Loguercio Alessandro Dourado, de Oliveira Bauer José Roberto, Reis Alessandra, Grande Rosa Helena Miranda
Department of Dental Materials, Dental School, University do Oeste de Santa Catarina, Joaçaba-SC, Brazil.
Quintessence Int. 2004 Jan;35(1):29-34.
To evaluate the microleakage in Class II resin restorations at different margins and the polymerization shrinkage of the composites used.
Four standardized Class II (3 x 5 x 2 mm) cavities were prepared in 32 teeth. The sample had the gingival margin either 1 mm below or above the cementoenamel junction. Teeth were divided and restored according to the following protocols: (1) Single Bond + P60; (2) Prime & Bond NT + Surefil; (3) Bond-1 + Alert; and (4) Prime & Bond 2.1 + TPH. After 7 days, the specimens were thermocycled (500 cycles between 5 to 55 degrees C with a 15-second dwell time), immersed in 0.5% methylene blue for 24 hours, sectioned, and evaluated (both surfaces) at the gingival margin by two examiners, using a 0 to 3 marginal infiltration score system. The polymerization shrinkage of the composites (n = 6) was evaluated by the disk deflective method. Microleakage data was evaluated by nonparametric repeated measures ANOVA. The percentage of polymerization shrinkage was evaluated by ANOVA and Tukey's test.
Only protocol 3 showed a significant difference between enamel and cementum margin. No difference was detected among the protocols in the enamel margin. Only protocol 1 provided a good seal in the cementum margin. All packable composites showed lower polymerization shrinkage than the hybrid tested.
All protocols are able to prevent dye penetration in enamel margins; however, protocol 1 is preferable to reduce the microleakage in the cementum margin. The packable composites showed lower polymerization shrinkage compared to the hybrid resin.
评估Ⅱ类树脂修复体在不同边缘处的微渗漏情况以及所用复合材料的聚合收缩率。
在32颗牙齿上制备4个标准化的Ⅱ类（3×5×2毫米）窝洞。样本的龈缘位于牙骨质釉质界下方或上方1毫米处。根据以下方案对牙齿进行分组和修复：（1）单键粘结剂+P60；（2）Prime & Bond NT粘结剂+Surefil复合材料；（3）Bond-1粘结剂+Alert复合材料；（4）Prime & Bond 2.1粘结剂+TPH复合材料。7天后，对样本进行热循环处理（在5至55摄氏度之间循环500次，每次停留15秒），浸入0.5%的亚甲蓝中24小时，切片，由两名检查者使用0至3的边缘渗透评分系统在龈缘处（两个表面）进行评估。通过圆盘挠度法评估复合材料（n = 6）的聚合收缩率。微渗漏数据通过非参数重复测量方差分析进行评估。聚合收缩率的百分比通过方差分析和Tukey检验进行评估。
只有方案3在釉质边缘和牙骨质边缘之间显示出显著差异。在釉质边缘，各方案之间未检测到差异。只有方案1在牙骨质边缘提供了良好的封闭效果。所有可压实复合材料的聚合收缩率均低于所测试的混合型复合材料。
所有方案都能够防止染料渗透到釉质边缘；然而，方案1在减少牙骨质边缘的微渗漏方面更具优势。与混合型树脂相比，可压实复合材料的聚合收缩率较低。
