title: RT-PCR quantification of periodontal pathogens in crack users and non-users.
abstract: OBJECTIVE
  To compare counts of Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis and Fusobacterium nucleatum between crack users and non-users.
  
  
  METHODS
  A cross-sectional study was conducted involving seventy-four crack cocaine users and eighty-one non-users matched for age, gender and tobacco use. Demographic and clinical variables were analysed. Subgingival bacterial samples were collected from four sites with the greatest probing depths and were analysed using real-time polymerase chain reaction.
  
  
  RESULTS
  No significant difference was found in the prevalence of total counts for each bacterial species analysed between groups. However, crack users had a 1.85 (95% CI: 1.03-3.31), 2.19 (95% CI 1.24-3.88), 2.53 (95% CI 1.27-5.04) and 2.40 (95% CI 1.22-4.75) greater probability of having the higher counts (≥75th percentile) for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum, respectively.
  
  
  CONCLUSIONS
  Although some crack users had higher (>75th percentile) bacterial counts for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum, total counts did not differ between crack users and non-users, leading to the hypothesis that the higher occurrence of periodontitis on crack users may be related to other non-bacterial factors.
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Santa Maria, Santa Maria, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Casarin
authors.affiliation: Dentistry Course, Franciscan University Center, Santa Maria, Brazil.
authors.forename: R P
authors.initials: RP
authors.lastname: Antoniazzi
authors.affiliation: Postgraduate Program in Biochemistry and Bioprospecting, Center of Chemistry, Pharmaceutical and Food Science, Federal University of Pelotas (UFPel), Pelotas, Rio Grande do Sul, Brazil.
authors.forename: R A
authors.initials: RA
authors.lastname: Vaucher
authors.affiliation: Postgraduate Program in Dentistry, Lutheran University of Brazil, Canoas, Brazil.
authors.forename: C A
authors.initials: CA
authors.lastname: Feldens
authors.affiliation: Postgraduate Program in Dentistry, Federal University of Santa Maria, Santa Maria, Brazil.
authors.forename: F B
authors.initials: FB
authors.lastname: Zanatta
mesh_terms: D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans; D016022:Case-Control Studies; D019970:Cocaine-Related Disorders / Q000453:epidemiology* / Q000382:microbiology*; D016578:Crack Cocaine; D003430:Cross-Sectional Studies; D005260:Female; D016967:Fusobacterium nucleatum; D006801:Humans; D008297:Male; D010518:Periodontitis / Q000453:epidemiology*; D010519:Periodontium / Q000382:microbiology*; D016966:Porphyromonas gingivalis; D015995:Prevalence; D018713:Prevotella intermedia; D055815:Young Adult
chemical_list: D016578:Crack Cocaine
keywords: Real-time Polymerase Chain Reaction; cocaine/crack; drug users; microorganisms; periodontitis