Lopes Guilherme C, Franke Margarete, Maia Hamilton P
Faculty of Dentistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
J Prosthet Dent. 2002 Jul;88(1):32-6.
Finishing of composites may adversely influence the sealing ability of direct adhesive restorations.
This study was conducted to determine whether finishing time and techniques under wet or dry conditions affect the microleakage of 2 types of class V composite restorations.
Eighty class V preparations were made in the buccal surfaces of noncarious molars with the occlusal margins ending in enamel and the gingival margins in dentin. Dental adhesive (Single Bond) was applied according to the manufacturer's instructions. Half of the preparations were restored with a microfilled composite (Silux Plus) and the other half with a hybrid composite (Filtek Z250). Within each major composite group (n = 40), 4 subgroups (n = 10) were established based on finishing technique (diamond finishing burs or aluminum oxide discs) and finishing time (immediate or delayed by 24 hours). The specimens were stored for 24 hours in 37 degrees C water, thermocycled for 250 cycles between 5 degrees C and 55 degrees C, immersed in 2% methylene blue solution for another 24 hours, and sectioned longitudinally. For both enamel and dentin margins, dye solution penetration at the tooth/composite interface was scored from 0 to 4 under stereoscopy at original magnification x 20. Data were analyzed with the Kruskal-Wallis test (P<.05).
Significantly lower leakage scores were recorded for teeth restored with microfilled composite and finished under wet conditions after 24 hours (P<.01). No significant differences were found among the hybrid composite groups.
For microfilled composite restorations on dentin margins, delayed wet finishing with diamond burs resulted in significantly lower microleakage scores than all other finishing protocols. Hybrid composite restorations had equivalent levels of microleakage regardless of the finishing method.
复合树脂的修整可能会对直接粘结修复体的封闭能力产生不利影响。
本研究旨在确定在湿或干条件下的修整时间和技术是否会影响两种V类复合树脂修复体的微渗漏。
在无龋磨牙的颊面制备80个V类洞形，咬合边缘止于釉质，牙龈边缘止于牙本质。按照制造商的说明应用牙科粘结剂（Single Bond）。一半的洞形用微填料复合树脂（Silux Plus）修复，另一半用混合复合树脂（Filtek Z250）修复。在每个主要复合树脂组（n = 40）中，根据修整技术（金刚石修整车针或氧化铝盘）和修整时间（立即或延迟24小时）建立4个亚组（n = 10）。将标本在37℃水中储存24小时，在5℃和55℃之间进行250次热循环，再浸入2%亚甲蓝溶液中24小时，然后纵向切片。对于釉质和牙本质边缘，在原始放大倍数x 20的立体显微镜下，对牙齿/复合树脂界面处染料溶液的渗透情况从0到4进行评分。数据采用Kruskal-Wallis检验进行分析（P <.05）。
用微填料复合树脂修复并在24小时后湿条件下修整的牙齿，其渗漏评分显著较低（P <.01）。混合复合树脂组之间未发现显著差异。
对于牙本质边缘的微填料复合树脂修复体，使用金刚石车针延迟湿修整导致的微渗漏评分显著低于所有其他修整方案。无论修整方法如何，混合复合树脂修复体的微渗漏水平相当。
