There is a considerable amount of evidence that the use of gum or candy with Xylitol prevents dental caries in the permanent teeth when used several times daily and the effectiveness varied between 30% and 60% when compared to controls without the gum use According the NIH Consensus Statement on the Diagnosis and Management of Dental Caries the evidence for Xylitol is strong as the primary prevention of dental caries. The preventive effect of Xylitol seems to derive from the remineralization of decalcified surfaces of teeth, replacement of fermentable dietary sugars and reduction of the amount of dental plaque or the amount of mutans streptococci in plaque and saliva (Trahan 1995).
The most significant effect demonstrated so far in caries reduction is its ability to reduce the growth and acid production of mutans streptococci the primary bacteria responsible for caries. Growth retardation of mutans streptococci is thought to result from an energy-spending “futile Xylitol cycle” and impaired glucose uptake and metabolism
With regard to plaque, several studies have shown Xylitol to reduce the amount, adhesiveness and acidogenic potential of it. Xylitol has the ability to reduce the number of mutans streptococci in plaque and loosen the plaque and mutans streptococci binding to the tooth surfaces Caries prevention seeks to prevent the onset of carious lesions, arrest progression and even to repair them. Prevention can be successfully carried out both by eliminating contributory factors of caries and by improving the resistance of teeth to caries attacks.