Carine T W Meereis1, Fernanda B Leal1, Giana S Lima2, Rodrigo V de Carvalho3, Evandro Piva1, Fabrício A Ogliari4. 1. Biomaterials Development and Control Center, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil. 2. Dentistry Course, University Center of Várzea Grande, Várzea Grande, MT, Brazil. 3. School of Dentistry, University of North of Paraná, Londrina, PR, Brazil. 4. Biomaterials Development and Control Center, School of Dentistry, Federal University of Pelotas, Pelotas, RS, Brazil; School of Materials Engineering, Federal University of Pelotas, Pelotas, RS, Brazil. Electronic address: ogliari@gmail.com.
Abstract
OBJECTIVES: This study evaluated the performance of phenylbis (2,4,6-trimethylbenzoyl)-phosphine oxide (BAPO) as an alternative photoinitiator in the polymerization kinetics (PK), flexural strength (σ) and elastic modulus (E) of a model dental resin. METHODS: A monomer mixture based on Bis-GMA and TEGDMA was used as model dental resin. Initially a screening was performed to evaluate BAPO concentrations (0.125, 0.25, 0.50, 1, 2, and 4 mol%). Photoinitiator systems were formed with the combination of camphorquinone (CQ), ethyl-dimethylamino benzoate (EDAB), diphenyliodonium hexafluorophosphate (DPIHFP), and BAPO. Groups with unitary photoinitiator systems (BAPO and CQ), binary (BAPO+EDAB, BAPO+DPIHFP and CQ+EDAB), ternary (BAPO+CQ+EDAB, BAPO+CQ+DPIHFP, BAPO+EDAB+DPIHFP and CQ+EDAB+DPIHFP) and quaternary (BAPO+CQ+EDAB+DPIHFP) were formulated for evaluation. Real-time Fourier transform infrared spectroscopy was used to investigate the PK and test mini-bending to evaluate σ and E. RESULTS: When only CQ was used, a slow polymerization reaction was observed and a lower monomer conversion. When only BAPO was used as photoinitiator an increase in the polymerization rate was observed and conversion was higher than CQ+EDAB. The ternary system (BAPO+EDAB+DPIHFP) showed the highest polymerization and conversion rate, in short photo-activation time. SIGNIFICANCE: BAPO it is a potential photoinitiator for the photopolymerization of dental materials.
OBJECTIVES: This study evaluated the performance of phenylbis (2,4,6-trimethylbenzoyl)-phosphine oxide (BAPO) as an alternative photoinitiator in the polymerization kinetics (PK), flexural strength (σ) and elastic modulus (E) of a model dental resin. METHODS: A monomer mixture based on Bis-GMA and TEGDMA was used as model dental resin. Initially a screening was performed to evaluate BAPO concentrations (0.125, 0.25, 0.50, 1, 2, and 4 mol%). Photoinitiator systems were formed with the combination of camphorquinone (CQ), ethyl-dimethylamino benzoate (EDAB), diphenyliodonium hexafluorophosphate (DPIHFP), and BAPO. Groups with unitary photoinitiator systems (BAPO and CQ), binary (BAPO+EDAB, BAPO+DPIHFP and CQ+EDAB), ternary (BAPO+CQ+EDAB, BAPO+CQ+DPIHFP, BAPO+EDAB+DPIHFP and CQ+EDAB+DPIHFP) and quaternary (BAPO+CQ+EDAB+DPIHFP) were formulated for evaluation. Real-time Fourier transform infrared spectroscopy was used to investigate the PK and test mini-bending to evaluate σ and E. RESULTS: When only CQ was used, a slow polymerization reaction was observed and a lower monomer conversion. When only BAPO was used as photoinitiator an increase in the polymerization rate was observed and conversion was higher than CQ+EDAB. The ternary system (BAPO+EDAB+DPIHFP) showed the highest polymerization and conversion rate, in short photo-activation time. SIGNIFICANCE: BAPO it is a potential photoinitiator for the photopolymerization of dental materials.
Authors: Carla Dos Reis Lima; Danilo Bandeira da Silva; Rafael Pino Vitti; Milton Edson Miranda; William Cunha Brandt Journal: Clin Cosmet Investig Dent Date: 2019-08-29
Authors: Isaac Jordão de Souza Araújo; Andréia Bolzan de Paula; Roberta Caroline Bruschi Alonso; Jesus Roberto Taparelli; Lúcia Helena Innocentini Mei; Rafael Nóbrega Stipp; Regina Maria Puppin-Rontani Journal: PLoS One Date: 2018-04-02 Impact factor: 3.240