Microbial profile of ligature-induced periodontitis in rats

Objective: The aim of this study was to evaluate the composition of the biofilm accumulated around ligatures in rats by checkerboard DNA-DNA hybridization using probes made from human oral bacterial species. Methods: 12 Wistar rats were selected for this study. One of the mandibular first molars of each animal received a ligature, while the contralateral tooth was left unligated to be used as a control. Forty-two days later, the ligatures and one sample of biofilm from each unligated teeth were analyzed by checkerboard DNA-DNA hybridization for 40 human periodontal species. The area of bone loss in the furcation area was determined histometrically. Results: The unligated teeth did not present any of the bacterial species tested. Twenty five species were detected in the ligatures. Streptococcus- and Actinomyces-like species were found in high mean counts, followed by Fusobacterium-, Prevotella nigrescens- and Parvimonas micra-like species and Porphyromonas gingivalis- and Aggregatibacter actinomycetemcomitans-like species. Greater bone loss was observed in the furcation area of the ligated than of the unligated group (p < 0.0001). Conclusion: At 42 days, the ligature biofilm in rats presents various bacterial species that hybridize to probes of periodontal bacterial species commonly observed in human. (C) 2009 Elsevier Ltd. All rights reserved.