Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, Berlin, Germany.
Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
Dent Mater. 2018 Oct;34(10):1585-1595. doi: 10.1016/j.dental.2018.08.290. Epub 2018 Sep 1.
To investigate the long-term stability of a metal-free zirconia two-piece implant assembled with a carbon fiber-reinforced (CRF) screw by means of transformation propagation, potential changes in surface roughness, the gap size of the implant-abutment connection, and fracture load values.
In a combined procedure, two-piece implants made from alumina-toughened zirconia were dynamically loaded (10 cycles) and hydrothermally aged (85°, 60days). Implants made from titanium (Ti) and a titanium-zirconium (TiZr) alloy with a titanium abutment screw served as control. Transformation propagation (ATZ) and gap size of the IAC were monitored at cross-sections by scanning electron microscopy (SEM). Furthermore, changes in surface roughness of ATZ implants were measured. Finally, implants were statically loaded to fracture. Linear regression models and pairwise comparisons were used for statistical analyses.
Independent of the implant bulk material, dynamic loading/hydrothermal aging did not decrease fracture resistance (p=0.704). All test and control implants fractured at mean loads >1100N. Gap size of the IAC remained stable (<5μm) or decreased. None of the CFR screws fractured during static or dynamic loading. Monoclinic layer thickness of ATZ implants increased by 2-3μm at surfaces exposed to water, including internal surfaces of the IAC. No changes in surface roughness were observed.
Combined hydrothermal aging and dynamic loading did not affect the above-mentioned parameters of the evaluated two-piece ATZ implant. Mean fracture loads >1100N suggest a reliable clinical application.
通过相变传播、表面粗糙度变化、种植体-基台连接间隙大小和断裂负荷值的研究，来探讨无金属氧化锆两段式种植体与碳纤维增强（CRF）螺钉组合的长期稳定性。
在联合手术中，对氧化铝增韧氧化锆两段式种植体进行动态加载（10 次循环）和水热老化（85℃，60 天）。以钛（Ti）和钛锆（TiZr）合金制成的种植体以及带有钛基台螺钉的种植体作为对照。通过扫描电子显微镜（SEM）在横截面监测相变传播（ATZ）和种植体-基台连接间隙大小。此外，还测量了 ATZ 种植体表面粗糙度的变化。最后，对种植体进行静态加载至断裂。采用线性回归模型和两两比较进行统计学分析。
无论种植体本体材料如何，动态加载/水热老化均未降低断裂阻力（p=0.704）。所有测试和对照种植体均在平均负荷>1100N 时断裂。种植体-基台连接间隙大小保持稳定（<5μm）或减小。在静态或动态加载过程中，没有 CFR 螺钉断裂。暴露于水的 ATZ 种植体表面（包括种植体-基台连接内部表面）的单斜层厚度增加了 2-3μm。未观察到表面粗糙度的变化。
联合水热老化和动态加载未影响评估的两段式 ATZ 种植体的上述参数。平均断裂负荷>1100N 表明其具有可靠的临床应用前景。
