title: [Antibacterial effects of a dental adhesive incorporating a quaternary ammonium monomer against Streptococcus mutans].
abstract: OBJECTIVE
  To incorporate an antibacterial monomer, methacryloxylethyl cetyl dimethyl ammonium chloride(DMAE-CB), into a dental adhesive, and to evaluate the antibacterial activity against Streptococcus mutans (Sm) of this DMAE-CB-incorporated adhesive after being cured.
  
  
  METHODS
  DMAE-CB was incorporated into a dimethacrylates-based dental adhesive as experimental group. The adhesive without DMAE-CB served as a negative control. Thirty-nine specimens were fabricated for each group. The effects of the cured adhesives on the growth and adherence of Sm were evaluated with growth inhibition assay and spectrophotometry respectively. The influence of aging treatment and saliva treatment on the antibacterial efficiency of the modified adhesive was evaluated. Moreover, the bacterial growth of Sm in the eluents of two different adhesives was examined.
  
  
  RESULTS
  Compared with negative control, the cured DMAE-CB-incorporated dental adhesive exhibited inhibitory effect on the growth and adherence of Sm. The inhibition rate was 99% and the absorbance value was (0.332 +/- 0.063) for experimental group, significantly lower than that of negative control (0.434 +/- 0.093, P = 0.021). Moreover, after aging treatment the DMAE-CB-incorporated adhesive could still inhibit the growth and adherence of Sm; the inhibition rate was 99%, and the absorbance value of experimental group was (0.372 +/- 0.062), significantly lower than that of negative control (0.455 +/- 0.066, P = 0.022). After saliva treatment the DMAE-CB-incorporated adhesive could still inhibit the growth and adherence of Sm; the inhibition rate was 90%, and the absorbance value of experimental group was (0.299 +/- 0.061), significantly lower than that of negative control (0.370 +/- 0.068, P = 0.045). However, the eluent of DMAE-CB-incorporated adhesive didn't show inhibitory effect on the growth of Sm when compared with negative control, and the antibacterial effect and the doubling time of experimental group [(130.5 +/- 8.4) min] had no statistical difference than negative control [(126.4 +/- 7.0) min, P = 0.298].
  
  
  CONCLUSIONS
  The incorporation of DMAE-CB can render the dental adhesive with antibacterial activity after polymerization via influencing the growth and adherence of Sm.
authors.affiliation: Department of Prosthodontics, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Ji-hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Sai
authors.initials: S
authors.lastname: Ma
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Yu-hong
authors.initials: YH
authors.lastname: Xiao
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
mesh_terms: D064751:Ammonium Compounds / Q000494:pharmacology*; D017220:Dentin-Bonding Agents / Q000494:pharmacology*; D013295:Streptococcus mutans / Q000187:drug effects*
chemical_list: D064751:Ammonium Compounds; D017220:Dentin-Bonding Agents