METHODS: Six different three-unit FDPs were prepared (n = 6) from three types of zirconia (3Y-TZP (Katana ML®), 4Y-TZP (Katana STML®), and 5Y-TZP (Katana UTML®)) in combination with two connector configurations (4 × 2.25, 3 × 3 mm). The Co-Cr master models were scanned, and the FDPs were designed and fabricated using CAD-CAM. The FDPs were cemented on the metal model and then loaded with a UTM at a crosshead speed of 1 mm/min until failure. Two-way ANOVA and Tukey\'s test were used for statistical analysis (α = .05).
RESULTS: Fracture loads of 3Y-TZP (2740.6 ± 469.2 and 2718.7 ± 339.0 N for size 4 × 2.25 mm and 3 × 3 mm, respectively) were significantly higher than those of 4Y-TZP (1868.3 ± 281.6 and 1663.6 ± 372.7 N, respectively) and 5Y-TZP (1588.0 ± 255.0 and 1559.1 ± 110.0 N, respectively) (P < .05). No significant difference was found between fracture loads of 4Y-TZP and 5Y-TZP (P > .05). The connector configuration within 9 mm2 was found to have no effect on the fracture loads on all three types of zirconia (P > .05).
CONCLUSIONS: Fracture loads of three-unit FDPs were affected by the type of zirconia. The fracture loads of conventional zirconia were higher than those of translucent zirconia. However, it was not affected by the connector configuration when the connector had a cross-sectional area of 9 mm2.
方法:由三种类型的氧化锆(3Y-TZP(KatanaML®))制备了六种不同的三单位FDP(n=6),4Y-TZP(KatanaSTML®),和5Y-TZP(KatanaUTML®))与两种连接器配置(4×2.25,3×3mm)相结合。扫描了Co-Cr主模型,FDP是使用CAD-CAM设计和制造的。将FDP粘合在金属模型上,然后以1mm/min的十字头速度加载UTM,直到失效。采用双因素方差分析和Tukey检验进行统计分析(α=0.05)。
结果:尺寸为4×2.25mm和3×3mm的3Y-TZP断裂载荷(2740.6±469.2和2718.7±339.0N,分别)显着高于4Y-TZP(1868.3±281.6和1663.6±372.7N,分别)和5Y-TZP(1588.0±255.0和1559.1±110.0N,分别)(P<.05)。4Y-TZP和5Y-TZP的断裂载荷差异无统计学意义(P>.05)。发现9mm2内的连接器配置对所有三种类型的氧化锆上的断裂载荷没有影响(P>.05)。
结论:三单位FDP的断裂载荷受氧化锆类型的影响。常规氧化锆的断裂载荷高于半透明氧化锆的断裂载荷。然而,当连接器的横截面积为9mm2时,它不受连接器配置的影响。