Effect of Light-emitting Diode Photopolymerization Modes on the Push-out Bond Strength of a Methacrylate-based Sealer


Nagas E. , ÇEHRELİ Z. C. , Durmaz V.

JOURNAL OF ENDODONTICS, vol.37, no.6, pp.832-835, 2011 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 6
  • Publication Date: 2011
  • Doi Number: 10.1016/j.joen.2011.03.006
  • Title of Journal : JOURNAL OF ENDODONTICS
  • Page Numbers: pp.832-835

Abstract

Introduction: The objective of this study was to investigate and compare the effect of different light-emitting diode (LED) polymerization modes on the bond strength of a methacrylate-based sealer used with Resilon or gutta-percha. Methods: Forty extracted single-rooted teeth were sectioned off below the cementoenamel junction, and the root canals were instrumented by using rotary instruments to ISO #30/0.06 taper. The roots were randomly assigned into 1 of the following groups for root canal obturation: (1) Real Seal + Resilon and (2) Real Seal + gutta-percha. In each group, specimens were further subgrouped according to the LED polymerization mode used to cure Real Seal: (1) standard (20 seconds of maximum intensity) and (2) exponential (5 seconds of exponential power increase, followed by 15 seconds of maximum intensity). Specimens were stored in 100% humidity for 1 week at 37 degrees C. Push-out test was performed at a crosshead speed of 1 mm/min on 2-mm-thick root slices obtained from coronal to apical direction. Multivariate analysis of variance and Tukey tests were used for statistical analysis of the data (P =.05). Failure modes were examined under the scanning electron microscope. Results: The tested polymerization modes had no significant effect on the bond strength values (P >.05). RealSeal + guttapercha yielded significantly greater bond strength than Real Seal + Resilon (P <.05). In all groups, the bond strength values decreased significantly from coronal to apical direction (P <.05). Adhesive failure at the sealer-dentin interface was the predominant fracture mode. Conclusions: The exponential photopolymerization mode had no significant advantage over the standard regimen in terms of dentin bond strength. (J Endod 2011;37:832-835)