OBJECTIVES: The aim of this study was to determine the prevalence of the 
different fimA genotypes of Porphyromonas gingivalis in adult Spanish patients 
with chronic periodontitis, patients with gingivitis and periodontally healthy 
subjects, and the relationship between these genotypes and other 
periodontopathogenic bacteria.
STUDY DESIGN: Samples of subgingival plaque were taken from 86 patients (33 with 
chronic periodontitis, 16 with gingivitis, and 37 periodontally healthy) in the 
course of a full periodontal examination. PCR was employed to determine the 
presence of the 6 fimA genotypes of Porphyromonas gingivalis (I-V and Ib) and of 
Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema 
denticola.
RESULTS: Porphyromonas gingivalis fimA genotypes II and Ib were present in 
significantly higher percentages in periodontal patients (39.4% and 12.1% 
respectively) than in healthy or gingivitis subjects. The prevalence of 
Tannerella forsythia, Treponema denticola, and Porphyromonas gingivalis fimA 
genotype IV was significantly higher in the group that presented bleeding 
greater than 30%. A positive correlation was found between Porphyromonas 
gingivalis fimA genotype IV and Treponema denticola.
CONCLUSIONS: A strong association between Porphyromonas gingivalis fimA 
genotypes II and Ib and chronic periodontitis exists in the Spanish population. 
The most prevalent genotype in periodontal patients is II.