Poly(methyl methacrylate) resin (PMMA) and conventional glass ionomer cement (GIC) are frequently used as dental restorative materials, as well as bone cement materials. The common drawbacks associated with these materials are relatively poor mechanical properties. Among various ways to improve mechanical properties, this study used incorporating method of metallic oxide powders. The 3-point transverse test showed that for PMMA. that total 1% admixing of titania and zirconia (mixed 1:1 fraction) and 2% of these oxides (mixed 1:2 and 2:1 fractions) exhibited significant beneficial effects on the mechanical properties (p<0.05). For GIC. it was found that (i) statistically samples with 10vol% of oxide powder incorporated to GIC powder exhibited higher strength, rigidity and toughness (p<0.05), and (ii) TiO2, ZrO2, and Al2O3 addition exhibited the highest strength (26-27MPa), zirconia showed the highest rigidity (5.5GPa) and alumina provided the highest toughness (0.7 N-mm).