Influence of different concentrations of an iodonium salt on properties of amine-free resins. Issue 6 (June 2022)

• Record Type: Journal Article
• Authors: Salvador, Marcos Vinícius de Oliveira; Fronza, Bruna M.; Braga, Roberto Ruggiero; Gonçalves, Luciano Souza; Oxman, Joe D.; Lima, Adriano F.
• Is Part Of: Dental materials. Volume 38:Issue 6(2022)
• Page Start: 1024
• Page End: 1029
• Publication Date: 2022-06
• Subjects: Degree of conversion -- Mechanical properties -- Polymerisation -- Amine; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2022.04.002
• Languages: English
• ISSNs: 0109-5641

Abstract

Abstract: Objectives: to evaluate the effect of different concentrations of an iodonium salt on the degree of conversion, polymerisation rate, flexural strength and modulus of an amine-free photopolymerizable resin system. Methods: Two series of UDMA/TEGDMA resin mixtures (1:1 mass ratio) containing 0, 0.5, 1.0 or 2.0 mol% of bis(4-methyl phenyl)iodonium hexafluorophosphate(BPI): and 1 mol% camphorquinone (CQ) were evaluated. One of the series contained 2 mol% of the amine (2-(dimethylamino)ethyl methacrylate-DMAEMA), while the other series had only CQ and BPI as photoinitiators. Polymerisation kinetics and degree of conversion (DC) were evaluated by Fourier transform near-infrared spectroscopy (n = 3). Flexural strength (FS) and modulus ( E ) were evaluated by a three-point bending method (n = 12). Data were analysed by two-way ANOVA and Tukey's test. Results: The system containing CQ + DMAEMA + BPI provided the highest DC and FS. Amine-free resins had similar E regardless of the presence of BPI. The resins containing CQ+DMAEMA with 1 and 2 mol% of BPI presented higher E compared with others. Significance: Amine-containing resins reached statistically higher DC, rate of polymerisation and FS than amine-free systems. The use of higher BPI concentrations did not improve the properties of amine-free resins. Highlights: Amine-free UDMA based resins can reach suitable properties for dental applications. There are no need high concentrations of iodonium salt to improve the polymerisation. UDMA resins with a ternary initiator system present high rate of polymerization.