title: Efficacy of a mouthrinse based on hydroxyapatite to reduce initial bacterial colonisation in situ.
abstract: OBJECTIVE
  The present in situ - investigation aimed to specify the impact of pure hydroxyapatite microclusters on initial bioadhesion and bacterial colonization at the tooth surface.
  
  
  METHODS
  Pellicle formation was carried out in situ on bovine enamel slabs (9 subjects). After 1min of pellicle formation rinses with 8ml of hydroxyapatite (HA) microclusters (5%) in bidestilled water or chlorhexidine 0.2% were performed. As negative control no rinse was adopted. In situ biofilm formation was promoted by the intraoral slab exposure for 8h overnight. Afterwards initial bacterial adhesion was quantified by DAPI staining and bacterial viability was determined in vivo/in vitro by live/dead-staining (BacLight). SEM analysis evaluated the efficacy of the mouthrinse to accumulate hydroxyapatite microclusters at the specimens' surface and spit-out samples of the testsolution were investigated by TEM.
  
  
  RESULTS
  Compared to the control (2.36×106±2.01×106bacteria/cm2), significantly reduced amounts of adherent bacteria were detected on specimens rinsed with chlorhexidine 0.2% (8.73×104±1.37×105bacteria/cm2) and likewise after rinses with the hydroxyapatite testsolution (2.08×105±2.85×105bacteria/cm2, p<0.001). No demonstrable effect of HA-particles on Streptococcus mutans viability could be shown. SEM analysis confirmed the temporary adsorption of hydroxyapatite microclusters at the tooth surface. Adhesive interactions of HA-particles with oral bacteria were shown by TEM.
  
  
  CONCLUSIONS
  Hydroxyapatite microclusters reduced initial bacterial adhesion to enamel in situ considerably and could therefore sensibly supplement current approaches in dental prophylaxis.
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstr. 74, D-01307 Dresden, Germany. Electronic address: Anna.Kensche@uniklinikum-dresden.de.
authors.forename: A
authors.initials: A
authors.lastname: Kensche
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstr. 74, D-01307 Dresden, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Holder
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstr. 74, D-01307 Dresden, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Basche
authors.affiliation: Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital, Saarland University, Building 73, D-66421 Homburg/Saar, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Tahan
authors.affiliation: Clinic of Operative and Pediatric Dentistry, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstr. 74, D-01307 Dresden, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hannig
authors.affiliation: Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital, Saarland University, Building 73, D-66421 Homburg/Saar, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Hannig
mesh_terms: D000328:Adult; D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D002417:Cattle; D002710:Chlorhexidine / Q000494:pharmacology; D003743:Dental Enamel / Q000187:drug effects* / Q000382:microbiology; D044622:Dental Pellicle / Q000382:microbiology; D017886:Durapatite / Q000494:pharmacology*; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009067:Mouthwashes / Q000494:pharmacology*; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000187:drug effects
chemical_list: D009067:Mouthwashes; D017886:Durapatite; D002710:Chlorhexidine
keywords: Bacteria; Bioadhesion; Hydroxyapatite; Pellicle