ABSTRACT

Implant-supported cement–screw-retained crowns combine the advantages of screw-retained and cement-retained crowns. However, the occlusal screw access hole interrupts porcelain integrity, which may result in porcelain cracks or fractures. There is insufficient scientific evidence to prove that screw access holes affect the fracture load of implant-supported monolithic zirconia crowns. In this study, we investigated the effects of the screw access hole and its preparation technique on the fracture load of implant-supported monolithic zirconia single crown. The crowns were designed for the maxillary right first premolar. Three techniques analysed for screw access hole preparations included computer-aided designed/computer-aided manufactured (CAD/CAM) before sintering, manually prepared after sintering, and then resintering. Our findings show that the screw access holes and preparation techniques have no significant effects on the fracture load of implant-supported monolithic zirconia single crown. On the other hand, the screw access hole preparation techniques affect failure initiation in implant-supported monolithic zirconia single crown.

摘要

种植体支持的骨水泥-螺钉固位冠结合了螺钉固位和骨水泥固位冠的优点。然而，咬合螺钉进入孔会中断瓷的完整性，这可能导致瓷裂纹或断裂。没有足够的科学证据证明螺钉进入孔会影响种植体支撑的整体式氧化锆冠的断裂载荷。在本研究中，我们研究了螺钉入孔及其制备技术对种植体支持的整体式氧化锆单冠断裂载荷的影响。牙冠是为右上颌第一前磨牙设计的。分析了三种用于螺钉进入孔准备的技术，包括烧结前的计算机辅助设计/计算机辅助制造 (CAD/CAM)、烧结后的手动准备和再烧结。我们的研究结果表明，螺钉入孔和制备技术对种植体支持的整体式氧化锆单冠的骨折负荷没有显着影响。另一方面，螺钉入孔准备技术会影响种植体支持的整体式氧化锆单冠的失效起始。