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. 2023 Feb;138:105597. doi: 10.1016/j.jmbbm.2022.105597. Epub 2022 Nov 23.
The aim of the study was to evaluate whether the region (internal or external) of the CAD/CAM block influences the mechanical performance of restorative materials. Blocks of different CAD/CAM materials (Composites: KAV - Katana Avencia; LULT - LULT Ultimate; Ceramics: ENAM - Vita Enamic; NICE - N!CE; EMP - IPS Empress CAD; VMII - Vita Mark II; EMAX - IPS e.max CAD) were selected, and direct resin composite blocks (APX - Clearfil AP-X; FSUP - Filtek Supreme) were built using the incremental technique on a mold from one of the CAD/CAM blocks. All blocks were sectioned into bar-shaped specimens (1 × 1 × 14 mm), which were separated into two groups according to the region of the block (inside or outside). 3-point bending tests were performed following ISO 6872:2015 and flexural strength data were analyzed using one-way ANOVA and Bonferroni post-hoc tests (p < 0.05). Weibull module and characteristic strength were also calculated. In general, the mean flexural strength values were not statistically different (p > 0.05) between the inside and outside regions of each material, except for LULT (inside > outside) and EMAX (outside > inside). Comparing the materials, a similar strength (only discrete variations) was observed for inside, outside or merged (inside and outside data assembled together) regions: EMAX > KAV = LULT > NICE = APX > EMP = ENAM = VMII ≥ FSUP (merged condition). Characteristic strength at 63.2% failure probability and at 5% failure probability generally corroborates such observations. There were no statistical differences for Weibull module data (inside, outside, or merged), except for KAV and NICE (outside > inside). Thus, the region from where the restoration is milled within the CAD/CAM block generally does not influence the mechanical performance hereof (flexural strength, failure probability, risk of premature failures, and mechanical reliability) of the material, except for LULT and EMAX.
本研究旨在评估 CAD/CAM 块的区域（内部或外部）是否会影响修复材料的机械性能。选择了不同 CAD/CAM 材料的块（复合材料：KAV - Katana Avencia；LULT - LULT Ultimate；陶瓷：ENAM - Vita Enamic；NICE - N!CE；EMP - IPS Empress CAD；VMII - Vita Mark II；EMAX - IPS e.max CAD），并使用增量技术在其中一个 CAD/CAM 块的模具上构建了直接树脂复合块（APX - Clearfil AP-X；FSUP - Filtek Supreme）。所有块均被切割成棒状试件（1×1×14mm），根据块的区域（内部或外部）将其分为两组。根据 ISO 6872:2015 进行了 3 点弯曲测试，并使用单向方差分析和 Bonferroni 事后检验（p<0.05）对弯曲强度数据进行了分析。还计算了威布尔模块和特征强度。总体而言，除 LULT（内部>外部）和 EMAX（外部>内部）外，除 LULT（内部>外部）和 EMAX（外部>内部）外，每种材料的内部和外部区域的平均弯曲强度值没有统计学差异（p>0.05）。比较这些材料时，在内部、外部或合并（内部和外部数据合并在一起）区域观察到相似的强度（仅离散变化）：EMAX>KAV=LULT>NICE=APX>EMP=ENAM=VMII≥FSUP（合并条件）。在 63.2%失效概率和 5%失效概率下的特征强度通常证实了这些观察结果。威布尔模块数据（内部、外部或合并）没有统计学差异，除了 KAV 和 NICE（外部>内部）。因此，从 CAD/CAM 块中铣削修复体的区域通常不会影响材料的机械性能（弯曲强度、失效概率、早期失效风险和机械可靠性），除了 LULT 和 EMAX 之外。
