The effect of toothpaste on the propensity of chlorhexidine and cetyl pyridinium chloride to produce staining in vitro: a possible predictor of inactivation

Abstract

Background/aims: Cationic antiseptics such as chlorhexidine (CHX) and cetyl pyridinium chloride (CPC) interact with dietary chromogens to produce extrinsic stain, and this can be used as a measure of activity of products. The aim of these studies in vitro was to determine if toothpaste influenced the tea staining effects of CHX and CPC as a predictor of action in vivo. Method: Clear acrylic specimens were soaked in pooled human saliva followed by sequential 2‐min soaks in pairs of agents, namely 0.05% CHX, 0.05% CPC, 0.2% CHX, water (W) and toothpaste slurry (TP). The combinations were; TP/CHX, CHX/TP, TP/CPC, CPC/TP, W/CHX, CHX/W, W/CPC, CPC/W, TP/W, W/TP, W/W. These treatments were followed by a 60 min soak in tea. Optical density readings were taken at baseline and after each of 8 cycles. Results: In the separate CHX and CPC studies by comparison with W/CHX, TP/0.05% CHX had little effect on staining, but TP/0.2% CHX showed a reduction in staining of 18%. 0.05% CHX/TP reduced staining by >40%, and 0.2% CHX by >78%. TP/CPC reduced staining by >26% and CPC/TP by 80%. Water after 0.2% CHX, 0.05% CHX and CPC reduced staining by 18%, 13% and 17% respectively. Little staining was seen with TP and W combinations. The data for CHX are in agreement with a study in vivo except TP followed by CHX reduced the activity of CHX. Conclusion: Toothpaste appears to adversely affect the activity of CHX and CPC particularly if used immediately after the antiseptics. The data further supports the concept of separating the use of antiseptics until sometime after the use of toothpaste, and the idea of developing mouthwash friendly toothpastes.

The effect of cetylpyridinium chloride‐containing mouth rinses as adjuncts to toothbrushing on plaque and parameters of gingival inflammation: a systematic review

“…Cationic antiseptics such as CPC have been shown to be inactivated when preceded by dentifrice ingredients such as sodium monofluorophosphate and sodium lauryl sulphate (SLS) (24, 81–83). In contrast to these findings, the potency of CPC appeared not to be diminished despite the use of dentifrice in studies included in this review.…”

Influence of Oral Rinse Solutions and Tooth Brushing on Stain Ability of Thermoplastic Tooth Colored Prosthetic Materials

“…57,58 More over CHX has been found to induce brown stains on enamel, composite restorations, oral mucosa, and tongue. [59][60][61] Three mechanisms have been suggested to explain this discoloration: 62,63 A. non-enzymatic browning reactions (Maillard reactions), B. formation of pigmented (Fe, Sn)sulphides, and C. reaction of dietary chromogens with CHX.…”

Antiplaque and Antigingivitis Toothpastes

“…Among the other active agents, CPC is a monocationic molecule, which may also be inhibited by different toothpaste ingredients, especially detergents [146].…”