OBJECTIVE To evaluate the mechanical performance of patient-specific prefabricated temporary shell versus laboratory-fabricated CAD/CAM provisional restorations on titanium temporary abutments, with and without thermo-mechanical ageing. MATERIALS AND METHODS Implants with a conical connection were divided into four groups (n = 24) and restored with temporary shell or laboratory-fabricated central or lateral incisor PMMA restorations that were relined or bonded on titanium temporary abutments. The diameter of the central and lateral incisor groups' implants was regular (ϕ 4.3 mm) or narrow (ϕ 3.5 mm), respectively. Half of each group's specimens were subjected to ageing, simultaneous thermocycling (5-55°C) and chewing simulation (120,000 cycles, 50 N, 1.7 Hz) resulting in eight groups in total (n = 12). The aged specimens were evaluated with optical microscopy, and survival and complication rates were determined according to modified USPHS criteria. The non-aged specimens and those that had survived ageing were loaded until failure, whereupon bending moments were calculated. RESULTS Survival rates after ageing were 100% for all groups. Apart from wear facets (ϕ 2-3 mm) on the palatal restoration surface, no complications were observed. The mean fracture load and bending moments ranged between 597.6-847.1 N and 433.3-550.6 Ncm, respectively, with no significant differences between the eight groups (p = .25; p = .20). CONCLUSIONS As patient-specific temporary shell central and lateral incisor provisional implant-supported restorations are mechanically stable enough to withstand clinical bite forces, even after thermo-mechanical ageing, they may serve as an alternative to laboratory-fabricated provisional restorations.

中文翻译：

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患者特定预制临时外壳与实验室制造的 CAD/CAM 临时种植体支持的单牙修复体的机械性能：一项实验室研究。


目的 评估患者专用预制临时外壳与实验室制造的钛临时基台 CAD/CAM 临时修复体的机械性能（有或没有热机械老化）。材料和方法 具有圆锥形连接的种植体被分为四组（n = 24），并使用临时外壳或实验室制造的中切牙或侧切牙 PMMA 修复体进行修复，这些修复体重新衬里或粘合在钛临时基台上。中切牙组和侧切牙组种植体的直径分别为规则（φ 4.3 mm）和狭窄（φ 3.5 mm）。每组的一半样本接受老化、同时热循环（5-55°C）和咀嚼模拟（120,000 次循环，50 N，1.7 Hz），总共八组（n = 12）。使用光学显微镜对老化标本进行评估，并根据修改后的 USPHS 标准确定存活率和并发症率。将未老化的样本和那些经受老化考验的样本加载直至失效，然后计算弯矩。结果 所有组的衰老后存活率均为 100%。除了腭修复体表面的磨损面（φ 2-3 mm）外，没有观察到任何并发症。平均断裂载荷和弯矩分别为 597.6-847.1 N 和 433.3-550.6 Ncm，八组之间没有显着差异 (p = .25; p = .20)。结论 由于患者特定的临时外壳中切牙和侧切牙临时种植体支持的修复体机械稳定，足以承受临床咬合力，即使在热机械老化后，它们也可以作为实验室制造的临时修复体的替代品。