Fracture strength of preformed zirconia crown and CAD-CAM zirconia, ceramic, and hybrid composite crowns for the restoration of primary molars: An in vitro study

Joy Elian El Hayek; Hani Tohme; Lara Nasr; Roula El Hachem; Nathalie Kabbani; Nada Farhat Mchayleh

doi:10.1111/ipd.13171

Fracture strength of preformed zirconia crown and CAD-CAM zirconia, ceramic, and hybrid composite crowns for the restoration of primary molars: An in vitro study

Int J Paediatr Dent. 2024 Feb 25. doi: 10.1111/ipd.13171. Online ahead of print.

Authors

Joy Elian El Hayek^{1

2

3}, Hani Tohme^{3

4}, Lara Nasr², Roula El Hachem^{2

5}, Nathalie Kabbani¹, Nada Farhat Mchayleh¹

Affiliations

¹ Department of Pediatric Dentistry, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon.
² Cranio-Facial Research Laboratory, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon.
³ Department of Digital Dentistry, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon.
⁴ Department of Removable Prosthodontics, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon.
⁵ Department of Endodontics, Faculty of Dental Medicine, Saint Joseph University of Beirut, Beirut, Lebanon.

PMID: 38403852
DOI: 10.1111/ipd.13171

Abstract

Background: Paediatric-preformed zirconia crowns have been associated with several issues, primarily their inability to be crimped and the need for extensive tooth preparation. Additionally, the capacity to adjust the size, shape, and fit of these crowns is very limited.

Aim: To evaluate and compare the fracture strength of four different types of dental crowns intended for paediatric patients.

Design: The fracture resistance of four types of paediatric crowns was evaluated using the universal testing machine; freshly extracted primary molars received one of the following: preformed zirconia crowns, custom-made computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia crowns, custom-made CAD-CAM ceramic crowns, and custom-made CAD-CAM hybrid composite crowns. Data were statistically compared using the Kruskal-Wallis test followed by the Bonferroni test, and the level of significance was set at 5%.

Results: Results showed that there was a statistically significant difference among the four groups (p < .001). The highest value of fracture force was observed for the milled zirconia crown and the lowest for the prefabricated zirconia.

Conclusion: The implementation of the CAD-CAM digital crown fabrication technique has the potential to address issues associated with preformed crowns in paediatric patients, particularly in terms of fracture resistance.

Keywords: ceramic CAD-CAM crowns; fracture strength; hybrid composite CAD-CAM crown; preformed zirconia crown; primary molars; zirconia CAD-CAM crown.