A non-staining chlorhexidine mouthwash? Probably not: a study in vitro.

BACKGROUND AND AIM: Tooth staining is a common side effect of chlorhexidine mouth rinses and caused by the interaction of the di-cationic antiseptic with dietary chromogens. A product is now available, which claims an anti-discolouration system (ADS) with one clinical study in support. This study in vitro aims to determine whether two ADS rinses do or do not bind dietary chromogens. METHOD AND MATERIALS: Optically clear acrylic specimens were cycled through human saliva (2 min), one of the three chlorhexidine rinses (two ADS and a positive control) (2 min) or water and then soaked in tea (60 min). After each cycle the optical density (OD) of specimens were read on a UV/visible spectrophotometer. The exit point was the cycle at which OD was >2.0. RESULTS: All three rinses exceeded OD 2 at 11 cycles and there was no significant difference in staining for the ADS rinses compared with the positive control rinse. CONCLUSION: Based on extensive literature for the correlation of this test in vitro with chlorhexidine anti-plaque activity and propensity to stain in vivo these ADS rinses will have the same anti-plaque efficacy and potential to cause stain as established chlorhexidine rinse products.