Department of Periodontology, School of Dentistry, Universidad Cientifica del Sur, Lima, Peru; School of Stomatology, Universidad Privada San Juan Bautista, Lima, Peru, Phone: +511 6106400 extn.: 324, e-mail:
Department of Periodontology, School of Dentistry, Universidad Cientifica del Sur, Lima, Peru; School of Stomatology, Universidad Privada San Juan Bautista, Lima, Peru.
J Contemp Dent Pract. 2020 Aug 1;21(8):868-873.
To compare fracture resistance between the cement-retained (CR), screw-retained (SR), and combined cement- and screw-retained (CCSR) metal-ceramic (MC) implant-supported molar restorations and the fracture mode after vertical loading simulation.
Thirty MC molar restorations were fabricated on thirty tilted dental implants that were repositioned using prefabricated or universal castable long abutments (UCLA) with 15° of angulation divided into three groups of ten specimens each. Group C: CR, group S: SR, and group CS: cement- and screw-retained. The crowns in group CS were adhesively bonded extraorally, and composite resin was used to fill the screw access holes (SAHs) in groups S and CS. Subsequently, all the specimens were tested for fracture resistance. A scanning electron microscope (SEM) evaluation of the fracture mode was also performed. Mean values of fracture loads were calculated and compared in Newtons (N) using one-way ANOVA and Tukey test ( < 0.05) for each group.
Mean fracture load values were 2718.00 ± 266.25 N for group C, 2125.10 ± 293.82 N for group S, and 2508.00 ± 153.59 N for group CS. Significant differences were found between group S and the other groups on fracture load values. However, no significant differences were found between groups C and CS ( = 0.154). The failures were at MC framework interfaces on mesiolingual cusps.
Cement and CCSR MC molar restorations showed comparable fracture resistance using abutments with 15° of angulation. However, SR design showed significantly the lowest values of resistance. Screw access hole did not significantly affect the fracture resistance of cemented MC molar restorations. All the specimens exhibited mixed adhesive fractures at the mesiolingual cusps.
Combined cement- and screw-retained restorations (CCSRRs) incorporate the simplicity of the cement method and the retrievability of the screw method, offering good resistance, allowing the removal of the excess of cement before clinical placement of the restoration, and providing another alternative for dental implant rehabilitation.
比较固位水泥型（CR）、螺丝固位型（SR）和固位水泥-螺丝联合型（CCSR）金属陶瓷（MC）种植体支持磨牙修复体的抗折能力以及垂直负载模拟后的骨折模式。
在 30 个倾斜种植体上制作 30 个 MC 磨牙修复体，使用预制或通用可铸造长基台（UCLA）将其重新定位，基台具有 15°的倾斜角，分为每组 10 个样本的三组。组 C：CR；组 S：SR；组 CS：固位水泥-螺丝联合。组 CS 的牙冠在体外进行粘合固定，组 S 和 CS 中的螺丝通道孔（SAHs）用复合树脂填充。随后，所有样本均进行抗折力测试。还通过扫描电子显微镜（SEM）对骨折模式进行评估。使用单向方差分析和 Tukey 检验（<0.05）对每组的断裂载荷平均值进行计算和比较。
组 C 的平均断裂载荷值为 2718.00±266.25N，组 S 为 2125.10±293.82N，组 CS 为 2508.00±153.59N。组 S 的断裂载荷值与其他组之间存在显著差异。然而，组 C 和 CS 之间没有发现显著差异（=0.154）。失败发生在近中颊尖的 MC 框架界面。
使用具有 15°倾斜角的基台，固位水泥和 CCSR MC 磨牙修复体具有相当的抗折能力。然而，SR 设计的阻力值明显最低。螺丝通道孔不会显著影响固位水泥 MC 磨牙修复体的抗折能力。所有样本在近中颊尖处均表现出混合性黏附性骨折。
固位水泥-螺丝联合修复体（CCSRRs）结合了固位水泥法的简单性和螺丝法的可取出性，提供了良好的抵抗力，允许在临床放置修复体之前去除多余的水泥，并为牙种植体修复提供了另一种选择。
