Cavities are very annoying and ugly, and chewing gum seems to many to be a bad habit, but can one evil prevent the other?
Yes… kinda. But only certain kinds of gum. Various systematic reviews have been done on this topic, and thy all focus only on sugar-free gum, so Wrigley’sDouble Mint is not going to give you less cavities anytime soon. The only systematic review I can find focusing entirely on sugar-free chewing gum (as opposed to ‘fluoride containing supplements’ or ‘xylitol’ ) was published in 2007, and of the 9 accepted studies that met the rigorous exclusion process of the review, 7 of them found beneficial effects of chewing sugar-free gum, such as Trident, and reduced cavities.
This actually might have little to do with the gum in general, and more to do with the lack of sugar. A study completed just in 2014 showed that increased Xylitol, a noted sugar substitute, intake was related with a decrease in cavities. A systematic review in 2008 of Xylitol containing gum further strengthens this point. The 2014 study also mentions this point:
Xylitol reduces the levels of mutans streptococci (MS) in plaque and saliva by disrupting their energy production processes, leading to futile energy cycle and cell death. It reduces the adhesion of these microorganisms to the teeth surface and also reduces their acid production potential.
Xylitol, like any other sweetener, promotes mineralization by increasing the salivary flow when used as chewing gum or large xylitol pastille. The uniqueness of xylitol is that it is practically nonfermentable by oral bacteria. Also, there is a decrease in levels of MS, as well as the amount of plaque, when there is habitual consumption of xylitol
Yes, saliva remineralizes your teeth. But even with the gum as a protective barrier, it is always best to brush twice a day and to also supplement with mouthwash. Chewing gum should never be an alternative to brushing, mainly because chewing gum does not get rid of significant plaque or as much acid-producing bacteria as brushing does.