Reduced chlorhexidine tooth stain coverage by sequential administration of monoperoxyphthalic acid in the beagle dog

Extrinsic tooth stain is sometimes a side-effect observed with the chronic use of chlorhexidine-containing oral care products. This chlorhexidine (CHX)-induced tooth staining is observed both in humans as well as in experimental animals. The present study tested the hypothesis that the sequential administration of monoperoxyphthalic acid (MPA) will reduce the development of chlorhexidine-induced tooth stain coverage in a beagle dog. For this study, dogs were treated with 30 mL of mouthrinse b.i.d. for 28 days. The following treatment groups ( = 12 dogs/group) were tested: water (negative control), 1.0% MPA rinse, 0.12% CHX rinse, and 1.0% MPA rinse followed by 0.12% CHX rinse. The sequential dosing of 1.0% MPA followed by 0.12+ CHX resulted in significantly (p < or = 0.05) less tooth stain than when dogs were dosed with 0.12% CHX alone. Additionally, the sequential dosing of MPA followed by chlorhexidine resulted in a 75% reduction in plaque formation in this model, which was significantly different (p < or = 0.05) from results with either treatment alone. A further study demonstrated that similar results could be obtained when MPA plus CHX treatment alone. A further study demonstrated that similar results could be obtained when MPA plus CHX treatments were separated by approximately a five-hour period in an AM and PM schedule. We conclude that the oxidizer, MPA, can significantly reduce tooth stain induced by CHX while enhancing its antiplaque and antigingivitis activity.