Shafiei Fereshteh, Yousefipour Bahareh, Farhadpour Hajar
Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Dent Res J (Isfahan). 2015 May-Jun;12(3):224-30.
Despite widespread clinical uses of resin-modified glass-ionomers (RMGIs), their sealing ability is still a concern. This study evaluated the effect of delayed light activation (DLA) of RMGI on marginal sealing in differently pretreated cavities.
In this in vitro study, two standardized Class V cavities were prepared on the buccal and lingual surfaces of 56 sound maxillary premolars at the cementoenamel junction. The cavities were randomly divided into eight equal groups. In groups 1-4 (immediate light activation [ILA]), no pretreatment (negative control [NC]) and three surface pretreatments were used, respectively as follows: Cavity conditioner, Vitremer primer, cavity conditioner plus and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). Fuji II LC (GC, Japan) was prepared and placed in the cavities and immediately light-cured according to manufacturer's instructions. In groups 5-8 (DLA), the same pretreatments were applied, respectively. After placing Fuji II LC in the cavities, the restorations were light-cured after a 3-min delay. After finishing the restorations, the specimens were placed in water for 1-week and thermocycled. Microleakage scores were determined using the dye penetration technique. Kruskal-Wallis test and Mann-Whitney U-test were used to analyze the obtained data (α = 0.05).
At the dentin margins, DLA resulted in a lower microleakage for no treatment (NC), cavity conditioner and cavity conditioner plus ACP-CPP pretreatments groups (P ≤ 0.004); however, no difference was observed for Vitremer group (P > 0.05). At the enamel margins, no difference was observed between DLA and ILA for all groups (P > 0.05); only NC group exhibited a lower microleakage in case of DLA (P = 0.007).
Delayed light activation of RMGI may lead to different effects on marginal sealing, depending on pretreatment procedures used in the cavity. It might improve dentin sealing when no treatment and conditioner alone or with CCP-ACP is used.
尽管树脂改性玻璃离子体（RMGIs）在临床上广泛应用，但其封闭能力仍是一个关注点。本研究评估了RMGI延迟光固化（DLA）对不同预处理窝洞边缘封闭的影响。
在这项体外研究中，于56颗健康上颌前磨牙牙釉质牙骨质界的颊面和舌面制备两个标准化V类窝洞。窝洞被随机分为八组相等数量的组。在第1 - 4组（即时光固化[ILA]）中，分别采用不进行预处理（阴性对照[NC]）和三种表面预处理，具体如下：窝洞处理剂、Vitremer底漆、窝洞处理剂加酪蛋白磷酸肽 - 无定形磷酸钙（CPP - ACP）。制备富士II LC（日本GC公司）并置于窝洞中，然后按照制造商说明立即进行光固化。在第5 - 8组（DLA）中，分别应用相同的预处理。将富士II LC置于窝洞后，延迟3分钟后进行修复体光固化。完成修复后，将标本置于水中1周并进行热循环。使用染料渗透技术确定微渗漏评分。采用Kruskal - Wallis检验和Mann - Whitney U检验分析所得数据（α = 0.05）。
在牙本质边缘，对于未处理（NC）、窝洞处理剂以及窝洞处理剂加ACP - CPP预处理组，DLA导致微渗漏较低（P≤0.004）；然而，Vitremer组未观察到差异（P>0.05）。在釉质边缘，所有组的DLA和ILA之间均未观察到差异（P>0.05）；仅NC组在DLA情况下微渗漏较低（P = 0.007）。
RMGI的延迟光固化可能对边缘封闭产生不同影响，这取决于窝洞所采用的预处理程序。当不进行处理以及单独使用处理剂或与CCP - ACP联合使用时，可能会改善牙本质封闭。
