Effect of "fast"-crystallization and simultaneous glazing on physicochemical properties of lithium-disilicate CAD/CAM ceramic

Fabián Murillo-Gómez; Federico Murillo-Alvarado; Fabián Vásquez-Sancho; Esteban Avendaño; Roberto Urcuyo

doi:10.1016/j.jdent.2024.105257

Effect of "fast"-crystallization and simultaneous glazing on physicochemical properties of lithium-disilicate CAD/CAM ceramic

J Dent. 2024 Sep:148:105257. doi: 10.1016/j.jdent.2024.105257. Epub 2024 Jul 21.

Authors

Fabián Murillo-Gómez¹, Federico Murillo-Alvarado², Fabián Vásquez-Sancho³, Esteban Avendaño³, Roberto Urcuyo⁴

Affiliations

¹ Restorative Dentistry Department, School of Dentistry, University of Costa Rica, San Jose, Costa Rica; Dental Materials Research Laboratory (LIMD), School of Dentistry, University of Costa Rica, San Jose, Costa Rica. Electronic address: fabian.murillogomez@ucr.ac.cr.
² Restorative Dentistry Department, School of Dentistry, University of Costa Rica, San Jose, Costa Rica.
³ Center of Research in Materials Science and Engineering (CICIMA), University of Costa Rica, San Jose, Costa Rica.
⁴ Department of Chemistry, University of Costa Rica, San Jose, Costa Rica; Center of Electrochemistry and Chemical Energy (CELEQ), University of Costa Rica, San Jose, Costa Rica.

PMID: 39043330
DOI: 10.1016/j.jdent.2024.105257

Abstract

Objective: Evaluate the impact of a "fast" crystallization and simultaneous-glazing on the physicochemical properties of lithium-disilicate CAD/CAM-ceramic.

Methods: Lithium-disilicate bars and crowns (IPS e.max CAD, Ivoclar-Vivadent) were divided into four groups (n = 30): WG/F (WG=with glaze/F=fast crystallization), NG/F (NG=no glaze), WG/C (C=conventional crystallization), and NG/C. A liquid/powder glaze system was used (IPS Ivocolor®, Ivoclar-Vivadent). Specimens were crystallized (Programat P310, Ivoclar-Vivadent) using the P161 program for C (approx. 20-25 min), and P165 for F (approx. 14-16 min). Bars (n = 30) underwent three-point bending tests (flexural strength-FS in MPa and modulus of elasticity-E in GPa) using a universal testing machine. Crowns were analyzed via scanning electron microscopy (SEM) after selective etching, and to Raman, FTIR-ATR, and X-ray diffraction (XRD) spectroscopies to assess chemical composition.

Results: For FS, both factors/interaction were statistically significant. C (427.48±42.41 MPa) showed significantly higher values than F (409.82±38.82 MPa). WG (398.32±29.80 MPa) exhibited significantly lower FS than NG (438.21±41.77 MPa). For E data, both factors/interaction were significant. NG (90.28±14.71 GPa) displayed higher E than WG (83.07±5.69 GPa), while C (90.08±12.98 GPa) exhibited higher E than F (83.46±9.40 GPa). NG/C showed the best results for both variables. F groups showed (SEM) porous surfaces and crack-like marks on crystals. FTIR, Raman and XRD spectra confirmed the typical composition of a lithium-disilicate glass ceramic, and some attenuated signals and structural variations (XRD) in WG.

Conclusions: "Fast" crystallization and simultaneous-glazing produced weaker/less-rigid structures with irregular crystals and glassy phases. Simultaneous glazing may have hindered proper thermal distribution during crystallization.

Significance: "Fast" crystallization and simultaneous glazing with non-recommended systems, can adversely affect the final properties of lithium disilicate restorations.

Keywords: Ceramic glazing; Fast crystallization; Lithium-disilicate; Mechanical properties; Spectroscopy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ceramics* / chemistry
Computer-Aided Design*
Crowns*
Crystallization*
Dental Porcelain* / chemistry
Dental Stress Analysis
Elastic Modulus
Flexural Strength
Humans
Materials Testing*
Microscopy, Electron, Scanning*
Spectroscopy, Fourier Transform Infrared
Spectrum Analysis, Raman
Surface Properties*
X-Ray Diffraction

Substances

Dental Porcelain
lithia disilicate