Department of Prosthetic Dentistry, LMU Munich, Munich, Germany.
Department of Prosthetic Dentistry, LMU Munich, Munich, Germany.
J Mech Behav Biomed Mater. 2021 Jun;118:104456. doi: 10.1016/j.jmbbm.2021.104456. Epub 2021 Mar 13.
To investigate the impact of hydrothermal aging on Martens parameter (Martens hardness: HM/elastic indentation modulus: E) and biaxial flexural strength (BFS) of recently available CAD/CAM silicate ceramics.
220 specimens (diameter: 12 mm, thickness: 0.95 mm) were fabricated from six CAD/CAM ceramics in two translucency levels (LT/HT): (a) two lithium disilicate (Amber Mill, ABM; IPS e.max CAD, IEM), (b) one lithium metasilicate (Cetra Duo, CEL), (c) one lithium alumina silicate (n!ce, NIC), and (d) two leucite ceramics (Initial LRF Block, LRF; IPS Empress CAD, IPR). HM/E and BFS were measured initially and after hydrothermal aging (134 °C/0.2 MPa/100 h) in an autoclave. The Kolmogorov-Smirnov-test, t-test, one-way ANOVA with post-hoc Scheffé test, Kruskal-Wallis-test, Mann-Whitney-U-test with Bonferroni correction and Weibull statistics were performed (α = 0.05).
CEL and IEM showed the highest and the leucite ceramics the lowest Martens parameter. Within HT, ABM and NIC were in same initial HM value range with CEL and IEM. ABM and NIC showed lower initial E values than CEL and IEM, however higher than IPR. The lowest aged values were analyzed for ABM. After aging, Martens parameter decreased for LRF, ABM, and CEL. IEM showed the initial highest BFS, followed by ABM. NIC and LRF showed the lowest BFS. IEM and ABM presented the highest aged BFS. Hydrothermal aging increased BFS values for LRF (HT), IPR, CEL (HT), and NIC (HT) compared to the initial values. CAD/CAM leucite ceramics showed higher Weibull modul values compared to lithium silicate ceramics.
The well-considered selection of ceramics in relation to the areas of indication has the highest influence on the long-term stability of restorations: CAD/CAM lithium disilicate ceramics presented the highest and leucite ceramics the lowest mechanical properties, whereas the reliability was better for leucite than for lithium silicate ceramics.
研究湿热老化对最近可用的 CAD/CAM 硅酸盐陶瓷的马氏体参数（马氏体硬度：HM/弹性压痕模量：E）和双轴弯曲强度（BFS）的影响。
从两种透光率水平（LT/HT）的六种 CAD/CAM 陶瓷中制备了 220 个试件（直径：12mm，厚度：0.95mm）：（a）两种锂硅石（琥珀 Mill，ABM；IPS e.max CAD，IEM），（b）一种锂硅酸镁（Cetra Duo，CEL），（c）一种锂铝硅酸锂（n!ce，NIC），和（d）两种透锂长石陶瓷（初始 LRF 块，LRF；IPS Empress CAD，IPR）。在高压釜中对 HM/E 和 BFS 进行了初始测量和湿热老化（134°C/0.2 MPa/100 h）后的测量。采用 Kolmogorov-Smirnov 检验、t 检验、单向方差分析和事后 Scheffé 检验、Kruskal-Wallis 检验、Mann-Whitney-U 检验和 Bonferroni 校正以及威布尔统计进行分析（α=0.05）。
CEL 和 IEM 显示出最高的马氏体参数，而透锂长石陶瓷显示出最低的马氏体参数。在 HT 中，ABM 和 NIC 的初始 HM 值与 CEL 和 IEM 相同。ABM 和 NIC 的初始 E 值低于 CEL 和 IEM，但高于 IPR。对 ABM 进行了最低老化值分析。老化后，LRF、ABM 和 CEL 的马氏体参数降低。IEM 显示出初始最高的 BFS，其次是 ABM。NIC 和 LRF 显示出最低的 BFS。IEM 和 ABM 呈现出最高的老化 BFS。与初始值相比，湿热老化增加了 LRF（HT）、IPR、CEL（HT）和 NIC（HT）的 BFS 值。CAD/CAM 透锂长石陶瓷的威布尔模数值高于锂硅石陶瓷。
在考虑到适应症的情况下对陶瓷进行仔细选择对修复体的长期稳定性有最大的影响：CAD/CAM 锂硅石陶瓷显示出最高的机械性能，而透锂长石陶瓷显示出最低的机械性能，而透锂长石陶瓷的可靠性优于锂硅石陶瓷。
