The optical behavior of pressable lithia-based glass-ceramics under two different heat treatment protocols
DOI:
https://doi.org/10.4322/bds.2024.e4356Abstract
Objective: This study aimed to evaluate the optical behavior of pressable lithia-silicate and lithia-zirconiasilicate glass ceramics toward additional heat treatment protocols. Material and Methods: 40 lithia-silicate discs (15mm x 1mm) were heat pressed following the manufacturers’ instructions. Discs were divided into four groups (n=10) according to type as follows: two groups of lithia-silicate-glass ceramics; Gp(E) (IPS e.max Press; Ivoclar Vivadent AG), Gp(L) (GC Initial LiSi Press, GC), two lithia-zirconia-silicate pressable glass ceramics; Gp(C) (Celtra Press, Dentsply Sirona) and Gp(A) (VITA Ambria, VITA Zahnfabrik). Each group was subdivided into (n=5): Subgroup(T1): the thermal tempering temperature was set 9% below the pressing temperature, Subgroup(T2): the temperature was set 5% below the pressing temperature. Optical properties: color, translucency parameter (TP), and contrast ratio (CR) were evaluated by spectrophotometer (Aglient Cary 5000 UV-Vis–NIR) after pressing and after thermal tempering. Results: Thermal tempering regardless of temperature resulted in a color shift within the acceptability level as deltaE for Gp(E) (3.18±2) followed by deltaE for Gp(L) (2.47±0.19) by deltaE for Gp(C) (2.26±0.14) and the last deltaE for Gp(A) (1.62±0.13). Subgroup(T2) showed a significantly higher color shift with mean deltaE (2.55±0.63) compared to Subgroup(T1) deltaE (2.35±0.59). There was a statistically significant increase in TP after tempering for all tested groups parallelled with a decrease in CR values. Conclusion: Heat tempering of the tested lithia-silicate pressable ceramics had a significant effect on the optical outcome of these materials, being lithia-zirconia-silicate ceramics more stable and less affected optically than other lithia-silicateglass ceramics.
KEYWORDS
Ceramics; Glass ceramics; Hot temperature; Silicates; Zirconium oxide.
Published
Issue
Section
License
COPYRIGHT TRANSFER AND RESPONSIBILITY STATEMENT
(PDF)
For all articles published in the BDS journal, copyright is retained by the authors. Articles are licensed under an open-access Creative Commons CC BY 4.0 license, meaning that anyone may download and read the paper for free. In addition, the article may be reused and quoted, provided that the original published version is cited. These conditions allow for maximum use and exposure of the work while ensuring that the authors receive proper credit. All metadata associated with published articles is released under the Creative Commons CC0 Universal Public Domain Dedication.
Before the submission, authors must obtain permission to reproduce any published material (figures, schemes, tables, or any extract of a text) that does not fall into the public domain or for which they do not hold the copyright. Permission should be requested by the authors from the copyright holder (usually the Publisher, please refer to the imprint of the individual publications to identify the copyright holder).
The authors hereby attest that the study is original and does not present manipulated data, fraud, or plagiarism. All names listed made a significant scientific contribution to the study, are aware of the presented data, and agree with the final version of the manuscript. They assume complete responsibility for the ethical aspects of the study.
This text must be printed and signed by all authors. The scanned version should be submitted as supplemental file during the submission process.
