D'Arcangelo Camillo, Vanini Lorenzo
Department of Operative Dentistry, Dental School, University of Chieti, Italy.
J Adhes Dent. 2007 Jun;9(3):319-26.
To evaluate the effect of different surface treatments of composite resin blocks on the adhesive properties of indirect composite restorations. The null hypothesis tested was that none of the performed surface treatments would produce greater bond strength.
The crowns of 80 extracted molars were transversally sectioned next to the pulp to expose flat, deep dentin surfaces. Eighty-eight cylindrical composite specimens measuring 3.5 mm in diameter and 10 mm in height were prepared and randomly divided into 4 groups (CG, HFSiG, SaG, SaSiG), which respectively received the following treatments: control (CG): etching with 9.5% HF acid gel and application of a silane (HFSiG); sandblasting (SaG) with 50-microm Al2O3 from a distance of 10 mm at a pressure of 2.5 bars for 10 s; combination of sandblasting and silanization procedures (SaSiG). Two composite specimens of each group were analyzed with SEM, while the remaining twenty cylindrical specimen were bonded to dentin samples using a two-step adhesive system and a thin layer of composite. After 24 h storage and 5000 thermocycles, all specimens were loaded to failure under tension in a universal testing machine. The mean differences of each group were analyzed with the Kruskal-Wallis test, while multiple comparisons were made using the Ryan-Einot-Gabriel-Welsch Range test. P-values less than 0.05 were considered to be statistically significant in all tests. The fracture pattern of bonded specimens was also evaluated by SEM.
SEM analysis showed morphological changes in each group. The mean values (in MPa) of TBS (+/- SD) for groups CG, HFSiG, SaG, and SaSiG were 11.17 +/- 3.48, 10.81 +/- 5.19, 16.51 +/- 3.45 and 16.55 +/- 3.16, respectively. Statistical analysis showed that the bond strength was significantly affected by surface treatment (p < 0.001). Multiple comparison analysis identified statistically significant differences for CG and HFSiG vs SaG and SaSiG (p < 0.05), while no significant differences were found for the comparisons CG vs HFSiG and SaG vs SaSiG (p > 0.05). Only a few adhesive failures were recorded (CG: 0.5%; SaG: 0.4%; HFSiG: 0.5%; SaSiG: 0.7%). The null hypothesis was rejected.
Composite surface treatments are important for adhesion of indirect composite restorations. Roughening the composite area of adhesion, sandblasting, or both sandblasting and silanizing can provide statistically significant additional resistance to tensile load. Hydrofluoric acid etching with silane treatment did not reveal significant changes in tensile bond strength. These findings suggest that sandblasting treatment was the main factor responsible in improving the retentive properties of indirect composite restorations.
评估复合树脂块不同表面处理对间接复合树脂修复体粘接性能的影响。所检验的无效假设是，所进行的任何表面处理均不会产生更高的粘接强度。
将80颗拔除磨牙的牙冠在靠近牙髓处横向切开，以暴露平坦、深层的牙本质表面。制备88个直径3.5 mm、高10 mm的圆柱形复合树脂标本，并随机分为4组（CG组、HFSiG组、SaG组、SaSiG组），分别接受以下处理：对照组（CG组）：用9.5%氢氟酸凝胶酸蚀并应用硅烷（HFSiG组）；用50微米的Al2O3在距离10 mm、压力2.5巴的条件下喷砂10秒（SaG组）；喷砂和硅烷化程序联合处理（SaSiG组）。每组取两个复合树脂标本进行扫描电子显微镜（SEM）分析，其余20个圆柱形标本使用两步粘接系统和薄层复合树脂粘接至牙本质样本。在储存24小时并进行5000次热循环后，所有标本在万能试验机上进行拉伸加载直至破坏。用Kruskal-Wallis检验分析每组的平均差异，同时使用Ryan-Einot-Gabriel-Welsch极差检验进行多重比较。在所有检验中，P值小于0.05被认为具有统计学意义。还通过SEM评估粘接标本的断裂模式。
SEM分析显示每组均有形态变化。CG组、HFSiG组、SaG组和SaSiG组的TBS（±标准差）平均值（单位：MPa）分别为11.17±3.48、10.81±5.19、16.51±3.45和16.55±3.16。统计分析表明，表面处理对粘接强度有显著影响（p<0.001）。多重比较分析确定CG组和HFSiG组与SaG组和SaSiG组之间存在统计学显著差异（p<0.05），而CG组与HFSiG组以及SaG组与SaSiG组之间的比较未发现显著差异（p>0.05）。仅记录到少数粘接失败情况（CG组：0.5%；SaG组：0.4%；HFSiG组：0.5%；SaSiG组：0.7%）。无效假设被拒绝。
复合树脂表面处理对间接复合树脂修复体的粘接很重要。使复合树脂粘接区域粗糙化、喷砂或喷砂与硅烷化处理均可提供具有统计学显著意义的额外抗拉伸载荷能力。氢氟酸酸蚀并硅烷处理未显示拉伸粘接强度有显著变化。这些发现表明喷砂处理是改善间接复合树脂修复体固位性能的主要因素。
