Baena Eugenia, Vignolo Valeria, Fuentes Maria Victoria, Ceballos Laura
Am J Dent. 2015 Oct;28(5):255-60.
To investigate the effect of different repair procedures and storage time on microtensile bond strength (μTBS) of a resin composite to an older one from a simulated previous restoration.
Composite disks were made by layering 2 mm-thick increments of a nanohybrid composite (Grandio) shade A1 in a Teflon mold (4 x 8 mm). Afterwards, they were light-cured and stored (37 degrees C/7 days) in a saline solution. Specimens were randomly divided into groups according to the surface treatment applied: (1) Composite surface was roughened with a bur (Cimara) and Solobond Plus adhesive was applied; (2) Sandblasting with 27 μm aluminum oxide particles (KaVo Rondoflex), and adhesive application; (3) Air-abrasion with 30 μm alumina particles coated with silica (CoJet Sand), silane (Monobond-S) and adhesive application; (4) Negative control group with only adhesive application. Afterwards, Grandio composite (shade A3.5) was packed incrementally on the treated surface obtaining another disk (4 x 8 mm). Repaired blocks were stored (24 hours or 6 months) and afterwards μTBS test was performed and failure mode was evaluated. Also, beams obtained from 8 mm-high composite blocks without any surface treatment were immediately submitted to μTBS test to determine Grandio composite cohesive bond strength (positive control group). Data were analyzed using ANOVA and Tukey's test (P < 0.05).
The repair procedure affected μTBS values (P < 0.001) while neither storage time nor interactions did (P > 0.05). All repair procedures achieved bond strength values higher than the negative control group but they did not reach the composite's cohesive bond strength. The overall conclusion was that an increased superficial roughness by means of a bur, silica coating or alumina sandblasting improved μTBS of the repaired composite and bond strength remained stable after 6 months.
研究不同修复程序和储存时间对树脂复合材料与模拟先前修复体中旧材料之间微拉伸粘结强度（μTBS）的影响。
在聚四氟乙烯模具（4×8mm）中逐层填入2mm厚的纳米混合复合材料（Grandio）A1色号材料制成复合盘。之后，对其进行光固化，并在盐溶液中储存（37℃/7天）。根据所应用的表面处理方法将样本随机分组：（1）用车针（Cimara）使复合表面粗糙化，并应用Solobond Plus粘结剂；（2）用27μm氧化铝颗粒喷砂（KaVo Rondoflex），并应用粘结剂；（3）用涂有二氧化硅的30μm氧化铝颗粒进行空气磨蚀（CoJet Sand），应用硅烷（Monobond-S）和粘结剂；（4）仅应用粘结剂的阴性对照组。之后，将Grandio复合材料（A3.5色号）逐层填充在处理过的表面上，制成另一个盘（4×8mm）。修复后的块体储存（24小时或6个月），之后进行μTBS测试并评估失效模式。此外，从未经任何表面处理的8mm高复合块体获得的梁立即进行μTBS测试，以确定Grandio复合材料的内聚粘结强度（阳性对照组）。使用方差分析和Tukey检验分析数据（P<0.05）。
修复程序影响μTBS值（P<0.001），而储存时间和交互作用均不影响（P>0.05）。所有修复程序获得的粘结强度值均高于阴性对照组，但未达到复合材料的内聚粘结强度。总体结论是，通过车针、二氧化硅涂层或氧化铝喷砂增加表面粗糙度可提高修复复合材料的μTBS，且粘结强度在6个月后保持稳定。
