title: Antimicrobial effect of an oxazolidinone, lantibiotic and calcium hydroxide against Enterococcus faecalis biofilm: An in vitro study.
abstract: OBJECTIVE
  The aim was to evaluate and compare the antimicrobial efficacy of an oxazolidinone (linezolid [LZ]), lantibiotic (nisin), and calcium hydroxide against Enterococcus faecalis biofilm formed on tooth substrate after 2 and 7 days.
  
  
  METHODS
  Single rooted human mandibular premolars were decoronated, biomechanically prepared, and vertically sectioned along the midsagittal plane to obtain a standardized tooth substrate. Standardized suspension of E. faecalis and tooth substrate was incubated for 3 weeks to allow growth of biofilm. At the end of 3 weeks, the grouping was done according to the medicament used - Group I - LZ, Group II - nisin, Group III - calcium hydroxide, Group IV - negative treatment. Disk of the medicaments used were prepared and placed upon Petri dishes along with bacterial emulsion on Mueller-Hinton agar. The zones of inhibition were checked after 2 and 7 days.
  
  
  METHODS
  The scores were statistically analyzed using Tukey honest significant difference test and one-way analysis of variance.
  
  
  RESULTS
  Zone of inhibition obtained with LZ was widest followed by nisin and calcium hydroxide after a period of 2 days (P < 0.001). The size of the zone of inhibition remain unchanged for LZ and nisin group after 7 days (P > 0.001) unlike calcium hydroxide group where the zone decreased (P < 0.001).
  
  
  CONCLUSIONS
  LZ showed maximum antimicrobial potential against E. faecalis biofilm followed by nisin and calcium hydroxide after 2 and 7 days. The antimicrobial effect of LZ and nisin was not affected with the lapse of time, but that of calcium hydroxide significantly decreased.
authors.affiliation: Department of Conservative Dentistry and Endodontics, I.T.S-C.D.S.R, Ghaziabad, Uttar Pradesh, India.
authors.forename: Sonali
authors.initials: S
authors.lastname: Taneja
authors.affiliation: Department of Conservative Dentistry and Endodontics, I.T.S-C.D.S.R, Ghaziabad, Uttar Pradesh, India.
authors.forename: Pragya
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Conservative Dentistry and Endodontics, I.T.S-C.D.S.R, Ghaziabad, Uttar Pradesh, India.
authors.forename: Komal
authors.initials: K
authors.lastname: Malhotra
authors.affiliation: Department of Conservative Dentistry and Endodontics, Gian Sagar Dental College and Hospital, Patiala, Punjab, India.
authors.forename: Jaidev
authors.initials: J
authors.lastname: Dhillon
keywords: Biofilm; Enterococcus faecalis; linezolid; nisin