Persistence of extracrevicular bacterial reservoirs after treatment of aggressive periodontitis.
BACKGROUND
The purpose of this study was to test the hypothesis that periodontal pathogens associated with aggressive periodontitis persist in extracrevicular locations following scaling and root planing, systemic antibiotics, and antimicrobial rinses.


METHODS
Eighteen patients with aggressive periodontitis received a clinical examination during which samples of subgingival plaque and buccal epithelial cells were obtained. Treatment consisted of full-mouth root planing, systemic antibiotics, and chlorhexidine rinses. Clinical measurements and sampling were repeated at 3 and 6 months. Quantitative polymerase chain reaction determined the number of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia (previously T. forsythensis), and Treponema denticola in the plaque. Fluorescence in situ hybridization and confocal microscopy determined the extent of intracellular invasion in epithelial cells.


RESULTS
Clinical measurements improved significantly following treatment. All bacterial species except P. gingivalis were significantly reduced in plaque between baseline and 3 months. However, all species showed a trend to repopulate between 3 and 6 months. This increase was statistically significant for log T. denticola counts. All species were detected intracellularly. The percentage of cells infected intracellularly was not affected by therapy.


CONCLUSIONS
The 6-month increasing trend in the levels of plaque bacteria suggests that subgingival recolonization was occurring. Because the presence of these species within epithelial cells was not altered after treatment, it is plausible that recolonization may occur from the oral mucosa. Systemic antibiotics and topical chlorhexidine did not reduce the percentage of invaded epithelial cells. These data support the hypothesis that extracrevicular reservoirs of bacteria exist, which might contribute to recurrent or refractory disease in some patients.
Johnson
Jason D
JD
Department of Developmental and Surgical Sciences, Division of Periodontology, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA.
Chen
Ruoqiong
R
Lenton
Patricia A
PA
Zhang
Guizhen
G
Hinrichs
James E
JE
Rudney
Joel D
JD
D000293:Adolescent; D000328:Adult; D000368:Aged; D016976:Aggregatibacter actinomycetemcomitans / Q000254:growth & development; D010520:Aggressive Periodontitis / Q000382:microbiology* / Q000628:therapy; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D001439:Bacteroides / Q000254:growth & development; D002710:Chlorhexidine / Q000627:therapeutic use; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology; D004847:Epithelial Cells / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006090:Gram-Negative Bacteria / Q000254:growth & development*; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008875:Middle Aged; D009061:Mouth Mucosa / Q000382:microbiology*; D009067:Mouthwashes / Q000627:therapeutic use; D016966:Porphyromonas gingivalis / Q000254:growth & development; D018713:Prevotella intermedia / Q000254:growth & development; D016745:Root Planing; D048373:Treponema denticola / Q000254:growth & development; D055815:Young Adult
D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D009067:Mouthwashes; D008795:Metronidazole; D000658:Amoxicillin; D002710:Chlorhexidine