The effect of therapeutic radiation on dental enamel and dentin: A systematic review

Objectives: The conventional radiotherapy protocol to treat head-and-neck cancer is usually followed by tooth-decay onset. Radiation impact on mineralized tooth structures is not well-understood. This systematic review aimed to collect the recorded effects of therapeutic radiation on tooth chemical, structural and mechanical properties, in relation with their means of investigation. Data: Systematic search (January 01 2012 - September 30 2021) terms were Radiotherapy, Radiation effects, Dental enamel, Dentin, Human and Radiotherapy NOT Laser. Sources: PubMed, DOSS and Embase databases were searched. Study selection: Selected studies compared dental enamel, coronal and root dentin properties before and after in vitro or in vivo irradiation up to 80 Gy. Results: The systematic search identified 353 different articles, with 28 satisfying inclusion criteria. Their reference lists provided two more. Twenty-two studies evaluated dental enamel evolution, nine assessed coronal dentin and eight concerned root dentin. Coronal and root dentin results indicate a major impact of the radiation on their organic matrix. Dental enamel's chemical properties are less modified. Enamel and root dentin's hardness are decreased by therapeutic radiation, but no consensus arises for coronal dentin. Conclusions: Our findings revealed some interesting information about enzymatic degradation mechanisms of dentin organic matrix and highlighted that dental hard-tissue characterization requires highly specific expertise in materials science. That scientific knowledge is necessary to design suitable protocols, adequately analyze the obtained data, and, thus, provide relevant conclusions. Clinical Significance statement: Better knowledge and understanding of the mechanisms involved in the degradation of enamel and dentin would enable development of new preventive and therapeutic methods for improved medical care of patients undergoing radiotherapy. (C) 2022 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Automated summary

This systematic review aims to summarize the effects of therapeutic radiation on tooth properties and emphasizes the need for expertise in materials science in dental hard-tissue characterization. The findings suggest a significant impact of radiation on the organic matrix of dentin, while the chemical properties of dental enamel are less modified. Better understanding of the degradation mechanisms of enamel and dentin would contribute to the development of new preventive and therapeutic methods for patients undergoing radiotherapy.