Dental Caries and Their Causes

Man preventing dental caries by brushing; man holding toothbrush with his teeth showing

Going to the dentist can be a daunting task for many, especially those who have cavities every time they have a check up. Having a tooth filled and caries removed does not cure the dental disease of caries.

 If you desire a cavity-free future, you may need to take a different approach to your oral health. You will need to be an active part of the team that manages your oral health.

What Causes Cavities?

Cavities, or the disease known as dental caries, are caused by an imbalance of the bacteria in your mouth. Several things contribute to one’s risk for dental caries, such as lack of saliva, diet, bacteria, genetics and pH. This disease can not be cured by just filling a cavity. 

Some people do everything recommended by their dentist—brush like crazy, floss, use mouthwash, but they still get cavities. Their partners or friends may do nothing special to care for their teeth and they get zero cavities. It is frustrating for so many!

Cavities occur because of an imbalance to the biofilm on the teeth. Most people don’t realize that there is a layer of microbes and bacteria on their teeth, and when this gets out of balance cavities happen. The pH in the mouth is one of the biggest factors associated with altering how the biofilm microorganisms behave. When the mouth becomes acidic, the biofilm gets out of balance and cavities occur. Keeping the pH in the mouth neutral or basic is key in preventing cavities.

How to Prevent Cavities

So many things influence the pH in the oral cavity. Smoking, eating, drinking, medications, oral appliances, brushing, flossing, and pretty much anything you put in your mouth can affect the pH in a positive or negative way. Saliva is so important because it neutralizes the pH in the mouth and brings the oral environment back to a basic or neutral level.

An important part of a thorough dental examination is a caries risk assessment. Your dentist or dental hygienist would, through a series of questions and clinical examination, determine your caries risk.

 Again, filling a cavity is not enough! Treating  caries and their root causes is what is necessary. Let’s look at the five different issues that predispose one to cavities in more detail.


Healthy saliva production is extremely important for all parts of oral health. Your saliva works with your digestive system to help digest food, with the immune system to fight germs, and with your teeth to keep them mineralized and strong.

Teeth are made of minerals, and acidic conditions can dissolve minerals making them susceptible to caries. Saliva keeps acid levels down by neutralizing the pH in the mouth. It also has antiviral, antifungal and antibacterial properties. 

Xerostomia, or dry mouth, is extremely common. Many medications can cause dry mouth and the severity often increases with the number of medications one is taking. Other causes of dry mouth are stress, mouth breathing, and certain medical conditions like diabetes and autoimmune diseases. Talk to your dentist about treating your dry mouth and the use of extra fluoride to strengthen your teeth


Your diet concerns not just what you eat, but how you eat it. Every time you put food in your mouth or drink something, the pH in the mouth is changed. 

An increase in the amount of food we eat keeps our oral cavity at a lower pH for a longer period of time, meaning a more acidic environment. Grazing and constant snacking don’t give saliva the time it needs to work properly and the cycle of repair is broken, leading to an increase in cavities. 

This pattern of eating also causes a change in the type of microbes found in the oral cavity. The “good” ones die in an acidic environment. Diet, what we eat, and our eating patterns are something that we can modify with conscious effort.


Your dental biofilm is a sticky collection of microbes and bacteria that gain strength from each other.

Everyone has their own unique biofilm. Over time, one’s biofilm can change. The number and type of bacteria can change. Biofilm issues are similar to when one has their gut flora out of balance. Treating an out-of-balance biofilm may be necessary for someone with frequent cavities.

Genetic issues 

Your genetics come into play with your dental health too. If your genetic predisposition affected your tooth development, you may have teeth that are more susceptible to caries. Saliva

production genes influence the amount and quality of the saliva one produces. The amount of minerals in the saliva helping to remineralize the teeth is key. 

Your taste in food also has a basis in your genetics, and can largely affect what you like to eat and drink. A preference for sweets and carbohydrates can lead to an increase in tooth decay.

pH Levels

The mouth’s pH levels also come majorly into play with dental caries and overall health. The pH of dental products, bottled water and all drinks can affect the pH in the mouth, and the pH in the mouth is constantly changing. 

Having an acidic pH can extend the shelf life of many products, so be wary of foods with lots of preservatives. Highly processed, artificial, and sugary drinks are also typically very acidic and contribute to faster tooth decay. The good news is pH is something you can control by making smarter choices and behavior modification.

There is hope for people with lots of cavities. Seeing your dentist to help you identify the root cause of your dental caries is essential. Contact your dentist today to form a plan to help prevent future cavities!

Kutsch, V. K. (2020). Why me? The unfair reason you get cavities and what to do about it. Soapbox Publishing.

Skip to content