IADR Abstract Archives
Compressive Strength and Deflection at Break of Four Cements
Objectives: Compare four cements with regard to compressive strength and deflection at break according to ISO 9917-1; 2010; Group 1: ACTIVA™ Bioactive Cement (Pulpdent Corporation); Group 2: Unicem Automix Relyx™ (3M); Group 3: FujiCem™2 (GC America); and Group 4: Ceramir® Crown & Bridge (Doxa).
Methods: Forty cylindrical samples (n=10), measuring 4mm in diameter by 8mm in height were prepared as follows: a glass plate was placed on the bottom of the mold followed by a Mylar® strip. Cement was extruded into the mold. A second Mylar film followed, which was covered by a second glass plate placed on top of the filled mold. Steady pressure was applied to the glass to displace any excess material. The cements were cured (DEMI™, Kerr) in accordance with manufacturers’ instructions and removed from the holder. They were wet-ground using 400-grit sandpaper (EcoMet250, Buehler) to standardize dimensions and then stored in 37○C distilled water for 24 hours. Compressive strength and deflection at break were measured using a universal testing machine (Instron®5566A Norwood, MA) with 1K load cell and 1mm/min cross head speed.
Results: Descriptive statistics were calculated for all groups’ compressive strength. The mean compressive strength was highest in Group 1 (Table 1). One way ANOVA and Tukey’s HSD showed that mean compressive strength was significantly different for each group tested (p<0.001) except for groups 2 and 3 (p>0.05). Descriptive statistics were calculated on deflection at break for all groups. The mean deflection at break was highest in Group 1 (Table 2). One way ANOVA and Tukey’s HSD was used to show that mean deflection at break was significantly different for all groups tested (p<0.001) except for groups 2 and 4 (p>0.05). Group 1 differed significantly from all groups (p<0.0001).
Conclusions: Group 1 has the greatest compressive strength and showed the greatest deflection at break for the methods tested.
Methods: Forty cylindrical samples (n=10), measuring 4mm in diameter by 8mm in height were prepared as follows: a glass plate was placed on the bottom of the mold followed by a Mylar® strip. Cement was extruded into the mold. A second Mylar film followed, which was covered by a second glass plate placed on top of the filled mold. Steady pressure was applied to the glass to displace any excess material. The cements were cured (DEMI™, Kerr) in accordance with manufacturers’ instructions and removed from the holder. They were wet-ground using 400-grit sandpaper (EcoMet250, Buehler) to standardize dimensions and then stored in 37○C distilled water for 24 hours. Compressive strength and deflection at break were measured using a universal testing machine (Instron®5566A Norwood, MA) with 1K load cell and 1mm/min cross head speed.
Results: Descriptive statistics were calculated for all groups’ compressive strength. The mean compressive strength was highest in Group 1 (Table 1). One way ANOVA and Tukey’s HSD showed that mean compressive strength was significantly different for each group tested (p<0.001) except for groups 2 and 3 (p>0.05). Descriptive statistics were calculated on deflection at break for all groups. The mean deflection at break was highest in Group 1 (Table 2). One way ANOVA and Tukey’s HSD was used to show that mean deflection at break was significantly different for all groups tested (p<0.001) except for groups 2 and 4 (p>0.05). Group 1 differed significantly from all groups (p<0.0001).
Conclusions: Group 1 has the greatest compressive strength and showed the greatest deflection at break for the methods tested.
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