title: Viability of intratubular bacteria after chemomechanical caries removal.
abstract: BACKGROUND
  The aim of this study was to assess the effect on bacterial viability within dentinal tubules after the application of sodium hypochlorite (NaOCl)- or enzyme-based chemomechanical caries removal agents.
  
  
  METHODS
  Twenty-five caries-free dentin discs prepared from 25 sound maxillary premolars were used. The discs were then infected with Streptococcus mutans suspension and randomly divided into the following 6 groups according to the dentin treatments: the negative control group: noninfected sound dentin discs, the positive control group: infected discs were left untreated; the NaOCl group: treated with 5% NaOCl solution, the chlorhexidine (CHX) group: 2% CHX solution, the Carisolv group: Carisolv gel (Medi Team Dentalutveckling AB, Savedalen, Sweden), and the Papacarie group: Papacarie gel (Formula & Acao, São Paulo, Brazil). All the agents were applied for 5 minutes. The dentin discs were fractured into 2 halves and stained with fluorescent LIVE/DEAD Stain (Molecular Probes, Eugene, OR). Each specimen was observed using confocal laser scanning microscopy at 5 different randomly selected sites.
  
  
  RESULTS
  The results of 1-way analysis of variance revealed that 5% NaOCl solution achieved the highest intratubular antibacterial effect, whereas Carisolv gel had the lowest antibacterial effect (P < .05). No significant difference in antibacterial effect was observed between the Papacarie gel and 2% CHX solution (P > .05).
  
  
  CONCLUSIONS
  The enzyme-based chemomechanical caries removal (Papacarie) was effective in the reduction of residual cariogenic bacteria in the dentinal tubules of coronal dentin.
authors.affiliation: Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Hamdi H
authors.initials: HH
authors.lastname: Hamama
authors.affiliation: Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China. Electronic address: ckyyiu@hkucc.hku.hk.
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Yiu
authors.affiliation: Department of Oral Diagnosis and Polyclinics, Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Burrow
mesh_terms: D002710:Chlorhexidine / Q000627:therapeutic use; D003731:Dental Caries / Q000382:microbiology* / Q000628:therapy; D003737:Dental Cavity Preparation / Q000379:methods*; D019551:Dental Disinfectants / Q000627:therapeutic use; D003804:Dentin / Q000382:microbiology*; D005456:Fluorescent Dyes; D005782:Gels; D018698:Glutamic Acid / Q000627:therapeutic use; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007930:Leucine / Q000627:therapeutic use; D008239:Lysine / Q000627:therapeutic use; D008422:Materials Testing; D050296:Microbial Viability / Q000187:drug effects*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010206:Papain / Q000627:therapeutic use; D011897:Random Allocation; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013295:Streptococcus mutans / Q000187:drug effects*; D013997:Time Factors
chemical_list: C119934:Carisolv; D019551:Dental Disinfectants; D005456:Fluorescent Dyes; D005782:Gels; C509557:Papacarie; D018698:Glutamic Acid; D012973:Sodium Hypochlorite; D010206:Papain; D007930:Leucine; D008239:Lysine; D002710:Chlorhexidine
keywords: Carisolv; Papacarie; Streptococcus mutans; chemomechanical caries removal; confocal laser microscopy