Effect of low-shrinkage monomers on the physicochemical properties of experimental composite resin

Figures & data

Figure 1. Chemical structure of monomers utilized in this study along with their abbreviations.

Table 1. Composition of resin matrix for each experimental composite.

	Components (%)
Resin matrix	bis-GMA	TEGDMA	SR833s	IBOA	CQ	DMAEMA
Control	49.3	49.3	0	0	0.7	0.7
EC-1	49.3	0	49.3	0	0.7	0.7
EC-2	49.3	0	44.3	5	0.7	0.7
EC-3	49.3	0	39.3	10	0.7	0.7
EC-4	49.3	0	34.3	15	0.7	0.7

Figure 2. Schematic illustration of the shrinkage-stress test set-up.

Table 2. Degree of conversion and mechanical properties mean values (±standard deviation) of investigated composites.

Material	FS (MPa)	FM (GPa)	FT (MPa m^1/2)	DC (%)
Control	104.8 ± 7.1^a	7.09 ± 0.65^a	1.26 ± 0.12^a	62.4 ± 0.3^a
EC-1	105.0 ± 2.2^a	7.79 ± 0.82^a	1.37 ± 0.20^a	55.5 ± 0.7^b
EC-2	101.8 ± 7.0^a	7.46 ± 0.67^a	1.32 ± 0.10^a	55.6 ± 0.8^b
EC-3	106.2 ± 5.2^a	7.56 ± 0.44^a	1.29 ± 0.12^a	56.9 ± 0.4^b,c
EC-4	105.0 ± 4.0^a	7.40 ± 0.41^a	1.37 ± 0.16^a	57.3 ± 0.5^c

FS: flexural strength; FM: flexural modulus; FT: fracture toughness; DC: degree of monomer conversion. Same superscript letter above the values indicates groups that were statistically similar (p > .05).

Table 3. Volumetric shrinkage, shrinkage strain, and shrinkage stress of investigated composites.

Material	VS (%)	Strain (μm/m)	Stress (MPa)
Control	4.86 ± 0.77^a	6484 ± 276^a	4.75 ± 0.31^a
EC-1	3.00 ± 1.15^b	4768 ± 245^b	3.83 ± 0.43^b
EC-2	2.67 ± 0.92^b,c	4686 ± 138^b	3.57 ± 0.70^b,c
EC-3	2.95 ± 0.78^b,c	4823 ± 429^b	2.83 ± 0.51^c
EC-4	2.51 ± 1.02^c	4515 ± 305^b	2.97 ± 0.16^c

VS: volumetric shrinkage. Same superscript letter above the values indicates groups that were statistically similar (p > .05).

Figure 3. Polymerization shrinkage strain of tested groups (Table 1) measured at room temperature.

Figure 4. Polymerization shrinkage-stress curve of tested groups (Table 1) measured at room temperature.