Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, São Paulo, Brazil.
J Mech Behav Biomed Mater. 2023 Jun;142:105794. doi: 10.1016/j.jmbbm.2023.105794. Epub 2023 Mar 24.
The aim of this study was to assess if the finishing/polishing of the bonding surface of lithium disilicate ceramic, prior to or after crystallization, would affect the fatigue behavior of a bonded restorations. For this, lithium disilicate ceramic (IPS e.max CAD) discs (n = 15) were milled and randomly divided into 3 groups: CAD-CAM group which remained untouched; PRE group which received a finishing/polishing protocol (OptraFine system) prior to its crystallization; and POST group, which received the treatment after its crystallization. After surface treatments, ceramic and glass-fiber reinforced epoxy resin discs were paired and bonded using a resin cement (Multilink N). A cyclical fatigue test was conducted (frequency 20 Hz, initial load 200 N for 5000 cycles, step-size of 100 N for 10,000 cycles/step) until failure occurrence. Surface roughness and topography were analyzed. An initial descriptive analysis of surface roughness, FFL and CFF was performed to obtain the mean, standard deviation and confidence interval values (SPSS v. 21, SPSS Inc.) for statistical analysis. Roughness data was using one-way ANOVA with Tukey's post hoc test (α = 0.05), while the fatigue data was submitted to survival analysis with Kaplan-Meier test (α = 0.05) and Weibull modulus (Weibull++, Reliasoft). Neither the finishing/polishing procedure of the bonding surface, nor the moment (prior to or after crystallization), affected the fatigue behavior of bonded milled lithium disilicate. There were also no differences for mechanical reliability among conditions. Despite this, finishing/polishing reduced surface roughness and led to smoother topography. Finishing/polishing the bonding surface of milled lithium disilicate, before or after crystallization, does not alter the fatigue behavior of the bonded restorative set, although there is some influence on roughness and topography.
本研究旨在评估在结晶前后对锂硅玻璃陶瓷粘结面进行修整/抛光是否会影响粘结修复体的疲劳性能。为此，我们使用 IPS e.max CAD 陶瓷（n=15）加工并随机分为 3 组：CAD-CAM 组不进行处理；PRE 组在结晶前进行修整/抛光处理（OptraFine 系统）；POST 组在结晶后进行处理。表面处理后，将陶瓷和玻璃纤维增强环氧树脂片配对并用树脂粘结剂（Multilink N）粘结。进行循环疲劳测试（频率 20Hz，初始负荷 200N 5000 次循环，100N 10000 次循环/步），直至失效发生。分析表面粗糙度和形貌。对表面粗糙度、FFL 和 CFF 进行初步描述性分析，以获得均值、标准差和置信区间值（SPSS v. 21，SPSS Inc.）进行统计分析。使用单因素方差分析和 Tukey 事后检验（α=0.05）进行粗糙度数据分析，而疲劳数据则采用 Kaplan-Meier 检验和 Weibull 模数（Weibull++，Reliasoft）进行生存分析（α=0.05）。粘结面的修整/抛光程序以及时刻（结晶前或后）均未影响粘结铣削锂硅玻璃陶瓷的疲劳性能。在不同条件下，机械可靠性也没有差异。尽管如此，修整/抛光仍可降低表面粗糙度并使形貌更加光滑。在结晶前后对铣削锂硅玻璃陶瓷的粘结面进行修整/抛光不会改变粘结修复体的疲劳性能，但会对粗糙度和形貌产生一定影响。
