Influence of Phosphoric, Glycolic, and Ferulic Acids on Dentin Enzymatic Degradation, Ultimate Tensile Strength, and Permeability.

This study evaluated dentin enzymatic degradation based on the total matrix metalloproteinase (MMP) activity of demineralized dentin matrices before and after exposure to phosphoric acid (PA), glycolic acid (GA), and ferulic acid (FA). The release of hydroxyproline (HP), ultimate tensile strength (UTS), and dentin permeability (DP) were also evaluated. Dentin collagen matrices were assessed according to total MMP activity before and after treatment with the tested acids (n=10) for 15 seconds and compared with the control (GM6001 inhibitor). Dentin beams were analyzed for HP release and UTS after the treatments. Dentin discs were tested for DP at a pressure of 5 psi before and after treatment with the acids (n=10). The FA group had a lower percentage of enzymatic inhibition than the PA and GA groups (p<0.0001). No significant difference in UTS was found among the acids (p=0.6824), but HP release was significantly higher in the FA group than in the PA and GA groups (p<0.0001). No significant difference in DP was found for the acids (p=0.0535). GA led to less activation of MMPs and less release of HP, whereas the UTS and DP for GA were like those found for PA. In contrast, FA promoted greater enzymatic activity and greater release of HP, while having similar results to GA and PA regarding mechanical properties.