Influência da radioterapia na estrutura intrarradicular e na condição pulpar de pacientes pós radioterapia em região de cabeça e pescoço

Abstract

Radiotherapy is the most common treatment for malignant neoplasms in the head and neck region, destroying neoplastic cells by modifying their molecular structures. However, it also affects healthy tissues in the irradiation field, causing side effects such as xerostomia, mucositis, dysphagia, dysgeusia and radiation-related caries. Extensively destroyed dental crowns, with indication for extraction and installation of implants and prostheses are challenging in irradiated patients due to the risk of osteoradionecrosis. Conventional treatment is therefore contraindicated. Alternatively, preservation of irradiated roots can be performed with intraradicular fiberglass retainers, cemented in the root canal and crowns reconstructed with composite resin, restoring function, aesthetics and quality of life to the patient. To understand the effects of ionizing radiation on intraradicular dentin, an in vitro laboratory study was carried out analyzing the chemical composition and microhardness of intraradicular dentin from lower incisor teeth extracted from patients irradiated in the head and neck. It was concluded that radiation altered the chemical composition and hardness of intraradicular dentin, especially in the cervical and middle thirds. The second objective was a cross-sectional observational study of a case series, in post-irradiated patients with head and neck cancer, with fiberglass posts cemented and reconstructed directly with composite resin. The decementation of the fiberglass post and the survival of the reconstructed crowns were evaluated using the FDI (World Dental Federation) criteria, through clinical and radiographic evaluations. The reconstructions carried out between November 2019 and October 2023, were evaluated in March/April 2024. There was no decementation and all restorations were classified as satisfactory or sufficient according to the FDI criteria. Accurate diagnosis of pulp condition is crucial in dental treatment. Radiotherapy can alter the response to the pulp vitality test, leading to incorrect diagnoses. Understanding the effects of radiation on pulp condition can prevent misdiagnosis and unnecessary endodontic treatments. Thus, the third study was a case report verifying the pulp condition, through the cold thermal test, in patients treated with radiotherapy, evaluated at 6 and 12 months post-treatment. It was found that radiation temporarily modified the pulp condition and the response to the cold pulp vitality test. Six months after radiotherapy, the teeth showed a negative response to the test, but, after 12 months, some teeth showed a return of the pulp vitality response.