Optical pen-size reflectometer for monitoring of early dental erosion in native and polished enamels

Abstract

Abstract. Application of the specular reflection intensity was previously reported for the quantification of early dental erosion. Further development of the technique and assembly of the miniaturized pen-size instrument are described. The optical system was adjusted to fit into a handy device which could potentially access different positions in the oral cavity. The assembled instrument could successfully detect early erosion progression in both polished (n ¼ 70) and native (n ¼ 20) human enamels. Different severities of enamel erosion were induced by varying incubation time of polished enamel in 1% citric acid (pH ¼ 3.60, 0.5 to 10 min), while the native incisors were treated in the commercial orange juice (Tropicana Pure Premium ® , pH ¼ 3.85, 10 to 60 min). The instrument provided a good differentiation between various severities of the erosion in vitro. The size of the measurement spot affected the erosion monitoring in native enamel (human incisors). The erosion measurement in the 0.7-mm (diameter) cervical spots showed systematically lower reflection intensities compared with the analysis of central and incisal small spots. The application of larger spot areas (2.3 mm) for the erosion monitoring revealed no effect (p > 0.05) of the spot position on the reflection signal. High variation of the teeth susceptibility toward in vitro erosion was detected in native enamel.

Analyses of the Erosive Effect of Dietary Substances and Medications on Deciduous Teeth

“…In this experiment, we used two parameters to measure enamel erosion: change in surface hardness (ΔSH) and surface reflection intenstiy (rSRI). Previous studies have shown that SRI is a viable additional method to measure the erosive demineralization of permanent enamel [ 37 , 38 , 54 ], because it highly correlates with Knoop surface microhardness, calcium release, and surface roughness [ 36 ]. In the present study, we were able to further demonstrate that SRI is significantly associated with surface hardness measured with Vickers nanoindentations.…”

Measurement of surface roughness changes of unpolished and polished enamel following erosion

“…A series of in vitro studies have attempted to model early clinical erosion [18,19]. They initially measured 2D roughness change of polished enamel along with other techniques such as calcium analysis and reflectometry.…”

“…In their earlier study, Rakhmatullina et al [18] reported that following erosion, polished enamel samples exhibited an increase in diffuse reflection and decrease in spectral reflection, concurrent with a loss in enamel surface microhardness and surface calcium, and suggested a relationship between the increase in diffuse reflection and increase in surface roughness with the progression of erosion. In a follow-up study, using native and polished enamel Rakhmatullina et al [19] reported that the increase in diffuse reflections was related to surface roughness. Other studies have used surface texture measurements to investigate the changes that occur from erosive tooth wear.…”

A new hand-held optical reflectometer to measure enamel erosion: correlation with surface hardness and calcium release

“…In addition, this method can be used in comparative studies 9 , but the acquired enamel pellicle can influence the results 10 . More recently, the principle of this reflectometer was transferred and adjusted into a portable optical device 11 . This new hand-held reflectometer (Hand-Held) was developed for the purpose of using in the clinical setting and on native enamel surfaces with promising results 11 .…”

“…More recently, the principle of this reflectometer was transferred and adjusted into a portable optical device 11 . This new hand-held reflectometer (Hand-Held) was developed for the purpose of using in the clinical setting and on native enamel surfaces with promising results 11 . Different to the reflectometer used by Rakhmatullina et al 7 , the miniaturized Hand-Held version has a laser diode source of 635 nm, and the laser beam is coupled into a 105 μm fibre, and the angle of incidence is fixed at ~23°.…”