Hosoya N, Cox C F, Arai T, Nakamura J
Department of Periodontics and Endodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan.
J Endod. 2000 Dec;26(12):716-8. doi: 10.1097/00004770-200012000-00011.
The purpose of this study was to compare the in vitro sealing capacity of five materials, each used as a temporary sealing agent for the walking bleach technique. All teeth received traditional biomechanical root canal instrumentation, after which the walking bleach agent was placed in the pulp chamber space. The occlusal access was sealed with one of five temporary materials: two hydraulic filling materials, a photoactivated resin composite, a zinc oxide-eugenol cement, and a zinc oxide phosphate cement with/without the placement of a piece of rubber sheet that was placed as a barrier to isolate filling material from the bleaching agent. All teeth were stored in a 1% solution of Alcian blue with thermal cycling stress. After 1 wk, they were sectioned longitudinally, and ranked by graded scores of 0 to 3, according to the degree of the dye penetration. Significantly less dye microleakage was observed in the two hydraulic materials than in the photoactivated resin. Both zinc oxide-eugenol and zinc phosphate cements showed a considerable amount of microleakage. There were no significant differences between the groups with and without a rubber sheet. Our data demonstrate that hydraulic filling materials provide the most favorable cavosurface seal when they are firmly packed into the cavity space to prevent microleakage.
本研究的目的是比较五种材料的体外封闭能力，每种材料均用作漂白术的临时封闭剂。所有牙齿均接受传统的生物力学根管预备，之后将漂白术剂置于髓腔空间。用五种临时材料之一封闭咬合入口：两种水硬性充填材料、一种光固化树脂复合材料、一种氧化锌丁香酚水门汀以及一种氧化锌磷酸锌水门汀，其中有/无放置一块橡胶片作为屏障以将充填材料与漂白剂隔离开。所有牙齿均置于含1%阿尔新蓝的溶液中并承受热循环应力。1周后，将其纵向切片，并根据染料渗透程度按0至3级评分进行排名。观察到两种水硬性材料中的染料微渗漏明显少于光固化树脂中的。氧化锌丁香酚水门汀和磷酸锌水门汀均显示出相当程度的微渗漏。有橡胶片组和无橡胶片组之间无显著差异。我们的数据表明，当水硬性充填材料紧密填入窝洞空间以防止微渗漏时，能提供最有利的洞缘封闭。
