Complicações da radioterapia no esmalte e dentina humanos: análise da adesão, composição química e propriedades mecânicas

Abstract

Radiotherapy (RT) is an effective therapy in the treatment and control of malignant neoplasms in the head and neck region. However, it can cause adverse reactions in healthy structures that inevitably participate in the irradiation field. One of the main consequences when RT involves the oral cavity is radiationrelated caries (CRR). Your treatment is challenging. This work involved 4 sequential objectives: Objective 1: to evaluate the literature seeking to condense information on enamel and dentin alterations after radiotherapy and its influence on adhesion to these substrates. Objective 2: to evaluate the bond strength of an adhesive system (Scothbond -3M, ESPE) by means of a microcrystalline test, between composite resin and irradiated enamel, before and after in vitro radiotherapy. Objective 3: to evaluate changes in the dentin of the cervical region after in vitro radiotherapy. For this, chemical analysis was used by Fourier Transform Infrared Spectroscopy and Raman Spectroscopy, and mechanical analysis by means of Nanodureza and Modulus of Elasticity. Objective 4: to associate the results found in objectives 1, 2 and 3 in an article with clinical focus, for communication to dentists. Through the literature review, performed in objective 1, it can be concluded that radiotherapy causes mechanical and chemical changes in the enamel and dentin, and these alterations negatively affect the bond strength of adhesive restorations. However, there is no standardized literature on the best adhesive system to be used in this clinical situation. Objective 2 confirms the conclusions of objective 1, showing that the radiotherapy performed prior to enamel restoration caused the formation of a heterogeneous adhesive interface and lower union strength values when compared to a non-irradiated group and to a group restored before radiotherapy. Objective 3, seeking to understand changes that contribute to the involvement of RRC in the cervical region, showed that the dentin of this region has its chemical composition altered and its mechanical properties diminished, contributing to the rapid progression of CRR. Finally, it was shown with objective 4, the importance of the dental surgeon to know the changes caused by radiotherapy in dental tissues and oral cavity, becoming aware of the care in the restorative treatment of patients after radiotherapy.