Comparing Fracture Resistance of Monolithic Zirconia Crowns Designed with three Different Thicknesses: An In Vitro Study

Safa M. Alzoubi; Abdel Ghani Alsahhar; Ebtisam Alsalameh

doi:10.33891/FSZ.114.4.172-177

Safa M. Alzoubi Department of Fixed Prosthodontics,Faculty of Dentistry, University of Hama, Syria https://orcid.org/0000-0002-5275-7967
Abdel Ghani Alsahhar Faculty of Public Health, University of Debrecen, Hungary https://orcid.org/0000-0002-8062-8791
Ebtisam Alsalameh Department of Fixed Prosthodontics,Faculty of Dentistry, University of Hama, Syria https://orcid.org/0000-0002-1283-2002

DOI: https://doi.org/10.33891/FSZ.114.4.172-177

Keywords: Fracture, Resistance, Monolithic, Zirconia, Crowns, Thickness

Abstract

A limited available inter-occlusal space has always been a challenge for many dental practitioners, which hinders
acquiring aesthetic restorations while conserving the remaining dental structure.
This research aims to analyze the relationship between the occlusal thickness of second-generation CAD/CAM
monolithic zirconia restorations, and their fracture resistance, in order to determine the feasibility of reducing the occlusal
thickness – particularly in the posterior oral area, where a limited inter-occlusal space is usually available, and high biting
forces are usually applied.
Thirty monolithic zirconia crowns were made using second generation zirconia block with different design settings
that divided them into 3 groups (n = 10) according to the occlusal thickness of the restorations: Group A: 2 mm, Group B:
1.5 mm, Group C: 1 mm.
Thirty designed crowns were cemented to extracted prepared natural upper premolars using glass ionomer cement,
then they were tested.
Fracture resistance of the monolithic zirconia crowns was significantly influenced by the occlusal thickness, the resistance
improved steadily as the thickness increased.
Nevertheless, the occlusal thickness could be reduced down to 1 mm and the monolithic zirconia restoration would
still own sufficient resistance to tolerate the maximum natural human biting loads of the posterior oral regions.

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