Why should we care about our saliva?
Saliva significantly affects our overall quality of life and is very important for maintaining a healthy mouth. We want to share some of the reasons why saliva stays at the top of our priority list when taking care of our health. It serves many functions other than just keeping the mouth wet!
For starters, saliva plays a critical role in the initial breakdown of food. It provides the enzyme known as salivary amylase – the first digestive enzyme in the gastrointestinal tract. It also makes it easier to swallow by lubricating food while chewing and enhances taste by facilitating the transmission of taste impulses.
Additionally, saliva lubricates mucous membranes and protects tissue from minor trauma and ulceration. It especially serves as a critical retention agent of removable prostheses such as dentures. Some investigators believe that it may also help in diagnosing other health problems.
Saliva is our body’s best defense against the formation of caries (aka cavities). So a lack of saliva is a genuine medical problem! Saliva contains minerals such as calcium and phosphate that help keep teeth healthy, fight tooth decay, and aid in remineralization. It even contains antibodies that help stop tooth decay before it starts!
The Effect of Saliva on Oral pH
And (perhaps) most importantly, saliva plays a role in modifying biofilm pH by cleansing the oral cavity. It neutralizes acids present from foods and beverages as well as those created by the microflora in plaque.
Depending on the frequency (and the acidity) of food intake, the bacteria in plaque will be prone to various challenges of low pH. Lower pH = more acidic. Pure water has a neutral pH of 7. Many of the predominantly healthy bacteria within dental plaque are inhibited or killed by more frequent or prolonged exposures to acidic conditions. Cavity-causing bacteria can colonize and will grow exponentially in more acidic environments.
In other words, prolonged or intense low pH in the mouth leads to the death of healthy bacteria and overgrowth of the bacteria that causes CAVITIES.
Many people can consistently consume lots of sugary food and drink and yet do not have cavities. Other people continue to get cavities even though they are diligent about their diet and oral hygiene. These people are very susceptible to small changes in pH. As previously stated, cavity-causing bacteria are more likely to grow at a lower or acidic pH. If a person can maintain their mouth at a neutral or alkaline pH, the shift to cavity-causing bacteria will not occur – regardless of sugar, food, or acidic drink consumption.
After eating or drinking, stimulated saliva dilutes and neutralizes biofilm acids. Therefore, saliva is responsible for the recovery of biofilm pH back toward neutrality. In the absence of normal salivary flow, the pH stays at a low level for an extended period after exposure to dietary sugars. Thus, reduced salivary flow can often lead to demineralization of teeth and dental decay. The American Dental Association (ADA) has shared extensive knowledge of the dangers of reduced saliva. You can find more information regarding problems of dry mouth here.