Reproducibility of a simplified microbiological test formutans streptococci

Abstract

The development of simple predictive microbiological tests allows targeting those children at highest risk for caries, even if they do not exhibit the disease activity. The aim of this study was to evaluate the reproducibility of CARITEST SM®, a dip slide test for mutans streptococci. Fourteen subjects participated in this study. Saliva was stimulated by having the subject chew an inert gum and then collected until there was enough to perform two CARITEST SM® tests - from different batches (set of kits 1 and set of kits 2) - applied twice for the same subject. Two calibrated examiners read each dip slide test once, by independent and blind means. The results were classified according to two criteria: scores from 1 to 6, recommended by the manufacturer’s instructions, and scores according to high and low microbiological count. Kappa statistics was applied according to Light. The reproducibility results according to the 6 scores exhibited distinct values for the set of kits 1 and for the set of kits 2, kappa = 0.57 and kappa = 0.21, respectively. The results according to high and low microbiological count were kappa = 1.00 for the set of kits 1 and kappa = 0.55 for the set of kits 2. This study showed a variability in the results of both kits from different batches. Furthermore, there was greater interexaminer agreement when the results were classified according to high and low microbiological count.