title: In vitro scanning electron microscopic study on the effect of doxycycline and vancomycin on enterococcal induced biofilm.
abstract: BACKGROUND
  Enterococcus (E) faecalis bacteria adhere to dentine of teeth root canals to form the biofilm. E. faecalis has been shown to be resistant to antibiotics. This in vitro study aimed to investigate the efficacy of vancomycin and doxycycline in inhibiting E. faecalis biofilm formation.
  
  
  METHODS
  A total of 60 extracted human teeth were incubated with E. faecalis (ATCC 35550 strain) for 45 days to allow biofilm formation. The teeth were equally divided into six groups (n=10): 1) positive control, 2) negative control, 3) doxycycline alone 4) doxycycline with filing, 5) vancomycin alone, 6) vancomycin with filing. The relevant canals were irrigated with 4µg/mL of either vancomycin or doxycycline antibiotic. Teeth were processed for scanning electron microscopy (SEM). Areas of biofilm remaining in the canals after antibiotic treatment were measured with Scion image analysis software using the SEM images.
  
  
  RESULTS
  Vancomycin is more effective in reducing the overall biofilm area compared with doxycycline; moreover filing after antibiotic administration increased this effect.
  
  
  CONCLUSIONS
  We can conclude that vancomycin had greater efficacy than doxycycline for inhibiting and reducing E. faecalis biofilms growth in root canals. However, it failed to completely eliminate biofilm formation.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Krishnaraj
authors.initials: K
authors.lastname: Somayaji
authors.forename: Shashi Rashmi
authors.initials: SR
authors.lastname: Acharya
authors.forename: Indira
authors.initials: I
authors.lastname: Bairy
authors.forename: Peralam Yegneswaran
authors.initials: PY
authors.lastname: Prakash
authors.forename: Muddanna Sakkattu
authors.initials: MS
authors.lastname: Rao
authors.forename: Nidambur Vasudev
authors.initials: NV
authors.lastname: Ballal
keywords: Biofilm; Doxycycline; Enterococcus faecalis; Root canal; Vancomycin