Diagnosis of apical periodontitis in root-filled teeth

Root filled teeth are common in adult populations worldwide. When a root-filled tooth causes swelling and/or pain it is usually a sign of infection. In combination with the presence of a periapical bone lesion visible in an intraoral radiograph the diagnosis of apical periodontitis is usually quite straightforward. However, when pain is present but radiographic signs are absent or, in particular, when the tooth is asymptomatic but signs of disease are present at an X-ray the diagnostic process is associated with several uncertainties. Asymptomatic periapical bone lesions indicating apical periodontitis is common in root-filled teeth. Based on the current state of knowledge, it is reasonable to assume that the condition does not pose a serious health problem at a population level. Therefore, it is reasonable for the clinician, in most situations, to adopt a diagnostic strategy that helps to refrain from overdiagnosis. Otherwise many patients will risk costly retreatments or even tooth extractions without significant benefit.