Difference between Tooth Decay and Cavity
By Theydiffer - June 21, 2016

Is the dentist’s office still one of the scariest places for some people? Probably. Even so, since there is no chance of auto diagnosis and self medication in the case of teeth; it always takes a dentist to tell you what is going on. But what are you most afraid of? What is worse: tooth decay or tooth cavity?


Tooth decay occurs when the germs in the mouth produce acid that eats away at the tooth. With everything we eat, a clear substance gets stuck to the teeth. This is called plaque and it is made out of bacteria that feed on the sugars on your teeth. As the bacteria feed, they produce acid which eats away at the tooth. The symptoms of tooth decay are black spots on the teeth, toothache and even bad breath.

Treating the tooth decay involves catching the process early on, when it is in the stage of a “white spot”. This means re-mineralizing the tooth through the application of fluoride in the form of gel or varnish. The dentist can do this in the early stages and prevent the bacteria from eating away more of the teeth.

A cavity is a black hole in the middle of the tooth, a sign that the bacteria in the plaque has already eaten through several layers of the tooth. The closer the cavity gets to the pulp, the more painful it becomes and the tooth reacts to sensations of cold, hot or sweet.

When dealing with a cavity, a dentist will remove the decaying parts of the tooth, then he will get the remaining holes filled up. If there is too little left of the tooth after the decay has been cleared away, a crown is recommended. This is an already built tooth top, most often made out of porcelain to match the color of the rest of the teeth, which is placed over the stub of your former tooth after it has been filed down.

Tooth decay vs Cavity

So what is the difference between tooth decay and cavity?

Tooth decay is the primary stage of the cavity, the one in which an intervention is possible by simply clearing away some of the plaque and by strengthening the tooth’s fluoride coating. The cavity is the process which has already begun and which can affect a tooth down to its pulp. A tooth that is completely damaged by cavity rots and needs to be pulled out. The reason why people should try to protect and preserve as much as possible of a tooth is that taking a rotten tooth out with the roots means a very invasive and expensive procedure for implanting a new one.

Comparison Chart

Tooth decayCavity
Is one of the initial phases of cavityContinues the process started by tooth decay
Recognizable by pain and “white spots”Recognizable by pain and black holes in the teeth
Can be treated with a fluoride gel or varnish to strengthen the toothThe rotten parts must be cleared away and a filling or a crown must be set in place