Objective: In an in vitro study to determine the colour stability of provisional restoration materials, the PMMA synthetics Trimm and Cronsin and the bis-acrylic composites Protemp Garant, Protemp Garant NF, Protemp II and Provipont DC were investigated.
Materials and methods: The colour changes of the cylindrical untreated samples were measured in comparison with samples after 24 and 72 hours of artificial ageing in a Suntest CPS+ UV ageing device using the Minolta CM 3500d spectrophotometer according to the CIE-L*a*b* system.
Results: Trimm (light), Cronsin (brown, yellow and universal), Provipont DC (yellow) and Protemp Garant NF (extra light) displayed the greatest discoloration with values > or = 4-21 delta E, where discoloration toward yellow could be discerned. The remaining materials showed lower luminance reflectance values of < or = 1-4 delta E, and therefore greater colour stability.
Conclusions: Because of their colour stability the materials Cronsin (grey), Protemp Garant (yellow), Protemp II (light), Protemp Garant NF (yellow, light and extra light) could also be used as long-term interim prosthetics.