Effect of Immersion of Denture Base Thermoplastic Nylon in Alkaline Peroxide and 10% Castor Oil (Ricinus Communis Oil) on Color Stability and Flexural Strength

Discoloration and flexural strength of denture bases are important factors affecting the comfort and durability of denture users. This study aims to determine the effect of immersion of nylon thermoplastic denture base in alkaline peroxide solution and 10% castor oil (Ricinus Communis Oil) on color stability and flexural strength. This study used a laboratory experimental design with samples of cylindrical (20 x 2 mm) thermoplastic nylon resin for color stability test and rectangular (65 x 10 x 3 mm) for flexural strength test. There were two study groups: one control group and two treatment groups immersed in alkaline peroxide and 10% castor oil solution, with two time variables, 8 days and 12 days. The total number of samples was 60, with each group having 10 samples. The color stability test used a colorimeter, and the flexural strength test used a universal testing machine. The results showed that there was no effect of soaking the nylon thermoplastic denture base in alkaline peroxide on color stability, with a value of p = 0.412 for 8 days and p = 0.179 for 12 days. In addition, there was no effect of immersion in alkaline peroxide and 10% castor oil on flexural strength, with p value = 0.076 for 8 days and p = 0.917 for 12 days. The implication of this study is that immersion in alkaline peroxide and castor oil solution does not affect the color stability or flexural strength of nylon thermoplastic denture bases, making them safe for long-term use.