An example of why your dentist cannot rely on just a visual examination of your teeth is highlighted in the case shown on the right.
This preoperative photo of tooth #3, (A), reveals no clinically apparent decay other than a small spot within the enamel surface. In fact, decay could not be detected with a dental probe.
Radiographic evaluation, (B), however, revealed an extensive region of demineralization within the dentin (arrows) of the front half of the tooth.
When a bur was used to remove the enamel overlying the decay, (C), a large hollow was found within the tooth.
After all of the decay had been removed, (D), the pulp chamber had been exposed and most of the front half of the tooth was either missing or poorly supported. Root canal treatment was necessary to save the tooth.
Dental x-rays provide valuable information about the health of your teeth. Areas of decay show up as dark spots in x-rays. Sometimes a dentist cannot see decay as it may be invisible to the naked eye. This may be because it is hidden by a filling or is located beneath the gum line. These x-rays can also show when teeth are not growing properly beneath the gum.
X-rays can also be used to plan tooth implants, reveal signs of cysts and cancers, and check for bone loss.
Bitewing X-rays show the upper and lower teeth and how the teeth touch each other in a single view. These X-rays are used to check for decay between the teeth and to show how well the upper and lower teeth line up. They also show bone loss when severe gum disease or a dental infection is present.
Periapical X-rays show the entire tooth, from the exposed crown to the end of the root and the bones that support the tooth. These X-rays are used to find dental problems below the gum line or in the jaw, such as impacted teeth, abscesses, cysts, tumours, and bone changes linked to some diseases.
Panoramic (OPG) X-rays show a broad view of the jaws, teeth, sinuses, nasal area, and jaw joints. These X-rays do not find cavities. These X-rays do show problems such as impacted teeth, bone abnormalities, cysts, solid growths (tumours), infections, and fractures.
How often dental X-rays (radiographs) should be taken depends on the patient’s individual health needs. Your dentist will review your history, examine your mouth and then decide whether you need radiographs and what type.The schedule for needing radiographs at recall visits varies according to your age, risk for disease and signs and symptoms.Recent films may be needed to detect new cavities, or to determine the status of gum disease or for evaluation of growth and development. Children may need X-rays more often than adults. This is because their teeth and jaws are still developing and because their teeth are more likely to be affected by tooth decay than those of adults.