Lasers in Medical Science

, Volume 31, Issue 6, pp 1105–1112 | Cite as

In vitro validation of a hand-held optical reflectometer to measure clinically observed erosive tooth wear

  • Thiago Saads CarvalhoEmail author
  • Cristiane Meira Assunção
  • Fabian Jost
  • Walter Bruno Bürgin
  • Jonas Almeida Rodrigues
  • Adrian Lussi
Original Article


In this study, we analyzed a newly developed optical reflectometer for measuring erosive tooth wear (ETW) in vitro. Three examiners independently assessed the labial surface of 80 deciduous canines and 75 permanent incisors. One examiner performed visual examinations (BEWE), and the other two used the optical pen-size reflectometer to measure surface reflection intensity (SRI) on the same labial surfaces. The examinations were made in duplicate with at least 1 week interval. Intra- and inter-rater agreements were calculated using weighted kappa analysis for BEWE, and intra-class correlation coefficients (ICC) as well as Bland-Altman plots for SRI. The teeth were separated into without (BEWE 0) or with (BEWE 1–3) ETW, and SRI cut-off points were calculated. Intra-rater agreement for the visual examination was 0.46 and 0.82 for deciduous and permanent teeth, respectively. Inter-rater and intra-rater agreement for SRI were good (ICC > 0.7; p < 0.001). SRI measurements produced high specificity values for deciduous and permanent teeth (≥0.74 and ≥ 0.84, respectively), and lower sensitivity values (≥0.37 and ≥ 0.64, respectively), but permanent teeth had generally higher SRI values (p < 0.05). We observed a significant association between BEWE and SRI (p < 0.05). The optical pen-size reflectometer was able to adequately differentiate ETW on permanent teeth, with highly reliable and reproducible measurements, but ETW on deciduous teeth was less accurately differentiated. The reflectometer is a good candidate for clinical research.


Dental erosion Basic erosive wear examination (BEWE) Permanent teeth Primary teeth Diagnostics Reflectometer 



We are very grateful to Isabel Hug and Marie-Loise Stämpfli from our department for their assistance in this work. We also show our gratitude to RP Shellis for his valuable comments and suggestions to this manuscript.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


One of the co-authors received a PhD scholarship from CAPES Foundation (Ministry of Education, Brazil).

Ethical standards

This article did not require the approval of an ethical committee, as detailed in the “Materials and methods” section.

Informed consent

For this type of study, formal written consent is not required.


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Copyright information

© Springer-Verlag London 2016

Authors and Affiliations

  • Thiago Saads Carvalho
    • 1
    Email author
  • Cristiane Meira Assunção
    • 1
    • 2
  • Fabian Jost
    • 1
  • Walter Bruno Bürgin
    • 1
  • Jonas Almeida Rodrigues
    • 2
  • Adrian Lussi
    • 1
  1. 1.Department of Preventive, Restorative and Pediatric DentistryUniversity of BernBernSwitzerland
  2. 2.School of DentistryFederal University of Rio Grande do SulPorto AlegreBrazil

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