While there is no question that chewing gum promotes tooth decay, there is clinical evidence that demonstrates just the opposite for sugar-free gum.
Studies have shown that chewing sugar-free chewing gum after meals and snacks, especially when toothbrushing at those times is impractical, helps to reduce the acid level in the mouth which has a potentially detrimental effect on tooth enamel.
The mechanism of action involved in chewing gum is the stimulation of many times the normal rate of saliva flow, due to both the act of chewing and the flavor of the artificial sweeteners in the chewing gum (sorbitol or xylitol). The saliva washes away food particles and acid produced by bacteria in the oral plaque and neutralizes the acid because of increased concentration of bicarbonates from the saliva. However helpful chewing sugar-free gum is not intended to replace toothbrushing and flossing.
Sugar-free chewing gum is also recommended for people with xerostomia (dry mouth) to stimulate increased salivary flow, along with drinking greater amounts of water (six to eight glasses a day). However, those experiencing TMJ (temporomandibular syndrome) symptoms should refrain from any gum chewing. Sugar-free mints, especially those sweetened with xylitol, can be an alternative to gum chewing.
"Chewing Gum." Mouth Healthy, American Dental Association. http://www.mouthhealthy.org/en/az-topics/c/chewing-gum.aspx. Accessed 2013.
"Dry Mouth." Mouth Healthy, American Dental Association. http://www.mouthhealthy.org/en/az-topics/d/dry-mouth.aspx. Accessed 2013.
"Dry Mouth." National Institute of Dental and Craniofacial Research. October 2012. http://www.nidcr.nih.gov/nidcr2.nih.gov/Templates/CommonPage.aspx?NRMODE=Published&NRNODEGUID=%7b74C254DD-1E86-4832-B5A3-BDB2729189AF%7d&NRORIGINALURL=%2fOralHealth%2fTopics%2fDryMouth%2fDryMouth%2ehtm&NRCACHEHINT=Guest#7Accessed 2013.