Another closely related study involving peri-implant disease revealed no significant difference in the level of FGF23 in peri-implant sulcus fluid in healthy subjects and those with peri-implantitis [19]. Porphyromonas gingivalis (P. gingivalis), a major pathogen in adult periodontitis, is thought to be the cause of high FGF23 in periodontitis. This evidence concerns the gene FGF23 and periodontitis.