Effect of Different Photoiniciers of Experimental Adhesive Systems on Adhesive Interface Union Resistance

Abstract

Aim: The objective of this study was to investigate the performance of experimental resinous adhesives containing different combinations of photoinitiators systems through the bending test.
 Material and Methods: Resinous adhesive formulations were prepared with monomer mixtures consisting of 50% by mass of bisphenol dimethacrylate glycidyl (BisGMA) and 50% by mass of triethyleneglycol dimethacrylate (TEGDMA). The photoinitiators were used, camphorquinone (CQ) and bis-alkyl phosphinic oxide (BAPO). The co-initiators were diphenyliodonium hexafluorophosphate (DFI) and the amine (dimethylamino methylmethacrylate - DMAEMA) in the 1:1 proportion by mass. The photopolymerizable initiator systems were dissolved in the organic matrix at 0.5% by mass concentrations, creating eight groups (G1- CQ, G2- CQ/amine, G3- CQ/DFI, G4- CQ/amine/DFI, G5- BAPO, G6- BAPO/amine, G7- BAPO/DFI, G8- BAPO/amine/DFI). Samples with 7.0 mm in length, 2.0 mm wide and 1.0 mm height were prepared (n=12). The curing light used was VALO – Ultradent and the curing time was 20 s. The samples were subjected to evaluation of bending test at three points at a speed of 1 mm/min to evaluate the flexural resistance (FR).
 Results: The results were submitted to analysis of variance with one criterion (p < 0,001) and multiple comparisons were performed using Tukey test. Systems with the photoinitiator BAPO showed higher or equivalent bending values that demonstrated by the conventional system containing CQ/amine. Systems with the DFI had higher flexural values in relation to those demonstrated by systems without the DFI to CQ.
 Conclusion: The use of systems with alternative photoinitiators and co-initiators allows to obtain superior properties to the conventional system, making these promising systems to act both in isolation as associated with conventional systems.

Microhardness and Diametral Compression Strength of Single Fill Composite

“…Factors such as translucency of the material, the type of resin, the exposure time, significantly interfere in the polymerization of composites. The degree of conversion of a material is measured indirectly through the microhardness test, by means of significant results on the depth of polymerization, both on the upper and lower surfaces of the samples (Abed et al, 2015;Fronza et al;Gonçalves et al, 2018;Alrahlah, 2018). In this study, it can be observed that for the same material, the lowest radiant exposure (5J) obtained the lowest results, both for microhardness and diametral compression strength.…”

“…In this line of reasoning Zorzin et al (2015) report that the association of Bis-GMA monomers with UDMA or TEGDMA will increase the degree of conversion, creating a network of highly rigid polymers, which consequently increase the polymerization of the resin at depths. The incorporation of new photoinitiators influences the resin curing process, such as increasing its ability to transfer light at its depths (Gomes et al, 2018;Ilie, 2019). Filtek resin™ One Bulk Fill has unique monomers in its composition, additional fragmentation (AFM) and aromatic dimethacrylate urethane (AUDMA) (Bucuta & Ilie, 2014).…”

Influence of Acid Etching on Bond Strength Between Feldspathic Ceramics and Resin Cement

“…Although there was no significant difference using acid of different concentrations, according to the results, there was a difference in bond strength when the conditioning time was increased. 16,17 Under the failure pattern analysis, 2/3 of the specimens had adhesive-type failure and 1/3 of the specimens had mixedtype failure. The specimens that showed mixed cement and mixed ceramic failures prove better bonding properties than specimens with adhesive failures, as stated by Lodi, Marks e Borba 18 in their study, which had similarity in the values of bond resistance between the groups in the shear test, but there was a difference in failure mode.The group that presented higher cement/ceramic resistance obtained more frequency Restorations with this type of ceramic have multifactorial failure means and the evaluation methods presented provide partial data, since the oral cavity is a complex environment, being difficult to reproduce all its variables in a mechanical test with an in vitro research.…”

Characterization of Bulk-Fill Resin Composites in Terms of Physical, Chemical, Mechanical and Optical Properties and Clinical Behavior

“…Polymerization requires a component called a photoinitiator that is an initiator molecule, the most used of which is camphorquinone. Some manufacturers have added a new initiator, Ivocerin, in their composites, which has a photopolymerization activity superior to camphorquinone, due to its greater absorption of visible light (Bucuta & Ilie, 2014;Gomes et al, 2018;Pereira et al, 2018;Rizzante et al, 2019). Farahat et al (2016) evaluated the effect of irradiation time and material thickness by the degree of polymerization of a universal resin (Tetric N Ceram Universal) and Bulk-Fill (Tetric N Ceram filler), where the samples were made in teflon molds with a diameter of 5mm and a height of 2, 4 and 6mm in a total of 96 samples divided into 12 groups (n = 8).…”