Aim: The aim of this study was to collect data on the prevalence of apical periodontitis in relation to the coronal status of teeth in xerostomic head and neck radiation patients and to compare these figures with data from a general population. Materials and methods: Panoramic radiographs of 43 patients lacking dental treatment during and after radiotherapy, taken on average 22.2 months after radiotherapy, were examined for periapical and coronal condition. The findings were compared with a matched control group (data in parentheses). Results: A total of 709 teeth were scored, and 5.6% (9.0%) were endodontically treated. Apical periodontitis was found in 7.8% (9.5%) of teeth and in 12.5% (43.1%) of the endodontically treated teeth. Of all teeth, 86.2% (17.5%) were decayed, with radiographic evidence of caries extending into the pulpal space in the majority of cases. Conclusions: No difference was found in the prevalence of apical periodontitis between the two populations in spite of a high incidence and severe degree of caries that could have lead to a higher incidence of apical periodontitis than in the general population. Bacterial shifts in the oral cavity and root canal, resulting in a less pathogenic flora and/or a change in cellularity and vascularisation of irradiated bone is a possible explanation.
Keywords: apical periodontitis, coronal leakage, head and neck irradiation, radiotherapy, xerostomia