title: Effect of root resection on the apical sealing ability of mineral trioxide aggregate.
abstract: OBJECTIVE
  The purpose of this in vitro study was to determine the minimum depth of mineral trioxide aggregate (MTA; ProRoot; DENTSPLY/Tulsa Dental, Tulsa, Okla) required to maintain an apical seal following root resection. Study design. In 10 instrumented teeth, MTA was used to obturate the apical 6 mm of the root canal and was allowed to set for 48 hours. Leakage was determined by means of a fluid filtration method at a pressure of 20 cm H(2)O. Leakage was measured before root resection, and after 3, 4, 5, and 6 mm apical resections. Data were analyzed by means of a Kruskal-Wallis one-way analysis of variance with P <.05.
  
  
  RESULTS
  Fluid leakage was shown to increase after each resection, but did not reach statistical significance (P <.05) until 4 mm of the apex had been removed.
  
  
  CONCLUSIONS
  The results indicate that root resection did not significantly affect the sealing ability of MTA when at least 3 mm of the MTA remained. Although there was a statistically significant difference in leakage following the 4 mm resection, it is unknown what the biological difference would be between the 3 mm and 4 mm resections.
authors.affiliation: Medical College of Georgia, Augusta, GA 30912-1244, USA. rloushin@mail.mcg.edu
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Lamb
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Loushine
authors.forename: R Norman
authors.initials: RN
authors.lastname: Weller
authors.forename: W Frank
authors.initials: WF
authors.lastname: Kimbrough
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000704:Analysis of Variance; D001047:Apicoectomy / Q000145:classification; D017610:Calcium Compounds / Q000737:chemistry*; D003481:Cuspid / Q000601:surgery; D001840:Dental Bonding; D003763:Dental Leakage / Q000145:classification; D004338:Drug Combinations; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D010087:Oxides / Q000737:chemistry*; D011312:Pressure; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation; D018915:Root Canal Preparation; D017640:Silicates / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate