The effect of different light curing units on Vickers microhardness and degree of conversion of flowable resin composites

Swe Zin Aung; Tomohiro Takagaki; Masaomi Ikeda; Kosuke Nozaki; Michael F Burrow; Ahmed Abdou; Toru Nikaido; Junji Tagami

doi:10.4012/dmj.2019-353

The effect of different light curing units on Vickers microhardness and degree of conversion of flowable resin composites

Dent Mater J. 2021 Jan 31;40(1):44-51. doi: 10.4012/dmj.2019-353. Epub 2020 Aug 25.

Authors

Swe Zin Aung¹, Tomohiro Takagaki^{1

2}, Masaomi Ikeda³, Kosuke Nozaki⁴, Michael F Burrow⁵, Ahmed Abdou¹, Toru Nikaido^{1

2}, Junji Tagami¹

Affiliations

¹ Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
² Department of Operative Dentistry, Division of Oral Functional Sciences and Rehabilitation, School of Dentistry, Asahi University.
³ Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
⁴ Department of Biofunction Research, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental Universit.
⁵ Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital.

PMID: 32848103
DOI: 10.4012/dmj.2019-353

Abstract

This study aimed to assess the influence of different light curing units (LCUs) on the polymerization of various flowable resin composites. Three LCUs (Optilux 501, Elipar™ DeepCure-L LED and Bluephase^®20i) and eight flowable resin composites: MI FIL Flow, Estelite Flow Quick, Estelite Universal Flow (medium), Estelite Universal Flow (super low), Beautifil Flow Plus, Clearfil Majesty ES Flow, Filtek Supreme Ultra flowable and TetricEvo Flow were tested. For Vickers microhardness (VHN) test and degree of conversion (DC), specimens were prepared and polymerized for 20 s. VHN test was performed at top surfaces (3 indentations) and DC for each specimen was measured using Fourier transform infrared (FT-IR) spectroscopy after 24 h dry storage in dark at 37˚C. The data were analyzed with 2-way ANOVA and t-test with Bonferroni correction. DC and hardness values showed a relationship between materials and LCUs. The curing efficacy of LCU type may depend on the material composition.

Keywords: Degree of conversion; Flowable resin composites; Light curing units; Polymerization efficacy; Vickers microhardness.

MeSH terms

Composite Resins
Curing Lights, Dental*
Hardness
Light-Curing of Dental Adhesives*
Materials Testing
Polymerization
Spectroscopy, Fourier Transform Infrared
Surface Properties

Substances

Composite Resins