To review and discuss important topics regarding periodontal treatment pre- and post-radiotherapy for head and neck cancer in human patients; to discuss the references for adequate techniques, the appropriate moment for tooth extractions and periodontal management; and to discuss the prevention of osteoradionecrosis. Thirty-nine studies including original studies, randomized clinical trials (RCTs) and reviews were searched in online databases MEDLINE (PubMed) and the Cochrane library. No year of publication restriction was applied. Language was restricted to English, and the following Medical Subject Heading terms were used: radiotherapy, radiation therapy and periodontal treatment. Studies regarding periodontal treatment and tooth extraction that involved clinical management of irradiated patients were selected. The treatment of periodontal diseases before radiotherapy is mainly required to avoid future dental extraction and to reduce the development of osteoradionecrosis. Periodontal treatment in irradiated patients mostly includes scaling and root planing, extraction of condemned teeth and topical and systemic antimicrobial therapy. Tooth removal should be planned at least 14 days before the first day of radiation treatment. Particular care and mouthwashes should be taken during and after radiation. The management of irradiated patients represents a challenge for health professionals, including dentists. It is important to establish recommendations for clinicians concerning dental and periodontal management in irradiated patients before, during and after treatment.