Objectives: To assess the mechanical properties of three resin cements after different storage conditions. Methods: Fifteen 4mm×4mm×2mm specimens were prepared with PanaviaF2.0 (Kuraray Co.), Corecem (RTD) and RelyXUnicem (3M ESPE) and light-polymerized for 30s. Five specimens of each cement were stored at 37°C in one of the following conditions: dry, deionised water or mineral oil. Modulus of elasticity (E), elastic work (We/Wtot), creep (Cr) and Vicker's hardness (VH) of each cement were measured 24h and 1month after storage. The mechanical properties measured 15min after polymerization served as control. Measurements were performed with a microhardness indenter (FischerscopeH100C, Fischer). Data were analyzed with a Multivariate ANOVA and Tukey's test (α=0.05). Results: The cement resulted as a significant factor affecting mechanical properties (p<0.001), time and storage condition affected the properties except of VH (p=0.56) and We/Wtot (p=0.431) respectively. The Table reports the measured mechanical properties. Conclusion: The tested cements exhibited different susceptibility of their mechanical properties to storage conditions over 1month.
Cement | Property | Storage | Control | |||||
dry | oil | water | ||||||
24h | 1month | 24h | 1month | 24h | 1month | |||
PanaviaF2.0 | E(GPa) | 4.50(1.19)b | 6.57(0.93)de | 5.22(1.80)bc | 7.57(1.52)ef | 6.10(1.48)cd | 6.66(0.70)de | 2.97(0.75)a |
We/Wtot(%) | 31.60(2.49)ab | 30.29(2.12)a | 34.31(4.47)bc | 31.05(3.94)a | 35.19(5.36)c | 28.95(4.74)a | 36.57(1.55)c | |
Cr(%) | 4.44(0.31)gh | 4.89(0.27)jk | 5.07(0.50)k | 4.73(0.22)ij | 4.61(0.39)hi | 4.83(0.49)ijk | 4.97(0.41)jk | |
VH(N/mm2) | 13.82(4.81)a | 21.00(3.58)b | 20.81(4.78)b | 25.95(3.58)b | 24.79(9.11)b | 20.97(5.99)b | 10.05(3.94)a | |
Corecem
| E(GPa) | 9.91(0.39)ij | 10.06(0.28)jk | 9.75(0.84)ij | 9.40(0.42)ghij | 8.80(0.93)ghi | 8.26(0.43)fg | 8.58(0.72)fgh |
We/Wtot(%) | 50.13(0.91)i | 49.82(0.92)hi | 51.06(1.14)i | 49.31(0.87)ghi | 51.09(0.71)i | 50.47(1.59)i | 51.39(4.02)i | |
Cr(%) | 3.75(0.08)de | 3.58(0.06)bcd | 3.69(0.16)cde | 3.79(0.15)de | 3.85(0.20)e | 3.90(0.17)e | 4.27(0.35)fg | |
VH(N/mm2) | 64.48(5.46)fg | 63.25(2.53)efg | 65.83(5.63)g | 58.84(3.35)def | 57.97(5.41)de | 54.36(3.65)cd | 62.16(13.57)efg | |
RelyXUnicem | E(GPa) | 14.78(1.30)mn | 15.61(2.19)n | 12.56(1.86)l | 14.40(1.00)m | 10.23(1.55)jk | 11.09(2.38)k | 9.48(0.80)hij |
We/Wtot(%) | 46.83(1.78)efg | 46.69(3.20)efg | 47.27(3.42)fgh | 44.77(1.30)def | 46.58(3.80)ef | 44.25(3.70)de | 42.96(1.66)d | |
Cr(%) | 3.48(0.17)bc | 3.18(0.15)a | 3.75(0.20)de | 3.42(0.18)ab | 4.16(0.16)f | 3.78(0.17)de | 4.61(0.27)hi | |
VH(N/mm2) | 87.85(6.14)i | 92.60(6.21)i | 79.26(9.34)h | 81.43(5.25)h | 63.12(4.41)efg | 62.30(5.29)efg | 50.95(5.59)c | |
Table: Means(SD) of the mechanical properties. Different superscript letters indicate significant differences(p<0.05).