title: Leakage of food-borne Enterococcus faecalis through temporary fillings in a simulated oral environment.
abstract: OBJECTIVE
  To evaluate the hypothesis that food-borne viable Enterococcus faecalis cells could enter the root canal space via coronal leakage.
  
  
  METHODS
  In a simulated oral environment under mastication the capacity of a calcium sulphate-based temporary filling material (Cavit W) to prevent leakage of E. faecalis from a cheese through the endodontic access cavity into the pulp chamber was assessed. Standardized class I access cavities were prepared in human maxillary molars. These were filled with Cavit of either 2 or 4 mm thickness (n=16, each). Empty access cavities served as positive, teeth filled with a light-curing composite material acted as negative controls (n=8, each). A cheese containing viable E. faecalis cells was placed on the occlusal aspects of test and control teeth, which were subsequently subjected to 680 mastication loads per day for 1 week in a masticator device perfused with artificial saliva at 37 degrees C. Leakage of E. faecalis from the cheese into the pulp chamber was assessed by culture on a kanamycin aesculin azide agar and compared between groups using Fisher's exact test.
  
  
  RESULTS
  All of the positive controls showed pure growth of E. faecalis. In addition, one of the negative control teeth leaked. The 4 mm application of Cavit prevented leakage of E. faecalis significantly better than the corresponding 2 mm application: 1 of 16 specimens compared with 6 of 16 specimens had leakage, respectively (P<0.05).
  
  
  CONCLUSIONS
  The current results substantiate the suspicion that food-derived microbiota could enter the necrotic root canal system via microleakage.
authors: Department of Preventive Dentistry, Periodontology, and Cariology, University of Zürich Centre of Dental Medicine, Zürich, Switzerland.
authors: J
authors: J
authors: Kampfer
authors: T N
authors: TN
authors: Göhring
authors: T
authors: T
authors: Attin
authors: M
authors: M
authors: Zehnder
mesh_terms: D001732:Bite Force; D002611:Cheese / Q000382:microbiology; D003188:Composite Resins / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000382:microbiology*; D003786:Dental Pulp Cavity / Q000382:microbiology; D003794:Dental Restoration, Temporary; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D005516:Food Microbiology; D006801:Humans; D008409:Mastication / Q000502:physiology; D008422:Materials Testing; D008963:Molar / Q000382:microbiology; D009055:Mouth / Q000382:microbiology*; D018915:Root Canal Preparation / Q000379:methods; D012464:Saliva, Artificial / Q000737:chemistry; D013696:Temperature
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D012464:Saliva, Artificial; C041941:Cavit W