Characterisation of mineral loss as a function of depth using confocal laser scanning microscopy to study erosive lesions in enamel: A novel non-destructive image processing model

Abstract

Objective: The aim was to develop a novel image processing protocol for confocal laser scanning microscopy (CLSM) to study mineral distribution within erosive lesions as a function of depth. Methods: Polished bovine enamel samples (n=80) were divided into groups (8/group) with similar mean surface microhardness (SMH) values. Samples underwent erosion (1% citric acid pH3.8) for 1,5,10,15, or 30min, with or without stirring giving 10 treatment groups in a 2*5 factorial design. SMH was used to measure erosive softening. Profilometry was used to measure bulk tissue loss. Samples were then stained with rhodamine-B (0.1mM, 24h) and imaged using CLSM. Image processing was used to measure fluorescence volume (FV) as a function of depth for each image. The data from reference images were subtracted from post-erosive data to determine changes in fluorescent volume (ΔFV) as a function of depth. 2-way ANOVA and linear regression analysis were used where applicable.Results: Surface softening and bulk tissue loss increased with acid erosion duration with or without stirring. Stirring significantly increased net softening at each time point; specimens underwent significantly more bulk tissue loss (P<0.05). CLSM showed the erosive lesion deepened as exposure to acid increased, and that at the near surface (0-10µm) FV and ΔFV increased rapidly for stirred solutions. The increase in pore space translated to a softer surface as measured by SMH. Conclusion:This novel non-destructive method allows concurrent quantification of dental erosion by mineral loss as a function of depth, and qualitative characterisation of microstructural changes during early erosion.

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

“…Additionally, Hookham et al 2020 demonstrated that calcium/phosphate loss following acid attack (1% citric acid) on bovine enamel resulted in deeper penetration of rhodamine B dye and thus an increase in fluorescence volume measuring using confocal laser scanning microscopy. Their study showed that as erosion lesion depth increased, so did the fluorescent volume detected due to the deeper penetration of rhodamine B dye into the eroded enamel [41]. However, whilst their study used polished bovine enamel, the principle outcome they demonstrated could potentially translate to the human enamel model; though this would require future study.…”

Etch‐and‐rinse versus self‐etch strategy of a universal adhesive in different application methods at the bonding interface of fiber post cementation

“…30 Furthermore, the stereomicroscope was chosen to analyze the failure pattern because it allows for the acquisition of high-resolution images and enables the measurement of gaps in the four quadrants of the adhesive interface. 31 Finally, laser confocal microscopy was planned to evaluate the extent of resin tags because it is a non-destructive technique 32 that provides better visualization of the interaction between the dentin surface and the SU adhesive through the fluorescence of Rhodamine B present in the material.…”

Tooth Wear and Tribological Investigations in Dentistry

“…CLSM is a nondestructive technique that can quantify and visualize erosive lesions [ 70 ]. The technology combines laser scanning with the capture of traditional visible light microscope images to produce a detailed 3D image of the surface [ 51 ] ( Figure 4 ).…”