IADR Abstract Archives
Compressive Strength, Microhardness, Acid Erosion of Restorative Glass Hybrid/Glass-ionomer Cements
Objectives: To evaluate the compressive strength (CS), acid erosion (AE) and knoop microhardness (KM) of restorative glass hybrid/glass-ionomer cements.
Methods: The materials tested were Equia Forte and Equia Forte HT (glass hybrid cements - GC) and Ketac Universal (glass-ionomer cement - 3M ESPE). Five specimens (sp) of each material were fabricated: 6mm x 4mm (CS) and 2mm x 5mm (AE) (ISO 9917-1). For KM the dimensions were 3mm x 5mm. For CS, the sp were stored in distilled water at 37oC and a relative humidity of 95% for 1 h. Then were removed from the molds and stored at 37oC for 23 hours. Tests were performed in a universal testing machine, with a 200 kgf load cell and of 0.75mm/min speed. For the AE, the whole assembly was stored, at 37oC and a relative humidity of 95%, for 24 h. The initial cement height was calculated and immersed for 24h in 30 ml of the eroding solution. New measurements were done. For KM, sp were immersed in distilled water at 37oC for 7 days. The KM was determined using a KH tester with a diamond indenter at 25 g load and 30 seconds dwell time. The data were submitted to 3-way ANOVA, followed by Tukey test (p<0.05).
Results: The CS values were 207.58MPa ± 15.34 (Equia Forte HT), 200.96MPa ± 15.14 (Equia Forte) and 164.47MPa ± 22.22 (Ketac Molar) (p=0.005). For the AE there was no statistical difference between the groups, Equia Forte HT (0.03mm ± 0.01), Equia Forte (0.05mm ±0.02) and Ketac Molar (0.11mm ± 0.09) (p=0.085). The KM values were 137.60KHN ± 5.08 (Equia Forte), 130.95KHN ± 9.43 (Equia Forte HT) and 115.09KHN ± 19.32 (Ketac Molar) (p=0.043).
Conclusions: The Equia Forte HT presented the best results for CS while Equia Forte presented the best results for KM.
Methods: The materials tested were Equia Forte and Equia Forte HT (glass hybrid cements - GC) and Ketac Universal (glass-ionomer cement - 3M ESPE). Five specimens (sp) of each material were fabricated: 6mm x 4mm (CS) and 2mm x 5mm (AE) (ISO 9917-1). For KM the dimensions were 3mm x 5mm. For CS, the sp were stored in distilled water at 37oC and a relative humidity of 95% for 1 h. Then were removed from the molds and stored at 37oC for 23 hours. Tests were performed in a universal testing machine, with a 200 kgf load cell and of 0.75mm/min speed. For the AE, the whole assembly was stored, at 37oC and a relative humidity of 95%, for 24 h. The initial cement height was calculated and immersed for 24h in 30 ml of the eroding solution. New measurements were done. For KM, sp were immersed in distilled water at 37oC for 7 days. The KM was determined using a KH tester with a diamond indenter at 25 g load and 30 seconds dwell time. The data were submitted to 3-way ANOVA, followed by Tukey test (p<0.05).
Results: The CS values were 207.58MPa ± 15.34 (Equia Forte HT), 200.96MPa ± 15.14 (Equia Forte) and 164.47MPa ± 22.22 (Ketac Molar) (p=0.005). For the AE there was no statistical difference between the groups, Equia Forte HT (0.03mm ± 0.01), Equia Forte (0.05mm ±0.02) and Ketac Molar (0.11mm ± 0.09) (p=0.085). The KM values were 137.60KHN ± 5.08 (Equia Forte), 130.95KHN ± 9.43 (Equia Forte HT) and 115.09KHN ± 19.32 (Ketac Molar) (p=0.043).
Conclusions: The Equia Forte HT presented the best results for CS while Equia Forte presented the best results for KM.