Comparison Between Quantitative and Colorimetric Tests for Saliva Buffering Capacity

Objectives: The purpose of this study was to evaluate the correlation between two quantitative and two colorimetric salivary buffering capacity tests, Ericsson test (laboratory quantitative test, standard in Sweden), Checkbuf (quantitative test using a hand-held pH meter, Morita, Japan), Saliva Check Buffer Test (colorimetric test: strips type, GC, Japan) and ORAL TESTER Buffer (colorimetric test: liquid type, Tokuyama, Japan). Methods: Stimulated whole saliva was collected from 101 subjects from School of Dental School, the University of Melbourne (age 22-66, average of age 38.5, male 43, female 58) after gaining ethical approval. Individual saliva buffer capacity was evaluated using the four tests. The correlations of ranking results (high, medium, low) between four different methods were statistically analyzed by Spearman Rank Correlation Test. Results: In the comparisons between the Ericsson test and each commercial test, correlations between the Ericsson test and Checkbuf was ρ= 0.826, Ericsson test and Saliva Check Buffer test was ρ= 0.594, and Ericsson test and ORAL TESTER Buffer was ρ= 0.658. In the saliva samples with low buffer capacity, there was good agreement in all tests. Conclusions: Both quantitative tests showed a higher correlation. The ability to quantitatively test saliva buffering capacity at the chair-side will aid dentists and patients to know more about caries risk and how it may change over time which the colorimetric tests are less able to do. Supported by Grant #17390507 from Japan Society for Promotion of Science and COE Program, FRMDRTB at TMDU.