Advance in study on 16S rRNA gene sequencing technology in oral microbial diversity.

The 16S rRNA gene is the most commonly used molecular marker for identifying microorganisms. It is used in sequencing technology, including the first-generation, the second-generation, and the third-generation sequencing technology. A large number of studies on the 16S rRNA gene have contributed to a deeper understanding of oral microbial diversity. In the healthy oral cavity, there is microbial diversity in time and space. With the occurrence or development of oral diseases such as caries, periodontal disease, or halitosis, the microbial diversity will be changed.