Microbiologic changes following administration of locally delivered doxycycline in smokers: a 15-month follow-up

J Periodontol. 2007 Nov;78(11):2143-9. doi: 10.1902/jop.2007.070189.


Background: Additional clinical benefits have been reported with the use of locally delivered antimicrobials in the treatment of smokers; however, long-term changes in the subgingival microbiota following the use of these drugs in smokers have not been documented. The aim of this study was to evaluate long-term microbiologic changes following locally delivered doxycycline in the treatment of smokers.

Methods: Sixteen smokers with chronic periodontitis presenting a minimum of four pockets (probing depth>or=5 mm) were selected. Patients were assigned randomly to receive scaling and root planing (SRP) or SRP and local doxycycline (SRP-D). Patients were treated at baseline and 12 months. Subgingival plaque samples were collected at baseline; 3, 6, and 12 months; and 45 and 90 days following retreatment. Polymerase chain reaction and DNA-DNA hybridization analyses were performed to detect the presence of selected periodontal pathogens.

Results: The reduction in the number of sites positive for Porphyromonas gingivalis and Tannerella forsythia (previously T. forsythensis) was statistically significant for SRP-D at 3 months (68% and 41.3%, respectively) and for SRP at 6 months (75% and 52%, respectively) following treatment. The SRP group showed a greater frequency of P. gingivalis than the SRP-D group at 3 months (58% and 25%, respectively). There also was a greater reduction in the frequency of P. gingivalis at 3 months following retreatment with SRP-D compared to SRP (47% and 8%, respectively).

Conclusion: In smokers, adjunctive local doxycycline resulted in a greater reduction in the frequency of P. gingivalis following initial and supportive therapy compared to conventional treatment.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinomyces / drug effects
  • Actinomyces / isolation & purification
  • Adult
  • Anti-Bacterial Agents / administration & dosage*
  • Chronic Disease
  • DNA Probes
  • Dental Plaque / drug therapy*
  • Dental Plaque / microbiology
  • Dental Scaling
  • Doxycycline / administration & dosage*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Periodontitis / drug therapy*
  • Porphyromonas gingivalis / drug effects
  • Porphyromonas gingivalis / isolation & purification
  • Root Planing
  • Smoking*
  • Statistics, Nonparametric


  • Anti-Bacterial Agents
  • DNA Probes
  • Doxycycline