 It is possible for both tooth decay and periodontal disease to be missed during a clinical exam, and radiographic evaluation of the dental and periodontal tissues is a critical segment of the comprehensive oral examination.The photographic montage at right depicts a situation in which extensive decay had been overlooked by a number of dentists prior to radiographic evaluation.There are numerous risks associated with the taking of dental radiographs, even though the dose to the patient is minimal, the collective dose needs to be considered in this context as well.