Determination of Stain Removal In Vitro by Asian Toothpowders

Objectives: Toothpowders are dentifrices that are widely used in India and by Asian communities worldwide as alternatives to toothpaste. They are an indigenous group of materials that have been used for maintenance of oral hygiene for many centuries. However, no detailed scientific investigations of their properties or performance in cleaning tooth tissue have been reported. The aim of this study was therefore to determine whether there was any scientific basis for the efficacy of a range of commercial toothpowders. Methods: Black Monkey (Nogi and Co, India), Borsad (Gujarat Company, India) and Vicco Vajradanti (Vicco Products Ltd., India) toothpowders were studied. Signal toothpaste (Unilever, UK) and distilled water were employed as controls. Toothpowders were characterised in the scanning electron microscope. Stain removal was evaluated using hydroxyapatite discs pre-treated with a colloidal iron III tannic acid complex. Toothpowders were applied as a slurry with water, using either the index finger or a mounted electric toothbrush. Stain was assessed before and after treatment using a Minolta chromameter. Antibacterial activity was assessed using 3 microorganisms (Streptococcus mutans, Prevotella intermedia, and Porphyromonas gingivalis) and agar diffusion methodology. Results: Toothpowders contained a very wide range of particle sizes and morphologies. All toothpowders and the toothpaste removed more stain than the distilled water control, although Black Monkey and Vicco Vajradanti performed best (both removing over 60% of the stain when applied using a finger, and over 80% when applied using a toothbrush). No evidence was found for antibacterial activity in any of the toothpowders. While encouraging, extensive further work is required before toothpowders could be recommended for oral healthcare. Conclusions: This data demonstrated that two tooth powders were effective at removing stains from a synthetic tooth tissue analogue and, while no antibacterial activity was detected, there is therefore some scientific basis to support the use of toothpowders.