Comparison of two chair-side tests for enumeration of Mutans Streptococci in saliva.

AIM To compare the prevalence and levels of salivary Mutans Streptococci (MS) assessed with two commercial chair-side methods based on culture growth or monoclonal antibodies, respectively. MATERIAL AND METHODS The study group consisted of a convenience sample of 89 adults, 23-72 years of age, referred to a maxillofacial hospital clinic with a caries history. Stimulated whole saliva samples were collected and the number of MS was assessed with the Dentocult-SM Strip Mutans (DSM) and the Saliva-Check Mutans (SCM). The outcome was compared with conventional anaerobic laboratory cultivation on selective MSB agar. RESULTS The prevalence of ≥ 5 × 10(5) CFU was 21%, 62%, and 73% with the SCM, DSM and MSB-cultivation, respectively. The correlation between DSM and SCM tests was r = 0.49 (p < 0.05) but the agreement on the high levels was fair. In comparison with the MSB agar, DSM provided acceptable levels of sensitivity and specificity while the SCM displayed a poor sensitivity but a perfect specificity. Both chair-side methods were significantly related to the prevalence of active root caries lesions (p < 0.05). CONCLUSIONS The two chair-side salivary tests were significantly correlated and due their high specificity, they may be sensitive enough for screening purposes and for patient-centered promotion of oral health.