title: In vivo evaluation of the effect of essential oil-containing oral strips on salivary bacteria using the checkerboard method.
abstract: OBJECTIVE
  The aim of this study was to evaluate the antimicrobial effect of essential oil-containing oral strips on different species of the oral microbiota.
  
  
  METHODS
  Saliva samples were collected from 20 subjects with good oral health, diluted and plated onto blood agar medium. The subjects were asked to place the strip (Listerine PocketPaks) on the tongue allowing it to dissolve. After 30 minutes, new saliva samples were collected again and the plates with the samples were incubated under anaerobic conditions at 37 degrees C for seven days. Colony counts (CFU/mL) were determined for each sample. The colonies on the plates were washed with 1 mL of TE buffer, and the bacterial suspensions were processed for the identification of 24 species by DNA probes and the Checkerboard DNA-DNA hybridization method. Differences in total counts, prevalence, and levels of the species evaluated before and after placement of the strips were determined by Wilcoxon sign rank and Chi-square tests.
  
  
  RESULTS
  A modest increase in the total bacterial number in saliva from 1.4 x 10(8) to 1.7 x 10(8) bacterial cells was observed 30 minutes after the strip placement, although this change was not significant (p = 0.632). Most of the species reduced in frequency and/or levels, including the pathogens A. actinomycetemcomitans, C. rectus, E. corrodens, Fusobacterium spp., P. intermedia, and S. noxia, as well as the beneficial species A. meyeri, A. georgia, A. gerencseriae, A. odontolyticus, and P. acnes after strip placement. In contrast, A. viscosus, P. melaninogenica, P. gingivalis, P. micros, Streptococcus spp., T. forsythensis, and V. parvula presented an increase in prevalence and/or levels. These changes were not statistically significant after adjusting for multiple comparisons (p > 0.0022).
  
  
  CONCLUSIONS
  The use of the essential oil-containing oral strips resulted in a short-term small increase in the total number of salivary microorganisms. In addition, a not significant decrease of certain periodontopathogens, and an increase in species compatible with oral health were observed.
authors.affiliation: Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. carinamacielsilva@yahoo.com.br
authors.forename: Carina Maciel
authors.initials: CM
authors.lastname: da Silva
authors.forename: Andréa Vieira
authors.initials: AV
authors.lastname: Colombo
authors.forename: Renata Martins
authors.initials: RM
authors.lastname: do Souto
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Colombo
mesh_terms: D000190:Actinomyces / Q000187:drug effects; D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D001419:Bacteria / Q000145:classification / Q000187:drug effects*; D001439:Bacteroides / Q000187:drug effects; D044883:Campylobacter rectus / Q000187:drug effects; D015169:Colony Count, Microbial; D004338:Drug Combinations; D016124:Eikenella corrodens / Q000187:drug effects; D005260:Female; D005673:Fusobacterium / Q000187:drug effects; D006801:Humans; D008297:Male; D009693:Nucleic Acid Hybridization; D009822:Oils, Volatile / Q000008:administration & dosage / Q000627:therapeutic use*; D016966:Porphyromonas gingivalis / Q000187:drug effects; D018720:Prevotella / Q000187:drug effects; D011425:Propionibacterium acnes / Q000187:drug effects; D012459:Salicylates / Q000008:administration & dosage / Q000627:therapeutic use; D012463:Saliva / Q000382:microbiology*; D020357:Selenomonas / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects; D013729:Terpenes / Q000008:administration & dosage / Q000627:therapeutic use; D014059:Tongue / Q000382:microbiology; D014678:Veillonella / Q000187:drug effects
chemical_list: D000891:Anti-Infective Agents, Local; D004338:Drug Combinations; D009822:Oils, Volatile; D012459:Salicylates; D013729:Terpenes; C057473:Listerine