Site selection criteria for microbiological testing of periodontal microorganisms

MICROBIOLOGICAL TESTING IS BECOMING an adjunct to the diagnosis and monitoring of periodontal patients. However, choosing which sites and how many sites among the many available in most patients is difficult. A study of 22 periodontitis patients was undertaken to attempt to provide some guidelines to these issues. All mesiobuccal sites along with sites with 4 mm or greater probing depth were sampled with endodontic points and analyzed by DNA probes for P. gingivalis, P. intermedia, and A. actinomycetemcomitans. The data suggest that sites with the deepest probing depths and sites that bleed on probing were most likely to harbor these pathogenic species. Using these clinical criteria, an approximation of the number of sites required for sampling was suggested.