title: A comparative in vitro study of microleakage by a radioactive isotope and compressive strength of three nanofilled composite resin restorations.
abstract: OBJECTIVE
  This study compares the compressive strength and microleakage of three nanofilled composites using radioactive isotope Ca(45).
  
  
  METHODS
  Thirty-six freshly extracted human premolars were used in this study. Standardized Class I preparation was carried out and then randomly divided into three different groups: A, B, and C with 12 teeth in each group which were restored with nanofilled composite restoration and then subjected to thermocycling. Microleakage was tested using radioactive isotope Ca(45). Kruskal-Wallis and Mann-Whitney tests were used to compare the microleakage scores of the three groups. For measuring the compressive strength of three nanofilled composite resin restorations, 12 specimens of each material were prepared in customized stainless steel cylindrical moulds of 6 mm ×4 mm. The compressive test was performed using the Universal Testing Machine. The values were analyzed with ANOVA and Bonferroni's test.
  
  
  RESULTS
  The findings of this study indicate that the synergy has the least microleakage and highest compressive strength followed by the Grandio and Filtek Z-350.
  
  
  CONCLUSIONS
  Introduction of nanocomposites (packable) appears to have improved the performance of both anterior and posterior restorations with regard to mechanical properties, marginal integrity, and esthetics.
authors.affiliation: Department of conservative dentistry, Government Dental College, Raipur (C.G), India.
authors.forename: Rupika
authors.initials: R
authors.lastname: Gogna
authors.forename: S
authors.initials: S
authors.lastname: Jagadis
authors.forename: K
authors.initials: K
authors.lastname: Shashikal