1,3-Diethyl-2-thiobarbituric acid as an alternative coinitiator for acidic photopolymerizable dental materials

• Published in: Journal of biomedical materials research. Part B, Applied biomaterials Vol. 101; no. 7; pp. 1217 - 1221
• Main Authors: Münchow, Eliseu A., Valente, Lisia L., Peralta, Sonia L., Fernández, María Raquel, Lima, Giana da S., Petzhold, Cesar L., Piva, Evandro, Ogliari, Fabrício A.
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 01.10.2013; Wiley-Blackwell
• Subjects: Adhesives; barbiturates; Biological and medical sciences; Biomedical materials; Camphor - analogs & derivatives; Camphor - chemistry; co-initiators; Conversion; Dental materials; Direct current; EDAB; Head and neck surgery. Maxillofacial surgery. Dental surgery. Orthodontics; Maxillofacial surgery. Dental surgery. Orthodontics; Medical sciences; Monomers; Photochemical Processes; Photoinitiators, Dental - chemistry; Polymerization; Polymers; Polymethacrylic Acids - chemical synthesis; Polymethacrylic Acids - chemistry; radical polymerization; real-time infrared spectroscopy; Resins; Resins, Synthetic - chemical synthesis; Resins, Synthetic - chemistry; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Thiobarbiturates - chemistry; EDAB; co-initiators; Free radical polymerization; Spectrometry; Dental restoration; real-time infrared spectroscopy; Exploration; Biomaterial; Barbiturates; radical polymerization; Biomedical engineering; barbiturates
• ISSN: 1552-4973; 1552-4981
• DOI: 10.1002/jbm.b.32933

The ethyl‐4‐dimethylaminobenzoate (EDAB) is widely used as a coinitiator of the camphorquinone (CQ), but in acidic circumstances it might present some instability, reducing the polymerization efficiency of the material. Considering this, new coinitiators are being evaluated. Hence, this study evaluated the kinetic of polymerization (KP), the degree of conversion (DC), and the rate of polymerization (RP) of experimental resin adhesives containing 1,3‐diethyl‐2‐thiobarbituric acid (TBA) as a coinitiator of the CQ. The experimental monomeric blend was prepared with bisphenol A glycidyl dimethacrylate, 2‐hydroxyethyl methacrylate, and acidic monomers. CQ was added at 1 mol % as photoinitiator. Six groups were formulated: four containing concentrations of 0.1, 0.5, 1, and 2 mol % of TBA, one without coinitiator, and the last one containing 1 mol % of EDAB (control group). The KP and the RP were performed using real‐time Fourier Transform infrared spectroscopy. The group without coinitiator has not formed a polymer, whereas the addition of TBA resulted in the conversion of monomers in polymer. The DC of the adhesives was as higher as the increase in the TBA content. The group with 2 mol % of TBA presented improved DC and reactivity (RP) than the other groups and the control one. Hence, the TBA has performed as a coinitiator of the CQ for the radical polymerization of methacrylate resin adhesives and it has improved the DC and the reactivity of the materials. Thus, it is a potential coinitiator for the photopolymerization of dental materials. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1217–1221, 2013.