To evaluate and compare lactobacilli species (LB) and mutans streptococci (MS) caries risk identification by means of a Caries Risk Test Bacteria (CRT Bacteria test), with a conventional laboratory test (CLT), as well as their correlation with the dental caries experience [(decayed-missing-filled teeth (DMFT index)] in subjects 60 years of age and older. Cross-sectional study. Epidemiologic and Health Service Research Unit, Aging Area. XXI Century National Medical Center; Mexican Institute of Social Security (IMSS). A total of 696 elderly subjects residing in southwestern Mexico City. The DMFT index was determined in 696 subjects and saliva collected by stimulation. This was processed with a CRT Bacteria test and a CLT (the gold standard) test. Subjects with high [> or =10(5) colony forming units (CFU)/ml] and low caries risk (