Dental X-ray


Wilhelm Conrad Roentgen was experimenting with vacuum tubes. In 1895, he produced, with one of these tubes, an invisible ray that was capable of penetrating substances opaque to life. When certain objects were place between the tube and the screen, there shadows were cast upon the screen. Unable to define the exact nature of this radiation, he named it the “x-ray”.

Dental x-rays went through major improvements.

 It is now possible to take dental x-rays exposing the patient to as little as one-tenth the amount of radiation of older, conventional x-rays. This is done with the use of digital x-rays that do not use film and do not need chemicals for development. Sensors instead of film are placed in the patient's mouth. These sensors are slightly thicker than the conventional x-ray film, but absolute majority of the patients will tolerate it as well as conventional film. After exposure, the image appears on a computer screen in just seconds. The resultant digital pictures are as clear as conventional film x-rays. They also provide a lot of information that was not available before. Instead of holding up small films that are hard to see, the dentist and the patient can look at the images on a computer screen together. The taken images can be enhanced and enlarged many times its actual size.

Bite wing X-ray
Arrows point to decay, not visible at the exam

 Extraoral X-rays


There are two principal kinds of dental x-rays.

 Extraoral X-rays mean that the film or digital sensor remains outside of the mouth while the machine shoots the beam through other structures from the outside. The most used dental extraoral x-ray is the panoramic x-ray (Panorex). The Panorex is a large, single x-ray film that shows the entire bony structure of the teeth and face.   It takes a much wider area than any intra oral film showing structures outside of their range including the sinuses, and the Temperomandibular Joints.  It shows many pathological structures such as bony tumors and cysts, as well as the position of the wisdom teeth. They are quick and easy to take. It gives full picture of the dentition, but it lacks some details that intraoral x-ray have.

Periapical Digital X-ray

Digital Intraoral Sensor

Digital Bite Wing X-ray

Digitally enhances same picture

Why the x-rays are are necessary?



More than 50 per cent of the decayed areas in teeth are discovered only through x-rays findings. Doctor or hygienist cannot see those cavities that form between the teeth and under the gum during examination. Secondary decay under old fillings also very easily missed without x-rays. Periapical infections may slowly develop not causing any symptoms and the only way to spot them through x- ray examinations.

Many times patient would refuse x-rays at the examination in order to save a few dollars. But if the cavity is small, it can be filled with filling material, as it becomes bigger and bigger RCT, post and core and the crown could be the only solutions. And these procedures do not come cheap.

Pnaoramic Digital X-ray

Intraoral X-ray


The intraoral x-ray is done to get the detailed image of a tooth and surrounding tissue. X-ray film or small sensor (digital X-ray) is placed inside patient mouth, behind the teeth, catching the light bin passing through the tooth. There are two kinds of intraoral x-rays:

Bitewings –they show the image of the crown part of the teeth and used to diagnose caries lesions, not visible during regular exam.

Periapical X-ray catches the full image of the tooth and used for viewing areas of the teeth below the gum line.

The full mouth series is the combination of periapical and bitewings x-rays, allowing the doctor to oversee the whole dentition for diagnoses and treatment planning.