Dear Editor,I read with great interest the article The transfer of hydrogen from inert gas to therapeutic gas by Li et al.1 in the Medical Gas Research. I would like to suggest certain updates to the above review article regarding hydrogen rich water in oral pathology with emphasis on recent studies done in 2017.23Hydrogen-rich water suppresses gingival oxidative stress and alveolar bone resorption in oral cavity2: The study was conducted in 344 male Fischer rats divided into three groups of six rats each with a control group fed om regular diet and drinking distilled water and two experimental groups fed a high-fat diet and drinking distilled water or hydrogen-rich water. Oxidative stress was assessed from 8-hydroxydeoxyguanosine and the bone mineral density of the alveolar bone was analyzed by micro-computerized tomography. Study group showed a higher gingival level of 8-hydroxydeoxyguanosine and a lower level of alveolar bone density compared to the control group. It was interfered that drinking hydrogen-rich water will suppress obesity, lower gingival level of 8-hydroxydeoxyguanosine and reduce alveolar bone resorption in rats on a high-fat diet.Hydrogen-rich water used for prevention or treatment of oxidative stress-related diseases in oral cavity3: The study was conducted to investigate protective effects of hydrogen-rich water against reactive oxygen species induced cellular harmful events and cell death in human gingival fibroblasts and three-dimensional gingival tissue equivalents. The study was an in vitro scratch assay, which showed hydrogen-rich water achieved cytoprotection from oxidative stress injury in human gingival fibroblasts in culture or three-dimensional tissue equivalents and wound-healing promotion, superadded with reactive oxygen species scavenging and relief from glutathione diminishment.