Surface form analysis on complex freeform organic structures – measuring erosive wear on human teeth in vitro

Mylonas, P., Moazzez, R., Joiner, A., Bartlett, D., Bull, T. and McBride, J 2021. Surface form analysis on complex freeform organic structures – measuring erosive wear on human teeth in vitro. Surface Topography: Metrology and Properties 9 (2) , 0205024. 10.1088/2051-672X/abfd07

PDF - Published Version Available under License Creative Commons Attribution. Download (1MB)

Abstract

Natural human enamel (NHE) is a complex freeform surface which has presented significant difficulties in measuring surface form change using non-contacting laser profilometry (NCLP). Measuring surface form change on NHE is a metrology proxy for measuring dental tooth structure loss, and characterising this using non-ISO parameters (volume, surface area, and normalised lesion depth) has been seldom studied due surface complexity and undetermined measurement errors. This study determines NCLP measurement errors (instrument repeatability and method reproducibility) for non-ISO parameters, characterises change in surface form on NHE following a dietary pH-cycling model. NHE (n = 1) was scanned consecutively twenty-times using NCLP with/without sample replacement producing consecutive surface profile data. Residual data was created after subtracting consecutive filtered profile data (80 μm, Gaussian filter), and mean (SD) volume, surface area, and normalised lesion depth was determined within a 1.5 mm circular region of interest (ROI). Volume error (expressed as height variation across ROI surface area) was 0.022 μm (instrument repeatability) and 0.149 μm (method reproducibility), whilst surface area error (expressed as percentage change of the surface area deviation across the entire surface area) was 0.034% (repeatability error) and 0.081% (reproducibility error). Sixty-four natural enamel surfaces taped with polyvinyl-chloride tape leaving 1.5 mm exposed ROI underwent dietary erosion cycling (three 5-min cycles, 0.3% citric acid w/v, pH 3.2) generating artificial erosion lesions. Samples were scanned with NCLP before/after each erosion cycle, scans filtered for microtexture, and after-erosion scans were subtracted from before-erosion scans. NCLP results show mean (SD) volume, surface area, normalised depth, and 3D step-height of the eroded area increased significantly after each erosion cycle, with no significant difference in calcium and phosphate release after each cycle. We demonstrate a robust and valid dental model with analysis workflow to measure surface form change in NHE using NCLP, improving understanding of measuring surface form change in complex freeform surfaces.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Dentistry
Publisher:	IOP Publishing: Hybrid Open Access
ISSN:	2051-672X
Date of First Compliant Deposit:	17 May 2021
Date of Acceptance:	29 April 2021
Last Modified:	04 May 2023 22:21
URI:	https://orca.cardiff.ac.uk/id/eprint/141379

Citation Data

Cited 2 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item