Objectives: The aim of this study was to evaluate the effect of the different mixing methods on tensile bond strength (TBS) of glass-ionomer-cement (GIC). This study evaluated TBS of GIC to bovine enamel (BE), bovine dentin (BD), and gold alloy (CASTWELL M.C. 12%GOLD:CW12 and CASTING GOLDM.C.TYPE III:CG3, GC) for prosthetic restoration.
Methods: The trial material FL-901 paste type GIC(GC) by hand-mix(FL-HM) and that by auto-mix(FL-AM) were evaluated. The latter were mixed by using the mixing tip. RelyX™ Luting Plus Cement(RXLP) paste type GIC(3M ESPE) in the clicker dispenser and RelyX™ Luting Cement(RXL) powder/liquid type GIC(3M ESPE), both were evaluated by hand-mix. All were mixed according to manufacturer's instructions. TBS test was carried out according to ISO/TS11405 (n=5). For the before thermocycled(TC0) specimens, TBS was measured (1mm/min) by an Autograph (SIMADZU) after 24hour at 37�C-100%RH. The other specimens were thermocycled (TC2000, 5/55�C) and followed by the measurement. The results were analyzed by three-way ANOVA and Turkey test.
Results: The mean values and S.D. were shown in the following table. There were no significant difference of TBS in the mixing methods and in among the different materials (p<0.01). However, there were significant difference in the factor of the substrate (p<0.01) and the thermocycle (p<0.05).
TBS:MPa | FL-HM(S.D.) | FL-HM(S.D.) | RXLP(S.D.) | RXL(S.D.) | ||||
TC0 | TC2000 | TC0 | TC2000 | TC0 | TC2000 | TC0 | TC2000 | |
BE | 10.0(�2.3) | 8.2(�2.3) | 9.2(�0.5) | 10.2(�2.4) | 11.9(�5.6) | 12.7(�3.1) | 9.8(�2.5) | 8.9(�1.2) |
BD | 7.2(�1.4) | 5.3(�1.4) | 7.0(�0.8) | 6.2(�1.6) | 7.9(�1.4) | 8.6(�3.2) | 8.4(�2.3) | 5.9(�1.5) |
CW12 | 11.2(�2.7) | 11.2(�5.0) | 9.2(�2.9) | 8.1(�0.8) | 7.9(�2.0) | 5.7(�0.7) | 8.0(�1.4) | 6.4(�1.7) |
CG3 | 11.4(�2.0) | 11.8(�2.5) | 10.0(�2.6) | 10.1(�1.5) | 8.7(�1.2) | 7.4(�2.0) | 12.1(�2.3) | 10.6(�1.2) |
Conclusions: In this study, there was no significant difference of TBS in the mixing methods. Therefore, it is thought that auto-mix system demonstrates bonding stability like hand-mixing in clinical.
Keywords: Bonding strength, Cements, Dental materials and Prostheses
See more of: Dental Materials 3: Ceramic-based Materials and Cements