Effect of Artificial Ageing on Optical Properties and Mechanical Strength of High-Translucency Zirconia: A Systematic Review and Meta-Analysis Publisher Pubmed



Saini RS ; Madhav VNV ; Kaushik A ; Gurumurthy V ; Kanji MA ; Alarconsanchez MA ; Heboyan A
Source: International Dental Journal Published:2025

Abstract

Purpose: The introduction of zirconia for dental applications revealed that ageing significantly affects optical and mechanical properties, resulting in impaired function and possible failure. The current research was developed to assess how artificial ageing affects the optical, crystalline and mechanical properties of high-translucency zirconia used in dental applications. Methods: Following PRISMA 2020 guidelines, we searched PubMed, ScienceDirect, Scopus, The Cochrane Library, and Google Scholar up to May 5, 2024, for studies comparing HT zirconia to alternative materials. Eligibility criteria included studies reporting artificial ageing effects on HT zirconia with defined control groups, published in English, including randomised controlled trials and laboratory studies. Data were pooled using a random-effects model in RevMan 5.4, with P = .01. Study quality was assessed using the QUIN tool. The study was registered with INPLASY (202540112). Results: The current study incorporated 30 different studies into its analysis. The artificial ageing process incorporated 3 different techniques which included hydrothermal methods, thermocycling procedures and UV light exposure. The artificial ageing process significantly alters HT zirconia's optical and mechanical properties because ageing protocols demonstrated powerful effects on translucency parameters (TP) with a pooled effectiveness of –3.60 (95% CI: –6.15, –1.05, I2 = 100%). This ageing process also demonstrated a substantial effect on contrast ratio, which resulted in 0.10 (95% CI: 0.02, 0.18) with high heterogeneity (I2 = 99%) at a significance level of P < .00001. Artificial ageing produced a significant effect on colour stability, which had a pooled effectiveness value of –0.68 (95% CI: –0.89, –0.48) with high heterogeneity (I2 = 97%) and statistical significance (P < .00001). The combined results demonstrated that artificial ageing reduced flexural strength by 95.14 Mpa between the range of –207.98 to 17.69 Mpa. Statistical analysis revealed a high level of heterogeneity across studies (I2 = 99%) along with a statistically significant difference (P < .00001). Every study displayed a medium risk of bias. Conclusions: Artificial ageing significantly alters HT zirconia's optical and mechanical properties, reducing transparency, colour stability, and flexural strength. Standardised ageing protocols are needed to predict long-term performance in dental applications. © 2025 Elsevier B.V., All rights reserved.