Barreto Larissa Araújo Lopes, Grangeiro Manassés Tercio Vieira, Prado Pedro Henrique Condé Oliveira, Bottino Marco Antonio, Dal Piva Amanda Maria de Oliveira, Ramos Nathalia de Carvalho, Tribst João Paulo Mendes, Junior Lafayette Nogueira
Department of Dental Materials and Prosthodontics, Institute of Science and Technology, São Paulo State University (Unesp), Eng. Francisco José Longo Avenue, 777, São José dos Campos, SP, Brazil.
Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Netherlands.
Int J Dent. 2023 Sep 22;2023:8882878. doi: 10.1155/2023/8882878. eCollection 2023.
In case of need for esthetical improvement of zirconia restorations, an individualization using extrinsic staining can be applied. This study aimed to evaluate the surface roughness and fatigue strength (survival) of high-translucency zirconia (3Y-TZP, YZ®HT, Vita Zanhfabrik) with extrinsic characterization and/or glaze.
Sixty (60) zirconia discs (12 × 1.2 mm) were obtained, sintered, and randomly distributed among three groups ( = 20) according to the surface finishing protocol: C (control), C + G (extrinsic characterization followed by a glaze layer), and G (glaze layer). The surface roughness (Ra) was analyzed with a contact profilometer. Subsequently, the specimens were subjected to a fatigue load profile starting at 120 N during 20,000 cycles at 4 Hz frequency, with a 5% increase at each step until failure. The failed specimens were evaluated under a stereomicroscope. Surface roughness analysis was evaluated by using one-way ANOVA and post hoc Tukey tests (95%); while fatigue survival probability was analyzed with Kaplan-Meier and Mantel-Cox (log- rank, 95%).
One-way ANOVA revealed that surface roughness was affected by the finishing protocol, where C + G showed the highest mean value (0.46 ± 0.18 m) followed by G (0.30 ± 0.10 m), and C (0.19 ± 0.02 m). While for fatigue strength, the G protocol presented a higher mean value (243.00, and 222.36-263.63), followed by C + G (192.75 and 186.61-198.88) and C (172.50 and 159.43-185.56).
Surface finishing protocols modify the surface roughness and fatigue strength of high-translucent zirconia. Regardless of the surface roughness, both glazing protocols improved the ceramic fatigue strength, favoring the restoration's long-term survival.
在需要对氧化锆修复体进行美学改善的情况下，可采用外部染色进行个性化处理。本研究旨在评估经过外部表征和/或上釉处理的高透明度氧化锆（3Y-TZP，YZ®HT，维他齿科）的表面粗糙度和疲劳强度（存活率）。
获取60个氧化锆圆盘（12×1.2毫米），进行烧结，并根据表面处理方案随机分为三组（每组 = 20个）：C（对照组）、C + G（先进行外部表征再施加釉层）和G（釉层）。使用接触式轮廓仪分析表面粗糙度（Ra）。随后，对试样施加疲劳载荷，从120 N开始，以4 Hz频率循环20,000次，每次步长增加5%，直至失效。在立体显微镜下评估失效的试样。使用单向方差分析和事后Tukey检验（95%）评估表面粗糙度分析；而使用Kaplan-Meier和Mantel-Cox（对数秩，95%）分析疲劳存活概率。
单向方差分析显示，表面粗糙度受处理方案影响，其中C + G的平均值最高（0.46±0.18μm），其次是G（0.30±0.10μm），C（0.19±0.02μm）。对于疲劳强度，G方案的平均值较高（243.00以及222.36 - 263.63），其次是C + G（192.75以及186.61 - 198.88）和C（172.50以及159.4以及185.56）。
表面处理方案会改变高透明度氧化锆的表面粗糙度和疲劳强度。无论表面粗糙度如何，两种上釉方案均提高了陶瓷的疲劳强度，有利于修复体的长期存活。
