Resistance to fracture of two all-ceramic crown materials following endodontic access
Resistance to fracture of two all-ceramic crown materials following endodontic access
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DOI：
10.1016/j.prosdent.2005.11.003
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发表时间：
2006-01-01
影响因子：
4.6
通讯作者：
Nagy, WW
中科院分区：
文献类型：
--
作者：
Wood, KC;Berzins, DW;Nagy, WW
问题陈述。目前，没有管理全瓷冠的根管入口的协议。直接修复材料通常用于修复入口，使修复的牙冠成为最终修复体。然而，这种根管治疗过程可能会削弱修复体或引发可能扩散的微裂纹，导致修复体过早失效。本体外研究的目的是评估通过全瓷冠制备的牙髓通路开口如何改变陶瓷的结构完整性，以及修复该通路对全瓷冠失效载荷的影响。材料和方法。制造了24个氧化铝（Procera）和24个氧化锆（Procera）牙冠，并将其粘合（Rely X Luting Plus骨水泥）到复制的环氧树脂模具上。每个12个牙冠进入模拟根管治疗治疗。用全环境扫描电子显微镜对所有试样的表面缺陷进行了评价。用瓷修复系统（标准粘合树脂/复合树脂方案）修复样本，并在万能试验机中加载至失效。通过目视和显微镜观察，发现饰面与芯层分层、芯层断裂、饰面瓷内剪切或其组合。Kruskal-Wallis检验用于确定4组之间的失效载荷是否存在显著差异（α = 0.05），Mann-Whitney检验和Bonferroni校正（P
Statement of problem. There is currently, no protocol for managing endodontic access openings for all-ceramic crowns. A direct restorative material is generally used to repair the access opening, rendering a repaired crown as the definitive restoration. This endodontic procedure, however, may weaken the restoration or initiate microcracks that may propagate, resulting in premature failure of the restoration.Purpose. The purpose Of this in vitro study was to evaluate how an endodontic access opening prepared through an all-ceramic crown altered the structural integrity of the ceramic, and the effect of a repair of this access on the load to failure of an all-ceramic crown.Material and methods. Twenty-four alumina (Procera) and 24 zirconia (Procera) crowns were fabricated and cemented (Rely X Luting Plus Cement) onto duplicate epoxy resin dies. Twelve crowns of each were accessed to simulate root canal treatment therapy. Surface defects of all accessed specimens were evaluated with ail environmental scanning electron microscope. The specimens were repaired with a porcelain repair system (standard adhesive resin/composite resin protocol) and were loaded to failure in a universal testing machine. Observations made visually and microscopically, noted veneer delamination from the core, core fracture, shear within the veneer porcelain, or a combination thereof. A Kruskal-Wallis test was used to determine if a significant difference (alpha=.05) in load to failure existed between the 4 groups, and a Mann-Whitney test with a Bonferroni correction (P