Objectives: To observe inert and dynamic mechanical properties of five different resin modified glass ionomer (RMGI) cements in comparison to one conventional GI cement.
Methods: six different RMGI and GI cements were selected: Exp. RMGIC (EX, 3M ESPE, USA), Photac® Fil Quick (PF, 3M ESPE, USA), Vitremer® (VT, 3M ESPE, USA), Fuji® II LC (F2, GC Corp., Japan), Fuji® Fil LC (FF, GC Corp., Japan) and Fuji® IX (F9, GC Corp., Japan). All specimens were prepared to final dimensions of 25 * 2 * 2 mm and stored for 14 d in dist water of 37 °C. Young‘s moduli (YM, n=12), flexural strengths (FS, n=12) and flexural fatigue limits (FFL, n=22, 10000 cycles, calculated by staircase approach) were measured under wet conditions. Data were subjected to analysis of variance (ANOVA, mod. LSD, p < 0.05).
Results: Homogenous subsets are labelled with same superscripts [Mean (SD)].
|
RMGIC |
YM [GPa] |
FS [MPa] |
FFL [MPa] |
FFL decrease |
|
EX |
4.42 (0.47) a |
44.1 (12.8) b,c |
29.5 (7.0) f,g |
- 32.9 % |
|
PF |
5.92 (0.79) |
48.2 (4.3) c |
24.6 (1.4) |
- 48.8 % |
|
VT |
9.84 (0.50) |
64.8 (5.7) d |
33.8 (1.2) f |
- 47.8 % |
|
F2 |
8.64 (0.75) |
69.9 (11.0) d |
27.9 (3.5) g |
- 60.1 % |
|
FF |
4.36 (0.27) a |
39.6 (6.1) b,e |
18.3 (2.6) h |
- 53.7 % |
|
F9 |
13.99 (1.68) |
34.2 (5.2) e |
17.7 (5.6) h |
- 50.0 % |
Conclusions: Initially F2 produced the highest FS, whereas under dynamic fatigue conditions VT showed the best FFL performance. A high scatter in strength is related to increased intrinsic porosity of all materials. Material inhomogeneities are found especially in EX to contribute to a high SD. Conventional GI cements showed superior YM but inferior FS and FFL performance.
This study was supported by 3M ESPE