A novel and visual test for oral malodour: first observations

Until now, the application of biogenic amines as bio-markers of oral malodour has been limited because of the complexity of their detection. This study explores the usability of a simple colorimetric reaction detecting amines in saliva as an adjunct test for the diagnosis of oral malodour. The colour reaction caused by a newly discovered enzyme capable of detecting amines in saliva was characterized in vitro. Two colour scales were developed by transforming the colours of selected dilutions of a mixture of cadaverine and putrescine into a 5- and a 10-point pink-colour scale. Afterwards, this new enzymatic test was used to assess the amount of amines in saliva samples of 50 volunteers with different degrees of oral malodour. The enzymatic reaction was shown to be linear towards the concentration of amines and stable over a time of ≥4 h. Colour scores correlated well with organoleptic scores and the volatile sulfur compounds. More importantly differences between patients with and without oral malodour were significant. Based on these results, we conclude that this new enzymatic test, interpreted by means of a simple colour scale, has the potential to be used as an adjunct chair-side test for oral malodour diagnosis.