Just as your heart rate and blood pressure are indicators of heart health, the pH of your saliva is an indicator of dental health. The salivary pH can increase or drop based on several factors, especially your diet.
The average pH of saliva is 6.7. However, it usually ranges between 6.2 and 7.6.
What Is the pH?
The "pH," which is the abbreviation for the chemical term "potential hydrogen," is a scale that measures how much free hydrogen is found in a substance, according to Clemson University. Acids tend to release free hydrogen ions, so the more acidic a substance is, the more free hydrogen ions it has.
The pH scale ranges from zero to 14, where zero is the most acidic and 14 is the least. Pure water has a pH of seven, so seven is considered to be a neutral pH. Values from zero to six are considered acidic, whereas pH values from eight to 14 are considered to be basic, or alkaline.
Just to help you put things in perspective, here are the pH values of some substances along the pH scale, as listed by Clemson University:
- Battery acid: 0
- Hydrochloric acid secreted by your stomach: 1
- Lemon juice: 2.3
- Vinegar: 2.9
- Orange juice: 3
- Tomato juice: 4.1
- Black coffee: 5
- Acid rain: 5.6
- Urine: 6
- Milk: 6.6
- Pure water: 7
- Eggs: 8
- Toothpaste: 9.9
- Milk of magnesium: 10.5
- Ammonia in cleaning products: 11.9
- Soapy water: 12
- Bleach: 13
- Caustic soda: 14
The pH can be tested in numerous ways. One of the easiest ways is to use litmus paper, an easily-available laboratory tool that is formulated with special dyes that make it turn red when it is exposed to acids, and blue when it is exposed to bases.
The Role of Saliva
Saliva, also known as spit or drool, is a liquid substance produced by the salivary glands in your mouth. According to Harvard Medical School, your mouth has three pairs of major salivary glands and 600 to 1,000 tiny, minor glands that are positioned all over your mouth and throat.
Your salivary glands are on the insides of your lips and cheeks, under your jaw, below your tongue, on your palate and at the back of your throat. You also have salivary glands in your pharynx and your sinuses.
It also contains minerals like calcium and phosphorus, which your teeth can absorb, and it acts as a lubricant for your mouth, preventing food from getting stuck in your teeth and gums. Saliva also neutralizes gastric acid and helps prevent gastroesophageal reflux, which is one of the primary causes of heartburn.
The pH of Your Mouth
According to Loma Linda University (LLU), keeping the pH of your mouth balanced is important to maintaining good oral health. Bacteria can thrive if the pH of your mouth is out of balance, and this can lead to a number of dental issues.
Maintaining this pH balance is tricky, because every time you eat something, the pH level in your mouth drops, affecting the minerals in your teeth. When the pH in your mouth becomes more acidic, it depletes the minerals in your teeth. This leaves your teeth vulnerable to bacterial damage and, ultimately, tooth decay. LLU notes that 10 minutes after you consume anything, apart from water, your teeth are the most vulnerable.
The American Dental Association (ADA) notes that an acidic environment in your mouth, caused by eating and drinking acidic foods, can also wear away the enamel of your teeth, resulting in dental erosion.
A study published in the July-August 2013 issue of the Journal of Indian Society of Periodontology notes that the pH of saliva is usually between 6.2 and 7.6. The average pH of saliva is 6.7. This natural fluid helps maintain the pH level of your mouth at a level above 6.3.
Researchers explain that saliva helps maintain the pH in your mouth in two ways. First, it neutralizes the acids from food and drinks, as well as those produced as a result of bacterial activity in your mouth.
Second, the flow of saliva helps remove carbohydrates from your mouth, where it is being metabolized by bacteria. When bacteria act upon food in your mouth, especially sugars, they produce harmful acids.
The study concluded that testing the pH of saliva is important. It can help determine how healthy the environment inside your mouth is for your teeth.
Maintaining a Healthy Mouth pH
The ADA lists some measures you can take to maintain a healthy pH in your mouth. These are a good hedge against tooth erosion and other dental problems.
To start with, the ADA recommends limiting your consumption of citrus and carbonated drinks. The major culprits in this category are carbonated beverages like soda and sports, which often have citrus flavorings. Adding bubbly fizz to drinks raises their acidity level, making them harmful to your teeth even if they are sugar-free.
If you do indulge, using a straw can help you minimize contact between the drink and your teeth. Avoid slowly sipping on the drink or swishing it around in your mouth. Instead, try to swallow it as soon as possible.
The ADA also recommends avoiding sour candies, many of which use citric acid for flavoring. They can be almost as acidic as battery acid and extremely harmful for your teeth, especially if you chew or suck on them for a while.
After you eat or drink something acidic, the ADA suggests rinsing your mouth with water or consuming a dairy product like milk or cheese, as calcium can help neutralize some of the acid. Your saliva can also help neutralize the acid, and chewing sugar-free gum after your meals can help keep your saliva flowing.
It is also recommended that you wait for an hour after eating or drinking something acidic before brushing your teeth. This gives your saliva a chance to wash away the acid naturally and lets your enamel harden once again.
- Clemson University: “What is pH?”
- Harvard Medical School: “Salivary Gland Disorders”
- Harvard Medical School: “Saliva Shortage: Seven Tips for a Dry Mouth”
- U.S. National Library of Medicine: “Salivary pH: A Diagnostic Biomarker”
- Loma Linda University: “The Key to Maintaining Proper pH Balance in Your Mouth”
- American Dental Association (ADA): “Erosion: What You Eat and Drink Can Impact Teeth”
- The GLOBE Program: “pH Protocol”