Use of sodium trimetaphosphate in the inhibition of dentin matrix metalloproteinases and as a remineralizing agent

Objectives: Because of its ability to act as an antiproteolytic agent, the effect of sodium trimetaphosphate (STMP) against specific enzymes extracted from sound dentin and its performance under acidic challenge on demineralized dentin were investigated. Methods: The antiproteolytic potential of STMP (0.5%, 1.0%, and 1.5%) was assessed in triplicate by zymography. For the evaluation of remineralization activity, 50 bovine-root dentin specimens were selected and randomly divided into 5 groups (n = 10). Three areas were determined for each specimen: 1) control (no treatment); 2) demineralized (artificial caries-like challenge); 3) treated (demineralized and subjected to pH-cycling for 7 days, and treated for 10 min with 1.5% STMP, 1.5% STMP + calcium hydroxide (Ca[OH] 2), 1.5% STMP + sodium fluoride (NaF), NaF, or deionized H2O). The dentin specimens were analyzed for superficial hardness (SH) and cross-sectional hardness (CSH) at different depths (10, 30, 50, 70, 90, 110, and 220 mu m) using a Knoop penetrator (10 g/10 s). Statistical analyses were performed with analysis of variance (ANOVA) and Tukey tests (p < 0.05). Results: The zymographic analysis showed that 1.5% STMP promoted complete inhibition of gelatinolytic activity. Therefore, 1.5% STMP was investigated in association with supplemented calcium or fluoride; a combination of 1.5% STMP and Ca(OH) 2 significantly increased the mechanical properties of the treated dentin. Conclusion: 1.5% STMP serves as an antiproteolytic agent against matrix metalloproteinases extracted from human dentin. Furthermore, when supplemented with Ca(OH) 2, 1.5% STMP may potentially induce remineralization.