Most common source of error in a false positive finding of dental caries is:

Although this can be caused by a variation in the morphology of the tooth, the most common source of error is the misinterpretation of cervical burnout as dental caries. Cervical burnout produces an artifact that mimics a carious lesion near the cementoenamel junction (CEJ) area of the tooth. As the X-ray beam meets the convex proximal surface of the tooth, those X-ray photons that pass almost tangentially through the tooth surface “see” less tooth structure than those photons that pass deeper through the tooth. This area of convexity is commonly located apical to the CEJ, near the normal height of the alveolar crest. The thinner tooth structure here absorbs fewer X-rays; consequently the area appears relatively more radiolucent on an image. Cervical burnout can also be seen in multirooted teeth, when roots that are more buccally positioned do not overlap perfectly with a lingual or palatal root in a mesiodistal direction. The presence of a shallow furcation on either the mesial or distal surface of the tooth can make the area appear more radiolucent. However, the presence of two overlapping roots can be confirmed by identifying the periodontal ligament spaces of each root.