Pereira P N, Okuda M, Sano H, Yoshikawa T, Burrow M F, Tagami J
Department of Operative Dentistry, Faculty of Dentistry, Tokyo Medical and Dental University, Japan.
Dent Mater. 1999 Jan;15(1):46-53. doi: 10.1016/s0109-5641(99)00013-5.
The aim of this investigation was to determine the influence of intrinsic wetness on regional bond strengths of adhesive resins to dentin.
Human caries-free third molars were randomly divided into three groups for bonding: Group 1--no pulpal pressure; Group 2--pulpal pressure of 15 cm H2O; and Group 3--dentin dried overnight in a desiccator. Clearfil Liner Bond II (Kuraray) or One Step (Bisco) adhesive resins systems were applied to the flat dentin surfaces and the teeth were restored with APX resin composite (Kuraray). After 24 h in water at 37 degrees C, the specimens were sectioned into 0.7 mm thick slabs and divided into three regional subgroups according to the remaining dentin thickness and visual criteria: pulp horn, center, and periphery. The slabs were then trimmed for the micro-tensile bond test and subjected to a tensile force and crosshead of 1 mm/min. The data were analyzed with ANOVA and Fisher's PLSD test at a confidence level of 95%. The fracture modes were determined under a scanning electron microscope (JXA-840, JEOL, Japan).
No significant regional difference was observed for the Group 1 and 2 specimens restored with Clearfil Liner Bond II (p > 0.05). However, bond strengths significantly decreased at the pulp horn region of the Group 1 and 2 specimens restored with One Step (p > 0.01). All bond strengths of Group 3 decreased significantly and regional differences were not evident (p > 0.05).
The dentin adhesive system should be chosen according to the substrate and region to be bonded, since bond strengths can vary according to the intrinsic wetness, region, and the adhesive system.
本研究旨在确定牙本质自身湿度对粘结树脂与牙本质区域粘结强度的影响。
将无龋的人类第三磨牙随机分为三组进行粘结：第1组——无牙髓压力；第2组——牙髓压力为15 cm H₂O；第3组——牙本质在干燥器中过夜干燥。将Clearfil Liner Bond II（可乐丽公司）或One Step（必思科公司）粘结树脂系统应用于平坦的牙本质表面，并用APX树脂复合材料（可乐丽公司）修复牙齿。在37℃水中浸泡24小时后，将标本切成0.7 mm厚的薄片，并根据剩余牙本质厚度和视觉标准分为三个区域亚组：髓角、中心和周边。然后对薄片进行修剪以进行微拉伸粘结试验，并以1 mm/min的拉伸力和十字头速度进行测试。数据采用方差分析和Fisher最小显著差异检验进行分析，置信水平为95%。在扫描电子显微镜（日本电子JXA - 840）下确定断裂模式。
用Clearfil Liner Bond II修复的第1组和第2组标本未观察到显著的区域差异（p > 0.05）。然而，用One Step修复的第1组和第2组标本在髓角区域的粘结强度显著降低（p > 0.01）。第3组的所有粘结强度均显著降低，区域差异不明显（p > 0.05）。
由于粘结强度会因牙本质自身湿度、区域和粘结系统的不同而有所变化，因此应根据粘结的底物和区域选择牙本质粘结系统。
