Comparison between a dip-slide test and plate count for determination of Streptococcus mutans infection.

A significant correlation was found between the results of a dip-slide test and a conventional agar-plate method for determination of the salivary Streptococcus mutants population. The growth density of S. mutans around bacitracin discs on the dip-slide was estimated and examination of the dip-slides with or without a microscope showed good agreement. The percentage of identical scores between two observers increased from 69 to 84% with the use of a microscope. Scores from dip-slides inoculated with saliva by means of a cotton swab showed good agreement with those obtained with stimulated saliva. The dip-slide method is simple and reliable and can be a valuable tool in general practice for the estimation of the S. mutans infection.