| 1280 Reinforcement of Traditional Glass-ionomer Cement | ||
|
G. HERNANDEZ, Y. OSHIDA, J.A. PLATT, and C.J. ANDRES, Indiana University, Indianapolis, USA Introduction: There has been an attempt to use glass ionomer cement (GIC) as restorative materiala. Because of its lack in mechanical properties, such as fracture toughness or modulus of elasticity, this material has been not been used on occlusal surfaces. Objective: The purpose of this study was to modify the powder portion of traditional GIC in order to improve mechanical properties (break strength, rigidity, and toughness). Materials and Methods: Fluroaluminosilicate glass ionomer powder was admixed with titania (TO), zirconia (ZO), alumina (AO), hydroxyapatite (synthetic) (HA), and bovine-bone originated hydroxyapatite (BB). Poly(acrylic acid) 35%, 30% and 25% liquids were employed to harden. Four different mixing rates; 2%vol, 5%vol, 10%vol, and 15%vol were examined. Using split molds, 12 samples (27x2x2mm) were fabricated for each combination (of oxide type, liquid concentration, and vol% addition) with powder/liquid ratio of 2:1. After 1 week in 37oC storage, samples were tested under 3-point bending (crosshead speed of .75mm/min). Control sample group was fabricated without incorporating with oxide powder. To ascertain any significant differences, a standard one-way ANOVA for each of averaged values of the three mechanical properties was performed. Results: (1) The 25% poly(acrylic acid) liquid produced highest control group with strength of 21.31(SD:4.39) MPa, rigidity of 3.913(1.334) GPa and toughness of 0.32(0.11) N-mm and these were significantly higher (p<0.05) than those from samples fabricated with 30% and 35% liquids. (2) Statistically samples with 10vol% of oxide powder incorporated to GIC powder exhibited higher strengths, rigidity and toughness (p<0.05). (3) TO addition exhibited the highest strengths of 24.78(5.76) MPa, ZO showed the highest rigidity of 4.38(1.06) GPa, and AO provided the highest toughness of 0.87 (0.17) N-mm. Conclusion: The mechanical parameters (strength, rigidity, and toughness) of the traditional glass ionomer cement were improved by incorporating with 10vol% of metallic oxide powders. | ||
| Seq #163 - Other Ceramics and Cements 3:45 PM-5:00 PM, Friday, 14 March 2003 Henry B. Gonzalez Convention Center Exhibit Hall C | ||
|
Back to the Dental Materials: III - Ceramics and Cements Program
| ||