Comparative analysis of three commercial saliva testing kits with a standard saliva buffering test

Abstract

In 1959, Ericsson developed a laboratory buffer capacity test. Because the Ericsson test is not practical for use as a chair-side test, commercially available saliva buffering capacity tests have been developed for use in the dental office. The purpose of this study was to evaluate the correlation between a modified Ericsson test and three commercially available quantitative and colourimetric tests. Stimulated saliva (by chewing paraffin wax) was collected from 113 patients. Individual saliva buffering capacity was assessed with the following four different methods: modified Ericsson test; quantitative test using a hand-held pH meter; paper strip; or liquid colourimetric test. The correlations of ranking results among the different tests were analysed using the Spearman Rank Correlation Test, p < 0.001. Spearman Rank Correlation indicated significant positive coefficients between the modified Ericsson test and the quantitative test (rho = 0.857), the paper strip colourimetric test (rho = 0.621) and the liquid-type colourimetric test (rho = 0.689). The detection level of medium and high buffering capacity was test dependent. The quantitative test using a hand-held pH meter showed a stronger positive correlation with the modified Ericsson test. The qualitative tests seemed less reliable, particularly for patients classified as having a medium buffering capacity.