Material Selection for Constructing an Intraoral Stent Used in Radiotherapy: Analysis of Density and Structure

Abstract

Neck and head cancer is a very common disease. Radiotherapy is one of the treatments, and its side effects affect the patient’s quality of life because the radiation targets both neoplastic and healthy tissues. This study aimed to select material that exhibited the greatest number of characteristics that are biocompatible with human tissue and that are strong enough to construct an intraoral stent. The stent would be used to mechanically isolate the palate, tongue, and mouth floor to prevent radiation in head and neck cancer cases requiring radiotherapy, thereby aiming to decrease the treatment’s side effects. The following materials were selected to be submitted to a first analysis by computed tomography: polyacetal (white and black), polymethylmethacrylate (PMMA), polyurethane, and polyvinyl chloride. By observing the density through Hounsfield unit (HU) analysis, the materials with HU values closest to that of water (HU = 0) were selected for the structural analysis after the radiotherapeutic protocol through micro Raman spectroscopy. After undergoing radiation, PMMA with HUs of 177 and 179 without structural modification had the best density results; this was verified by micro Raman spectroscopy. PMMA seems to be a promising material due to its density and structural integrity after the radiotherapeutic protocol. Clinical Significance: The material with the HU value that is most compatible with the oral tissues does not interfere with the action of x-ray beams or with the main function of mechanically isolating the oral tissues, thus reducing the side effects from radiotherapy, improving the patient’s quality of life after the treatment.