A Novel ex-vivo Model to Study Oral Malodour

Objectives:
Currently assessing the effect of anti-malodour actives in toothpastes requires time consuming and expensive clinical studies. There is a clear need to develop rapid model systems that can effectively measure the effect of actives in toothpastes. The objective of this work was to develop an ex-vivo model via measurement of Volatile Sulphur Compounds (VSCs) from salivary bacteria.
Methods:
Early morning saliva was collected (with ethical approval) from subjects in good general and oral health. The saliva samples were pooled, oral epithelial cells separated, sterilized and layered on the surface of agarose in a 12 well plate. Mixed salivary bacteria from saliva were then added in the plate. This was followed by treatment with toothpaste samples. Cysteine-HCl was added post treatment as a precursor for VSCs. Lead acetate paper was placed over the plate as an indicator of the VSCs generated. The dark coloration of the lead acetate paper was recorded using a reflectometer as L*a*b* values and the separation between the initial and final L*a*b* values ΔE, was used to quantify the VSCs formation.
Here we demonstrate the utility of the model, comparing a toothpaste containing 0.2% zinc sulphate heptahydrate, a control toothpaste and water.
Results:
A clear differentiation was observed between the two toothpastes and water control using the above described model. A Toothpaste containing 0.2% zinc sulphate heptahydrate was significantly better in reducing the VSCs over the control toothpaste (p<0.05).
Conclusions: We have developed a robust and rapid ex vivo substrate model to evaluate the efficacy of toothpastes in reducing VSCs. This model will help demonstrate the ability to measure efficacy of various actives used in oral care products to reduce salivary thiols.