Radiotherapy simulation methods used in laboratory studies of radiation damage to the dentition: a systematic review

Objective To investigate the radiation simulation methods used in vitro and ex vivo studies to assess the direct effects of radiation on dental microhardness, chemical, and biochemical alterations. Study Design Searches were performed in PubMed, Scopus, Embase, and grey literature. Preclinical studies that examined the effect of radiation on permanent teeth were included. We used the modified CONSORT checklist of items for reporting preclinical studies to assess the risk of bias. Results Thirty-two studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and 69 (±1) Gy in ex vivo studies. Twenty-two studies used five different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting, and 6 m-V was the energy most often used. Twenty studies used linear accelerators, and seven used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the most reported storage solution for the dental structure used. Conclusion The heterogeneity between radiation simulation methods used in the laboratory studies, such as radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used, limit the conclusion regarding the direct effect of radiation on dental microstructure changes. To investigate the radiation simulation methods used in vitro and ex vivo studies to assess the direct effects of radiation on dental microhardness, chemical, and biochemical alterations. Searches were performed in PubMed, Scopus, Embase, and grey literature. Preclinical studies that examined the effect of radiation on permanent teeth were included. We used the modified CONSORT checklist of items for reporting preclinical studies to assess the risk of bias. Thirty-two studies met the inclusion criteria. The average radiation dose of in vitro studies was 53 (±22) Gy and 69 (±1) Gy in ex vivo studies. Twenty-two studies used five different fractionation schemes. Twenty-two of the included studies did not report the radiotherapy modality of those reporting, and 6 m-V was the energy most often used. Twenty studies used linear accelerators, and seven used Cobalt-60 with the source-surface-distance of radiation ranging from 1.5 to 100 cm. Distilled water was the most reported storage solution for the dental structure used. The heterogeneity between radiation simulation methods used in the laboratory studies, such as radiation dose, radiotherapy modality, fractionation regime, and the storage solutions used, limit the conclusion regarding the direct effect of radiation on dental microstructure changes.