Optimal photoinitiator concentration for light-cured dental resins. (February 2021)

• Record Type: Journal Article
• Authors: Wang, Kun; Li, Bei; Ni, Ke; Li, Bei; Wang, Zhengzhi
• Is Part Of: Polymer testing. Volume 94(2021)
• Publication Date: 2021-02
• Subjects: Photopolymerization -- Photoinitiator -- Conversion -- Mechanical properties -- Curing depth; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2020.107039
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: In this paper, we study the optimal photoinitiator (camphorquinone, CQ ) concentration for light-cured dental resins by combining such properties as the degree of conversion, mechanical properties, and curing depth (the depth at which the hardness is 80% of the surface hardness). The material properties of the light-cured dental resins (Bis-GMA/TEGDMA in a mass ratio of 70:30) are characterized by in-situ near-infrared (NIR) spectroscopy and nanoindentation tests. Experimental results indicate that the degree of conversion ( DC ) and mechanical properties such as elastic modulus and hardness increase, while the curing depth decreases with the increase of CQ concentration. However, above a certain concentration (~0.5 wt%), these properties do not benefit from the further increasing CQ concentration because of potential self-annihilation between free radicals. The presented study offers a method to determine the optimal photoinitiator concentration for light-cured resins and establishes the correlations between the photoinitiators, polymerization kinetics, and mechanical properties of the light-cured resins. Highlights: Photoinitiator concentration can affect the properties of light-cured resins. High photoinitiator concentration has a negative effect on light-cured resins. The optimal photoinitiator concentration is determined by cured resin properties.