Shook Larry W, Turner Edgar W, Ross Judith, Scarbecz Mark
Department of Restorative Dentistry, University of Tennessee Health Science Center, College of Dentistry, Memphis, TN, USA.
Oper Dent. 2003 Nov-Dec;28(6):779-85.
This study determined whether surface roughness of the internal walls of a Class V resin composite preparation, using a carbide bur, a medium-grit diamond bur and a fine-grit diamond bur, affected the degree of microleakage of the restoration. The facial and lingual surfaces of 45 non-carious extracted human molars provided 90 samples for evaluation. The specimen surfaces were assigned randomly in equal numbers to one of three groups (n = 30). Conservative Class V composite preparations were made using one of three different burs: a 330-carbide bur, a 330 fine-grit diamond bur or a 330 medium-grit diamond bur (Brasseler USA). After acid etching, PQ1 (Ultradent Products Inc) primer/bonding resin and Vitalescence (Ultradent Products Inc) were applied and cured following the manufacturers' instructions. After minor finishing, the apices of all root surfaces were sealed with Vitrebond (3M), and the unprepared external surfaces were sealed with nail polish to within 1 mm of the restoration margins. The specimens were stored in distilled water at room temperature for 24 hours, then subjected to 1,200 thermocycles at 5 degrees C and 55 degrees C with a 30-second dwell time. After cycling, the teeth were immersed in a 5% solution of methylene blue dye for 12 hours. The molars were invested in clear acrylic casting resin, labeled, then sectioned once vertically approximately midway through the facial and lingual surfaces using a diamond coated saw blade. Microleakage was evaluated using a 10x microscope for the enamel and cementum surfaces and blindly scored by two independent examiners. In all cases, regardless of the examiner, at both the enamel and the dentin margins, the analysis revealed no statistically significant differences in microleakage across bur types. Further results show that dentin margins leaked significantly more than enamel margins for all bur types.
本研究确定了使用硬质合金车针、中粒度金刚石车针和细粒度金刚石车针制备Ⅴ类树脂复合材料洞形时，洞壁表面粗糙度是否会影响修复体的微渗漏程度。45颗非龋性拔除的人类磨牙的颊面和舌面提供了90个样本用于评估。将样本表面随机平均分为三组（n = 30）。使用三种不同的车针之一进行保守的Ⅴ类复合树脂洞形制备：330号硬质合金车针、330号细粒度金刚石车针或330号中粒度金刚石车针（美国Brasseler公司）。酸蚀后，按照制造商的说明应用PQ1（Ultradent Products公司）底漆/粘结树脂和Vitalescence（Ultradent Products公司）并固化。轻微修整后，用Vitrebond（3M公司）封闭所有牙根表面的根尖，并用指甲油封闭未预备的外表面至修复边缘内1毫米处。将样本在室温下的蒸馏水中储存24小时，然后在5℃和55℃下进行1200次热循环，每次停留时间为30秒。循环后，将牙齿浸入5%的亚甲蓝染料溶液中12小时。将磨牙包埋在透明丙烯酸浇铸树脂中，标记后，使用金刚石涂层锯片在颊面和舌面大约中间位置垂直切割一次。使用10倍显微镜评估釉质和牙骨质表面的微渗漏情况，并由两名独立的检查者进行盲法评分。在所有情况下，无论检查者如何，在釉质和牙本质边缘，分析均显示不同车针类型之间的微渗漏没有统计学上的显著差异。进一步的结果表明，对于所有车针类型，牙本质边缘的渗漏明显多于釉质边缘。
