title: Frequency of reactivity for Porphyromonas gingivalis and Prevotella spp. in supra- and subgingival plaques, and periodontal clinical parameters according to subject age.
abstract: BACKGROUND
  The present study was conducted to assess the association between selected clinical parameters and the distribution of Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Prevotella nigrescens (Pn), and Prevotella melaninogenica (Pm) in supra- and subgingival plaque samples measured by an immunoslot blot assay (IBA) using their monoclonal antibodies.
  
  
  METHODS
  Plaque samples from 299 patients aged 6 to 69 randomly chosen from a group of dental outpatients were examined. Plaque index, gingival index, and probing depths were evaluated according to the criteria of positive (cell number > or = 10(6)) or negative (<106) reactivity to the 4 different monoclonal antibodies.
  
  
  RESULTS
  An increase in probing depth in subjects exhibiting either a positive or negative reaction for the 4 test bacteria was associated with increasing age. Comparing bacteria-positive subgingival plaque samples to their corresponding bacteria-negative counterparts, we found an increased plaque index in children positive for any of the 4 bacteria; in addition, that for Pg and Pi was increased in subjects 40 to 49 years old. The gingival index increased with increasing amount of Pi and Pn, but not with Pg and Pm in those 20 to 29 years of age. The frequency of Pg reactivity in subgingival plaque was markedly enhanced in subjects older than 30 to 39 years of age, and was significantly higher than that in supragingival plaque. The frequency of Pi and Pn reactivity was significantly increased in adults aged 20 to 29 and plateaued at older ages. The frequency of Pm reactivity was relatively low and independent of subject age.
  
  
  CONCLUSIONS
  The increase in probing depth with increasing age was not affected by the occurrence of periodontopathic bacteria. The high rate of occurrence of Pg, together with Pi and Pn, in subgingival plaque of the adult age groups was suggested to be associated with the high frequency of periodontal disease in the older age groups (above 30 to 49 years of age). The IBA appears to be useful for the efficient and rapid detection of periodontopathic bacteria.
authors.affiliation: Department of Oral Diagnosis, Meikai University School of Dentistry, Saitama, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yukio
authors.initials: Y
authors.lastname: Murakami
authors.forename: Takako
authors.initials: T
authors.lastname: Ogiwara
authors.forename: Masao
authors.initials: M
authors.lastname: Shoji
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Seto
authors.forename: Masahumi
authors.initials: M
authors.lastname: Nagasaki
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Fujisawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D000911:Antibodies, Monoclonal; D016009:Chi-Square Distribution; D002648:Child; D015169:Colony Count, Microbial; D003773:Dental Plaque / Q000382:microbiology*; D003774:Dental Plaque Index; D005260:Female; D005881:Gingiva / Q000382:microbiology; D006801:Humans; D015151:Immunoblotting; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000302:isolation & purification*; D018720:Prevotella / Q000145:classification / Q000302:isolation & purification*; D018713:Prevotella intermedia / Q000302:isolation & purification; D001443:Prevotella melaninogenica / Q000302:isolation & purification
chemical_list: D000911:Antibodies, Monoclonal