title: Investigation of the marginal adaptation of root-end filling materials in root-end cavities prepared with ultrasonic tips.
abstract: OBJECTIVE
  To compare the surface topography of root apices following ultrasonic root-end preparation, and again after root-end fillings submitted to three different finishing techniques.
  
  
  METHODS
  Eighty-one root-end cavities prepared ultrasonically in human canines, were divided at random into three test groups of 27 each. The cavities were filled with Super-EBA, IRM, or ProRoot-MTA and finished by ball burnishing. Eighteen roots from each group received a final finish with either a 30-fluted tungsten carbide finishing bur, or a Zekrya carbide 28 mm bur after storage in water at 37 degrees C for 24 h. The root-end surface topographies were reproduced by means of polyvinylsiloxane impressions and epoxy resin replicas. Scanning electron micrography (SEM) images of each replica were taken prior to and after root-end filling. An image analysis system was used to compare the alteration of the marginal chipping areas and to calculate the gaps located in the dentine/root-end filling interface.
  
  
  RESULTS
  When a bur was used to finish the set materials, a significant (P < 0.05) area of marginal chipping was eliminated. The finishing technique did not significantly (P > 0.05) affect the incidence of gaps in groups root-end filled with MTA or IRM. Super-EBA and IRM retrofillings finished with a ball burnisher or a Zekrya bur displayed a significantly (P < 0.05) larger calculated gap area than roots filled with MTA.
  
  
  CONCLUSIONS
  Under this in vitro study, the marginal adaptation of MTA was good with or without finishing procedures. Applying a finishing bur over the condensed and set IRM and Super-EBA created better marginal adaptation.
authors.affiliation: Endodontic Unit, School of Dentistry of Piracicaba, State University of Campinas - UNICAMP, Piracicaba - SP, Brazil. gondimjr@ajato.com.br
authors.forename: E
authors.initials: E
authors.lastname: Gondim
authors.forename: A A
authors.initials: AA
authors.lastname: Zaia
authors.forename: B P F A
authors.initials: BP
authors.lastname: Gomes
authors.forename: C C R
authors.initials: CC
authors.lastname: Ferraz
authors.forename: F B
authors.initials: FB
authors.lastname: Teixeira
authors.forename: F J
authors.initials: FJ
authors.lastname: Souza-Filho
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D000704:Analysis of Variance; D017610:Calcium Compounds / Q000737:chemistry; D002244:Carbon; D018772:Dental Marginal Adaptation; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004338:Drug Combinations; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008768:Methylmethacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry; D016628:Replica Techniques; D012184:Retrograde Obturation; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation*; D017640:Silicates / Q000737:chemistry; D013499:Surface Properties; D019227:Tooth Apex / Q000648:ultrastructure; D017973:Tungsten Compounds; D014464:Ultrasonic Therapy / Q000295:instrumentation*; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D017220:Dentin-Bonding Agents; D004338:Drug Combinations; D008768:Methylmethacrylates; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; D017973:Tungsten Compounds; D015035:Zinc Oxide-Eugenol Cement; C086631:mineral trioxide aggregate; C002802:tungsten carbide; C031667:IRM cement; D002244:Carbon; C084074:Super EBA