Radiotherapy to the head and neck region (HN) bears the risk of a rampant development of caries, making intensified prevention necessary. Aim of this systematic review was to summarize the evidence on the efficacy of caries preventive measures in these patients.

Clinical studies investigating caries in patients with radiotherapy in the HN with at least one caries preventive intervention compared to any control were included. Reports in languages other than English or German were excluded. Records were identified on PubMed, Web of Science, Google Scholar and Cochrane Library mid-January 2024. Risk of bias was assessed with RoB2. Results were summarized. Planned meta-analyses could not be performed, because of heterogenous data.

Five studies were included, with a total of 355 participants. They were irradiated with up to 70Gy and received different caries preventive interventions, including sodium fluoride or stannous fluoride gels, remineralizing solutions, an “Intraoral Fluoride Release System” and sucrose restricted diet. Caries score increased between 0.48 DMF-S and 9.2 DF-S per year. Largest differences in caries increments were measured between groups with insufficient and with rigorous fluoride application.

The main limitations were compromised randomisation, heterogeneity of patients and small sample sizes. Clinical studies on caries prevention after radiotherapy to the HN are lacking and the existing ones bear extensive limitations. However, the large effect size and broad consensus suggest the use of fluoride to be indispensable in preventing caries in these patients.

The study was funded by the Medical Center - University of Freiburg and was not registered.