title: Inhibitory properties of Coffea canephora extract against oral bacteria and its effect on demineralisation of deciduous teeth.
abstract: OBJECTIVE
  The antibacterial activity of Coffea canephora extract was evaluated in vitro against Streptococcus mutans and Streptococcus sobrinus. The viability of planktonic cells was analysed by susceptibility tests (MIC and MBC) and time-kill assays. The effect of the extract on dental demineralisation was also investigated.
  
  
  METHODS
  Primary 1st molar fragments (n=24) were inoculated with a saliva pool and sustained in a multiple plaque growth system for 10 days to form biofilm. The biofilm was treated with light roasted C. canephora extract at 20%, Milli-Q water (negative control) and chlorhexidine (positive control) once a day, during a week. Blank controls comprised fragments without treatment. Biofilm pH was monitored in the last day of treatment. Changes in tooth mineralisation were assessed by cross-sectional microhardness (CSMH) test.
  
  
  RESULTS
  MIC and MBC for S. mutans were 7±2 mg/mL and 160±0 mg/mL, respectively, showing no activity for S. sobrinus. The extract produced a 4-log reduction in the number of colonies of S. mutans after 3-h treatment (p<0.05) with undiluted extract (20%) and MBC concentration (16%). There was no difference among negative/blank controls and coffee plaque pH. Differences between CSMH values of dental fragments subjected to the coffee extract and to chlorhexidine were not significant. At depths up to 30 μm from the enamel surface, coffee extract and chlorhexidine promoted higher CSMH values when compared to blank/negative controls (p<0.05).
  
  
  CONCLUSIONS
  Our data suggest that light roasted C. canephora extract is beneficial as an anticariogenic substance.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Brazil.
authors.forename: A G
authors.initials: AG
authors.lastname: Antonio
authors.forename: N L P
authors.initials: NL
authors.lastname: Iorio
authors.forename: V S S
authors.initials: VS
authors.lastname: Pierro
authors.forename: M S
authors.initials: MS
authors.lastname: Candreva
authors.forename: A
authors.initials: A
authors.lastname: Farah
authors.forename: K R N
authors.initials: KR
authors.lastname: dos Santos
authors.forename: L C
authors.initials: LC
authors.lastname: Maia
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D018441:Biofilms / Q000187:drug effects; D040503:Coffea / Q000737:chemistry; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D016986:Streptococcus sobrinus / Q000187:drug effects* / Q000254:growth & development; D017001:Tooth Demineralization / Q000517:prevention & control*; D014094:Tooth, Deciduous / Q000187:drug effects*
chemical_list: D010936:Plant Extracts