title: Prevention of bacterial leakage through instrumented root canals by bioactive glass S53P4 and calcium hydroxide suspensions in vitro.
abstract: OBJECTIVE
  The capacities of bioactive glass S53P4 and calcium hydroxide suspensions to prevent microbial leakage through instrumented root canals were compared.
  
  
  METHODS
  Root canals of caries-free extracted human mandibular premolars were instrumented and randomly filled with calcium hydroxide or S53P4 (n = 14 each). Crowns were exposed to Enterococcus faecalis ATCC 29212 suspensions in a test setup with 2 broth chambers, and leakage was checked daily. Event times were compared using log rank test. After 50 days, teeth were fractured and inspected in a scanning electron microscope (SEM).
  
  
  RESULTS
  Calcium hydroxide prevented leakage significantly better than S53P4 (P < .05). Estimated mean days to leakage were 26 for calcium hydroxide and 4 days for S53P4. The SEM observations revealed substantial calcification of the glass material in the root canal but also gaps containing clusters of coccoidal bacteria.
  
  
  CONCLUSIONS
  The bioactive glass material under investigation could not prevent contamination of instrumented root canals.
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cardiology, University of Zürich, Zürich, Switzerland. matthias.zehnder@zzmk.unizh.ch <matthias.zehnder@zzmk.unizh.ch>
authors.forename: Matthias
authors.initials: M
authors.lastname: Zehnder
authors.forename: Gerhard
authors.initials: G
authors.lastname: Baumgartner
authors.forename: Klaus
authors.initials: K
authors.lastname: Marquardt
authors.forename: Frank
authors.initials: F
authors.lastname: Paqué
mesh_terms: D001641:Bicuspid; D002126:Calcium Hydroxide; D015169:Colony Count, Microbial; D003763:Dental Leakage / Q000382:microbiology / Q000517:prevention & control*; D003786:Dental Pulp Cavity / Q000382:microbiology; D013293:Enterococcus faecalis; D005898:Glass; D006801:Humans; D053208:Kaplan-Meier Estimate; D008855:Microscopy, Electron, Scanning; D016016:Proportional Hazards Models; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000379:methods*
chemical_list: D012387:Root Canal Filling Materials; C403922:bioactive glass S53P4; D002126:Calcium Hydroxide