Dentifrices with MMP Inhibitors Prevent Dentin Loss in situ

Method: Ten Subjects were enrolled in this crossover in situ study, which was performed in 4 phases of 5 days. Participants wore acrylic palatal appliances containing 4 bovine dentin blocks, divided into two rows, corresponding to the groups erosion without toothbrushing (ERO) and erosion with powered toothbrushing (ERO+ABR). Experimental toothpastes with similar composition and pH (7.0) were prepared, with the exception of the compound tested, as follows: 1100 ppm of Fluoride as NaF, 0.61% green tea extract, 0.12% chlorhexidine digluconate. Placebo toothpaste gel contained the same basic composition and no active compound. The specimens were subjected to erosion extra-orally by immersion of the appliances in a cola drink for 5 minutes, 4 times a day. Subsequently, no treatment was performed in one row (ERO), whereas the other was brushed for 15 seconds with a slurry of dentifrice and water (1:3) (ERO+ABR) twice a day with an electric toothbrush. The appliance was then replaced into the mouth. Dentin loss was assessed by profilometry. Data was analyzed by Two-way repeated-measures ANOVA, followed by Bonferroni's test (p<0.05).

Result: Mean dentin loss was: Placebo (ERO: 1.39±0.32; ERO+ABR: 1.67±0.21); EGCG (ERO: 0.83±0.17; ERO+ABR: 0.99±0.26); CHX (ERO: 0.92±0.16; ERO+ABR: 0.75±0.18); NaF (ERO: 0.73±0.27; ERO+ABR: 0.93±0.29). Abrasion (ERO+ABR) treatment induced significantly higher dentin loss compared to erosion (ERO) (p=0.001) and significant differences were detected among the treatments (p=0.0025). No interactions were found between these criteria (p=0.851). All toothpastes tested led to significantly lower dentin loss when compared to placebo (p=0.001), but no significant differences were observed among them.

Conclusion: Dentifrices containing MMP inhibitors are effective in preventing dentin erosion