brushing · interdental care · oral concerns ·Jul 21, 2025

Are all cavities the same?

When most people hear the word cavity, they picture a small hole in a tooth that needs to be filled. But did you know that not all cavities are created equal? In fact, there are several types of cavities, each with its own causes, characteristics, and treatment approaches. Understanding the differences can help you better protect your oral health.

What Is a Cavity?
A cavity, or dental caries, is a permanently damaged area in the hard surface of your tooth that develops into tiny openings or holes. Cavities are caused by a combination of factors, including bacteria in your mouth, frequent snacking, sugary drinks, and poor oral hygiene.

Stages of Cavity Development

Demineralization: Acid produced by bacteria in the mouth starts to break down the tooth enamel, the outer layer of the tooth.
Enamel Decay: The Initial caries (picture below) shows how the acid has removed enough tooth structure to form a hole within the enamel.
Dentin Decay: The manifest caries (picture below) shows how the acid has reached the softer layer of dentin under the enamel.
Pulp Damage: Pulpitis (picture below) shows how the bacteria can then infect the pulp where the nerve and blood supply are located. Treatment for pulp damage requires a root canal.

The 4 Main Types of Cavities

Smooth Surface Cavities
These cavities form on the flat, smooth surfaces of your teeth, especially between teeth where plaque tends to accumulate. They develop slowly, giving you time to catch them early with good oral hygiene and fluoride treatments. These are the easiest to prevent and treat if detected early.
Pit and Fissure Cavities
Found on the chewing surfaces of the back teeth (molars and premolars), these cavities form in the natural grooves and crevices. Because these areas are harder to clean, they are more prone to decay. Dental sealants are often used to protect these vulnerable spots.
Root Cavities
These occur on the roots of teeth, typically when gum recession exposes the root surface. Since roots are covered by a softer tissue called cementum (not enamel), they are more susceptible to decay. Root cavities are more common in older adults and can progress quickly if not treated.
Recurrent Cavities
Also known as secondary cavities, these form around existing fillings, crowns, or dental work. They often result from plaque buildup in areas where dental restorations meet natural tooth structure. Regular dental checkups are key to catching these early.

Why It Matters
Understanding the type of cavity you have can influence how it’s treated. For example:

Smooth surface cavities may be reversed with fluoride if caught early.
Pit and fissure cavities often require fillings due to their depth.
Root cavities may need more extensive treatment due to their rapid progression due to softer tooth structure.
Recurrent cavities might require replacing old dental work.

Prevention Tips
The best defense against cavities is prevention:

Brush twice a day.
Clean between the teeth daily.
Limit sugary and acidic foods and drinks.
Visit your dentist regularly.
Consider dental sealants for children or adults with deep grooves in their molars.

By understanding the differences between the types of cavities, you can take more targeted steps to protect your teeth and maintain a healthy smile.