Flexural Strength of Different Monolithic Computer-Assisted Design and Computer-Assisted Manufacturing Ceramic Materials Upon Accelerated Aging

• Published in: European journal of dentistry 2024-10, Vol.18 (4), p.1124-1134
• Main Authors: Juntavee, Niwut, Juntavee, Apa, Chansathien, Orapun, Prasertcharoensuk, Natcha, Leesuraplanon, Boonsita
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 1305-7456; 1305-7464
• DOI: 10.1055/s-0044-1785185

The durability of ceramic is crucial, which is probably influenced by aging. This study evaluated the effect of aging on flexural strength of different ceramics.  One-hundred twenty ceramic discs (Ø 12 mm, 1.5 mm thickness) were prepared from zirconia-reinforced lithium silicate (ZLS, C), lithium disilicate (LS , E), precolored yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP, Ip), and customized color Y-TZP (Ic). Samples were randomly divided into two groups for accelerated aging (A) between 5 and 55°C water baths, 30-second immersing time each, for 10,000 cycles, and nonaged group (N), serving as control. Biaxial flexural strength (σ) was evaluated utilizing the piston-on-three-balls at 0.5 mm/min speed. Analysis of variance and Tukey comparisons were determined for significant differences (     ). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic strength (σ ). Microstructures were evaluated with scanning electron microscopy and X-ray diffraction (XRD).  The highest σ and σ were seen for IcN, followed by IcA, IpN, IpA, EN, CA, CN, and EA, respectively. CN showed the highest m, while EA showed the lowest m. Significant differences of σ for each ceramic were indicated (  0.05). Aging caused a significant difference in σ (  0.05). XRD showed t→m phase transformation of Ip and Ic after aging.  Aging affected strength of ceramics. Comparable strength between LS and ZLS was evidenced, but both were less strength than Y-TZP either aging or non-aging. Comparable strength between precolored Y-TZP and customized color Y-TZP was indicated. Better resisting aging deterioration of Y-TZP than LS and ZLS is suggested for fabrication restorative reconstruction.