Effects of an Ascorbic Acid–Derivative Dentifrice in Patients With Gingivitis: A Double‐Masked, Randomized, Controlled Clinical Trial

BACKGROUND: Reactive oxygen species might be associated with the onset and progression of gingival inflammation. The aim of this study is to investigate the effect of a dentifrice containing L-ascorbic acid 2-phosphate magnesium salt (APM), a long-acting ascorbic acid derivative with antioxidant properties, on gingival inflammation. METHODS: The clinical effects of APM were investigated in a multicenter, randomized, parallel-group, controlled clinical trial comprising 300 individuals with gingivitis. Half of the participants were given an APM-containing dentifrice and half were given a control dentifrice. The primary outcome was the gingival index (GI) at 3 months. Secondary outcomes included gingival redness as an indicator of the degree of local gingival inflammation, gingival bleeding as a measure of the gingivitis severity index, and total antioxidant activity of the saliva. RESULTS: Under the intent-to-treat analysis, GI did not significantly differ between the groups (P = 0.12). However, under the per-protocol analysis, GI was significantly lower in the APM group (P = 0.01) than in the control group. In the APM group, gingival redness was significantly lower, and the difference from the baseline gingivitis severity index was significantly greater (P = 0.04 and P = 0.02, respectively). The total antioxidant activity of the saliva was significantly higher in the APM group (P = 0.03). The incidence of adverse events did not significantly differ between the groups (P > 0.15). CONCLUSION: These findings indicate that the regular application of an APM-containing dentifrice could reduce gingival inflammation.