Comparative Study of Two Chemical-Models Used for Induction of White-Spot-Lesions

Objectives: There are various in vitro models used for chemical induction of artificial caries lesions. Diverse chemical models exist with respect to solutions’ ingredient, acid challenges’ duration, and caries lesions’ depths. The aim of this study was to compare the practicality and suitability of a short-term model (Queiroz’s solution) vs a relatively longer-term model (Buske’s solution).
Methods: Twenty sound posterior human teeth were sectioned into halves and randomly divided into two groups of 20 specimens each. Using FluoreCam (DARZA, Nobesville) enamel surfaces of both groups were imaged under standardized conditions and base-line data (area, intensity and impact) were recorded. To create white-spot lesions, each specimen was covered by an acid resistant polish, except for a 2x5mm² window. Group1: immersed in Queiroz’s-solution (64 hours/37C°/pH5 with agitation), Group2: immersed in Buske’s-solution (14 days/37C° /pH5 with agitation). After the acid attack, both groups were again imaged using FluoreCam. Changes over time were evaluated using Wilcoxon signed-rank test; groups were compared using Mann-Whitney U test. Polarized light microscopy was used to calculate the mean lesion depth of representative specimens.
Results: Both groups showed statistical significant changes (P<0.05) over time. Group 2 showed a greater increase in area and smaller increases in intensity and impact than Group1, but the differences were not statistically significant (p>0.05). The mean lesion depths of representative samples were 51.4 and 73.0μm for Group1 and 2, respectively.
Conclusions: Due to the lack of statistical significance, the Queiroz’s-solution appears to be more practical, with less potential for error while changing the demineralization solution and a significant gain in time.