Dental radiographs, or x-rays, are an essential tool in your dentist’s diagnostic toolbox. It took only fourteen days after Wilhelm Roentgen discovered x-rays in 1895 for a dentist, Friedrich Walkhoff, to see their benefit for dentistry. Dental radiography has changed significantly since Dr. Walkhoff’s first x-ray, which required twenty-five minutes of radiation exposure. The quality and safety of dental x-rays has been indispensable for gaining a complete picture of one’s oral health. Dental x-rays have helped save the teeth and the lives of patients for many years since the work of Drs. Roentgen and Walkhoff.
Why Are Dental X-Rays Necessary?
Many conditions requiring dental treatment are readily visible to your dentist with the naked eye. Tooth decay, gum disease, abscessed teeth, and oral cancer can reveal signs and symptoms that allow visual diagnosis. However, these conditions and others often lie hidden beneath the gums and soft tissues in and around the mouth. In these cases, the tooth may not be salvageable by the time visual detection is possible, or oral cancer may be far advanced.
Dental x-rays allow your dentist to inspect:
- The areas between your teeth.
- The roots of teeth.
- The bone surrounding and supporting each tooth.
- The developing adult teeth in children.
- The sinuses located around the upper back teeth.
- The dental pulp (nerve of the tooth) found within the tooth’s hard structures.
- The entire jawbone.
- The temporomandibular joint. (TMJ)
What Do X-Rays Show?
During a comprehensive dental exam, your dentist visually inspects your mouth for signs of oral disease. Dentists also use their fingers to palpate or feel around your teeth, gums, and jaws to detect any irregularities. However, dentists also rely on dental x-rays for the detection of certain conditions and diseases such as:
- Interproximal tooth decay. This is decay on the sides of the teeth, between adjacent teeth.
- Decay under existing dental fillings or crowns.
- Bone loss around a tooth or an implant.
- A dental abscess forming in the bone at the tip of a root.
- Root resorption that can occur after dental trauma.
- Dental cysts and tumors.
- Extra teeth (known as supernumerary teeth) submerged in the bone.
- The location of impacted wisdom teeth.
What Types of Dental X-Rays Are There?
There are two broad categories of dental x-rays:
- Extraoral X-Rays.These can show the entire skull, jaws, and teeth. Extraoral x-rays are not part of routine general dental exams. Orthodontists and oral surgeons use these more to evaluate conditions such as the growth and development of the jaws and temporomandibular joint disorder.
However, the one extraoral x-ray that your dentist might use is the panoramic x-ray. These are not taken as frequently as intraoral x-rays. Still, everyone should have one periodically since these can reveal cysts and tumors in the jaws not visible on routine x-rays.
- Intraoral X-rays. These are commonly used during a comprehensive dental examination. Dentists rely on intraoral x-rays for detailed images of the teeth, roots, and surrounding bone.
There are several types of intraoral x-rays, but two are most used regularly.
- Bitewing x-rays. Bitewings are the most common intraoral dental x-rays. Bitewings show the sides of the teeth and the bone between the teeth. A bitewing reveals the top halves of opposing upper and lower teeth but does not show the roots of these teeth. These are important to diagnose early tooth decayand early periodontal bone loss from gum disease. A complete set of bitewings includes four x-rays, two taken on each side of the mouth.
- Periapical x-rays. This is a single x-ray that reveals the entire tooth, including bone beyond the tip of the root. Periapical x-rays are routinely taken if you have a toothache because they can reveal an abscessed tooth.
What Are Digital Dental X-Rays?
In recent years dental radiography has entered the digital age. Your dentist may use either conventional or digital x-rays. The advantages of digital x-rays are:
- The image is available immediately on a computer screen.
- Image quality. The digital image quality is superior, especially with the possibility of digital adjustment if necessary, instead of needing to retake an x-ray.
- Less radiation. Although conventional dental radiography requires very little radiation exposure, digital x-rays reduce this by as much as 90%.
Are X-Rays Safe?
All dentists should follow the ALARA principle, which means radiation exposure should be As Low As Reasonably Achievable. Radiation safety is a primary concern for their patients, staff, and themselves. Although x-rays are essential to delivering quality oral health care, your dentist takes only those that are necessary for an accurate and complete diagnosis.
Dental x-rays require radiation exposure, but the amount is minimal and even less than some natural radiation sources. As safe as dental x-rays are, especially digital x-rays, there are precautions for pregnant patients. Although medical experts have declared dental x-rays safe during pregnancy, you should inform your dentist if you suspect you are pregnant.
How Often Should You Get Dental X-Rays?
The health of your teeth and gums determines when you need dental x-rays. If you are prone to tooth decay or gum disease, you may need x-rays every six months. If you are a new patient, your dentist will likely request a full set of x-rays. These serve as a baseline to determine any changes in your teeth, gums, and surrounding bone.
Can Dental X-rays Reveal Nerve Damage?
The nerve inside the tooth is visible on a dental x-ray. However, an x-ray does not show any disease of the nerve until it has become abscessed or infected. Once this happens, a periapical x-ray can reveal the presence of the infection in the bone.
Dental x-rays can help save a tooth from extensive dental treatment or even extraction with the early detection of tooth decay or gum disease. They might also save a patient’s life in the early detection of oral cancer. There are many benefits to having regular dental x-rays. However, it is common for patients to be apprehensive about radiation exposure. You should discuss your concerns thoroughly with your dentist until you are comfortable with the dental radiographs you will receive.
--- By Dr. Steven I Received his Doctor of Dental Medicine (DMD) from the Medical College of Georgia before practicing general dentistry in the United States Navy. He then completed a residency in endodontics at the Medical College of Georgia.