Objective: Methacrylic acid (MAA), acidic monomer containing one carboxyl group and one conjugated carbonyl group, was reported as an excellent potential of improving the mechanical properties of UDMA based resin (Tanaka J et al. abs#2680, JDR 81 (SIA); 336, 2002). The objective of this study was to evaluate the flexural properties; the flexural strength (FS) and the flexural modulus (FM) of the novel comonomers (UDMA/MAA, UM) comparing to conventional BisGMA/TEGDMA (BT) and UDMA/TEGDMA (UT) comonomers as a composite. Method: Three kinds of photopolymerized experimental composite resins made from three comonomers, UM, BT and UT mixed with 65 mass% silanated spherical filler were prepared. Eighteen, 2x2x25-mm specimens, n=6, were fabricated. Six specimens from each group were tested after immersion in 37°C water for 24 hours. All specimens were subjected to a 3-point bending test in 37°C water. Data were analyzed using one-way ANOVA and Tukey HSD at p< 0.05. Results: FSs±sd and FMs±sd were summarized in table.
|
UM |
BT |
UT |
|
|
FS / MPa |
127.6 ± 5.1 |
96.7 ± 13.3 |
94.6 ± 7.0 |
|
FM / GPa |
6.3 ± 0.5 |
4.9 ± 0.4 |
3.9 ± 0.1 |
FS and FM from UM were significantly greater than those from BT and UT. Conclusions: The UM comonomers demonstrates the higher FS and FM reflecting potential for being used as resin matrix for composite.