Dietrich T, Kraemer M, Lösche G M, Roulet J
Department of Periodontology and Synoptic Dentistry, Humboldt-University, Charité, Berlin, Germany.
J Dent. 2000 Aug;28(6):399-405. doi: 10.1016/s0300-5712(00)00022-1.
The aim of the present study was to investigate the marginal integrity of total-bond Dyract AP restorations in large Class II restorations with cervical margins in dentine. The efficacy of a new non-rinse conditioner and the effect of beveling the enamel margins were also studied.
Large MOD cavities with cervical margins located 1mm below the CEJ were prepared in 48 extracted human molars. Six groups (n=8) were filled using a total-bond technique with Spectrum TPH or Dyract AP or a sandwich technique with Dyract in combination with Spectrum TPH. For Dyract AP total-bond restorations, a new non-rinse conditioner was tested vs. a total-etch with 36% phosphoric acid in beveled and butt-joint cavities. After water storage for 21 days and thermocycling (2000x, 5-55 degrees C), replicas were produced for quantitative marginal analysis in the SEM. Afterwards, teeth were immersed in 0.5% basic fuchsin for 24h and dried. Percent dye penetration over the total margin length was analysed in three layers using a sequential grinding technique. Statistical analysis was performed with non-parametric tests and the Bonferroni correction for multiple comparisons at p<0.05.
All restoration types showed microleakage. On cervical margins in dentine, Dyract AP restorations showed better marginal adaptation than Spectrum TPH total-bond restorations (marginal openings (MO), median 33.8 vs. 79.6%), but were inferior to Dyract/Spectrum TPH sandwich restorations (MO: 0. 0%). The non-rinse conditioner improved the marginal adaptation of Dyract AP restorations in dentine (MO: 4.7 vs. 38.4%, p=0.0206 for beveled cavities, 12.2 vs. 33.8%, p=0.0238, for butt-joint cavities) and yielded similar results in enamel margins provided that enamel margins were beveled. Beveling of enamel significantly reduced the occurrence of enamel microcracks.
The use of a non-rinse conditioner in combination with Dyract AP may improve the marginal adaptation of Class II restorations compared to composite restorations. The sandwich technique with Dyract results in better marginal adaptation in cervical dentine compared to all other restorative techniques tested in this study. However, microleakage cannot predictably be prevented with the sandwich technique.
本研究旨在调查在牙本质中具有颈部边缘的大型Ⅱ类修复体中全粘结Dyract AP修复体的边缘完整性。还研究了一种新型免冲洗调节剂的功效以及牙釉质边缘斜面制备的效果。
在48颗拔除的人类磨牙上制备颈部边缘位于牙釉质牙骨质界（CEJ）下方1mm处的大型近中-牙合面-远中（MOD）洞。六组（n = 8）使用全粘结技术用Spectrum TPH或Dyract AP进行充填，或使用Dyract与Spectrum TPH联合的夹层技术进行充填。对于Dyract AP全粘结修复体，在有斜面和对接面的窝洞中，将一种新型免冲洗调节剂与36%磷酸全酸蚀进行对比测试。在水储存21天和热循环（2000次，5 - 55摄氏度）后，制作复制品用于扫描电子显微镜（SEM）下的定量边缘分析。之后，将牙齿浸入0.5%碱性品红中24小时并干燥。使用连续磨片技术在三层中分析染料在总边缘长度上的渗透百分比。采用非参数检验和Bonferroni校正进行统计学分析，用于p < 0.05时的多重比较。
所有修复类型均显示有微渗漏。在牙本质颈部边缘，Dyract AP修复体显示出比Spectrum TPH全粘结修复体更好的边缘适应性（边缘开口（MO），中位数分别为33.8%和79.6%），但不如Dyract/Spectrum TPH夹层修复体（MO：0.0%）。免冲洗调节剂改善了Dyract AP修复体在牙本质中的边缘适应性（斜面窝洞的MO：4.7%对38.4%，p = 0.0206；对接面窝洞的MO：12.2%对33.8%，p = 0.0238），并且在牙釉质边缘进行斜面制备时也产生了类似的结果。牙釉质斜面制备显著减少了牙釉质微裂纹的发生。
与复合树脂修复体相比，使用免冲洗调节剂联合Dyract AP可能改善Ⅱ类修复体的边缘适应性。与本研究中测试的所有其他修复技术相比，Dyract夹层技术在颈部牙本质中产生了更好的边缘适应性。然而，夹层技术不能可预测地防止微渗漏。
