The most dreaded words during a dental appointment: “Mr./Ms. So-n-so, you have a cavity”. You cringe, your heart drops, and you think to yourself, “How is that possible? My tooth doesn’t even hurt!”
The truth is, dental cavities may not hurt until the decay (infected tooth material) reaches all the way to the pulp (nerve) of the tooth. At that point, a regular filling is usually no longer an option, which means more invasive treatment, more time in the chair, and greater financial commitment.
Here’s a cartoon that illustrates why cavities sometimes do not cause pain in the early to middle stages:
The tooth on the right has medium sized cavities that have “eaten” through the enamel (the 1-2mm super hard outer shell) and part of the dentin (the less hard inner bulk of the tooth). The enamel and dentin do not have any nerve endings and therefore there is no pain associated with a bacterial invasion (cavities) into these materials. The tooth on the left shows what happens when fillings are not done to stop the bacteria (cavity) from growing–it eventually travels all the way to the middle of the tooth (the pulp/nerve) and that’s when you get that horrible toothache :(.
As you can see, decay (cavity) has around 4mm of hard material to get through before it reaches the pulp/nerve of your tooth. Sometimes this process takes months to happen, and other times it happens very rapidly. It all depends on your individual tooth make-up (genetics), what type of bacteria is present, and your diet (see blog post on enamel for more details on this).
To sum up, you only have about 4mm of tooth to work with before you start feeling pain from cavities!! Please don’t wait till it’s too late. Ask us to show you what the decay looks like on your x-rays, or in your mouth. Sometimes a visual will help you see the importance of getting a cavity filled before its too late! Cavities most likely will NOT hurt until you’ve waited too long and your pulp is infected–more on pulpal infections (pulpitis) in a subsequent blog 🙂
Note: Tooth decay, cavity, caries, bacterial infection of tooth, bacterial invasion of tooth are all synonymous