Availability of laboratory testing services for identification of periodontal pathogens in dental plaque

Microbiologic monitoring of key subgingival plaque organisms has been proposed to enhance management of some patients with destructive forms of periodontal disease. However, isolation and identification of many of these species is available only through selected microbiology laboratories possessing special expertise with periodontal microorganisms. The purpose of this study was to determine the availability of periodontal microbiology laboratory services in the U.S. and Canada that identify suspected periodontal pathogens for dentists in clinical practice. A survey questionnaire was mailed to all U.S. and Canadian dental schools. Six laboratories that process plaque samples for dentists in private clinical practice were identified. All of the testing services examine plaque specimens for Actinobacillus actinomycetemcomitans and Bacteroides gingivalis. Four of the laboratories used bacterial culturing to characterize a wide range of plaque species and to determine antibiotic sensitivity of isolates. Two other laboratories use indirect immunofluorescence microscopy or DNA probes to screen for three putative periodontal pathogens. All but one of the testing services analyze plaque samples that are collected by private practitioners in their offices and forwarded to the laboratory through next-day delivery services or regular mail. The availability of these adjunctive diagnostic services may enhance the ability of dentists in clinical practice to apply recent advances in knowledge on periodontal microbiology into routine preventive and therapeutic patient care.