Characterization of Methacrylate-Based Resins Containing Methacryl-Polyhedral Oligomeric Silsesquioxanes (MA-POSS-8)

Abstract

The use of functionalized dental adhesives that might prevent degradation of the dentin hybrid layer has been proposed. The aim of the study was to characterize the physicochemical properties and the potential to induce mineral precipitation of methacrylate-based resins containing methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS-8). In total, six different compositions of resins based on bisphenol A glycerolate dimethacrylate (BisGMA, 40 to 60 wt.%), triethylene glycol dimethacrylate (TEGDMA, 5 to 35 wt.%) and 2-hydroxyethyl methacrylate (HEMA, 25 or 35 wt.%) were prepared and infiltrated with 5 wt.% MA-POSS-8. Unfilled resins served as control. Degree of conversion, viscosity, Martens hardness, indentation modulus, water sorption, and sol fraction were investigated. Polymerized specimens were examined by SEM/EDX for the presence of Ca/P precipitates after immersion in artificial saliva for 28 days at 37 °C. Statistical analysis was performed with two-way ANOVA and Tukey’s post-hoc test (p < 0.05). The degree of conversion ranged from 55.0 to 59.8% and was not affected by the addition of MA-POSS-8. Viscosity ranged from 60.0 to 422.3 mPa*s and was not affected by MA-POSS-8 except for one methacrylate-based resin with 60 wt.% BisGMA. Martens hardness and indentation modulus ranged from 161.3 to 138.1 N/mm2 and 4.2 to 3.9 kN/mm2 and were affected by MA-POSS-8 in only one resin (50 wt.% BisGMA, 25 wt.% TEGDMA, 25 wt.% HEMA). Water sorption was not affected by MA-POSS-8; sol fraction was below the detection limit. Formation of Ca/P precipitates was observed on all specimens of test and control groups. Material properties were not affected adversely by MA-POSS-8 except for slight differences in Martens hardness, indention modulus, viscosity in some groups. However, bioactive properties could not be improved by MA-POSS-8.

Effect of Bioactive and Antimicrobial Nanoparticles on Properties and Applicability of Dental Adhesives

“…The experimental adhesive used in this study was based on the study by Kreutz et al [31], which analyzed the physicochemical properties and mineral inducing capacity of different experimental methacrylate-based resins containing MA-POSS. The monomers used are the most commonly contained in adhesives or dental resins [36].…”

“…The monomers used are the most commonly contained in adhesives or dental resins [36]. The resin with the composition 60 wt% BisGMA, 15 wt% TEGDMA, 25 wt% HEMA and 5 wt% MA-POSS showed the lowest water sorption and a significantly reduced viscosity [31] and was therefore used in this study.…”

“…An experimental adhesive consisting of 60 wt% BisGMA, 15 wt% TEGDMA and 25 wt% HEMA (Sigma-Aldrich Chemistry, St. Louis, MO, USA) was prepared and magnetically mixed in dark for 10 min as described previously [31]. As photoinitiators, camphorquinone (Sigma-Aldrich Chemistry, St. Louis, MO, USA) and 2(dimethylamino)-ethyl methacrylate (Sigma-Aldrich Chemistry, St. Louis, MO, USA) were added at 0.5 wt% each to enable light-induced polymerization and the mixture was mixed for 10 min with a magnetic stirrer.…”

Thermoplastic polyurethane/POSS nanohybrids: Synthesis, morphology, and biological properties

“…Reactive substituents enable the covalent bonding into the polyurethane structure. POSS can be used as a rigidly bonded 48–58 or a pendant comonomer, 59–64 as well as a chain modifier, grafting, 65–69 and crosslinking 70–72 agent, in telomerization, 73–76 and in polymeric networks 69,77–79 . POSS may also be mixed as a composite component, especially if it is equipped with inert substituents that promote compatibility 80–87 .…”

“…POSS can be used as a rigidly bonded [48][49][50][51][52][53][54][55][56][57][58] or a pendant comonomer, [59][60][61][62][63][64] as well as a chain modifier, grafting, [65][66][67][68][69] and crosslinking [70][71][72] agent, in telomerization, [73][74][75][76] and in polymeric networks. 69,[77][78][79] POSS may also be mixed as a composite component, especially if it is equipped with inert substituents that promote compatibility. [80][81][82][83][84][85][86][87] Depending on the way POSS is attached to polyurethane macrochains, it may produce different microscopic effects in the material structure, such as reduction of microphase separation by steric hindrance or reduced chain mobility, enhancement of microphase separation by crystallization of POSS segments, and cocrystallization with HS.…”