Optical properties, biaxial flexural strength, and reliability of new‐generation lithium disilicate glass‐ceramics after thermal cycling
Year: 2022
Type: article
Abstract: Purpose To investigate the color stability, translucency, biaxial flexural strength (BFS), and reliability of nano‐lithium disilicate and fully crystallized lithium disilicate after thermal cycling and to compare with those of a commonly used lithium disilicate. Materials and methods Three lithium disilicate glass‐ceramics were used to prepare disk‐shaped specimens (ø:12 mm, thickness: 1.2 mm) from A2 shaded HT blocks (Amber Mill, AM; Initial LiSi Block, IN; IPS e.max CAD, EX). AM and EX specimens were crystallized, and all specimens were polished with a polishing paste (Diamond Polish Mint). A spectrophotometer (CM‐26d) was used to measure color coordinates before and after thermal cycling. BFS test was performed after thermal cycling. Color differences (ΔE00) and relative translucency parameter (RTP) values were calculated. One‐way analysis of variance (ANOVA) (ΔE00 and BFS), two‐way ANOVA followed by Tukey's HSD tests (RTP), and chi‐square tests (Weibull modulus and characteristic strength) were used for the statistical analyses (α = 0.05). Results No significant differences were observed among the ΔE00 values of tested materials (df = 2, F = 2.933, p = 0.070). RTP values were only affected by material type (p < 0.001) as AM had the highest RTP (p < 0.001), whereas IN and EX had similar values (p ≥ 0.165). BFS values varied among tested materials (df = 2, F = 21.341, p < 0.001). AM and EX had similar BFS values (p = 0.067) that were higher than that of IN (p ≤ 0.001). Weibull moduli of the materials were similar (p = 0.305), whereas EX had the highest and IN had the lowest characteristic strength values (p < 0.001) Conclusions Although nano‐lithium disilicate had the highest translucency, all materials had imperceptible color and translucency changes after thermal cycling when reported threshold values were considered. Newly introduced lithium disilicate glass–ceramics had adequate flexural strength as compared to the precursor material.
Source: Journal of Prosthodontics
DOI: 10.1111/jopr.13632
Institutions: Biruni University, FH Kärnten, University of Bern, Istinye University
Language: English
Subfield: General Dentistry
Field: Dentistry
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4313339643