How Long Does it Take for a Cavity to Form?

How Long Does it take for a cavity to form

Your cosmetic dentist is just as concerned about your oral health as they are about the appearance of your smile. Unfortunately, cavities pose a threat to your oral health, while also affecting the way your smile looks. While you have most likely heard about cavities before, have you ever considered how long it takes a cavity to form? Understanding more about how long it takes cavities to form can give you a greater understanding of how to care for your teeth in order to avoid or minimize cavities. 

Before getting into how long it takes a cavity to form, let’s make sure that we have a clear definition of what cavities are. Cavities, also known as tooth decay or caries, are holes in the enamel, or outer layer, of your teeth. These holes form when the bacteria that resides in plaque release harmful acids that weaken the enamel over time, eventually causing it to dissolve. Since plaque is sticky, it not only holds the bacteria close to your teeth, but it catches food particles that bacteria can feed on to produce more acids. 

Although plaque covers the entire surface of your teeth, there are certain locations that can accumulate more plaque and bacteria than others. These areas are at an increased risk of developing cavities due to the high concentration of bacteria. There are different types of cavities that can form such as: root cavities, pit and fissure cavities, and smooth-surface cavities. 

dental cavity shown in dental mirror
  • Root cavities: cavities that form of the tooth roots after gum recession has exposed them. Your tooth roots are susceptible to cavities because they have a thinner layer of enamel than the rest of your tooth. 
  • Pit and fissure cavities: cavities that form in the textured surface of your molars. This is a common location for cavities since it is easy for plaque to become trapped in the various grooves. 
  • Smooth-surface cavities: these are slow-growing cavities that form on the smooth, flat surfaces of the teeth. 

Now that you know what cavities are and where they can form, let’s take a look at how they develop. Despite what you may think, cavities don’t just spontaneously appear. Instead, there is a process by which they form that consists of five stages: 

Stage 1: Demineralization

Your tooth enamel is the hardest tissue in the body since it is mostly composed of various minerals. When your enamel is exposed to acids, these minerals start to dissolve in a process known as demineralization. The first stage of cavity formation occurs when the enamel begins to demineralize and a white spot appears on the tooth. At this stage it may be possible to remineralize the tooth with a fluoride treatment that helps replace some minerals. 

Stage 2: Enamel Decay

After demineralization occurs, the acids produced by bacteria will continue to work their way through the enamel. At this point, holes will form in the enamel that are known as cavities. Once a cavity has been formed, it cannot be reversed and will need to be treated with a dental filling. 

Step 3: Dentin Decay

When a cavity is not caught in the enamel decay stage, it will continue to grow until it reaches the dentin layer. Because the dentin layer is sensitive, cavities that affect the dentin usually cause pain or tooth sensitivity. At this point, the cavity will need to be treated with a large filling such as an inlay or onlay. In some cases, a dental crown may also be needed. Once decay has reached the dentin layer, it is important to note that the rate of decay will increase since it is easier for the acids to erode dentin. 

the stages of tooth decay

Step 4: Pulp Decay

When a cavity continues to grow past the dentin layer, it will eventually reach the innermost layer of the tooth known as the pulp layer. When bacteria reaches the pulp, which houses the tooth nerve and blood vessels, it causes an infection that results in inflammation and pain. The only way to treat a pulp infection is to remove the infected tissue with a root canal and restore the affected tooth with a dental crown. 

Step 5: Abscess

Once the bacteria have infected the pulp layer, they can work their way down through the root canals into the very bottom of the tooth. This usually causes an abscess to form underneath the tooth roots that causes unbearable pain. While some dental abscesses can be treated with a root canal, others are treated by extracting the tooth to prevent the infection from spreading. 

While there is no exact timeline for how long it takes a cavity to form, most cavities tend to form over a series of years, but some can form within months. Ultimately how fast a cavity forms depends on a number of factors such as your oral hygiene routine, diet, and how many times you visit the dentist. Additionally, cavity formation speeds up deeper in your tooth, since the enamel is the only tough, protective layer. Generally speaking, practicing good dental hygiene, limiting your sugar intake, and attending regular dental exams and cleanings help to prevent or slow the formation of cavities. On the other hand, forgetting to brush or floss, eating sugary and sticky foods, and avoiding dental appointments can cause tooth decay to progress faster. 

In addition to understanding how long it takes a cavity to form, it is also important to know at what point a cavity can cause you to lose your tooth. After all, tooth decay is one common cause of tooth loss or extraction. By the time decay-causing bacteria have reached the pulp layer, your tooth is at risk of being lost. While root canals are an effective way to save a tooth with a pulp infection, they are not always successful. If the infection continues and causes an abscess, then you will most likely need to have the tooth extracted. 

Overall, if you start to notice white spots on the surface of your teeth or you think you may have a cavity, it is important to schedule an appointment with your local dentist as soon as possible. The sooner you seek treatment for a cavity, the less invasive the treatment will be. Additionally, seeking treatment earlier will also save you from the excruciating pain of a pulp infection, as well as the risk of losing your tooth. 

Dr. Sam Sadati wearing black suite portrait

Dr. Sadati possesses extensive experience in all aspects of advanced restorative dentistry, with an emphasis in cosmetic and implant dentistry.  He has attained Accredited Fellow status in the American Academy of Cosmetic Dentistry (AACD), the most rigorous, demanding credentialing process in the world. He is the only AACD Accredited Fellow in South Florida.