title: Evaluation ofEnterococcus faecalisadhesion, penetration, and method to prevent the penetration ofEnterococcus faecalisinto root cementum: Confocal laser scanning microscope and scanning electron microscope analysis.
abstract: OBJECTIVE
  To ascertain the role ofEnterococcus faecalisin persistent infection and a possible method to prevent the penetration ofE. faecalisinto root cementum.
  
  
  METHODS
  One hundred and twenty human single-rooted extracted teeth divided into five groups. Group I (control): intact teeth, Group II: no apical treatment done, Group III divided into two subgroups. In Groups IIIa and IIIb, root apex treated with lactic acid of acidic and neutral pH, respectively. Group IV: apical root cementum exposed to lactic acid and roughened to mimic the apical resorption. Group V: apical treatment done same as Group IV and root-end filling done using mineral trioxide aggregate (MTA). Apical one-third of all samples immersed inE. faecalisbroth for 8 weeks followed by bone morphogenetic protein and obturation and again immersed into broth for 8 weeks. Teeth split into two halves and observed under confocal laser scanning microscope and scanning electron microscope, organism identified by culture and polymerase chain reaction techniques.
  
  
  RESULTS
  Adhesion and penetration was observed in Group IIIa and Group IV. Only adhesion in Group II and IIIB and no adhesion and penetration in Group I and V.
  
  
  CONCLUSIONS
  Adhesion and penetration ofE. faecalisinto root cementum providing a long-term nidus for subsequent infection are the possible reason for persistent infection and root-end filling with MTA prevents the adhesion and penetration.
authors.affiliation: Department of Conservative and Endodontics, Al- Badar Rural Dental College and Hospital, Kalaburagi, Karnataka, India.
authors.forename: Rahul S
authors.initials: RS
authors.lastname: Halkai
authors.affiliation: Department of Conservative and Endodontics, A B Shetty Memorial Institute of Dental Sciences, NITTE University, Mangalore, Karnataka, India.
authors.forename: Mithra N
authors.initials: MN
authors.lastname: Hegde
authors.affiliation: Department of Conservative and Endodontics, HKES SN Institute of Dental Sciences and Research, Kalaburgi, Karnataka, India.
authors.forename: Kiran R
authors.initials: KR
authors.lastname: Halkai
keywords: Confocal laser scanning microscope; Enterococcus faecalis; mineral trioxide aggregate; persistent infection; polymerase chain reaction technique; root cementum; scanning electron microscope