title: Bacterial contamination of the fitting surfaces of restorations in teeth with pulp and periapical disease: a scanning electron microscopy study.
abstract: BACKGROUND
  The aim of this study was to evaluate the fitting surfaces of restorations in teeth with infected root canal systems and apical periodontitis to determine whether the restoration-tooth interface is a potential pathway for bacterial penetration.
  
  
  METHODS
  Thirty clinically satisfactory restorations were sectioned and removed from teeth that had infected root canal systems and apical periodontitis. In the control group, three clinically satisfactory restorations were sectioned and removed from extracted teeth with clinically healthy pulps. In order to confirm the clinical diagnosis of a healthy pulp, histological examination was performed. All restorations were placed in 10% formalin immediately and then prepared for examination using scanning electron microscopy. The degree of bacterial contamination on each restoration was recorded as low, moderate or high. The morphotypes observed were classified as cocci, filaments, rods or spirochaetes.
  
  
  RESULTS
  The fitting surfaces of all restorations in both experimental and control groups showed signs of bacterial contamination.
  
  
  CONCLUSIONS
  This study has demonstrated the presence of bacteria on the fitting surfaces of restorations that were judged to be clinically satisfactory in teeth with infected root canal systems. The restoration-tooth interface is a potential pathway for bacteria to enter teeth and infect the root canal systems.
authors.affiliation: School of Dentistry, The University of Western Australia, Nedlands, WA, Australia. stephen.kwang@uwa.edu.au
authors.forename: S
authors.initials: S
authors.lastname: Kwang
authors.forename: P V
authors.initials: PV
authors.lastname: Abbott
mesh_terms: D003786:Dental Pulp Cavity / Q000382:microbiology; D003788:Dental Pulp Diseases / Q000382:microbiology*; D003793:Dental Restoration, Permanent; D004866:Equipment Contamination; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010483:Periapical Diseases / Q000382:microbiology; D010485:Periapical Periodontitis / Q000382:microbiology*; D014070:Tooth / Q000382:microbiology; D019227:Tooth Apex / Q000382:microbiology