We identified SLC7A7, BTK, CYTH4, BIN2, ITGAL, P2RX4, C4orf48, CMTM7, TPST2, RAC2, ARID3A, VOPP1, FUCA2 and CCDC88A as important crosstalk genes in periodontitis and atherosclerosis, three machine learning methods were used to build diagnostic models and evaluate the value of the 14 crosstalk genes for disease diagnosis. The gene discussed is RAC2; the disease is periodontitis.