The effect of a dithiol spiroorthocarbonate on mechanical properties and shrinkage of a dental resin

Figures & data

Figure 1. FTIR spectrum of SOC DITHIOL.

Figure 2. ¹H NMR spectrum of SOC DITHIOL.

Figure 3. Methacrylate conversion vs. irradiation time for dimethacrylate control resin and the dimethacrylate-thiol system, with different concentrations of SOC DITHIOL.

Figure 4. Functional group conversion vs. irradiation time for dimethacrylate-thiol system (50:50 mixture of acrylates: SOC DITHIOL).

Figure 5. Schematic representation of the polymer obtained by photopolymerization of the formulations of dimethacrylates monomers with SOC DITHIOL.

Figure 6. Results of DMA analysis of the acrylic polymers photopolymerized in the presence of SOC DITHIOL in a range between 5 and 30 mol%.

Figure 7. Comparison of the Tan delta curves of the polymer obtained with different concentrations of SOC DITHIOL.

Table 1. Densities, specific volumes, and volume changes during photopolymerization of dental formulations studied.

Sample	ρ(l) (g mL^−1)	Vl (mL g^−1)	ρ(p) (g mL^−1)	Vp (mL g^−1)	ΔV (%)	% Red
CONTROL	1.1218	0.8914	1.1854	0.8435	−5.37	–
5% SOC DITHIOL	1.1316	0.8837	1.1876	0.8420	−4.72	12
10% SOC DITHIOL	1.1510	0.8688	1.1994	0.8337	−4.06	24
20% SOC DITHIOL	1.1821	0.8460	1.2202	0.8195	−3.13	42
30% SOC DITHIOL	1.2215	0.8187	1.2491	0.8005	−2.21	59

Notes:

ρ_(l) is the density of the liquid formulation, Vl is the specific volume of the liquid formulation, ρ_(p) is the density of the cured polymer, Vs is the specific volume of the cured polymer, ΔV is the volume changes that occurred in the samples, and % Red is the percent reduction of shrinkage.