Dental radiographs are commonly called X-rays. Dentists use radiographs for many reasons: to find hidden dental structures, malignant or benign masses, bone loss, and cavities.
A radiographic image is formed by a controlled burst of X-ray radiation which penetrates oral structures at different levels, depending on varying anatomical densities, before striking the film or sensor. Teeth appear lighter because less radiation penetrates them to reach the film. Dental caries, infections and other changes in the bone density, and the periodontal ligament appear darker because X-rays readily penetrate these less dense structures. Dental restorations (fillings, crowns) may appear lighter or darker, depending on the density of the material.
Placing the radiographic film or sensor inside the mouth produces an intraoral radiographic view.
Pulp vitality test is crucial in monitoring the state of health of dental pulp, especially after traumatic injuries. The traditional pulp testing methods such as thermal and electric pulp testing methods depend on the innervation and often yield false positive and negative response. The newer pulp testing device, some of which are still under development stage, detect the blood supply of the pulp, through light absorption and reflection, are considered to be more accurate and non-invasive.