Interexaminer agreement for readings of dip slide tests for salivary mutans streptococci and lactobacilli

This study reports the interexaminer agreement of three pairs of evaluators of salivary dip slide tests for mutans streptococci and lactobacilli. 717 Cariescreen SM and Bactotest LB dip slides were available for assessment by 2 dentists and 1 dental hygienist. A single calibration session was held prior to the onset of the study. Each dip slide was read once by each examiner independently. Among the three pairs of examiners, Pearson R values ranged from 0.84 to 0.90 for Cariescreen and from 0.78 to 0.87 for Bactotest. Kappa statistic values ranged from 0.56 to 0.61 for Cariescreen and from 0.70 to 0.74 for Bactotest. The range of agreement was from 72.2 to 76.9% for Cariescreen and from 86.4 to 88.3% for Bactotest. The majority of disagreements were of one category in magnitude, though there were a few disagreements of greater magnitude. This study found moderately strong agreement among the three examiners; it suggests that multiple examiners of dip slide tests carefully calibrated initially and periodically to ensure a high level of agreement.