I was fairly disappointed when Oragenics abandoned their modified streptococcus treatment, designed to replace the most harmful bacteria in the human mouth with a non-damaging one.
Last I heard, the few people who had tried the treatment are still completely free of decay and gum issues, but it's been a long time and there's no follow up, sadly.
https://www.oragenics.com/technology-pipeline/lbp/smart
Last I heard, the few people who had tried the treatment are still completely free of decay and gum issues, but it's been a long time and there's no follow up, sadly.