Duarte Sillas, Perdigão Jorge, Lopes M Manuela
Department of Restorative Dentistry, Araraquara School of Dentistry, São Paulo State University (UNESP), Brazil.
Oper Dent. 2006 Jul-Aug;31(4):500-11. doi: 10.2341/05-86.
To study the nanoleakage pattern in the dentin hybrid layer by using different dentin adhesives. The null hypotheses tested in this study were: 1) dentin conditioning time does not affect nanoleakage within the hybrid layer; 2) the type of dentin adhesive used does not affect nanoleakage.
Standardized Class V cavities were prepared in 30 intact human molars on the buccal and lingual surfaces. The specimens were randomly assigned to 2 total-etch dentin adhesives (OptiBond SOLO Plus [OPS, Kerr] and One-Step [ONS, BISCO Inc]) and 2 self-etch dentin adhesives (Clearfil SE Bond [CSE, Kuraray] and Adper Prompt L-Pop [APL, 3M ESPE]). The specimens were etched or conditioned for 15 seconds, 30 seconds or 60 seconds. Upon restoration of the Class V cavities with the proprietary resin composite, the specimens were isolated with nail polish except for a 2.0-mm rim around the restoration, and they were immersed in 50 wt% ammoniacal silver nitrate solution (pH=9.5) for 24 hours followed by 8 hours of immersion in photo-developing solution to reduce the silver ions to metallic silver. The specimens were fixed, dehydrated and processed for FESEM and TEM. Silver penetration was measured along the cervical wall, and data were analyzed with Kruskal-Wallis non-parametric tests at a significance level of 95%.
There were no statistically significant differences among the experimental groups for the factor "conditioning time" (p>0.926). There were significant differences for the variable "dentin adhesive" (p<0.0001). The least amount of nanoleakage within the hybrid layer occurred with CSE, while ONS resulted in the greatest penetration of silver ions. The adhesives OPS and APL ranked in the intermediary subset. Under TEM, all adhesives resulted in some degree of nanoleakage within the hybrid layer. Both spotted/reticular and water-tree nanoleakage patterns were observed.
Longer conditioning times did not increase nanoleakage within the hybrid layer. Nanoleakage varied with the type of adhesive used.
通过使用不同的牙本质黏结剂来研究牙本质混合层中的纳米渗漏模式。本研究中检验的无效假设为：1）牙本质预处理时间不影响混合层内的纳米渗漏；2）所使用的牙本质黏结剂类型不影响纳米渗漏。
在30颗完整人磨牙的颊面和舌面制备标准化的V类洞。将标本随机分为2种全酸蚀牙本质黏结剂（OptiBond SOLO Plus [OPS， Kerr公司]和One-Step [ONS， BISCO公司]）以及2种自酸蚀牙本质黏结剂（Clearfil SE Bond [CSE，可乐丽公司]和Adper Prompt L-Pop [APL，3M ESPE公司]）。将标本酸蚀或预处理15秒、30秒或60秒。用专用树脂复合材料修复V类洞后，除修复体周围2.0毫米边缘外，标本用指甲油隔离，然后将其浸入50重量%的氨性硝酸银溶液（pH = 9.5）中24小时，接着在显影液中浸泡8小时，将银离子还原为金属银。标本固定、脱水并进行场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）处理。沿着颈壁测量银的渗透情况，并使用Kruskal-Wallis非参数检验在95%的显著性水平下分析数据。
对于“预处理时间”因素，各实验组之间无统计学显著差异（p > 0.926）。对于变量“牙本质黏结剂”存在显著差异（p < 0.0001）。混合层内纳米渗漏量最少的是CSE，而ONS导致银离子渗透最多。黏结剂OPS和APL处于中间水平。在透射电子显微镜下，所有黏结剂在混合层内均导致一定程度的纳米渗漏。观察到斑点状/网状和水树状纳米渗漏模式。
更长的预处理时间并未增加混合层内的纳米渗漏。纳米渗漏随所使用的黏结剂类型而变化。
