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 Original Research Articlecharacteristics 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.

Assessment of mouth opening before and after head and neck radiotherapy in patients with intraoral stents

“…Typically, only two consultations are required: one to determine the size of the mandible and maxilla and the other to build the anterior abutments [ 7 , 9 ]. Acrylic resin is considered the ideal material for manufacturing this device because it is a non-toxic, durable, and low-cost substance that does not interact with radiation [ 7 , 30 ]. Hence, acrylic resin was the dental material selected in this study.…”

Protective and positioning devices in maxillofacial prosthodontics and radiotherapy: Overview

“…Four materials were selected: Polyacetal (white and black), polymethylmethacrylate (PMMA) polyurethane, and polyvinyl chloride (PVC). The study concluded that PMMA showed the ideal density for making these protective stents [30] .…”

“…The elementary material of the intraoral stents should not irritate the oral mucosa. It should be non-toxic, inert, thermo-mechanically resistant, and easy to handle [30] .…”

Avaliação do PETG como material para imobilizadores utilizados em radioterapia para cabeça e pescoço

“…Most of intraoral prosthesis for radiotherapy are made of polymethylmethacrylate (PMMA), an acrylic resin used for laboratory techniques for dental prosthesis, presenting an atomic number close to that of the water, with excellent structural resistance [11][12][13][14][15]. Some authors have already described the use of thermoplastics to produce such devices, as ethylene vinyl acetate [16,17], polyester [18] and polyethylene terephthalate (PET) [19,20].…”