Silane content influences physicochemical properties in nanostructured model composites

Larissa Maria Cavalcante; Lucielle Guimarães Ferraz; Karinne Bueno Antunes; Isadora Martini Garcia; Luis Felipe Jochims Schneider; Fabrício Mezzomo Collares

doi:10.1016/j.dental.2020.10.022

Silane content influences physicochemical properties in nanostructured model composites

Dent Mater. 2021 Feb;37(2):e85-e93. doi: 10.1016/j.dental.2020.10.022. Epub 2020 Nov 24.

Authors

Larissa Maria Cavalcante¹, Lucielle Guimarães Ferraz², Karinne Bueno Antunes³, Isadora Martini Garcia⁴, Luis Felipe Jochims Schneider⁵, Fabrício Mezzomo Collares⁴

Affiliations

¹ School of Dentistry, Federal Fluminense University, Niterói, RJ, Brazil; Nucleus for Dental Biomaterials Research, School of Dentistry, Veiga de Almeida University, Rio de Janeiro, RJ, Brazil. Electronic address: lara_cavalcante@yahoo.com.br.
² School of Dentistry, Federal Fluminense University, Niterói, RJ, Brazil.
³ Nucleus for Dental Biomaterials Research, School of Dentistry, Veiga de Almeida University, Rio de Janeiro, RJ, Brazil.
⁴ Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
⁵ School of Dentistry, Federal Fluminense University, Niterói, RJ, Brazil; Nucleus for Dental Biomaterials Research, School of Dentistry, Veiga de Almeida University, Rio de Janeiro, RJ, Brazil.

PMID: 33243439
DOI: 10.1016/j.dental.2020.10.022

Abstract

Objective: To determine the effect of organosilane content on the physicochemical properties of model composites formulated with nano-sized fillers.

Methods: Model composites were formulated with dimethacrylate-based monomers, a photoinitiator/co-initiator system and silicon dioxide nano-sized fillers treated with different amounts of 3-methacryloxypropyltrimethoxysilane (MPTS): 1.0 (G_1%), 2.0 (G_2%), 5.0 (G_5%), 7.5 (G_7.5%) and 10 (G_10%) wt.% relative to SiO₂. Non-silanized fillers (G_0%) were used in the control group. Degree of conversion (DC) was assessed by Fourier-transformed infrared spectroscopy (ATR-FTIR). Knoop hardness (KHN) and elastic modulus were determined before and after water storage for 4 months. Water sorption (Wsp) and solubility (Wsl) were calculated by successive mass determinations in analytical balance. Surface gloss and roughness were characterized before and after toothbrushing simulation.

Results: With the exception of those fillers treated with 1% MPTS, DC was not dependent on the silane content. Within the silanized groups, G_1% showed the lowest initial and final KHN, without statistical difference from G_0%. The elastic modulus was not affected by the silane content, regardless of the storage condition, but those groups formulated with at least 5% silane presented improved values after storage. Silane content did not affect the WSl, but affected Wsp, in which those groups formulated with at least 2 wt.% of MPTS produced a more resistant material than G_0%. The use of treated particles with at least 2 wt.% of silane was able to produce materials that did not change their gloss after the brushing process. Additionally, these materials presented lower surface roughness than G_0% after the brushing process (p < 0.05).

Significance: The concentration of MPTS affected the physicochemical properties of nano-filled composites. Therefore, 2 wt.% of silane was the optimized quantity to produce materials resistant to degradation, both in bulk and surface properties.

Keywords: Bisphenol a-glycidyl methacrylate; Hydrolysis; Nanocomposites; Operative dentistry; Polymerization; Silanes; Toothbrushing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bisphenol A-Glycidyl Methacrylate
Composite Resins
Materials Testing
Methacrylates
Polyethylene Glycols
Polymethacrylic Acids
Silanes*
Silicon Dioxide*
Surface Properties

Substances

Composite Resins
Methacrylates
Polymethacrylic Acids
Silanes
Polyethylene Glycols
Bisphenol A-Glycidyl Methacrylate
Silicon Dioxide