Chewing gum
The most commonly recognised bacteria that are responsible for initiating the biofilm formation that can eventually lead to caries are streptococcus mutans and lactobacillus. The key factors for virulence include their ability to metabolise glucose and similar sugars, their tolerance for a low pH environment and their acidogenicity. The presence of streptococci encourage adherence of more cariogenic bacteria, which in turn increases the likelihood for caries. Although factors such as the quality of saliva, using fluoridated toothpaste and chewing gum after meals can inhibit the growth of these bacteria and change the biofilm environment. Saliva containing more buffering agents such as calcium and phosphate ions alter the internal environment of dental plaque to become less acidic, favouring the growth of less cariogenic organisms. The fluoride components of fluoridated toothpaste can be bacteriostatic to cariogenic bacteria, decreasing their acidogenicity and proliferation. Chewing gum can disturb the mature and fairly stable acid producing plaque to alter the bacterial composition of the biofilm. In turn the disease causing organisms may still be present, but are so in reduced numbers. Chewing gum containing sufficient levels of xylitol also has the ability to reduce the number of streptococcus mutans present in the saliva as well as the mechanisms for the bacteria to adhere to tooth tissue, which reduces the chance for reinfection.