Evaluation of the Effectiveness of Polyether Silicone-based and Polyvinyl Siloxane Dental Impression Materials for Shielding Scattered Radiation During Radiotherapy

Objective: Radiation-induced oral mucositis is a major problem associated with radiotherapy. This study aimed to investigate the effectiveness of polyether silicone-based (PE) and polyvinyl siloxane (PVS) impression materials in protecting adjacent tissues from radiation scattered from dental materials.Materials and Methods: Amalgam, zirconium, and titanium dental material specimens were covered with 5 mm PE and PVS in the study group. The dental materials were placed in a linear accelerator device at a distance of 100 cm from the radiation source and coincided with a field size of 15x15 mm. Samples placed perpendicular to the central beam were irradiated with 6 MV photons at a fractional daily therapeutic radiation dose of 2 Gy. Thermoluminescent dosimeters (TLD-100) placed 90 degrees lateral to the specimens were used to record the scattered dose data. In the control group, uncovered dental materials were irradiated, and scattered doses were measured by TLD. The TLD data of the study and control groups were compared by independent t-test to analyze the shielding effect of PE and PVS. In addition, the photon stopper properties of PE and PVS were compared. The photon interaction parameters and effective atomic numbers of dental materials were calculated.Results: It was calculated that the PE and PVS significantly prevent the dose enhancement caused by dental materials (p<0.05). There was no difference between impression materials in the photon-stopping properties (p>0.05).Conclusion: PE and PVS can be used as scatter dose shields for the 2 Gy daily fractional dose. This study demonstrates the radiation-shielding properties of PE for the first time.