Use of technopolymer clasps in prostheses for patients due to have radiation therapy

Patients with large oral defects as a result of a maxillectomy procedure, who are due to have postoperative radiotherapy, need to have the density of the defect restored to ensure standardised radiation distribution. This is achieved with various types of boluses that often require tissue surface positioning stents to help support them. Traditional metal-clasp retained stents were discarded as the clasps caused backscatter of the radiation beams. A radiolucent material was needed to retain these prostheses. Dental D, an acetal resin was used in the fabrication of a positioning stent. It was assessed in terms of ease of manufacture, cost, fit, retention and radiolucency. The material was found to be more costly and time-consuming to manufacture than conventional metal-retained acrylic resin prostheses, but its radiolucency made it ideal for use in patients during radiotherapy treatment. Future studies will determine if the long-term strength of the material will allow the clasps to be used in a definitive prosthesis and thus help offset the initial time and costs.