title: Comparative evaluation of sealing ability of four different restorative materials used as coronal sealants: an in vitro study.
abstract: BACKGROUND
  The purpose of the present study was to evaluate and compare the sealing ability of glass ionomer cement (GIC), composite resin, gray mineral trioxide aggregate (GMTA) and white mineral trioxide aggregate (WMTA) when placed coronally as double - sealing material over gutta-percha in root canal treated teeth.
  
  
  METHODS
  A sample of 70 freshly extracted human single rooted teeth were cleaned, shaped and obturated with gutta-percha and AH Plus. The gutta-percha was reduced to a depth of 4 mm from the cemento enamel junction using hot plugger and standardized access cavities with 4 mm depth were prepared at the coronal ends of the roots. The specimens were randomly divided into four groups containing 15 teeth each depending on the restorations they received in the coronal cavity. A positive control group of five teeth received no restorative barrier over gutta-percha. All root surfaces were covered with two coats of nail varnish, leaving only the access openings uncovered except teeth in the negative control group, which were completely covered with nail varnish. All teeth were immersed in India ink, cleared and observed under stereomicroscope for the depth of dye penetration.
  
  
  RESULTS
  The results were tabulated and analyzed using Kruskal-Wallis test and multiple comparison between each group was carried out using Mann-Whitney test. The groups sealed with GMTA and WMTA showed least dye penetration than other groups and the difference was statistically significant. Highest dye penetration was seen with groups sealed with GIC and was statistically significant compared with other three groups.
  
  
  CONCLUSIONS
  The results showed that the GMTA and WMTA provided significantly better coronal seal when compared to other two restorations. The composite resin also showed significantly better seal than the unsealed group and the group sealed GIC, which showed highest leakage that was equivalent to that of unsealed group.
authors.affiliation: Lecturer, Department of Conservative Dentistry & Endodontics, Government Dental College & Research Institute, Vijayanagar Institute of Medical Science, Bellary, Karnataka, India.
authors.forename: K T
authors.initials: KT
authors.lastname: Divya
authors.affiliation: Associate Professor, Department of Conservative Dentistry and Endodontics, Darshan Dental College & Hospital, Loyara, Udaipur, Rajasthan, India.
authors.forename: G
authors.initials: G
authors.lastname: Satish
authors.affiliation: Associate Professor, Department of Periodontics, Rungta College of Dental Sciences & Research, Bhilai, Chhattisgarh, India.
authors.forename: T S
authors.initials: TS
authors.lastname: Srinivasa
authors.affiliation: Senior Dental Health Officer, Department of Public Health Dentistry, General Hospital, Molakalmuru, Karnataka, India.
authors.forename: Veera
authors.initials: V
authors.lastname: Reddy
authors.affiliation: Associate Professor, Department of Orthodontics, Government Dental College & Research Institute, Vijayanagar Institute of Medical Science, Bellary, Karnataka, India.
authors.forename: K
authors.initials: K
authors.lastname: Umashankar
authors.affiliation: Senior Lecturer, Department of Conservative Dentistry & Endodontics, Anil Neerukonda Institute of Dental Sciences, Visakhapatnam, Andhra Pradesh, India.
authors.forename: B Mohan
authors.initials: BM
authors.lastname: Rao
keywords: Coronal microleakage; coronal seal; double-seal technique; mineral trioxide aggregate