Hussien Ahmed Naguib M, Rayyan Mohammad M, Sayed Nagwa M, Segaan Lucette G, Goodacre Charles J, Kattadiyil Mathew T
Professor, Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University, Cairo, Egypt; and Professor, Intern Department, Future University, Cairo, Egypt.
Associate Professor, Department of Oral Rehabilitation Sciences, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon; and Associate Professor, Department of Fixed Prosthodontics, Faculty of Dentistry, Misr University for Science and Technology, Giza, Egypt.
J Prosthet Dent. 2016 Aug;116(2):214-20. doi: 10.1016/j.prosdent.2015.12.016. Epub 2016 Mar 3.
Access channels for retrieving ceramic implant-supported screw-retained crowns may decrease their fracture resistance.
The purpose of this in vitro study was to evaluate the effect of screw-access channels on 3 types of ceramic implant-supported crowns.
Sixty computer-aided designed and computer-aided manufactured (CAD-CAM) ceramic implant-supported screw-retained maxillary premolar crowns were fabricated, 30 with an occlusal screw-access channel and 30 without access channels. Each group was further divided into the following 3 subgroups of 10 specimens each: monolithic zirconia, veneered zirconia, and lithium disilicate. Identical milled titanium implant abutments were fabricated. Crowns were fabricated with standardized thicknesses and subjected to cyclic loading until failure occurred. Data analysis was performed using 1-way analysis of variance test of significance followed by Tukey honest significant difference (HSD) test (α=.05).
No significant differences in fracture resistance were found between access channel groups and corresponding groups without access channels (P>.05). Among the subgroups, monolithic zirconia recorded the highest fatigue failure mean load values (2047.8 ±83.2 N for crowns with access channels and 2028.7 ±104.5 N for crowns without access channels), which was significantly higher (P<.05) than values for the lithium disilicate group (605.4 ±37.9 N for crowns with access channels and 615.3 ±76.6 N for crowns without access channels) and the veneered zirconia group (411 ±34.4 N for crowns with access channels and 461.2 ±72.7 N for crowns without access channels), which recorded the lowest fatigue failure load mean values.
Screw-access channels did not affect the fatigue failure load of monolithic zirconia, monolithic lithium disilicate, or veneered zirconia ceramic crowns. Monolithic zirconia crowns recorded significantly higher fatigue failure load among the 3 types of crowns tested.
用于取出陶瓷种植体支持的螺丝固位冠的通路可能会降低其抗折性。
本体外研究的目的是评估螺丝通路对3种陶瓷种植体支持冠的影响。
制作60个计算机辅助设计和计算机辅助制造（CAD-CAM）的陶瓷种植体支持的螺丝固位上颌前磨牙冠，其中30个有咬合螺丝通路，30个没有通路。每组再进一步分为以下3个亚组，每组10个标本：整体式氧化锆、饰瓷氧化锆和二硅酸锂。制作相同的铣削钛种植体基台。制作的冠具有标准化厚度，并进行循环加载直至发生破坏。使用单因素方差分析进行显著性检验，随后进行Tukey诚实显著差异（HSD）检验（α=0.05）进行数据分析。
有通路组与相应的无通路组之间在抗折性方面未发现显著差异（P>0.05）。在亚组中，整体式氧化锆记录的疲劳破坏平均载荷值最高（有通路的冠为2047.8±83.2N，无通路的冠为2028.7±104.5N），显著高于二硅酸锂组（有通路的冠为605.4±37.9N，无通路的冠为615.3±76.6N）和饰瓷氧化锆组（有通路的冠为411±34.4N，无通路的冠为461.2±72.7N），后两组记录的疲劳破坏载荷平均值最低。
螺丝通路不影响整体式氧化锆、整体式二硅酸锂或饰瓷氧化锆陶瓷冠的疲劳破坏载荷。在测试的3种冠中，整体式氧化锆冠记录的疲劳破坏载荷显著更高。
Zotero 插件