Your teeth: A complex set of layers

From the outside, each tooth looks like a solid white object, but teeth actually are complex living tissues made up of several layers:

(1) Enamel

(2) Dentin

(3) Pulp

Enamel is the white, outermost layer of the tooth that covers the crown (the part of your tooth that you see, above the gumline). Enamel is the hardest substance in your body. It provides strength for biting and chewing, and it protects the inner layers from plaque and bacteria that lead to decay.

Dentin is the second, yellowish layer inside your tooth. This hard tissue contains millions of tubules. Dentin is softer than enamel and provides support for it, acting like a shock absorber to take the impact of biting and chewing. When a cavity develops, it breaks through the enamel and attacks the dentin.

Pulp is the innermost layer, which includes the nerves and blood supply for a tooth. This soft tissue reaches from the pulp chamber at the top of the tooth, down through the root canals in the tooth roots. If decay reaches the pulp or root canals, a filling may not be sufficient to protect the strength and health of your tooth.

The roots of your teeth (the parts of your teeth below the gumline) also contain blood vessels and nerves that connect your teeth to the nerves and blood vessels of your jawbone. The roots are covered with cementum. This extremely thin layer of tissue "cements" your teeth to the bone.

Disease and decay that reach the roots are extremely serious and painful. That's why it's important for us to examine both the outsides and the insides of your teeth.

X-rays: A safe view inside your teeth

As part of your regular dental checkup, we may take x-rays. Different types of x-ray images help us to identify areas of decay, worn-out fillings, cracks, tartar, periodontal disease, bone infections, impacted wisdom teeth, long or crooked roots, abscesses or cysts, problems with sinuses, or anything else that may appear unusual or abnormal.

Depending on your age and your dental health situation, we may use different kinds of x-rays, including:

Bitewing x-rays: These are the most common type of x-rays. They capture images of your upper and lower teeth above the gumline (the crowns) simultaneously.

Full series of x-rays: Using 18 different locations, these give us a complete picture of your mouth. We often take a full series during your first visit with us.

Periapical x-rays: These give an excellent view of your entire tooth, including the roots, any bone loss, and cysts or abscesses. We may use these x-rays as a followup measure for monitoring your teeth and jaw.

Panographic x-rays: These give us a complete picture of your entire mouth in one image, including wisdom teeth, the sinuses, and the jawbone.

To ensure an accurate view, we may ask you to tie back synthetic hair braids or remove jewelry, especially nose rings, mouth jewelry, or earrings with large hoops. This is particularly important with panographic x-rays.

Dental x-rays are safe, because our sensitive x-ray equipment quickly and accurately targets only a specific area of your mouth. Our highly trained staff give you a lead apron and collar to provide additional protection. And our modern technology effectively minimizes the amount of radiation and how long you are exposed to it.

Radiation from a dental x-ray is very low, not much more than the normal background radiation of everyday life (household appliances, minerals in the ground, ultraviolet rays from the sun, airplane travel or high altitudes, etc.). And the benefits of using dental x-rays far outweigh the risks.

Now that you've learned a bit about your teeth from the inside out, we hope this will inspire you to take good care of them from the outside in!