The primary goal of this study is to observe whether PRP promotes the wound healing before a radiation therapy or not, compared to the natural healing of a tooth extraction socket.

Secondary aim is to monitore the effect on the pain perception.

Head and neck cancer patients are required for a dental checkup before the beginning of the radiation therapy. During this checkup the patients gets a radiological and clinical examination in order to determine any tooth or alveolar bone bound inflammatory processes. Teeth associated to those conditions, or those which are likely to result in any of this, have to be extracted in order to prevent radiation associated complications such as osteomyelitis or further osteoradionecrosis of the jaw. In order to prevent this illness it is essential to not start before the healing of the post-extraction socket has reached a sufficient state, which is usually around 3 weeks post-extracitonem. To facilitate the healing, recent studies have shown an positive effect by applying PRF and a lower pain perception after surgical tooth removal. So far it is not documented for the prevention of a osteoradionecrosis of the jaw.

The patients who receive two or more tooth extractions before radiation therapy can participate in the study. The preliminary diagnosis has to be a head and neck tumor which is planned to be treated with ionizing radiation equally on both sides of the jaw(s). Both teeth have to have a similar size (e.g. molar and molar).

Patient and Doctors a blinded, the site of PRF Application is chosen by random. After surgical removal of the teeth one extraction socket is filled with PRF while the other is left for its natural formation of a blood clot.

During the first 7 days the patient protocols the pain perception and the amount of painkillers used for both sides of the jaw. After 7d, 14d, 21d, 30d, the wound healing is recorded until it reached is end in complete epithelization.

3 Months after the surgery a intermediate clinical examination is performed for early signs of any complication due to the radiation therapy. 6 Months after the surgery a OPG-radiograph will be taken to determine the bone healing comparing the test site and the control site.

Inclusion Criteria:

• Head and neck cancer with planed radiation therapy
• Bilateral tooth extraction
• Similar tooth size
• Atraumatic tooth extractions without flap surgery
• Patients age above 18y of age

Exclusion Criteria:

• Prior radiation therapy in the head and neck area
• Prior and current therapy with bisphosphonates or equivalent modern biologics
• Patients during pregnancy or breastfeeding

Investigator as well as the Patient are blinded.