Table 1.
Material composition for commercial restorative materials used in this study.
Fig 1.
FTIR spectra and chemical structure of dimethacrylates Bis-GMA, UDMA, TEGDMA and monomethacrylates HEMA and 10-MDP.
C-O stretch doublet can be seen at 1300 and 1320 cm-1 together with 1636 [v(C = C)] bond.
Table 2.
Peak absorbance of individual monomers (Part I), from the spectra acquired and peak height per mole per cc, derived using Eq (1) (Part II), for the different reaction peaks and peak bases.
Fig 2.
FTIR spectra of VF, Constic and Activa, initial and final (1200 s) spectra.
Absorbance changes due to polymerisation can be seen at the C-O stretch doublet at 1300 and 1320 cm-1 together with 1636 [v(C = C)] bond, highlighted in grey. Samples with 2 mm thickness, light cured for 20 s (n = 3).
Fig 3.
FTIR difference spectra (initial–final spectrum).
Graph shows peak shifts owing to the polymerisation reaction. Absorbance changes are seen in the 1160 cm-1 [v(C-O-C)], 1300–1320 [v(C-O)] which shift to lower wavenumbers, at 1230 and 1268 cm-1, and absorbance change of [v(C = C)] at 1640 cm-1. Spectra also show noise around the 1500–1800 cm-1 region, with a smooth region between 1100–1500 cm-1.
Table 3.
Peak heights and resulting DC (%) at 1200 s, for the different peak selection methods.
Fig 4.
Reaction extent for VF, Constic and Activa.
Graph indicates how far the reaction has gone towards its final value at each given time point. Reaction extent reaches 95% of the final value (determined by extrapolation of data versus inverse time to zero) by 1200 s for all the materials.