-The theory is that the 'bad' bacteria do not like oxygen and do not like a more alkaline pH. It is believed that these can slow down their reproduction and hopefully kill the 'bad' bacteria that cause dental health problems - ie gum disease, cavities and bad breath.
Mouthwash listed in this category are pH balanced and oxygenated.
The idea or theory behind this concept is that the anaerobic bacteria that may be responsible for causing dental disease such as bad breath, gum disease and gingivitis do not do well when there is plenty of oxygen in the environment. They are anaerobic in nature - meaning that they thrive in a low oxygen environment. It is thought that the oxygen will cause a problem for their metabolic processes, either causing them to revert to a different form of metabolism which is less harmful to humans or for the bacteria to die.
In a similar fashion it is believed that the anaerobic or 'bad' bacteria do not like a higher pH. When the environment of your mouth is more acidic, the bacteria are believed to multiply much more rapidly. With more 'bad' bacteria - more harmful waste products will be secreted onto your teeth and gums.
Another important reason to balance your pH: It is thought that when the mouth is more acidic, the crystals that form your dental enamel will come out of the teeth - essentially weaking your enamel. A higher pH on the other hand theoretically allows the minerals in your saliva to 'remineralize' your enamel - thereby making your teeth stronger. Therefore, it may be an excellent idea to use the mouthwash to balance your mouth pH anytime you have an acidic soft drink, energy drink or coffee - in addition to certain juices and other acidic foods.