Hyperbranched polymers: Their use in dental resins to reduce polymerization contraction

Objectives . The purpose of this study was to investigate, in dental neat resins, the effect of adding hyperbranched polymers (HBPs) on polymerization contraction ( C ), degree of conversion (DC) and elastic modulus ( E ).

Materials and methods . Neat resins were formulated with varying weight ratios of three different HBPs added at a reference matrix Bis-GMA/TEGDMA.

Raman micro-spectroscopy was used to determine the degree of conversion, volume contraction was determined by pycnometry and by means of a density column and elastic modulus was measured by a Dynamic Mechanical Analyzer (DMA). Data were submitted to analysis of variance (ANOVA).

Results

Organic matrix Bis-GMA/TEGDMA/HBP % w/w C (%) n = 3 DC (%) n = 3 E (GPa) n = 3
R 50/50/0 9.07 (0.36) a 65.2 (3.4) a 2.32 (0.27) bcde
HBP 1 – 5% 47.5/47.5/5 8.95 (0.06) ab 64.5 (3.4) a 2.51 (0.16) abd
HBP 1 – 10% 45/45/10 8.53 (0.18) c 65.8 (2.6) a 2.76 (0.03) a
HBP 1 – 20% 40/40/20 8.05 (0.15) e 68.3 (2.5) a 2.53 (0.14) abd
HBP 1 – 30% 35/35/30 7.49 (0.07) f 69.2 (1.6) a 2.21 (0.16) de
HBP 1 – 40% 30/30/40 7.03 (0.02) g 75.6 (1.3) b 1.77 (0.08) f
HBP 2 – 5% 47.5/47.5/5 8.78 (0.03) bc 66.4 (0.3) a 2.68 (0.08) ac
HBP 2 – 10% 45/45/10 8.60 (0.08) c 66.8 (1.0) a 2.78 (0.10) a
HBP 2 – 20% 40/40/20 8.26 (0.01) d 66.8 (1.1) a 2.46 (0.12) abd
HBP 2 – 30% 35/35/30 7.68 (0.04) f 67.0 (3.5) a 2.32 (0.14) bde
HBP 2 – 40% 30/30/40 7.05 (0.02) g 68.3 (2.9) a 1.26 (0.04) g
HBP 3 – 5% 47.5/47.5/5 8.67 (0.07) c 71.4 (0.3) a 2.51 (0.05) ab
HBP 3 – 10% 45/45/10 8.50 (0.07) c 67.9 (1.0) a 2.67 (0.25) ab
HBP 3 – 20% 40/40/20 8.02 (0.07) de 70.7 (1.1) a 2.53 (0.08) abd
HBP 3 – 30% 35/35/30 7.22 (0.14) g 70.5 (3.5) ab 2.16 (0.08) e
HBP 3 – 40% 30/30/40 6.51 (0.06) h 67.0 (2.9) a 1.61 (0.06) f
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Nov 30, 2017 | Posted by in Dental Materials | Comments Off on Hyperbranched polymers: Their use in dental resins to reduce polymerization contraction
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