Effectiveness of an Antigen-Specific Streptococcus mutans Chairside Test as Compared to a Culture-Based S. mutans Test.

Purpose: To compare the effectiveness of an antigen-specific Streptococcus mutans (S. mutans) chairside test to a culture based S. mutans test. Methods: Fifty-three patients receiving dental hygiene care at the University of Missouri-Kansas City, School of Dentistry were enrolled in the study. Stimulated saliva was collected from the patients and utilized for both bacteria tests. The antigen-specific test was compared to the culture-based bacteria test and to a caries risk assessment measuring sensitivity and specificity. Results: The majority of participants were male (53%) with high caries risk (60%). The culture based test results were primarily negative (62%); while the antigen-specific test had more positives (76%). The sensitivity and specificity comparing the antigen-specific test to the culture based test was high (88%, 95% CI = (78%, 97%) and low (25%, 95% CI = (13%, 37%), respectively. The sensitivity and specificity comparing the antigen-specific test to caries risk was high (83%, 95% CI = (72%, 93%) and low (38%, 95% CI = (24%, 51%) respectively. Conclusions: While the sensitivity of the antigen-specific test was high for both the culture-based test and caries risk, the specificity was low for both. These results suggest that the antigen-specific test tends to give a higher proportion of false positive results.