title: [Antibacterial effect of self-etching adhesive systems on Streptococcus mutans].
abstract: OBJECTIVE
  To investigate the antibacterial effect of different self-etching adhesive systems against Streptococcus mutans (S. mutans).
  
  
  METHODS
  Six reagents Clearfil(TM) SE Bond primer (SP), Clearfil(TM) SE Bond adhesive (SA),Clearfil(TM) Protect Bond primer (PP), which contained antibacterial monomer methacryloyloxydodecylpyridinium bromide (MDPB), ClearfilTM Protect Bond adhesive (PA), positive control chlorhexidine acetate [CHX, 1% (mass fraction)], and negative control phosphate buffer solution (PBS) were selected. They were mixed with S. mutans for 30 s respectively, then colony-forming units (CFU) were counted after incubated for 48 h on brain heart infusion (BHI) agar medium. The 6 reagents were applied to the sterile paper discs, and distributed onto the BHI agar medium with S. mutans and incubated for 24 h, then the inhibition zones were observed. CHX, PBS, PP, and SP were added on the dentin with artificial caries induced by S. mutans and kept for 30 s, then confocal laser scanning microscope (CLSM) was used to observe the live and dead bacteria after staining. The ratio of live to dead bacteria was calculated. PP+PA and SP+SA were applied on the dentin according to the manual and light cured. S. mutans were incubated on the samples for 2 h, ultrasonically treated and incubated on BHI agar medium for 48 h, then CFU was counted. The data were analyzed by non-parametric analysis and one-way ANOVA.
  
  
  RESULTS
  Compared with PBS, the PP, SP, PA, SA and CHX showed the antibacterial effect on free S. mutans (P<0.05); SP and PP showed stronger antibacterial effect than PA, SA and CHX (P<0.05). CHX, SP and PP presented inhibition zones, while PBS, SA and PA did not. Compared with PBS, the CHX, SP and PP could lower the ratio of the live to dead bacteria significantly (P<0.05). Cured self-etching adhesive systems did not show any antibacterial effect on the free S. mutans.
  
  
  CONCLUSIONS
  The primer of self-etching adhesives Clearfil(TM) SE Bond and Clearfil(TM) Protect Bond showed significant antibacterial effect on free and attached S. mutans. The adhesive only showed antibacterial effect on free S. mutans before light-cured polymerization. After being cured, the self-etching adhesive systems did not show antibacterial effect anymore.
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Chong-yang
authors.initials: CY
authors.lastname: Yuan
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Fu-cong
authors.initials: FC
authors.lastname: Tian
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xiao-yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xue-jun
authors.initials: XJ
authors.lastname: Gao
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003731:Dental Caries; D045662:Dental Etching; D003804:Dentin / Q000737:chemistry; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D011726:Pyridinium Compounds / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects*
chemical_list: D000269:Adhesives; D000900:Anti-Bacterial Agents; D017220:Dentin-Bonding Agents; D011726:Pyridinium Compounds; C089392:methacryloyloxydodecylpyridinium bromide