There are a number of factors that affect the usefulness and quality of the radiographic examination.2
- A certain amount of mineral must be lost before it can be detected in a radiograph. Technical aspects, such as film contrast and viewing conditions, determine this minimum amount of mineral loss.
- The shape, extent, and location of the lesion, together with the anatomy of the tooth, also influence the radiographic depiction. A shallow, widespread lesion may create an image of being deeper than a deep lesion that is narrowly spread on the surface.
- The direction of the X-rays affects the image. Most dentists now use film-holders or beam-aiming devices that prevent deviations of the rays that cause a decreased image contrast, and could result in the under- or over-estimation of the extent of a lesion.
- An important aspect of correctly diagnosing caries using radiography is the interpretation by the professional. Having no expectation to detect caries may result in insufficient examination of the image, a neglected diagnosis, and insufficient treatment. On the other hand, there is also the possibility of over diagnosis and overtreatment if a dentist assumes almost all patients have caries. Therefore, it is important to understand caries prevalence of the population under treatment, meaning that not all patients should be handled in the same way.