The effect of different curing times on the hardness, fracture resistance and color change of visible light cured denture base resin

الملخص EN

Aim: To evaluate the effect of the organic acid solution on color stability of the facing heat-cured acrylic resin.

Materials and methods: Two heat-cured facing acrylic resins were used in this study.

Sixty four rectangular shape specimens were prepared to evaluate the color changes of the heat-cured acrylic resin after immersion in three organic acids (acetic, citric and lactic acids).

The specimens were divided into two groups according to tested resin materials, and then subdivided into four tested groups according to immersion solution, eight specimens for each subgroup.

The assessment of color property (opacity) done by using ultra-violet visible spectrophotometer at wavelength 345 nm.

Mean values were compared statistically with one way analysis of variance (ANOVA) followed by Duncan , s multi¬ple range test to determine the significant difference among the tested groups at (p<0.05) level of sig¬nificance.

Results: The results showed that there is a significant difference of the means value of the color change among the four tested groups for both tested materials for two different immersion peri¬ods, but there is no significant difference of color change between tested materials.

Specimens im¬mersed in acetic acid have a higher value than that immersed in other organic acids.

Conclusion: The result of this study show that immersion in organic acids for different immersion periods had a signifi¬cant effect on color stability of the facing heat-cured acrylic resin cured acrylic resin Key words : color change , heat-cured acrylic resin, organic acids