title: The influence of chlorhexidine on the antibacterial effects of MTA.
abstract: OBJECTIVE
  To investigate the influence of chlorhexidine in different concentrations when mixed with mineral trioxide aggregate gray (MTA-G) or white (MTA-W). The antibacterial effect on Enterococcus faecalis was used as the primary parameter.
  
  
  METHODS
  Similar to the agar diffusion test, Mueller-Hinton agar plates were inoculated with E faecalis (ATCC 19433), and 14 groups (n = 21) were prepared. The specimens consisted of MTA-W and MTA-G, and these were enriched with chlorhexidine concentrations of 0.1%, 0.2%, 0.5%, 1.0%, 1.5%, and 2.0%. Pure MTA-W and MTA-G (each combined with distilled water) were used as controls. After incubation periods of 24 and 48 hours, the inhibiting areolae were measured.
  
  
  RESULTS
  Pure MTA-W, in contrast to pure MTA-G, had no bactericidal effects. With increasing chlorhexidine concentrations of up to 1.5%, a linear increase in bactericidal activity was observed. In contrast, MTA-G showed only a low self-bactericidal influence, and the antibacterial effects with increasing chlorhexidine concentrations were significantly lower than those of MTA-W (P < .001).
  
  
  CONCLUSIONS
  When mixed with distilled water, pure MTA-G revealed a low bactericidal effect against E faecalis. The use of chlorhexidine with MTA mixtures leads to an antibacterial effect against E faecalis, and within the first 48 hours, this effect is significantly higher in combination with MTA-W when compared with MTA-G.
authors.affiliation: Department of Endodontics, Centre for Operative Dentistry and Periodontology, University of Dental Medicine and Oral Health, Danube Private Universtiy (DPU), Krems, Austria.
authors.forename: Sven-Georg
authors.initials: SG
authors.lastname: Mittag
authors.forename: Christof
authors.initials: C
authors.lastname: Eissner
authors.forename: Lutz
authors.initials: L
authors.lastname: Zabel
authors.forename: Karl-Thomas
authors.initials: KT
authors.lastname: Wrbas
authors.forename: Andrej M
authors.initials: AM
authors.lastname: Kielbassa
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology*; D017610:Calcium Compounds / Q000737:chemistry / Q000494:pharmacology*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology*; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects*; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology*; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000494:pharmacology*; D017640:Silicates / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D017607:Aluminum Compounds; D000891:Anti-Infective Agents, Local; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D002710:Chlorhexidine