title: Long-term sub-antimicrobial doxycycline (Periostat) as adjunctive management in adult periodontitis: effects on subgingival bacterial population dynamics.
abstract: Previous trials had indicated that various schedules of sub-antimicrobial doxycycline significantly reduced gingival crevicular fluid (GCF) collagenase activity in adult patients with periodontitis with no evidence of emergent tetracycline-resistant (Tcr) marker oral flora. The purpose of this nine-month study was to expand these observations, emphasizing newer microbial diagnostic methods. Subgingival paper point samples were obtained at baseline (BL), 3, 6, and 9 months. Four subject treatment groups in a double-blind design were evaluated by mechanical scaling and root planing (SRP) and/or 20 mg doxycycline BID (Periostat). Thirty-eight patients entered the study at baseline (BL). Dark-field microscopy on 260 samples showed that morphotype distribution was independent of treatment schedule. Culture analysis of the 3 most prevalent isolates recovered showed that Streptococcus and Prevotella species accounted for approximately 85% of the 724 cultures. There did not appear to be any overgrowth or replacement by opportunistic oral flora. Of 658 susceptibility patterns evaluated by Etest, the MIC50/90 and mode MIC showed stable patterns, independent of treatment group. Our findings were different from those of previously published reports, but may be partly explained by the lack of universally standardized methods in oral microbiology and interpretive criteria for susceptibility testing.
authors.affiliation: Department of Pathology, West Virginia University, Morgantown 26506-9203, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Thomas
authors.forename: R J
authors.initials: RJ
authors.lastname: Metheny
authors.forename: J M
authors.initials: JM
authors.lastname: Karakiozis
authors.forename: J M
authors.initials: JM
authors.lastname: Wetzel
authors.forename: R J
authors.initials: RJ
authors.lastname: Crout
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D003777:Dental Prophylaxis; D004311:Double-Blind Method; D004318:Doxycycline / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D017753:Ecosystem; D006089:Gram-Negative Anaerobic Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D010518:Periodontitis / Q000188:drug therapy* / Q000382:microbiology*; D015003:Yeasts / Q000187:drug effects