Effect of MMP Inhibitors in the Progression of Dentin Erosion

Objectives: The aim of this study was to compare, in vitro, the protective effect of matrix metalloproteinases (MMPs) inhibitors (green tea and chlorhexidine) on the progression of early erosive lesions in dentin subjected to additional erosive challenge (EC) for 5 days.
Methods: Forty human dentin slabs were evaluated by profilometry and submitted to an initial erosion process by immersion in 0.1% citric acid (pH 2.5) for 30 min. After further profilometric evaluation, they were randomly divided into 4 groups: 1 – EC (cola drink, 4x/90s/day), tap water immersion (1 min) between EC (negative control); 2 – EC, green tea immersion (1 min) between EC; 3 – EC, 0.12% chlorhexidine solution immersion (1 min) between EC; 4 – EC, 0.05% sodium fluoride (NaF) solution immersion (1 min) between EC (positive control). After 5 days, samples were evaluated for final profilometry (FP). Three blocks of each group were evaluated in 3D profilometer and scanning electron microscope (SEM) and compared to healthy and eroded dentin blocks for qualitative analysis of dentin surface after treatments. Data were statistically analyzed in SPSS v.20 software through Kruskal-Wallis and Dunn tests (P <0.05).
Results: No significant difference (P > 0.05) was observed in the FP averages between experimental groups and controls. Regarding percentage recovery of the surface profile (%RSP), just G2 and G3 were able to promote recovery of 21.45% and 23.46%, respectively, whereas in G1 and G4, a higher roughness was observed in 54.76% and 7.61% of the samples, respectively. In SEM and 3-D evaluations, only in G2 and G3, the images showed dentin tubules filled by smear layer as observed in healthy dentin.
Conclusions: It was concluded that, MMP inhibitors have better performance in preventing the progression of dentin erosion than NaF solution, thus the use of these products may reduce the progression of dentin erosion and, therefore, help minimize dentin sensitivity.