Effect of Ortho-Phthaladehyde Disinfectant on Color Stability of Two Different Acrylic Resin Teeth Using Spectrophotometer

Abstract

Background: Prosthodontics procedure usually be contaminated by saliva, blood and secretion. The American Dental Association has recommended to disinfect dentures using intermediated-level chemical disinfectants at least for preventing cross-contamination and decreasing the spread of infection. Ortho-Phthaladehyde (OPA) is a high-level disinfectant with rapid onset and easy to use. However, Studies support effectiveness of OPA in dentistry still limited. Objective: The purpose of this study was to evaluate the effect of OPA disinfectants on the color stability of acrylic denture teeth using spectrophotometric analysis. Methods: A two different brands of acrylic central incisor were Cosmo and Major dent. The specimens from each band (n=30) were randomly divided into 2 groups (n=15) and immersed in distilled water (control group) and OPA. Each acrylic tooth was immersed repeatedly and measured the color using a spectrophotometer at the end of cycle 1, 5, 10, 20, 30, and 50. Color differences (∆E*)were then evaluated using CIE Lab system. Friedman, Mann-Whitney U and Wilcoxon signed rank tests were used as a statistical analysis at 95% confidence level. Result: There were decreases in ∆L*∆a*∆b* of an acrylic tooth from both brands after immersion in OPA. Both brands of acrylic teeth showed significant differences in ∆E* values (p < 0.05) between the control and the experimental group after cycle 1, 20, 30 and 50 of an immersion. In addition, the ∆E* values increased along with the number of immersion cycles and became highest when the tooth was immersed for 50 cycles. While comparison between Cosmo and Major dent displayed a significant difference in ∆E* values after immersion for 10 cycles.  Conclusion: OPA disinfectant can significantly alter color stability of acrylic resin teeth. The number of repetitive immersion cycles and the type of acrylic denture teeth can affect the change in color stability with a significant difference.