Water Sorption, Water Solubility, and Rheological Properties of Resin-Based Dental Composites Incorporating Immobilizable Eugenol-Derivative Monomer

Abstract

The present study aimed to evaluate the properties of new dental formulations incorporating a new polymerizable-derivative of eugenol (EgGMA). The experimental composites were prepared (by weight) with 35% resin-based matrix (1:1, bisphenol A-glycidyl methacrylate/triethylene glycol dimethacrylate) and 65% reinforcing materials (4:3, hydroxyapatite/zirconium oxide). A portion of 0.0, 2.5, and 5.0% of the resins with respect to the total composite was replaced by EgGMA monomer to obtain TBEg0, TBEg2.5, and TBEg5, respectively. The complex viscosity (at 25 and 37 °C), degree of conversion (DC), and water sorption (WSP) and water solubility (WSL) (3 cycles of sorption-desorption process) were investigated. Data were statistically analyzed using one-way and Tukey post-hoc tests. The results revealed a viscosity reduction with shear-thinning behavior as the EgGMA amount and temperature increased. The average complex viscosities at a lower frequency (ω = 1.0 rad/s) and at 25 °C were 234.7 ± 13.4, 86.4 ± 16.5, and 57.3 ± 17.1 (kPa·s) for TBEg0, TBEg2.5, and TBEg5, respectively. The inclusion of EgGMA led to a lower DC and WSP but higher WSL, compared to those of the reference (TBEg0). However, no significant differences between TBEg2.5 and control were detected (p > 0.05). Therefore, the incorporation of EgGMA in a low quantity, e.g., up to 8.45 mol% of resins, within the matrix may enhance the composite’s performance, including handling and solubility properties without any apparent effect on DC and water sorption, making it a promising monomeric biomaterial for various applications including restorative dentistry.

Influence of Eugenol and Its Novel Methacrylated Derivative on the Polymerization Degree of Resin-Based Composites

“…However, the observed drop in the DC of UG6.8 may be due to both the monomers' structure and reactivity differences [10]. This could support the potential use of EgGMA in dental composites at a low but effective concentration, as previously reported [7,14].…”

“…For example, eugenyl methacrylate and ethoxyeugenyl methacrylate [8], ethoxy eugenyl acrylate [9], and eugenyl-2-hydroxypropyl methacrylate (EgGMA) [10] were synthesized through etherification or esterification of the eugenolphenoxy group; however, other derivatives fabricated via the allyl terminal were also reported [9,11,12]. Most of these polymerizable Eg derivatives were evaluated for their physicochemical, biocompatibility, and applicability as additives to resin-based dental composites with the potential to act as bactericidal and physicochemical enhancers [7,13,14].…”

“…EgGMA, a new, recently introduced monomer, has been investigated for its monomeric chemical, thermal, and reactivity properties [10], as well as for its potential incorporation in resin-based dental composites [7,14], reporting comparable features to that of MMA with better biocompatibility and water sorption against EgGMA-free composites. However, some properties, such as the degree of conversion (DC) and water solubility, were slightly affected, thus necessitating further investigation.…”

“…However, some properties, such as the degree of conversion (DC) and water solubility, were slightly affected, thus necessitating further investigation. The DC, in particular, is a crucial determiner of majority of the final composite properties; thus, according to a previous study [14] in which DC was evaluated for 0-17 mol% per organic phase, it is an EgGMA concentration-dependent property. However, the analyzed concentrations were limited to 0.00, 5.45, and 16.66 mol% and, therefore, a wider analysis with a small concentration increment is important to find the valuable upper concentration of EgGMA in the matrix.…”

Hybrid Bio-Based Silicone Coatings with Anti-adhesive Properties

“…Following this line, several new antibacterial and bacteriostatic silicones have been designed by us and others [ 25 , 26 , 27 , 28 , 29 , 30 ]. The use of natural substances with antimicrobial properties (for example, 4-allyl-2-methoxyphenol (eugenol) and 3,7-dimethylocta-1,6-dien-3-ol (linalool)) may be another interesting approach to environmentally acceptable antibiofilm materials [ 31 , 32 , 33 ]. Poor water solubility and volatility of those bioactive phytochemicals limit their use in treating biofilm-related infections.…”