Coutinho E, Cardoso M V, De Munck J, Neves A A, Van Landuyt K L, Poitevin A, Peumans M, Lambrechts P, Van Meerbeek B
Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium.
Dent Mater. 2009 Nov;25(11):1347-57. doi: 10.1016/j.dental.2009.06.004.
Glass-ionomers (GIs) exhibit excellent clinical bonding effectiveness, but still have shortcomings such as polishability and general aesthetics. The aims of this study were (1) to determine the micro-tensile bond strength (microTBS) to enamel and dentin of a nano-filled resin-modified GI (nano-RMGI; Ketac N100, 3M-ESPE), and (2) to characterize its interfacial interaction with enamel and dentin using transmission electron microscopy (TEM).
The nano-RMGI was used both with and without its primer, while a conventional RMGI restorative material (conv-RMGI; Fuji II LC, GC) and a packable conventional GI cement (conv-GI; Fuji IX GP, GC) were used as controls. After bonding to freshly extracted human third molars, microspecimens of the interfaces were machined into a cylindrical hourglass shape and tested to failure in tension. Non-demineralized TEM sections were prepared and examined from additional teeth.
The microTBS to both enamel and dentin of nano-RMGI and conv-GI were not statistically different; the microTBS of non-primed nano-RMGI was significantly lower, while that of conv-RMGI was significantly higher than that of all other groups. TEM of nano-RMGI disclosed a tight interface at enamel and dentin without surface demineralization and hybrid-layer formation. A thin filler-free zone (<1 microm) was formed at dentin. A high filler loading and effective filler distribution were also evident, with localized areas exhibiting nano-filler clustering.
The nano-RMGI bonded as effectively to enamel and dentin as conv-GI, but bonded less effectively than conv-RMGI. Its bonding mechanism should be attributed to micro-mechanical interlocking provided by the surface roughness, most likely combined with chemical interaction through its acrylic/itaconic acid copolymers.
玻璃离子水门汀（GIs）具有出色的临床粘结效果，但仍存在诸如可抛光性和总体美观性等缺点。本研究的目的是：（1）确定纳米填充树脂改性玻璃离子水门汀（纳米RMGI；Ketac N100，3M-ESPE）与釉质和牙本质的微拉伸粘结强度（microTBS）；（2）使用透射电子显微镜（TEM）表征其与釉质和牙本质的界面相互作用。
纳米RMGI使用时有无底漆，同时使用传统的树脂改性玻璃离子水门汀修复材料（传统RMGI；Fuji II LC，GC）和可填充的传统玻璃离子水门汀（传统GI；Fuji IX GP，GC）作为对照。粘结到新鲜拔除的人类第三磨牙后，将界面的微观标本加工成圆柱形沙漏形状并进行拉伸破坏试验。从额外的牙齿制备并检查未脱矿的TEM切片。
纳米RMGI和传统GI与釉质和牙本质的microTBS在统计学上无差异；未使用底漆的纳米RMGI的microTBS显著更低，而传统RMGI的microTBS显著高于所有其他组。纳米RMGI的TEM显示在釉质和牙本质处有紧密的界面，无表面脱矿和混合层形成。在牙本质处形成了一个薄的无填料区（<1微米）。还明显有高填料含量和有效的填料分布，局部区域呈现纳米填料聚集。
纳米RMGI与传统GI一样有效地粘结到釉质和牙本质，但粘结效果不如传统RMGI。其粘结机制应归因于表面粗糙度提供的微机械互锁，很可能还结合了通过其丙烯酸/衣康酸共聚物的化学相互作用。
