engleski

Effects of hydroxyapatite on the mechanical properties of glassionomer cements

The purpose of this in vitro study was to evaluate the effects of incorporation hydroxyapatite (HA) into glass-ionomer cements (GIC) on the mechanical properties. Two commercially available GICs were used in this study: Fuji II LC and Fuji IX extra GP. Cylindrical shaped specimens (4x6 mm) were used for compressive strength (CS) testing, and 6x3 mm for diametral-tensile strength (DTS) testing. For the flexural strength (FS) testing bar shaped specimens (2x2x25 mm) were made. Four groups (n=11-18) were prepared for each material group. The first group served as a control, without addition of HA, while the other three groups were modified by incorporation of HA 2, 5 and 10 % by weight. Samples were left in distilled water for 1 week before testing and were tested on Universal testing machine, Shimadzu. Statistical analysis was performed using ANOVA and Tukey test. Results showed significantly higher values in all three tested mechanical properties for Fuji II in comparison to Fuji IX. Regarding Fuji IX, control group had the highest values for CS (111.3±31.2 MPa) and FS (15.6±5.0 MPa). The only significant difference was observed in CS in comparison to group modified with 2% HA. Regarding Fuji II, the group modified with 5 % HA had the highest values for DTS (14.3±2.6 MPa) and CS (158.3±25.5 MPa), although not statistically significant. The highest average FS value for Fuji II, significantly different from the control group, was recorded in the group modified with 10 % NHA (48.4±8.7 MPa).Fuji II has better mechanical properties then Fuji IX. Hydroxyapatite incorporated in Fuji II and Fuji IX showed no significant impact on mechanical properties. Only Fuji II modified with 10% NHA showed most favorable results with respect to flexural strength.

Hydroxyapatite ; mechanical properties ; glassionomer cements

nije evidentirano