Work

Effect of glazing and hydrothermal aging on the fracture strength of metal-ceramic single restorations after additional firing: an in vitro study

Year: 2025

Type: article

Abstract: BACKGROUND: Additional firing to repair a lost proximal contact or porcelain chipping might affect the fracture strength of a metal-ceramic crown. This study aimed to evaluate the effect of glazing and hydrothermal aging on the fracture strength of metal-ceramic crowns after additional firing. METHODS: A total of 40 metal-ceramic crowns were fabricated and divided evenly into five groups: not aged/glazed (G0), 3-month-old/glazed (G3), 24-month-old/glazed (G24), 3-month-old/unglazed (nG3), and 24-month-old/unglazed (nG24). Autoclaving was used as the aging protocol. All groups underwent an additional firing cycle, and fracture strength was measured. Data were analyzed using ANOVA and independent t-tests. RESULTS: G0 demonstrated the highest fracture strength (4405.00 ± 1528.20 N), followed by G3, nG3, G24, and nG24, respectively. There was a significant difference between G0 and G24 (P =.01), G0 and nG3 (P =.00), and G0 and nG24 (P =.00). CONCLUSION: Glazing does not significantly affect the fracture strength of a metal-ceramic crown undergoing additional firing; however, aging has a significant adverse effect on fracture strength. This negative effect is not significant until after 3 months.

Source: BMC Oral Health

DOI: 10.1186/s12903-025-05972-w

Authors: Zahra Parvizi, Elham Ansarifard, Masumeh Taghva, Seyed Ali Mosaddad

Institutions: Shiraz University of Medical Sciences, Shahid Sadoughi University of Medical Sciences and Health Services, Shiraz University, Universidad Complutense de Madrid, Saveetha University

Language: English

Topic: Dental materials and restorations

Subfield: Orthodontics

Field: Dentistry

Domain: Health Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funders: Shiraz University of Medical Sciences, Shiraz University