Tribst João P M, Dal Piva Amanda M O, Borges Alexandre L S, Anami Lilian C, Kleverlaan Cornelis J, Bottino Marco A
Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp/SJC), Institute of Science and Technology, 12245-000 São José dos Campos, Brazil.
Department of Dentistry, Santo Amaro University (UNISA), 04743-030 São Paulo, Brazil.
Materials (Basel). 2020 Apr 16;13(8):1879. doi: 10.3390/ma13081879.
Different techniques are available to manufacture polymer-infiltrated ceramic restorations cemented on a chairside titanium base. To compare the influence of these techniques in the mechanical response, 75 implant-supported crowns were divided in three groups: CME (crown cemented on a mesostructure), a two-piece prosthetic solution consisting of a crown and hybrid abutment; MC (monolithic crown), a one-piece prosthetic solution consisting of a crown; and MP (monolithic crown with perforation), a one-piece prosthetic solution consisting of a crown with a screw access hole. All specimens were stepwise fatigued (50 N in each 20,000 cycles until 1200 N and 350,000 cycles). The failed crowns were inspected under scanning electron microscopy. The finite element method was applied to analyze mechanical behavior under 300 N axial load. Log-Rank ( = 0.17) and Wilcoxon ( = 0.11) tests revealed similar survival probability at 300 and 900 N. Higher stress concentration was observed in the crowns' emergence profiles. The MP and CME techniques showed similar survival and can be applied to manufacture an implant-supported crown. In all groups, the stress concentration associated with fractographic analysis suggests that the region of the emergence profile should always be evaluated due to the high prevalence of failures in this area.
有多种技术可用于制造粘结在椅旁钛基台上的聚合物渗透陶瓷修复体。为了比较这些技术对力学响应的影响，将75个种植体支持的牙冠分为三组：CME（粘结在中结构上的牙冠），一种由牙冠和混合基台组成的两件式修复解决方案；MC（整体式牙冠），一种由牙冠组成的一体式修复解决方案；MP（带穿孔的整体式牙冠），一种由带有螺丝通道孔的牙冠组成的一体式修复解决方案。所有样本均进行逐步疲劳试验（每20,000次循环施加50 N力，直至1200 N和350,000次循环）。对失败的牙冠进行扫描电子显微镜检查。应用有限元方法分析300 N轴向载荷下的力学行为。对数秩检验（= 0.17）和威尔科克森检验（= 0.11）显示在300 N和900 N时的存活概率相似。在牙冠的龈缘外形处观察到更高的应力集中。MP和CME技术显示出相似的存活率，可用于制造种植体支持的牙冠。在所有组中，与断口分析相关的应力集中表明，由于该区域失败的发生率很高，应始终评估龈缘外形区域。
