The effect of xylitol on dental caries

Infections of the teeth and oral mucosa are caused by micro-organisms in dental plaque, from which hundreds of bacterial species have been identified. Of these, partic tilarly S t r e pt o c o c c us mut ans, S t r e p t o c o c - cus sobrinus and their relatives (collectively known as "mutans streptococci") and lactobacilli are associated with the development of dental caries. Since the mutans streptococci belong to the viridans group, they are also significant in causing local infections of the mouth. Abstract Both the short and Long terrn beneficial effec* of rylitol in dental caries prevention appear to be mainly related to decreased adherence of the plaque to the tooth surfaces. In vitro, ryIitol modifies the synthesis of polysaccharides from sucrose in Streptococcus mutans, thereby decreasing the ability of sffeptococci to adhere to hard ,ur|or"r. In long term habitnai use some loss of sensirtvity of mutans streptococci to rylitol occurs, but the ability of "ryIitol resistant" streptococci to cause caries in the presence of glucose is still Iower than that oT more rylitol-sensitive sfteptococci. As a result, the long term use will change the preval.ent strains of mutans streptococci to strains with decreased ability to cause caries. In addition, the levels ofmutans striptococci on tooth surfacis and the plaque are decreased by an order of magnitude over a long term course of hnbituat rylitol consimption as in chewing gum. This is probably mainly due to the low adherence of the plaque and not due to the intrinsic inhibition of mutans streptococci, since the bactertal counts in saliya are essentially unaffected in long term use of rylito carbon sweeteners, xylitol is not metabolised by the streptococci. Positive effects of rylitol consumption on d.ental also been r"porraa. e'ir.i"g g"*' ;r;r"*"a with rylitol appears to be an effective vehicle to introduce sufficient amounts of rytitol to the tooti surfaces. The ifficient dose is suggested to be about 8 g/day.