Abstract
This study evaluated the physico-mechanical properties of experimental composite resins made with different resin matrix and light-curing units. Experimental composite groups were divided according to monomers (BisGMA + TEGDMA-BT and BisGMA + BisEMA + UDMA + TEGDMA-BBUT) and photoinitiator system (camphorquinone-CQ and 1-phenyl-1,2-propanedione-PPD). A quartz tungsten halogen (QTH) or light-emitting diode (LED) were used to light cure all materials. Knoop microhardness (n = 10) was determined using Knoop microhardness test. Compressive strength, diametral tensile strength, and Young modulus (n = 7) were obtained using a universal testing machine at crosshead speed of 1.0 mm/min. The data were submitted to a three-way ANOVA and the Tukey post-hoc test (α = 0.05). QTH presented the highest total irradiance values and similar total radiant exposure to LED. For the compressive strength test, BT-PPD light-cured with LED group showed the lowest mean value. BT-CQ light-cured with LED group exhibited the lowest diametral tensile strength results. The BBUT-composite resins presented lowest Young modulus values, with no statistical difference between light-curing units (QTH and LED) and photoinitiators system (CQ and PPD). Application of QTH or LED in BT-based composite resins with PPD photoinitiator generated suitable results regarding the physico-mechanical properties. Keywords: Biomaterials; blends; dental composites; polymerization; shrinkage
Highlights
The physicochemical properties of composites resins may be influenced by several factors, such as light-curing unit (LCU), time, irradiance, emitted light spectrum as well as increment thickness and composite resin shade [1]
This study evaluated the physico-mechanical properties of experimental composite resins made with different resin matrix and light-curing units
Experimental composite groups were divided according to monomers (BisGMA + triethylene glycol dimethacrylate (TEGDMA)-BT and BisGMA + bis-phenol A dimethacrylate (BisEMA) + urethane dimethacrylate (UDMA) + TEGDMA-BBUT) and photoinitiator system
Summary
The physicochemical properties of composites resins may be influenced by several factors, such as light-curing unit (LCU), time, irradiance, emitted light spectrum as well as increment thickness and composite resin shade [1]. LCUs composed of quartz tungsten halogen (QTH) lamps consists of a tungsten filament enclosed in a crystalline quartz casing, filled with a halogen-based gas, and connected to electrodes. The electricity flows through the filament generating light and heat [5]. The QTH lamps emit white light, i.e. they are considered broad-banded in its spectral emission. QTH LCU require filters to limit the wavelength range. Only the blue spectral region is selected for composite resin light-curing, since it is the camphorquinone (CQ) absorption peak [4, 6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
