engleski

„Influence of thermo-curing on the flexural strength of GIC“.

Objectives: The aim of this study was to test the influence of thermo-curing (externally applied heat) on flexural strength (FS) of glass-ionomer cement. Material and Methods: The FS of commercial glass ionomer (Fuji Equia Fil, GC) was measured using a method based on ISO9917-2:1998. Specimens (n=10 per group) were prepared in split moulds (2x2x25mm), compressed and thermo-cured with polymerization unit or according to manufacturers' instructions and stored at 37oC (100% RH) in distilled water for 1 week. Samples of Group 1 were allowed to set without coat and thermo-cure application, in the Group 2 samples were set with coat (Equia Coat, GC) application without thermo- curing. Samples of Group 3 were thermo-cured with polymerization unit (Bluephase G2, IvoclarVivadent) for 60s without coat application and in the Group 4 samples were coated and thermo- cured for 60s. Samples were stored in distilled water for 1 week and FS tested. Each specimen was tested using an Universal testing machine at 1 mm/min crosshead speed and loaded to fracture using a 3-point bending test (l=20mm), with 1kN load cell. Data were analysed by ANOVA and Tukey HSD post hoc test p<0.05. Results: FS of coated and thermo-cured GIC samples (Group 4) showed significantly higher values (69, 66 MPa) comparing to all other groups. Values of FS of samples of Group 3 (thermo-curing without coat) (35, 8 MPa) were significantly higher comparing to groups without thermo-curing. Groups (1 and 2) without thermo-curing were not significantly different in FS (21, 8 and 18, 8 MPa respectively). Conclusion: Results showed that application of thermo-curing during setting can significantly improve flexural strength of GIC.

flexural strength ; GIC

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