Effect of two light activated in-office bleaching agents on microhardness of different esthetic restorative materials

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Selcuk Dental Journal, vol.5, no.2, pp.142-149, 2018 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 5 Issue: 2
  • Publication Date: 2018
  • Doi Number: 10.15311/selcukdentj.344313
  • Journal Name: Selcuk Dental Journal
  • Journal Indexes: TR DİZİN (ULAKBİM)
  • Page Numbers: pp.142-149
  • Istanbul Medipol University Affiliated: Yes


Background: Irradiation sources have been used to reduce the total in-office bleaching time. However, little is known about the effects of the light irradiation bleaching systems on the restorative materials. This in vitro study evaluated the microhardness of 6 different restorative materials during office bleaching procedures with blue light emitted diode and diode laser photoactivation.Methods: FiltekTM supreme (nanofilled), Tetric EvoCeram (nanohybrid), Tescera ATL (ormocer), Clearfill Majesty Esthetic (nanofilled), Durafill VS (microfilled) and IPS Empress II (ceramic) restorative materials were selected in this study. Twenty specimens, 10 mm in diameter and 2 mm thick, were fabricated from each material using a Teflon mold. All specimens were randomly assigned to two groups (n=10). Group 1 received two topical applications of 35% hydrogen peroxide and was photoactivated using blue light emitted diode for 20s. Group 2 received topical application of 46% hydrogen peroxide using diode laser for 30s. Baseline and after bleaching microhardness measurements were taken with a Vickers hardness tester that was used with a 300 g for the porcelain and 100 g for the composite and ormocer specimens, the dwell time was 30 s for all groups. Data were analyzed statistically, with one-way-analysis of variance (ANOVA), post-hoc Tamhane's T2 and independent t tests. Results: After application of both office bleaching agents, microhardness of all restorative materials tested were significantly decreased (p<.05). However, Tetric EvoCeram composite resin material showed the least microhardness value (p<.05). Conclusion: Blue light emitted diode and diode laser activation hydrogen peroxide office bleaching agents have similar effects on the reduction of microhardness of restorative materials. The data of this study revealed that after bleaching, nanofilled (FS, CME), microfilled (Df) specimens demonstrated lower changes in microhardness values than nanohybrid (TEC) composite material.