Effects of Aging on the Color and Translucency of Monolithic Translucent Y-TZP Ceramics: A Systematic Review and Meta-Analysis of In Vitro Studies

Chang-Yuan Zhang; Check Agingu; James Kit Hon Tsoi; Hao Yu

doi:10.1155/2021/8875023

Effects of Aging on the Color and Translucency of Monolithic Translucent Y-TZP Ceramics: A Systematic Review and Meta-Analysis of In Vitro Studies

Biomed Res Int. 2021 Jan 25:2021:8875023. doi: 10.1155/2021/8875023. eCollection 2021.

Authors

Chang-Yuan Zhang¹, Check Agingu¹, James Kit Hon Tsoi², Hao Yu^{1

3}

Affiliations

¹ Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350002, China.
² Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China.
³ Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.

Abstract

Background: Monolithic restorations made of translucent yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) have become popular over the past few decades. However, whether aging affects the color and translucency of monolithic translucent Y-TZP is unclear.

Objective: The aim of this systematic review and meta-analysis of in vitro studies was to evaluate the effects of aging on the color and translucency of monolithic translucent Y-TZP ceramics.

Materials and methods: This systematic review/meta-analysis was reported according to the PRISMA statement and registered in the OSF registries (https://osf.io/5qjmu). Four databases including Medline via the PubMed, Embase, and Web of Science databases and the Cochrane Library were searched using no publication year and language limits. The last search was executed on November 20, 2020. In vitro studies comparing the translucency and/or color of monolithic translucent Y-TZP ceramics before and after simulated aging were selected. Meta-analyses were performed using Review Manager software (version 5.3, Cochrane Collaboration, Oxford, UK) with random-effects models at a significance level of 0.05. A risk-of-bias assessment was also performed for the included studies.

Results: Of the 188 potentially relevant studies, 13 were included in the systematic review. The hydrothermal aging duration ranged from 1 to 100 h at relatively similar temperatures (~134°C). In the general meta-analyses, the aged Y-TZP ceramics exhibited similar translucency parameter (TP), L^∗, and b^∗ values compared with the nonaged controls (P = .73, P = .49, and P = .62, respectively). Moreover, there was a significant difference between the aged and nonaged Y-TZP ceramics in the a^∗ value (P = .03; MD = -0.26; 95% CI = -0.51 to - 0.02), favoring the nonaged Y-TZP ceramics. The subgroup analyses showed that the duration of aging contributed to changes in the translucency and color of the Y-TZP ceramics.

Conclusions: The optical properties of monolithic translucent Y-TZP ceramics were stable after hydrothermal aging at 134°C and 0.2 MPa for ≤20 h. Moreover, clinically unacceptable changes in the translucency and color of monolithic translucent Y-TZP ceramics were found after hydrothermal aging for >20 h.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Ceramics* / analysis
Ceramics* / chemistry
Color
Materials Testing
Surface Properties
Temperature
Time Factors
Yttrium* / analysis
Yttrium* / chemistry
Zirconium* / analysis
Zirconium* / chemistry

Substances

yttria stabilized tetragonal zirconia
Yttrium
Zirconium