title: Experimental gingivitis: reproducibility of plaque accumulation and gingival inflammation parameters in selected populations during a repeat trial.
abstract: OBJECTIVE
  This study aimed to assess whether and to what extent the experimental gingivitis clinical parameters are reproducible within selected populations with different gingival inflammatory response (high or low) to plaque accumulation. In addition, the consistency in developing a high or low gingival inflammatory response within the selected populations was evaluated.
  
  
  METHODS
  Thirty-seven subjects previously identified as high (HR, n=20) or low responders (LR, n=17) during an experimental gingivitis trial (first trial) were enrolled in a "repeat" experimental gingivitis trial.
  
  
  RESULTS
  No significant differences in plaque accumulation parameters and bleeding index values were detected between first and repeat trial for the 37 participants. Gingival index was higher during the repeat trial but behaved consistently in terms of the temporal changes in the course of both trials in both populations. Of the 17 LR participants, 10 manifested low susceptibility to inflammation after repeat trial. Among the 20 HR, 10 manifested high susceptibility to inflammation after repeat trial.
  
  
  CONCLUSIONS
  These results indicate that our experimental gingivitis model is reproducible to some extent in selected populations. The high reproducibility of plaque and, to a lesser extent, of inflammation parameters under the employed controlled conditions could be a valuable tool in gingivitis research.
authors.affiliation: Research Center for the Study of Periodontal Diseases, University of Ferrara, Ferrara, Italy. l.trombelli@unife.it
authors.forename: Leonardo
authors.initials: L
authors.lastname: Trombelli
authors.forename: Roberto
authors.initials: R
authors.lastname: Farina
authors.forename: Luigi
authors.initials: L
authors.lastname: Minenna
authors.forename: Alberto
authors.initials: A
authors.lastname: Carrieri
authors.forename: Chiara
authors.initials: C
authors.lastname: Scapoli
authors.forename: Dimitris N
authors.initials: DN
authors.lastname: Tatakis
mesh_terms: D000704:Analysis of Variance; D003773:Dental Plaque / Q000150:complications*; D003774:Dental Plaque Index; D004198:Disease Susceptibility; D005260:Female; D005891:Gingivitis / Q000209:etiology* / Q000628:therapy*; D006801:Humans; D008297:Male; D009910:Oral Hygiene; D010512:Periodontal Index; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results; D012107:Research Design; D018709:Statistics, Nonparametric; D055815:Young Adult