title: A comparative study between resilon and gutta-percha as a secondary root canal filling materials: an in vitro study.
abstract: BACKGROUND
  Adequate root canal seal following retreatment is essential for a successful outcome. Resilon/Epiphany (R/E) obturation system has been introduced as a substitute for conventional gutta-percha/sealer method. This in vitro study compared the amount of apical microleakage of R/E with gutta-percha/AH26 (GP/AH26) sealer as secondary root canal filling following retreatment in human teeth.
  
  
  METHODS
  Fifty human single-rooted lower premolar teeth were selected. After preparing them with ProTaper rotary NiTi instruments, all the canals were obturated using GP/AH26 sealer. After 10 days, all the samples were retreated using the same rotary NiTi instruments. The samples were divided randomly into two experimental groups A and B (n=20) and positive and negative control groups (n=5). In group A, all canals were obturated using GP/AH26 sealer and in group B all canals were obturated using R/E. After one week incubation in 37˚C with 100% humidity, the amount of apical microleakage was evaluated with fluid filtration model. All the apical microleakage data were analyzed with Mann-Whitney U test.
  
  
  RESULTS
  The mean amounts of apical microleakage were 0.317 ± 0.287 and 0.307 ± 0.281 µL/8min (fluid pressure=30 cm H2O) in experimental group A and B respectively; the difference was not statistically significant (P>0.05).
  
  
  CONCLUSIONS
  R/E seems to be a good alternative for retreatment as a secondary root canal filling material. However, Resilon/Epiphany obturation system does not completely avert microleakage.
authors.affiliation: Department of Endodontics, Dental School, Azad University of Medical Science, Tehran, Iran.
authors.forename: Payman
authors.initials: P
authors.lastname: Mehrvarzfar
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Saghiri
authors.forename: Kasra
authors.initials: K
authors.lastname: Karamifar
authors.forename: Zohre
authors.initials: Z
authors.lastname: Khalilak
authors.forename: Nahid
authors.initials: N
authors.lastname: Maalek
keywords: Apical Microleakage; Fluid Filtration Model; Resilon; Retreatment