Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by
acetate buffer (pH 5) to induce
carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12%
chlorhexidine for 1 min, 2) 2%
fluoride for 1 min, 3)
Nd:YAG Laser (400 μm diameter
optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of
collagen). Samples were exposed to degradation by a
collagenase enzyme for five days. The
enzyme solution was collected, by colorimetry in a spectrophotometer, from the
collagen matrix for the
hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of
mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and
mineral loss). ANOVA was applied to compare
hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements.
RESULTS: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09).
Fluoride and
chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control.
CONCLUSION: