title: Propolis--based chitosan varnish: drug delivery, controlled release and antimicrobial activity against oral pathogen bacteria.
abstract: BACKGROUND
  Dental caries is the most prevalent oral disease in several Asian and Latin American countries. It is an infectious disease and different types of bacteria are involved in the process. Synthetic antimicrobials are used against this disease; however, many of these substances cause unwarranted undesirable effects like vomiting, diarrhea and tooth staining. Propolis, a resinous substance collected by honeybees, has been used to control the oral microbiota. So, the objective of this study was to develop and characterize sustained-release propolis-based chitosan varnish useful on dental cariogenic biofilm prevention, besides the in vitro antimicrobial activity.
  
  
  METHODS
  Three formulations of propolis - based chitosan varnish (PCV) containing different concentrations (5%, 10% and 15%) were produced by dissolution of propolis with chitosan on hydro-alcoholic vehicle. Bovine teeth were used for testing adhesion of coatings and to observe the controlled release of propolis associated with varnish. It was characterized by infrared spectroscopy, scanning electron microscopy, casting time, diffusion test in vitro antimicrobial activity and controlled release. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were tested for the main microorganisms involved in the cariogenic biofilm through the microdilution test in 96-well plates.
  
  
  RESULTS
  The formulations presented a tooth surface adherence and were able to form films very fast on bovine tooth surface. Also, propolis-based chitosan varnishes have shown antimicrobial activity similar to or better than chlorhexidine varnish against all oral pathogen bacteria. All microorganisms were sensitive to propolis varnish and chitosan. MIC and MBC for microorganisms of cariogenic biofilme showed better results than chlorhexidine. Propolis active components were released for more than one week.
  
  
  CONCLUSIONS
  All developed formulations turn them, 5%, 10% and 15% propolis content varnish, into products suitable for clinical application on dental caries prevention field, deserving clinical studies to confirm its in vivo activity.
authors.forename: Juçara R
authors.initials: JR
authors.lastname: Franca
authors.forename: Mariana P
authors.initials: MP
authors.lastname: De Luca
authors.forename: Tatiana G
authors.initials: TG
authors.lastname: Ribeiro
authors.forename: Rachel O
authors.initials: RO
authors.lastname: Castilho
authors.forename: Allyson N
authors.initials: AN
authors.lastname: Moreira
authors.affiliation: Department of Oral Clinical, Oral Pathology and Oral Surgery, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. vegneer2003@yahoo.com.br.
authors.forename: Vagner R
authors.initials: VR
authors.lastname: Santos
authors.forename: André A G
authors.initials: AA
authors.lastname: Faraco
mesh_terms: D000327:Adsorption; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D056705:Apitherapy; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001516:Bees; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D002710:Chlorhexidine / Q000494:pharmacology; D003692:Delayed-Action Preparations; D003731:Dental Caries / Q000382:microbiology* / Q000517:prevention & control; D006801:Humans; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000382:microbiology*; D010150:Paint; D011429:Propolis / Q000008:administration & dosage / Q000494:pharmacology*; D014070:Tooth
chemical_list: D000890:Anti-Infective Agents; D003692:Delayed-Action Preparations; D011429:Propolis; D048271:Chitosan; D002710:Chlorhexidine