Prolonged curing time reduces the effects of simulated pulpal pressure on the bond strength of one-step self-etch adhesives

Oper Dent. 2013 Sep-Oct;38(5):545-54. doi: 10.2341/12-180-L. Epub 2012 Dec 6.

Abstract

The aim of this study was to evaluate the effects of extended light-curing procedures on the microtensile bond strength (μTBS) of one-step self-etch adhesives (1-SEAs) submitted to simulated pulpal pressure. Coronal deep-dentin specimens were bonded using Clearfil S3 Bond (S3), Adper Easy Bond (EB), or G-Bond Plus (GB) following the manufacturers' recommendations and light-cured for 10 seconds or 40 seconds. The dentin-bonded specimens were stored in distilled water for 24 hours without pulpal pressure (control) or submitted to 20 cm H2O simulated pulpal pressure for 24 hours. The specimens were cut into matchsticks and subjected to μTBS testing. The data were statistically analyzed using the three-way analysis of variance and Tukey's tests (p<0.05). Debonded sticks were investigated through scanning electron microscopy. EB obtained higher bond strengths than GB and S3. However, prolonged light activation (40 seconds) provided higher μTBS for all adhesives when submitted to pulpal pressure. Conversely, pulpal pressure caused a drop in μTBS in EB and S3 when light-cured for 10 seconds. A mixed failure mode was mainly attained for the control groups, whereas the specimens submitted to pulpal pressure failed in the adhesive mode. The μTBS of GB was not affected by pulpal pressure when light-cured for 10 seconds. Adhesive was the most prevalent failure mode, except when light-cured for 40 seconds, which showed predominantly cohesive failure. Extended curing times improved the resistance of 1-SEAs to simulated pulpal pressure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Etching, Dental / methods*
  • Adolescent
  • Adult
  • Bisphenol A-Glycidyl Methacrylate / therapeutic use
  • Curing Lights, Dental*
  • Dental Bonding / methods*
  • Dental Pulp / physiology
  • Dental Stress Analysis / methods
  • Dentin-Bonding Agents / therapeutic use
  • Humans
  • Light-Curing of Dental Adhesives / methods
  • Methacrylates / therapeutic use
  • Microscopy, Electron, Scanning
  • Molar, Third
  • Organophosphates / therapeutic use
  • Resin Cements / therapeutic use
  • Time Factors
  • Young Adult

Substances

  • Adper Prompt Self-Etch
  • Clearfil S3 Bond
  • Dentin-Bonding Agents
  • G-Bond
  • Methacrylates
  • Organophosphates
  • Resin Cements
  • Bisphenol A-Glycidyl Methacrylate