The propensity of different brands of tea and coffee to cause staining associated with chlorhexidine

Dental staining is a well known and probably the most problematic side effect of using chlorhexidine oral products. Whatever mechanisms are involved, there is no doubt that cationic antiseptics, such as chlorhexidine, can precipitate or bind to surfaces anionic chromogens contained in foods and beverages. The aim of this study in vitro was to determine whether, under controlled conditions, different brands of tea or coffee varied in their propensity to cause staining associated with chlorhexidine. Optically clear acrylic specimens were cycled through saliva, chlorhexidine and different tea and coffee solutions. Staining was measured using a spectrophotometer. After 15 cycles, it was apparent that staining varied at the extreme, both within and between the tea and coffee groups. All coffee brands produced less staining than the tea brands. The least staining coffee and least staining tea brands were approximately 3x less chromogenic than the most staining equivalent beverage. Previous randomised controlled clinical trials have indicated that tea and coffee contribute to dental and tongue staining associated with chlorhexidine mouthrinses. Additionally, abstinence from tea and coffee significantly reduces staining. The results of this study in vitro suggest that when abstinence is difficult, tea and coffee brands of low chromogenicity may be recommended. Clearly these data in vitro require validation in vivo.