title: Possibilities of gutta-percha-centered infection in endodontically treated teeth: an in vitro study.
abstract: BACKGROUND
  Implanted biomaterials could provide surface for bacterial adherence and formation of biofilm, eventually leading to biomaterial-centered infections (BCIs). In this in vitro study, we examined the biofilm-forming capacity of Enterococcus faecalis on gutta-percha (GP) points under different nutrient status and surface conditioning with saliva and serum.
  
  
  METHODS
  GP points (n = 420) coated with different root canal sealers (Sealapex or Roth) were conditioned with saliva or serum for 2-, 4-, and 12-week intervals and subsequently were incubated with E. faecalis for 2 weeks under nutrient-rich and nutrient-deprived environments. The biofilm-forming capacity and the nature of biofilm formed on GP were assessed by using a viable cell assay and scanning electron microscopy (SEM).
  
  
  RESULTS
  E. faecalis produced biofilms on GP points (with and without root canal sealers) under both nutrient-rich and nutrient-deprived environments after conditioning with saliva or serum. SEM reflected that the biofilms formed under nutrient-rich conditions were regular, whereas the biofilms formed under nutrient-deprived conditions were irregular and scanty. Under nutrient-deprived conditions, longer conditioning periods in saliva or serum were required for bacterial adherence.
  
  
  CONCLUSIONS
  Under the conditions of this study, saliva and serum conditioning of GP points plays an important role in the biofilm formation under tough environmental conditions.
authors.affiliation: Discipline of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Saji
authors.initials: S
authors.lastname: George
authors.forename: Bettina
authors.initials: B
authors.lastname: Basrani
authors.forename: Anil
authors.initials: A
authors.lastname: Kishen
mesh_terms: D001422:Bacterial Adhesion; D001431:Bacteriological Techniques; D018441:Biofilms; D001769:Blood; D002126:Calcium Hydroxide / Q000737:chemistry; D015169:Colony Count, Microbial; D003470:Culture Media; D013293:Enterococcus faecalis / Q000254:growth & development / Q000502:physiology*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012459:Salicylates / Q000737:chemistry; D012463:Saliva; D013499:Surface Properties; D013997:Time Factors; D019553:Tooth, Nonvital / Q000382:microbiology*; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: D003470:Culture Media; D012387:Root Canal Filling Materials; D012459:Salicylates; D015035:Zinc Oxide-Eugenol Cement; C055601:Sealapex; C074935:Roth's 801 Sealer; D006171:Gutta-Percha; D002126:Calcium Hydroxide