Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
Department of Restorative Dentistry, College of Dentistry, Taibah University, Al Madinah, Al Munawwarah 41311, Saudi Arabia.
Molecules. 2021 Apr 13;26(8):2259. doi: 10.3390/molecules26082259.
The fracture resistance of computer-aided designing and computer-aided manufacturing CAD/CAM fabricated implant-supported cantilever zirconia frameworks (ISCZFs) is affected by the size/dimension and the micro cracks produced from diamond burs during the milling process. The present in vitro study investigated the fracture load for different cross-sectional dimensions of connector sites of implant-supported cantilever zirconia frameworks (ISCZFs) with different cantilever lengths (load point). A total of 48 ISCZFs (Cercon, Degudent; Dentsply, Deutschland, Germany) were fabricated by CAD/CAM and divided into four groups based on cantilever length and reinforcement of distal-abutment: Group A: 9 mm cantilever; Group B: 9 mm cantilever with reinforced distal-abutment; Group C: 12 mm cantilever; Group D: 12 mm cantilever with reinforced distal-abutment ( = 12). The ISCZFs were loaded using a universal testing machine for recording the fracture load. Descriptive statistics, ANOVA, and Tukey's test were used for the statistical analysis ( < 0.05). Significant variations were found between the fracture loads of the four ISCZFs ( = 0.000); Group-C and B were found with the weakest and the strongest distal cantilever frameworks with fracture load of 670.39 ± 130.96 N and 1137.86 ± 127.85 N, respectively. The mean difference of the fracture load between groups A (810.49 + 137.579 N) and B (1137.86 ± 127.85 N) and between C (670.39 ± 130.96 N) and D (914.58 + 149.635 N) was statistically significant ( = 0.000). Significant variations in the fracture load between the ISCZFs with different cantilever lengths and thicknesses of the distal abutments were found. Increasing the thickness of the distal abutment only by 0.5 mm reinforces the distal abutments by significantly increasing the fracture load of the ISCZFs. Therefore, an increase in the thickness of the distal abutments is recommended in patients seeking implant-supported distal cantilever fixed prostheses.
计算机辅助设计和计算机辅助制造 CAD/CAM 制作的种植体支持的悬臂氧化锆框架（ISCZF）的抗断裂能力受到尺寸/尺寸和在铣削过程中产生的金刚石钻头微裂纹的影响。本体外研究调查了不同悬臂长度（加载点）的种植体支持的悬臂氧化锆框架（ISCZF）的连接部位的不同横截面尺寸的断裂载荷。总共制作了 48 个 ISCZF（Cercon，Degudent；Dentsply，Deutschland，Germany），并根据悬臂长度和远侧邻接体的加固分为四组：组 A：9 毫米悬臂；组 B：9 毫米悬臂，带有加固的远侧邻接体；组 C：12 毫米悬臂；组 D：12 毫米悬臂，带有加固的远侧邻接体（ = 12）。使用万能试验机对 ISCZF 进行加载，以记录断裂载荷。使用描述性统计、方差分析和 Tukey 检验进行统计分析（<0.05）。发现四种 ISCZF 的断裂载荷之间存在显着差异（= 0.000）；组-C 和 B 的悬臂框架最弱和最强，断裂载荷分别为 670.39 ± 130.96 N 和 1137.86 ± 127.85 N。组 A（810.49 + 137.579 N）和 B（1137.86 ± 127.85 N）以及 C（670.39 ± 130.96 N）和 D（914.58 + 149.635 N）之间的断裂载荷的平均差异具有统计学意义（= 0.000）。发现不同悬臂长度和远侧邻接体厚度的 ISCZF 之间的断裂载荷存在显着差异。仅将远侧邻接体的厚度增加 0.5 毫米就会显着增加 ISCZF 的断裂载荷，从而增强远侧邻接体。因此，建议在寻求种植体支持的远侧悬臂固定义齿的患者中增加远侧邻接体的厚度。
