Turku sugar studies IV. An intermediate report on the differentiation of polysaccharide-forming streptococci (S. mutans)

Abstract

Colony count determinations were carried out in order to detect quantitative changes of Streptococcus mutans in the plaque samples of the test persons in the Turku sugar studies. The lyophilized plaque samples were homogenized and incubated under anaerobic conditions. In addition, the pH-values were measured after incubation in culture media containing various sugars. The 1-year results showed a significantly lower incidence of S. mutansin the xylitol group in comparison to the fructose and sucrose groups. The pH-measurements carried out at the 4 and 12 month phases showed that only in the presence of xylitol the mean values did not fall below the pH-limit of 5.5. No evidence was obtained of the involvement of microorganisms capable of decomposing xylitol after one year of diet.

Key Words:

• Streptococcus mutans
• dental plaque
• xylitol
• fructose
• sucrose
• sorbitol