Structure–property relationships in hybrid dental nanocomposite resins containing monofunctional and multifunctional polyhedral oligomeric silsesquioxanes

Abstract

Organic-inorganic hybrid materials, such as polyhedral oligomeric silsesquioxanes (POSS), have the potential to improve the mechanical properties of the methacrylate-based composites and resins used in dentistry. In this article, nanocomposites of methacryl isobutyl POSS (MI-POSS [bears only one methacrylate functional group]) and methacryl POSS (MA-POSS [bears eight methacrylate functional groups]) were investigated to determine the effect of structures on the properties of dental resin. The structures of the POSS-containing networks were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Monofunctional POSS showed a strong tendency toward aggregation and crystallization, while multifunctional POSS showed higher miscibility with the dimethacrylate monomer. The mechanical properties and wear resistance decreased with increasing amounts of MI-POSS, indicating that the MI-POSS agglomerates act as the mechanical weak point in the dental resins. The addition of small amounts of MA-POSS improved the mechanical and shrinkage properties. However, samples with a higher MA-POSS concentration showed lower flexural strength and flexural modulus, indicating that there is a limited range in which the reinforcement properties of MA-POSS can operate. This concentration dependence is attributed to phase separation at higher concentrations of POSS, which affects the structural integrity, and thus, the mechanical and shrinkage properties of the dental resin. Our results show that resin with 3% MA-POSS is a potential candidate for resin-based dental materials.

Nanomaterials in dentistry – potential capabilities, applications, limitations and hazards. Review of the literature. Part 2

“…This concentration dependence is attributed to phase separation at higher concentrations of POSS, which affects the structural integrity and thus the mechanical and shrinkage properties of the dental resin. These results show that resin with 3% MA-POSS is a promising candidate for resin-based dental materials [23].…”

Evaluation of the Mechanic and Electrochemical Properties of an Epoxy Coating with Addition of Different Polyhedral Oligomeric Silsesquioxanes (POSS) Applied on Substrate of Low Alloy Steel

“…Conradi et al highlight an increase of up to 40% in roughness and hardness of the material for adding silica nanoparticles in epoxy resin 21 . For Wang et al, the addition of methacrylisobutyl-POSS in dental resin promoted an increase of surface roughness of the hybrid material 22 .…”

Microstructural Features of Current Resin Composite Materials

“…The advantage of this type of additive is that the structure can be designed to target specific properties (refractive index, toughness, hydrophilicity) and also to include polymerizable functionalities and/or photoinitiator molecules to locally control polymerization rate [48,49]. Polyhedral oligomeric silsesquioxanes (POSS) have also been described for use as dental materials [50,51]. POSS is an organic-inorganic hybrid nanoparticle consisting of a silica cage core, as well as other organic groups attached to the corners of the cage.…”

“…POSS is an organic-inorganic hybrid nanoparticle consisting of a silica cage core, as well as other organic groups attached to the corners of the cage. The addition of small amounts of POSS leads to material reinforcement and increased resistance to wear [50].…”