MSciD and PhD Post-Graduate Program in Oral Science, Prosthetic Dentistry Unit, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands.
J Mech Behav Biomed Mater. 2022 Feb;126:104989. doi: 10.1016/j.jmbbm.2021.104989. Epub 2021 Nov 22.
This study evaluated the influence of ceramic surface conditioning and storage regimen (baseline vs. aging) on the fatigue performance of simplified lithium disilicate glass-ceramic restorations. A total of 90 ceramic discs (Ø= 10 mm; thickness= 1.0 mm) were allocated into 6 groups (n= 15), considering 2 factors: "ceramic surface treatment" - CA (only silane-based coupling agent, Monobond N), HF (5% hydrofluoric acid etching), or HF+CA (5% HF acid etching plus silane-based coupling agent); and "storage regimen" - baseline (24 hours - 5 days of distilled water at 37 °C), or long-term aging (180 days of distilled water at 37 °C + 25,000 thermal cycles). After intaglio ceramic conditioning, adhesive bonding (Multilink N) was performed onto epoxy resin discs (Ø= 10 mm; thickness= 2.5 mm) and the bonded sets were subjected to step-stress fatigue tests (initial load: 200 N; step-size: 50 N; 10,000 cycles per step; 20 Hz). Fatigue data were analyzed using Kaplan-Meier and Weibull statistical analyses. Fractography and topography analyses were also conducted. The fatigue findings demonstrated that the performance among groups for both baseline and aging conditions maintained a tendency: the CA groups had the worst behavior (baseline: 893 N/143,667 cycles; aging: 639 N/84,179 cycles), while the surface etching with HF (baseline: 1247 N/214,333 cycles; aging: 816.67 N/128,333 cycles) and HF+CA groups (baseline: 1290 N/222,333 cycles; aging: 900 N/145,000 cycles) had no statistically significant difference between them. The aging protocol reduced the performance of all groups. The groups with better fatigue performance (HF and HF+CA) did not have statistical differences regarding structural reliability (Weibull modulus). Most failures were radial cracks from the cementation interface, except for CA aging specimens, with 27% failing from debonding. The HF etching led to noteworthy surface topographical alterations. Micromechanical interlocking resulting from HF acid etching remained prevalent in the fatigue behavior. Thus, the silane-based coupling agent (Monobond N) does not need to be applied after HF etching in terms of fatigue behavior outcomes.
本研究评估了陶瓷表面处理和储存方案（基线与老化）对简化锂硅玻璃陶瓷修复体疲劳性能的影响。将 90 个陶瓷圆盘（Ø=10mm；厚度=1.0mm）分为 6 组（n=15），考虑 2 个因素：“陶瓷表面处理”-CA（仅硅烷偶联剂，Monobond N）、HF（5%氢氟酸蚀刻）或 HF+CA（5%HF 酸蚀刻加硅烷偶联剂）；以及“储存方案”-基线（24 小时-37°C 蒸馏水中 5 天）或长期老化（37°C 蒸馏水中 180 天+25,000 次热循环）。对凹印陶瓷进行处理后，将多联 N 胶粘剂涂于环氧树脂圆盘（Ø=10mm；厚度=2.5mm）上，然后对粘合组件进行分步应力疲劳测试（初始载荷：200N；步长：50N；每步 10,000 次循环；20Hz）。使用 Kaplan-Meier 和 Weibull 统计分析对疲劳数据进行分析。还进行了断口和形貌分析。疲劳结果表明，基线和老化条件下各组的性能保持一致趋势：CA 组表现最差（基线：893N/143,667 循环；老化：639N/84,179 循环），而 HF 表面蚀刻（基线：1247N/214,333 循环；老化：816.67N/128,333 循环）和 HF+CA 组（基线：1290N/222,333 循环；老化：900N/145,000 循环）之间无统计学差异。老化方案降低了所有组的性能。具有更好疲劳性能（HF 和 HF+CA）的组在结构可靠性（Weibull 模数）方面没有统计学差异。大多数失效是从粘结界面开始的径向裂纹，除了 CA 老化试样，有 27%的失效是从脱粘开始的。HF 蚀刻导致显著的表面形貌变化。HF 酸蚀刻产生的机械锁合作用在疲劳行为中仍然普遍存在。因此，就疲劳性能而言，HF 蚀刻后不需要应用硅烷偶联剂（Monobond N）。
