title: Preliminary evaluation of a novel polymer nanocomposite as a root-end filling material.
abstract: OBJECTIVE
  To evaluate two nanoparticle-enhanced polymer root-end filling materials (NERP1 and NERP2) on the initial apical seal as compared to a polymer-based commercial compomer.
  
  
  METHODS
  One hundred and forty extracted roots with completely formed apices were resected 3 mm from the apex. Cavities were then prepared in the apical openings of the resected root ends using an ultrasonic handpiece to a depth of 3 mm. The roots were then randomly divided into five groups to receive one of five root-end filling materials. Roots in groups 1 and 2 received NERP1 and NERP2, whilst those in groups 3 and 4 received identical polymers as groups 1 and 2 but without nanoparticle addition (RP1 and RP2, respectively). The root-end cavities for the fifth group were filled with commercially available root-end filling compomer. Roots were mounted in a dual-chamber leakage apparatus and inoculated coronally with Enterococcus faecalis. Turbidity of the apical broth was assessed daily for 4 weeks as a sign of initial leakage. The results were statistically analysed using odds ratio and Fisher's chi-square analysis.
  
  
  RESULTS
  Nanoparticle-enhanced root-end filling polymer 1 displayed significantly fewer leaked samples compared to all other tested groups as early as 5 days, whilst NERP2 was not significantly different compared to other groups. Odds ratio analysis revealed leakage of the commercial compomer was 12 times more likely than NERP1.
  
  
  CONCLUSIONS
  Nanoparticle-enhanced root-end filling polymer 1 can reduce apical microleakage significantly under laboratory conditions.
authors.affiliation: Department of Endodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, USA. sxc89@case.edu
authors.forename: S M A
authors.initials: SM
authors.lastname: Chogle
authors.forename: C F
authors.initials: CF
authors.lastname: Duhaime
authors.forename: A K
authors.initials: AK
authors.lastname: Mickel
authors.forename: S
authors.initials: S
authors.lastname: Shaikh
authors.forename: R
authors.initials: R
authors.lastname: Reese
authors.forename: J H
authors.initials: JH
authors.lastname: Bogle
authors.forename: D K
authors.initials: DK
authors.lastname: Chan
authors.forename: S
authors.initials: S
authors.lastname: Potluri
authors.forename: S
authors.initials: S
authors.lastname: Qutubuddin
mesh_terms: D003763:Dental Leakage / Q000517:prevention & control*; D004338:Drug Combinations; D006801:Humans; D008437:Maxilla; D008963:Molar; D053761:Nanocomposites / Q000737:chemistry* / Q000627:therapeutic use; D053758:Nanoparticles / Q000737:chemistry* / Q000627:therapeutic use; D011108:Polymers / Q000737:chemistry / Q000627:therapeutic use; D012184:Retrograde Obturation / Q000379:methods; D012387:Root Canal Filling Materials / Q000737:chemistry* / Q000627:therapeutic use; D019227:Tooth Apex
chemical_list: D004338:Drug Combinations; D011108:Polymers; D012387:Root Canal Filling Materials