Two-body wear test of enamel against laboratory polished and clinically adjusted zirconia

Kazi Rizwana Mehzabeen; Philip Boughton; Wen Hao Kan; Andrew J Ruys; Massimiliano Guazzato

doi:10.1016/j.jmbbm.2020.103760

Two-body wear test of enamel against laboratory polished and clinically adjusted zirconia

J Mech Behav Biomed Mater. 2020 Aug:108:103760. doi: 10.1016/j.jmbbm.2020.103760. Epub 2020 Apr 7.

Authors

Kazi Rizwana Mehzabeen¹, Philip Boughton², Wen Hao Kan³, Andrew J Ruys⁴, Massimiliano Guazzato⁵

Affiliations

¹ Biomedical Engineering, School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, NSW, 2006, Australia. Electronic address: kazi.mehzabeen@sydney.edu.au.
² Biomedical Engineering, School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, NSW, 2006, Australia; Sydney Spine Institute & School of Pharmacy, University of Sydney, NSW, 2006, Australia.
³ School of Civil Engineering, University of Sydney, NSW, 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia.
⁴ Biomedical Engineering, School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, NSW, 2006, Australia.
⁵ Faculty of Dentistry, University of Sydney, NSW, 2006, Australia.

PMID: 32469712
DOI: 10.1016/j.jmbbm.2020.103760

Abstract

Aim: A two-body wear test experiment was performed on human enamel, in simulated chewing motion, against non-veneered zirconia ceramic. Aim-1 was to ascertain the effect of zirconia roughness on enamel wear. Aim-2 was to ascertain the relative enamel wear between enamel-zirconia wear pair and enamel-enamel control pair.

Materials: Six molar and premolar human enamel cusps per group were used for a dental wear test against laboratory polished (LP) zirconia and laboratory polished and clinically adjusted (LP + CA) zirconia. Enamel antagonists were tested against incisor teeth as a control group to demonstrate laboratory enamel wear.

Methodology: Two-body wear tests were conducted in a dual-axis biomimetic dental wear simulator. 49N loading force was used for 120,000 cycles with 1 mm lateral movement of the test specimen at 1.6Hz frequency, under constant ambient temperature water flow. Surface roughness before testing was determined using 3D profilometry. Loss of enamel height and volume i.e. vertical wear and volumetric wear respectively, were measured by superimposition of before and after testing scans by 3D laser scanning. Scanning electron microscopy was used for surface morphology assessment. One-way ANOVA and Post Hoc Multiple Comparisons with Bonferroni corrections were used at the 5% significance level to determine whether surface finish affected volumetric and vertical enamel loss. The relationship between volumetric and vertical loss of enamel was assessed using Pearson's correlation test.

Results: No significant difference was found between LP and LP + CA zirconia in vertical and volumetric enamel wear results. Control enamel had significantly higher vertical and volumetric enamel wear than LP and LP + CA zirconia. Pearson correlation revealed a strong relationship between vertical wear and volumetric wear of enamel.

Conclusion: Within the constraints of the test method in this experiment, zirconia irrespective of surface preparation, was found to cause less vertical and volumetric enamel wear compared to control enamel. No statistically significant difference was seen between LP zirconia and LP + CA zirconia.

Keywords: Dental wear simulation; Enamel wear; Laboratory study; Surface roughness; Two-body wear test; Zirconia.

Publication types

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

MeSH terms

Dental Enamel
Dental Porcelain
Dental Restoration Wear
Humans
Laboratories*
Materials Testing
Surface Properties
Zirconium*

Substances

Dental Porcelain
Zirconium
zirconium oxide