Abstract
Measurement Uncertainty Associated With Profilometry of Tooth Wear In Vitro
Austin RS 1, Giusca C 2, Leach R 2, Festy F 3, Dunne S 1, Moazzez R 4, Bartlett DW 5.
1 Department of Primary Dental Care, King's College London Dental Institute, London Bridge, SE1 9RT 2 Higher Research Scientist, National Physical Laboratory, Hampton Rd, Teddington, Middlesex, UK, TW11 0LW 2 Principal Research Scientist, Mass & Dimensional Group, Engineering Measurement Division, National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW 3 Department of Biomaterials Science, King's College London Dental Institute, London Bridge, SE1 9RT 1 Department of Primary Dental Care, King’s College London Dental Institute, King’s College Hospital Denmark Hill, London. SE5 9RW 4 Department of Conservative Dentistry, King’s College London Dental Institute, London Bridge, SE1 9RT 5 Department of Fixed and Removable Prosthodontics, King’s College London Dental Institute, London Bridge, SE1 9RT.
Abstract
Objectives: To identify and quantify all possible sources of measurement uncertainty associated with a tooth wear measurement system. To carry out an analysis of uncertainty in accordance with international guidelines. To analyse the relative merits of tooth wear outcome parameters.
Methods: An analysis of uncertainty associated with the use of a white light confocal profilometer (XYRIS 4000 WL, TaiCaan Technologies Ltd., Southampton, UK) in combination with custom designed software (ImageJ v1.42q, Rasband, W. S., U. S. National Institutes of Health, Bethesda, Maryland, USA) for measuring tooth wear in vitro, was carried out following the principles outlined in the ISO Guide to the Expression of Uncertainty in Measurement. Uncertainty budgets were compiled by summating the variances of each potential source of uncertainty and the effect of the measurement of tooth wear was considered. The relationship between step height and volume loss of enamel after erosion; erosion-abrasion and erosion-attrition was then examined.
Results: The main contribution to the uncertainty budget was from a flatness deviation (max 0.49 µm), whereas the contributions from noise, non-linearity, sample shrinkage during dehydration and software errors were negligible. Despite the flatness error, the overall combined uncertainty was < 6 %, even when measuring a simulated depth of wear of 0.3 µm. Investigation of the use of step height and volume loss outcome parameters suggested that for erosion and erosion-abrasion the preferred outcome measure should be step height loss and for erosion-attrition the preferred outcome measure should be volume loss.
Conclusion: The uncertainty analysis quantitatively expressed of the comprehensive effect of the likely degree of uncertainty introduced during tooth wear measurement. This allows users to gauge how ‘fit for purpose’ a measurement system is in order that the results of tooth wear research can be readily understood and properly interpreted.
Austin RS 1, Giusca C 2, Leach R 2, Festy F 3, Dunne S 1, Moazzez R 4, Bartlett DW 5.
1 Department of Primary Dental Care, King's College London Dental Institute, London Bridge, SE1 9RT 2 Higher Research Scientist, National Physical Laboratory, Hampton Rd, Teddington, Middlesex, UK, TW11 0LW 2 Principal Research Scientist, Mass & Dimensional Group, Engineering Measurement Division, National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW 3 Department of Biomaterials Science, King's College London Dental Institute, London Bridge, SE1 9RT 1 Department of Primary Dental Care, King’s College London Dental Institute, King’s College Hospital Denmark Hill, London. SE5 9RW 4 Department of Conservative Dentistry, King’s College London Dental Institute, London Bridge, SE1 9RT 5 Department of Fixed and Removable Prosthodontics, King’s College London Dental Institute, London Bridge, SE1 9RT.
Abstract
Objectives: To identify and quantify all possible sources of measurement uncertainty associated with a tooth wear measurement system. To carry out an analysis of uncertainty in accordance with international guidelines. To analyse the relative merits of tooth wear outcome parameters.
Methods: An analysis of uncertainty associated with the use of a white light confocal profilometer (XYRIS 4000 WL, TaiCaan Technologies Ltd., Southampton, UK) in combination with custom designed software (ImageJ v1.42q, Rasband, W. S., U. S. National Institutes of Health, Bethesda, Maryland, USA) for measuring tooth wear in vitro, was carried out following the principles outlined in the ISO Guide to the Expression of Uncertainty in Measurement. Uncertainty budgets were compiled by summating the variances of each potential source of uncertainty and the effect of the measurement of tooth wear was considered. The relationship between step height and volume loss of enamel after erosion; erosion-abrasion and erosion-attrition was then examined.
Results: The main contribution to the uncertainty budget was from a flatness deviation (max 0.49 µm), whereas the contributions from noise, non-linearity, sample shrinkage during dehydration and software errors were negligible. Despite the flatness error, the overall combined uncertainty was < 6 %, even when measuring a simulated depth of wear of 0.3 µm. Investigation of the use of step height and volume loss outcome parameters suggested that for erosion and erosion-abrasion the preferred outcome measure should be step height loss and for erosion-attrition the preferred outcome measure should be volume loss.
Conclusion: The uncertainty analysis quantitatively expressed of the comprehensive effect of the likely degree of uncertainty introduced during tooth wear measurement. This allows users to gauge how ‘fit for purpose’ a measurement system is in order that the results of tooth wear research can be readily understood and properly interpreted.
| Original language | English |
|---|---|
| Journal | Journal of Dental Research |
| Volume | 90 |
| Issue number | Spec Iss B |
| Publication status | Published - 2011 |