Evaluation of a simplified method for site-specific determination of mutans streptococci levels.

To determine the oral mutants streptococcal "load" of an individual, saliva samples reflecting the number of colonized tooth surfaces, are often applied. Sometimes a plaque sample from a specific site would be an advantage, for example in connection with local antimicrobial treatments. The aim of the present paper was to evaluate a chairside method for determination of mutans streptococci interproximally. One hundred subjects participated. Four approximal tooth surfaces of each individual were sampled using toothpicks. The toothpicks were then let to contaminate a pad on a specially designed plastic strip and, for comparison, a MSB-agar plate. The strips were incubated in the standard "Strip mutans" broth. The yield of colony forming units on the strip surface corresponded significantly with that on agar plates. Being a simple chair-side method for the evaluation of the site-specific load of mutans streptococci, it is suggested that the method will be used in various investigations to clarify its potential in different clinical situations.