层（3L），并按照制造商的说明进行光固化。作为对照,将粘合剂施加至蚀刻的釉质(H3PO4-37%磷酸)。将粘结的样品切成棒,在μTBS测试之前将其储存在去离子水中24小时或6个月。采用双因素方差分析和Tukey检验对α=5%的粘结强度进行统计分析。对于形态学SEM分析，如上所述处理釉质表面并立即用丙酮冲洗。通过红外光谱(ATR-FTIR)测量来自每种处理的单体-钙盐形成的强度。所有处理在老化后在μTBS上没有表现出显著的降低(p>0.05)。然而,当应用于3L时,SBU达到最高μTBS。当应用于H3PO4蚀刻牙釉质时,PBU的µTBS高于1L或2L。通过3L应用增强了蚀刻图案，特别是PBU。SBU的化学相互作用明显高于PBU，与更多层或先前的H3PO4蚀刻没有相关差异。在自蚀刻模式下使用三种通用粘合剂的粘合剂涂层可以增强搪瓷的粘合性能和蚀刻图案，超过SBU的H3PO4蚀刻搪瓷键。与来自釉质的钙的化学相互作用不受涂层数量或先前的磷酸蚀刻的影响。
