A study on a dental device for the prevention of mucosal dose enhancement caused by backscatter radiation from dental alloy during external beam radiotherapy

Abstract

The changes in dose distribution caused by backscatter radiation from a common commercial dental alloy (Au–Ag–Pd dental alloy; DA) were investigated to identify the optimal material and thicknesses of a dental device (DD) for effective prevention of mucositis. To this end, 1 cm3 of DA was irradiated with a 6-MV X-ray beam (100 MU) in a field size of 10 × 10 cm2 using a Novalis TX linear accelerator. Ethylene vinyl acetate copolymer, polyolefin elastomer, and polyethylene terephthalate (PET) were selected as DD materials. The depth dose along the central axis was determined with respect to the presence/absence of DA and DDs at thicknesses of 1–10 mm using a parallel-plate ionization chamber. The dose in the absence of DDs showed the lowest value at a distance of 5 mm from the DA surface and gradually increased with distance between the measurement point and the DA surface for distances of ≥5 mm. Except for PET, no significant difference between the DA dose curves for the presence and absence of DDs was observed. In the dose curve, PET showed a slightly higher dose for DA with DD than for DA without DD for thicknesses of ≥4 mm. The findings herein suggest that the optimal DD material for preventing local dose enhancement of the mucosa caused by DA backscatter radiation should have a relatively low atomic number and physical density and that optimal DD thickness should be chosen considering backscatter radiation and percentage depth dose.

Utility of intraoral stents in external beam radiotherapy for head and neck cancer

“…6,7 Additionally, the use of intraoral stents can reduce the effects of dental alloys in radiotherapy. [12][13][14][15] In dental therapy, intraoral stents are used in various situations including sports, anesthesia, treatment of sleep disorders, and orthodontic treatment. [16][17][18][19] These intraoral devices are often convenient enough for daily use.…”

“…[12][13][14][15] In dental therapy, intraoral stents are used in various situations including sports, anesthesia, treatment of sleep disorders, and orthodontic treatment. [16][17][18][19] These intraoral devices are often convenient enough for daily use. However, they have been less utilized for modern radiotherapy purposes, including for IMRT using IGRT with CBCT, despite their ease of use.…”

How to improve root canal filling in teeth subjected to radiation therapy for cancer

“…11,14 Furthermore, water is a major constituent of human tissue, thus the use of distilled water during radiation therapy can physically and chemically simulate the surrounding soft tissues by formation of free radicals. 11 Teeth with amalgam restorations were excluded since, when in contact with irradiation, these restorations can increase the amount of secondary radiation, 11,22 which could hamper the control of variables and the standardization of results. 11 In this study, regardless of the final irrigation solution and root third, irradiated teeth had lower bond strength than non-irradiated ones, which is probably associated with changes in the dentin ultrastructure such as obliteration of dentinal tubules, 14,23 alterations in the intertubular, peritubular, and intratubular dentin, 14 and with the fragmentation of the network of collagen fibers of the dentinal tissue and its deproteinization.…”

A custom-made mouthpiece incorporating tongue depressors and elevators to reduce radiation-induced tongue mucositis during carbon-ion radiation therapy for head and neck cancer

“…Mouthpieces made from EVA are widely used in radiation therapy, and their characteristics are well understood. 7 The EVA splint includes the residual teeth as a means to anchor the device. Next, it is necessary to establish a fixed-bite position for treatment.…”