Adhesive Resins with High Shelf-Life Stability Based on Tetra Unsaturated Monomers with Tertiary Amines Moieties

Abstract

This work reports the use of two monomers with two tertiary amines and four methacrylic (TTME) or acrylic (TTAC) terminal groups as co-initiators in the formulation of experimental resin adhesive systems. Both monomers were characterized by FT-IR and 1H NMR spectroscopies. The control adhesive was formulated with BisGMA, TEGDMA, HEMA, and the binary system CQ-EDAB as a photo-initiator system. For the experimental adhesives, the EDAB was completely replaced for the TTME or the TTAC monomers. The adhesives formulated with TTME or TTAC monomers achieved double bond conversion values close to 75%. Regarding the polymerization rate, materials formulated with TTME or TTAC achieved lower values than the material formulated with EDAB, giving them high shelf-life stability. The degree of conversion after shelf simulation was only reduced for the EDAB material. Ultimate tensile strength, translucency parameter, and micro-tensile bond strength to dentin were similar for control and experimental adhesive resins. Due to their characteristics, TTME and TTAC monomers are potentially useful in the formulation of photopolymerizable resins for dental use with high shelf-life stability.

Impact of photoinitiator quality on chemical-mechanical properties of dental adhesives under different light intensities

“…The hydrolytic degradation caused by phase separation of the adhesive under clinical conditions of the presence of intrapulpal fluid requires adhesive systems with improved performance in hydrophilic environments. Therefore, the evaluation of the behavior of new combinations of hydrophilic and hydrophobic photoinitiators is relevant to optimize resistance to degradation with no prejudice to the mechanical properties [10].…”

“…The decrease in band ratio profile for intensity at 1638 cm -1 to that at 1608 cm -1 was monitored continuously during polymerization [16][17][18]. The degree of conversion (DC) was determined using the following formula, which was based on the intensity band ratios before and after lightpolymerization [10,16]:…”

“…Therefore, i n a d d i t i o n t o c a m p h o r q u i n o n e , o t h e r photoinitiatiors with hydrophobic characteristics, such as ethyl-4-(dimethylamino) benzoate (EDMAB) and hydrophilic characteristics, such as 2-(dimethylamino) ethyl methacrylate (DMAEMA), are used in adhesive systems to improve polymerization in the presence of water. In addition, a new co-initiator, DHIHP (salt) has been introduced into adhesive systems to replace inactive radicals with active radicals of both camphorquinone and phenyl, optimizing polymerization [7,10].…”

Characterization of Experimental Nanoparticulated Dental Adhesive Resins with Long-Term Antibacterial Properties

“…Despite significant investments by the manufacturing and scientific communities, newly developed materials containing antibacterial agents, quaternary ammonium compounds, [ 13 ] or metaloxide nanoparticles (e.g., zinc and titanium) [ 24 , 25 ] failed to sustain long-term antibacterial properties and did not extend the service lives of composite restorations, thereby underscoring the need for the development of novel materials with long-term biological properties. Pérez-Mondragón et al, [ 26 ] while investigating the shelf-life stability in terms of the degree of conversion, ultimate tensile strength, and color of dental adhesive resins (commercially available and experimental) at different periods of simulated shelf-life (37 °C; 6, 18, and 24 months), have demonstrated that experimental materials displayed higher shelf-life stability (in terms of the degree of conversion), when compared to commercially available materials. However, experimental materials displayed mechanical and optical properties that were similar ( p > 0.05) to those of the control group, independently of the time-point considered [ 26 ].…”

“…Pérez-Mondragón et al, [ 26 ] while investigating the shelf-life stability in terms of the degree of conversion, ultimate tensile strength, and color of dental adhesive resins (commercially available and experimental) at different periods of simulated shelf-life (37 °C; 6, 18, and 24 months), have demonstrated that experimental materials displayed higher shelf-life stability (in terms of the degree of conversion), when compared to commercially available materials. However, experimental materials displayed mechanical and optical properties that were similar ( p > 0.05) to those of the control group, independently of the time-point considered [ 26 ].…”