title: Microbiological response of localized sites with recurrent periodontitis in maintenance patients treated with tetracycline fibers.
abstract: BACKGROUND
  Whether adjunctive tetracycline fibers can provide an additive effect to scaling and root planing in treating non-responsive sites in maintenance subjects is still controversial. Recolonization of the bacteria from untreated sites or from the extracrevicular region may explain the insignificant response to local therapy. The purpose of the present study was to evaluate the microbiological response of sites treated with tetracycline fibers combined with scaling and root planing.
  
  
  METHODS
  The study was conducted in a split-mouth design. Thirty patients on maintenance therapy having at least 2 non-adjacent sites in separate quadrants with probing depths between 4 to 8 mm with bleeding on probing, or aspartate aminotransferase enzyme levels > 800 microIU in the gingival crevicular fluid, were treated with scaling and root planing plus tetracycline fibers or with scaling and root planing only. Subgingival plaque samples were collected at baseline, and 1, 3, and 6 months following treatment. A. actino-mycetemcomitans, C. rectus, B. forsythus, E. corrodens, F. nucleatum, P. gingivalis, and P. intermedia were detected by culture, immunofluorescence, or PCR technique.
  
  
  RESULTS
  There was a reduction of total bacterial cell count, as well as of certain periodontal pathogens, following treatment. The prevalence of A. actinomycetemcomitans, B. forsythus, and P. gingivalis and the mean proportions of C. rectus, P. intermedia, F. nucleatum, and P. gingivalis decreased after therapy, but there was no statistically significant difference between the 2 treatment groups with respect to bacterial proportions or the number of positive sites. Besides, the pathogens could not be eliminated from the periodontal pocket, and recolonization of the pocket was noted at 3 months post-treatment.
  
  
  CONCLUSIONS
  Bacteria located within the cheek, tongue mucosa, saliva, or untreated sites may contribute to reinfection of the pockets and explain the insignificant response to local tetracycline therapy.
authors.affiliation: School of Dentistry, College of Medicine, National Taiwan University, Taipei. veronica@ha.mc.ntu.edu.tw
authors.forename: M Y
authors.initials: MY
authors.lastname: Wong
authors.forename: C L
authors.initials: CL
authors.lastname: Lu
authors.forename: C M
authors.initials: CM
authors.lastname: Liu
authors.forename: L T
authors.initials: LT
authors.lastname: Hou
mesh_terms: D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D001421:Bacteria, Anaerobic / Q000187:drug effects* / Q000302:isolation & purification; D001439:Bacteroides / Q000187:drug effects; D002167:Campylobacter / Q000187:drug effects; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology; D016124:Eikenella corrodens / Q000187:drug effects; D005260:Female; D016967:Fusobacterium nucleatum / Q000187:drug effects; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D015999:Multivariate Analysis; D010518:Periodontitis / Q000188:drug therapy* / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000187:drug effects; D018713:Prevotella intermedia / Q000187:drug effects; D055502:Secondary Prevention; D013752:Tetracycline / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D013752:Tetracycline