Magnesium oxide (MgO) nanoparticles' biocompatibility and degraded by-products are the two most important factors that make this material preferable in dental care. Their specific characteristics, such as antibacterial action against cariogenic microbes, are potential antibacterial agents for dental applications. This paper investigates the properties of MgO in dentistry and sets the groundwork for future research. Electronic databases, including PubMed/Medline, Scopus, Google Scholar, and scientific-research journals of domestic universities were reviewed from 1972 to 2022, and all the relevant papers were surveyed. After a search in electronic databases, 60 articles were involved, and the needed details were extracted. The biochemical features and application of magnesium oxide nanoparticles (MgONPs) in dentistry and new fields have been discussed in detail. Nanoparticles (NPs) may provide a unique method for treating and preventing dental infections. MgO nanoparticles are a good choice in several fields because their unique properties, such as antibacterial activity against cariogenic microorganisms, make them ideal antibacterial agents for dental applications.