Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Feb;36(2):284-295.
doi: 10.1016/j.dental.2019.11.007. Epub 2019 Dec 3.

Multifunctional monomer acts as co-initiator and crosslinker to provide autonomous strengthening with enhanced hydrolytic stability in dental adhesives

Linyong Song  1 , Rizacan Sarikaya  2 , Qiang Ye  3 , Anil Misra  4 , Candan Tamerler  2 , Paulette Spencer  5
Affiliations

Multifunctional monomer acts as co-initiator and crosslinker to provide autonomous strengthening with enhanced hydrolytic stability in dental adhesives

Linyong Song et al. Dent Mater. 2020 Feb.

Abstract

Objective: The purpose of this study was to evaluate a new synthesized multifunctional monomer, aminosilane functionalized methacrylate (ASMA), containing polymerizable methacrylate, tertiary amine, and methoxysilane functionalities in dental adhesive formulations, and to investigate the polymerization kinetics, leachates, thermal and mechanical properties of copolymers.

Methods: Adhesive contained HEMA/BisGMA (45/55, w/w) was used as a control, and mixtures based on HEMA/BisGMA/ASMA at the mass ratio of 45/(55-x)/x were used as experimental adhesive. Adhesives were characterized with regard to water miscibility, photo-polymerization behavior (Fourier transform infrared spectroscopy, FTIR), leached co-monomers (high performance liquid chromatography, HPLC), thermal properties (modulated differential scanning calorimeter, MDSC), and mechanical properties (dynamic mechanical analyzer, DMA). Stress relaxation times and the corresponding moduli, obtained from stress relaxation tests, are used in a simulated linear loading case.

Results: As compared to the control, ASMA-containing adhesives showed higher water miscibility, lower viscosity, improved monomer-to-polymer conversion, significantly greater Tg and rubbery modulus. HPLC results indicated a substantial reduction of leached HEMA (up to 85wt%) and BisGMA (up to 55wt%) in ethanol. The simulation reveals that the ASMA-containing adhesive becomes substantially stiffer than the control.

Significance: ASMA monomer plays multiple roles, i.e. it serves as both a co-initiator and crosslinker while also providing autonomous strengthening and enhanced hydrolytic stability in the adhesive formulations. This multifunctional monomer offers significant promise for improving the durability of the adhesive at the composite/tooth interface.

Keywords: Autonomous strengthening; Co-initiator; Dental adhesive; Hydrolytic stability; Mechanical property; Modulated DSC; Multifunctional monomer; Prony series; Stress relaxation.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Reaction scheme, FTIR and 1H NMR spectra for the synthesized ASMA.
Figure 2.
Figure 2.
Real-time conversion of C=C bond (A) and maximum polymerization rates (B) of the control (HB45) and experimental formulations. (Light irradiation starts at approximately 33 seconds).
Figure 3.
Figure 3.
Reversing heat flow (A and C) and nonreversing heat flow (B and D) versus temperature of the control and experimental polymer specimens in the first and second cycle.
Figure 4.
Figure 4.
Representative storage modulus (Top) and tan δ (Bottom) vs. temperature curves of the control (A), HBA10 (B), and HBA20 (C) samples for three-cycle test in dry conditions.
Figure 5.
Figure 5.
Representative stress relaxation behavior and fitted Prony series profiles of the control (HB45) and experimental adhesive (HBA10) at 75 °C: (A) fresh samples, (B) heated samples, and (C) simulated stress-strain curves under monotonic loading, with strain rate at 0.02% per min.
Figure 6.
Figure 6.
Cumulative monomers release from the ASMA-containing polymers as a function of incubation time in ethanol: (A) HEMA, (B) BisGMA, and (C) ASMA.
See this image and copyright information in PMC

References

    1. Afrashtehfar KI, Emami E, Ahmadi M, Eilayyan O, Abi-Nader S, Tamimi F, Failure rate of single-unit restorations on posterior vital teeth: A systematic review, J Prosthet Dent, 117 (2017) 345–353 e348. - PubMed
    1. Ferracane JL, Resin-based composite performance: are there some things we can’t predict?, Dent Mater, 29 (2013) 51–58. - PMC - PubMed
    1. Schwendicke F, Gostemeyer G, Blunck U, Paris S, Hsu LY, Tu YK, Directly Placed Restorative Materials: Review and Network Meta-analysis, J Dent Res, 95 (2016) 613–622. - PubMed
    1. Makvandi P, Jamaledin R, Jabbari M, Nikfarjam N, Borzacchiello A, Antibacterial quaternary ammonium compounds in dental materials: A systematic review, Dent Mater, 34 (2018) 851–867. - PubMed
    1. Stewart CA, Finer Y, Biostable, antidegradative and antimicrobial restorative systems based on host-biomaterials and microbial interactions, Dent. Mater, 35 (2019) 36–52. - PMC - PubMed

Publication types