Jump to main content
Jump to site search

Issue 57, 2016, Issue in Progress
Previous Article Next Article

Self-strengthening hybrid dental adhesive via visible-light irradiation triple polymerization

Author affiliations


A self-strengthening methacrylate-based dental adhesive system was developed by introducing an epoxy cyclohexyl trimethoxysilane (TS) which contains both epoxy and methoxysilyl functional groups. The experimental formulation, HEMA/BisGMA/TS (22.5/27.5/50, wt%), was polymerized by visible-light. Real-time Fourier transform infrared spectroscopy (FTIR) was used to investigate in situ the free radical polymerization of methacrylate, ring-opening cationic polymerization of epoxy, and photoacid-induced sol–gel reactions. Among the three simultaneous reactions, the reaction rate of the free radical polymerization was the highest and the hydrolysis/condensation rate was the lowest. With 40 s-irradiation, the degrees of conversion of the double bond and epoxy groups at 600 s were 73.2 ± 1.2%, 87.9 ± 2.4%, respectively. Hydrolysis of the methoxysilyl group was initially <5%, and increased gradually to about 50% after 48 h dark storage. Photoacids generated through the visible-light-induced reaction were effective in catalyzing both epoxy ring-opening polymerization and methoxysilyl sol–gel reaction. The mechanical properties of copolymers made with TS concentrations from 5 to 35 wt% were obtained using dynamic mechanical analysis (DMA). In wet conditions, the storage moduli at 70 °C and glass transition temperature were significantly higher than that of the control (p < 0.05); these properties increased with TS concentration and storage time. The post reaction of hydrolysis/condensation of alkoxysilane could provide persistent strengthening whether in a neutral or acidic environment and these characteristics could lead to enhanced mechanical properties in the oral environment. The cumulative amount of leached species decreased significantly in the TS-containing copolymers. These results provide valuable information for the development of dental adhesives with reduced leaching of methacrylate monomers and enhanced mechanical properties under the wet, oral environment.

Graphical abstract: Self-strengthening hybrid dental adhesive via visible-light irradiation triple polymerization

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Apr 2016, accepted on 24 May 2016 and first published on 25 May 2016

Article type: Paper
DOI: 10.1039/C6RA09933E
RSC Adv., 2016,6, 52434-52447

  •   Request permissions

    Self-strengthening hybrid dental adhesive via visible-light irradiation triple polymerization

    L. Song, Q. Ye, X. Ge, A. Misra, C. Tamerler and P. Spencer, RSC Adv., 2016, 6, 52434
    DOI: 10.1039/C6RA09933E

Search articles by author