Hemadri M, Saritha G, Rajasekhar V, Pachlag K Amit, Purushotham R, Reddy Veera Kishore Kumar
Reader, Department of Conservative Dentistry & Endodontics, CKS Theja Institute of Dental Sciences & Research Centre, Tirupati, Andhra Pradesh, India.
Reader, Department of Conservative Dentistry & Endodontics, Pullareddy Dental College, Kurnool, Andhra Pradesh, India.
J Int Oral Health. 2014 Nov-Dec;6(6):22-5.
Enhancement of bond strength between new and old composite usually requires increased surface roughness of old composite to promote mechanical interlocking and subsequent coating with bonding agents to improve surface wetting and chemical bonding. So this study was carried out to evaluate and compare the effects of different surface treatments and repair materials on the shear bond strength (SBS) of composite repairs The mode of failure of repaired composites whether cohesive or adhesive was also evaluated.
The substrates for 60 composite specimens were fabricated and aged with water treatment and subjected to various surface treatments. The surface treatment regimens used in the study were: No surface treatment, abraded with diamond bur, air abraded (sandblasted) with 50 µ aluminum oxide particles. Specimens were then repaired with fresh composite using either Clearfil(™) repair or all-bond two adhesive systems. Specimens were water stored, thermocycled and tested for SBS using universal testing machine. Fractured specimens were then examined under stereomicroscope to determine the mode of failure.
It was clearly showed that surface roughening of the aged composite substrate with air abrasion, followed by the application of Clearfil(™) repair adhesive system (Group IIIa) yielded the highest repair bond strength (32.3 ± 2.2 MPa).
Surface treatment with air abrasion followed by bonding with Clearfil(™) repair adhesive system can be attempted clinically for the repair of composite restorations.
增强新旧复合材料之间的粘结强度通常需要增加旧复合材料的表面粗糙度以促进机械互锁，并随后使用粘结剂涂层以改善表面润湿性和化学键合。因此，本研究旨在评估和比较不同表面处理和修复材料对复合材料修复体剪切粘结强度（SBS）的影响。还评估了修复后的复合材料的失效模式是内聚性还是粘结性。
制备60个复合材料试件的基底，进行水处理老化，并进行各种表面处理。本研究中使用的表面处理方案为：不进行表面处理、用金刚砂钻磨、用50µ氧化铝颗粒进行空气磨蚀（喷砂）。然后使用Clearfil（™）修复或全粘结两种粘结系统用新鲜复合材料修复试件。将试件进行水储存、热循环处理，并使用万能试验机测试SBS。然后在立体显微镜下检查断裂的试件以确定失效模式。
结果清楚地表明，用空气磨蚀对老化的复合材料基底进行表面粗糙化处理，然后应用Clearfil（™）修复粘结系统（IIIa组）产生了最高的修复粘结强度（32.3±2.2MPa）。
临床上可以尝试用空气磨蚀进行表面处理，然后用Clearfil（™）修复粘结系统进行粘结，以修复复合修复体。
