One of the biggest concerns we hear from our patients and parents of our younger patients is if whether dental x-rays are really necessary. To really dive into this age old question and giving an answer, we must understand how dentists use these x-rays to diagnose and detect gum decease, cavities, infections, and other diagnosis that can cause a simple tooth ache, to other severe problems and maybe even death.
X-rays are used to check below the gum line and in between your teeth where a lot can go on. Lets take a look at the photo below to understand how much we actually see when looking into our mouth:
And here is an animated photo below showing just the molar and how much we can see:
The photo here shows the top part of a molar in which we can clearly see when looking into a mirror. The part of the tooth that is visible is called the crown and is the part that is above the gum line. When a dentist probe around your mouth, they are able to check for problems that are only visible to the naked eye. In an x-ray photo below, you can see the crown of the tooth just like the animated photo above.
If toothache-causing cavities and gum disease can we be seen visibly by just looking into your mouth, that would make things a lot easier to diagnose. Unfortunately, getting to the source of the problem or the pain isn’t always easy. Or at least without the help of taking an x-ray. Lets take another look at the anatomy of the tooth for a clearer image of what other components of a tooth that needs to be seen before we can accurately determine treatment for the patient.
And this is what that anatomy of a tooth looks like on an x-ray:
This type of x-ray shown above is called periapical x-rays. Periapical x-rays ( are sometimes called P.A. x-rays) show the whole tooth, from the crown to beyond the end of the root to where the tooth is anchored in the jaw. Each periapical X-ray shows this full tooth dimension and includes all the teeth in one portion of either the upper or lower jaw. Periapical X-rays are used to detect any abnormalities of the root structure and surrounding bone structure. Periapical X-rays are also used to detect abscess or infection at the root cause by trauma to the tooth or a large cavity infecting the pulp of the tooth.
You can clearly see in this photo below that an abscess is present and symptom such as shooting pain, swollen face, neck and/or jaw.
Treatment for an abscess like this would be endodontic therapy or also known as root canal therapy to remove the nerve, or have the tooth extracted.
Another type of x-rays taken at office visits is called bitewing X-rays. Bitewing x-rays show details of the upper and lower teeth in one area of the mouth. Each bite-wing shows a tooth from its crown to about the level of the supporting bone. Bite-wing x-rays are used to detect decay between teeth and changes in bone density caused by gum disease. They are also useful in determining the proper fit of a crown and the marginal integrity of fillings.
A cavity can be detected as a dark grey area on the tooth with a bite-wing x-ray. The dentist can also determine how deep the cavity is to see whether other treatment is needed. In the photo below, you can see the cavity coming close to the nerve of the tooth and can potentially cause an abscess.
Bite-wing x-rays are also used to diagnose gum disease and and determine tartar or dental calculus under the gums. Calculus are seen as white translucent smudge on the x-rays. Here is an x-ray with calculus surrounding the root of the teeth:
A procedure known as scaling and root planing or “deep cleaning” , where a dentist or dental hygienist would scale below the gum line to remove the calculus build-up. In more serious cases, the dentist would refer the patient to a periodontist to evaluate the treatment needed.
Dentistry has changed a lot over the years, with new updated technology in dental x-ray imaging that help reduce the use of radiation. Digital x-rays uses a fraction of the radiation needed to an image. Also, using x-ray guide rings made of lead will cut that radiation by another 30%. To put the amount of radiation needed to take annual x-rays(about 6 pictures) into perspective, it is the same amount of radiation exposure as you would get from walking around in the sun for a day. Dentists can of course diagnose a lot of issues without the use of x-rays, but a lot of them can go undetected as well. You can get away with taking less x-rays but it’s a lot harder to get away with not taking any x-rays at all. Modern technology also allows other means of checking for cavities such as near-infrared detection devices such as the CariVu which checks for cavities, lessions, and fractures. You can read more about CariVu here.