Temporary fixed prosthesis materials and beverage colorants: an in vitro study

Area of Science:

• Dental Materials Science
• Prosthodontics
• Esthetic Dentistry

Background:

• The esthetic appearance of temporary dental prostheses is critical, particularly for anterior restorations.
• Evaluating the color stability of temporary restorative materials is essential for maintaining predictable esthetic outcomes.

Purpose of the Study:

• To compare the color stability of three temporary restorative materials: self-curing (SC) acrylic resin, heat-curing acrylic resin (polymerized via pressure or flasking techniques), and computer-aided design/computer-aided manufacturing (CAD/CAM) polymethyl methacrylate resin blocks.
• To assess the influence of different polymerization methods and staining agents on the color stability of these materials.

Main Methods:

• Four experimental groups were established: SC acrylic resin, heat-curing acrylic resin (pressure technique - PT), heat-curing acrylic resin (flasking technique - FT), and CAD/CAM resin blocks.
• Specimens were polished and subsequently immersed in pigmented beverage agents (coffee, cola, turmeric, tea) for four weeks.
• Color change was quantitatively evaluated using Fourier-transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy, alongside macroscopic observation.

Main Results:

• CAD/CAM resin blocks exhibited the most significant color stability with minimal color variation.
• Heat-curing acrylic resin polymerized with the flasking technique (FT) showed less color change than self-curing (SC) and pressure technique (PT) heat-curing resins.
• Turmeric solution caused the most pronounced staining among the tested agents.

Conclusions:

• CAD/CAM resin demonstrates superior color stability among the evaluated temporary restorative materials.
• Material type, polymerization technique, polishing, staining agent, and exposure duration significantly influence the color stability of temporary dental prostheses.
• The findings provide valuable insights for material selection to ensure long-term esthetics in temporary restorations.