Monzavi Mona, Noumbissi Sammy, Nowzari Hessam
Private practice, 120 South Spalding Drive, Suite 201, Beverly Hills, CA, 90212, USA.
Private practice, 801 Wayne Ave, Suite G200, Silver Spring, MD, 20910, USA.
Clin Implant Dent Relat Res. 2017 Apr;19(2):245-252. doi: 10.1111/cid.12462. Epub 2016 Nov 9.
Despite increased popularity of Zirconia dental implants, concerns have been raised regarding low temperature degradation (LTD) and its effect on micro-structural integrity.
This study evaluated the effect of LTD on four types of Zirconia dental implants at 0, 30, and 60 years of artificial aging. The impact of aging on t-m transformation and micro crack formation was measured.
Accelerated aging at 15 and 30 hours, approximating 30 and 60 years in vivo, aged 36 Zirconia dental implants: Z systems (A), Straumann (B), Ceraroot (C), and Zeramex (D). Focused ion beam-scanning electron microscopic analysis determined the micro structural features, phase transformation, and the formation of micro cracks.
At 15 hours, type A implant presented with micro cracks and t-m transformation of 0.9 µm and 3.1 µm, respectively. At 30 hours, micro cracks remained shallow (1 µm). At 15 hours, type B implant presented micro cracks (0.7 µm) and grain transformation (1.2 µm). At 30 hours, these features remained superficial at 0.6 and 1.5 µm, respectively. Type C implant presented surface micro cracks of 0.3 µm at 15 hours. The depth of t-m transformation slightly increased to 1.4 µm. At 30 hours, number of micro cracks increased at the surface to an average depth of 1.5 µm. Depth of t-m transformation increased to an average of 2.5 µm. At 15 hours, micro cracks remained superficial (0.8 µm) for type D implant and depth of t-m transformation increased to 2.3 µm. At 30 hours, the depth of micro cracks increased to an average of 1.3 µm followed by increased t-m transformation to a depth of 4.1 µm.
Depth of grain transformation remained within 1-4 µm from the surface. The effect of aging was minimal for all Zirconia implants.
尽管氧化锆牙科植入物越来越受欢迎，但人们对低温降解（LTD）及其对微观结构完整性的影响提出了担忧。
本研究评估了LTD对四种类型的氧化锆牙科植入物在0、30和60年人工老化后的影响。测量了老化对t-m转变和微裂纹形成的影响。
对36颗氧化锆牙科植入物进行加速老化，分别在15小时和30小时，近似于体内30年和60年，这些植入物包括：Z系统（A）、士卓曼（B）、Ceraroot（C）和Zeramex（D）。聚焦离子束扫描电子显微镜分析确定了微观结构特征、相变和微裂纹的形成。
在15小时时，A类植入物出现微裂纹，t-m转变深度分别为0.9 µm和3.1 µm。在30小时时，微裂纹仍然很浅（1 µm）。在15小时时，B类植入物出现微裂纹（0.7 µm）和晶粒转变（1.2 µm）。在30小时时，这些特征分别保持在0.6 µm和1.5 µm的浅表位置。C类植入物在15小时时表面微裂纹深度为0.3 µm。t-m转变深度略有增加至1.4 µm。在30小时时，表面微裂纹数量增加，平均深度为1.5 µm。t-m转变深度增加至平均2.5 µm。在15小时时，D类植入物的微裂纹仍处于浅表位置（0.8 µm），t-m转变深度增加至2.3 µm。在30小时时，微裂纹深度增加至平均1.3 µm，随后t-m转变深度增加至4.1 µm。
晶粒转变深度在距表面1-4 µm范围内。老化对所有氧化锆植入物的影响最小。
