Influence of different glaze firing protocols on the mechanical properties of CAD-CAM ceramic materials

Joissi Ferrari Zaniboni; Aryvelto Miranda Silva; Cristiane de Melo Alencar; Thiago Soares Porto; Renato Goulart Jasinevicius; Carlos Alberto Fortulan; Edson Alves de Campos

doi:10.1016/j.prosdent.2022.03.009

Influence of different glaze firing protocols on the mechanical properties of CAD-CAM ceramic materials

J Prosthet Dent. 2022 Jun;127(6):925.e1-925.e8. doi: 10.1016/j.prosdent.2022.03.009. Epub 2022 Apr 22.

Authors

Joissi Ferrari Zaniboni¹, Aryvelto Miranda Silva², Cristiane de Melo Alencar³, Thiago Soares Porto⁴, Renato Goulart Jasinevicius⁵, Carlos Alberto Fortulan⁶, Edson Alves de Campos⁷

Affiliations

¹ PhD student, Department of Restorative Dentistry, Araraquara Dental School, Sao Paulo State University (UNESP), Araraquara, São Paulo, Brazil. Electronic address: joissizaniboni@gmail.com.
² Professor, School of Dentistry, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Brazil.
³ Professor, Department of Integrated Clinical, University Center of the State of Pará (CESUPA), Belém, Pará, Brazil.
⁴ Assistant Professor, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio.
⁵ Full Professor, Department of Mechanical Engineering, São Carlos School of Engineering, Universidade de São Paulo (USP), São Carlos, São Paulo, Brazil.
⁶ Associate Professor, Department of Mechanical Engineering, São Carlos School of Engineering, Universidade de São Paulo (USP), São Carlos, São Paulo, Brazil.
⁷ Associate Professor, Department of Restorative Dentistry, Araraquara Dental School, Sao Paulo State University (UNESP), Araraquara, São Paulo, Brazil.

PMID: 35469648
DOI: 10.1016/j.prosdent.2022.03.009

Abstract

Statement of problem: The influence of different glaze firing protocols and cooling on the behavior of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramics is unclear.

Purpose: The purpose of this in vitro study was to investigate the influence of different glaze firing protocols on the abrasion resistance, surface roughness, microhardness, and brittleness index of CAD-CAM ceramics.

Material and methods: Rectangular specimens of IPS e.max CAD (MAX), IPS Empress CAD (PRE), and CEREC Blocs (CER) were obtained and divided into 5 groups according to the glaze firing protocol (n=8): control (CO), 1 conventional glaze firing (GF), 2 conventional glaze firings (GF₂), 1 extended glaze firing (EG), and 2 extended glaze firings (EG₂). The coefficient of friction (μ) was determined with the pin-on-disk test, and specimens were analyzed with an optical interferometer to calculate volume loss and roughness. Vickers microhardness and the brittleness index were obtained with a microdurometer. Microhardness data were evaluated by 2-way ANOVA and the Sidak tests (α=.05). Data from other tests were assessed with nonparametric ANOVA and Bonferroni tests (α=.05).

Results: Groups GF₂, EG, and EG₂ of MAX and PRE and all groups of CER presented higher levels of coefficient of friction. Groups EG and EG₂ of MAX and CER showed high volume loss and surface roughness. Groups EG and EG₂ of MAX and PRE showed lower hardness, as did all groups of CER. MAX-CO and groups GF and EG of PRE showed a lower brittleness index (P<.05), while CER groups showed no significant differences (P>.05).

Conclusions: Ceramic specimens with conventional glaze firing presented less surface wear than those with extended glaze firing. The number of firings did not have a statistically significant influence.

MeSH terms

Ceramics*
Computer-Aided Design
Dental Porcelain*
Materials Testing
Surface Properties

Substances

Dental Porcelain