Color stability of provisional crown and fixed partial denture resins.

Statement Of Problem: Provisional resins are used extensively during fixed prosthodontic treatment and exhibit varying degrees of color change/discoloration over time. Data are needed to help predict color stability of provisional resins.

Purpose: The purpose of this in vitro study was to measure the color change of 12 provisional prosthodontic materials after immersion in artificial saliva and artificial saliva-coffee solutions for 1, 2, and 4 weeks.

Material And Methods: Twelve provisional materials were studied. Methacrylates consisted of Alike, Jet, Temporary Bridge Resin, Unifast, and Zeta CC. Bis-acryl resins included Instatemp, Integrity, Luxatemp, Protemp Garant, Provipont, Provitec, and Temphase. Ten specimens (25.4 mm x 25.4 mm x 2.4 mm) of each material were fabricated. Five specimens were stored at 37 degrees C in artificial saliva and 5 were stored in a solution of artificial saliva (400 cc) and coffee (800 cc). Baseline color was measured using a colorimeter. Further color measurements were made after 1, 2, and 4 weeks of immersion. CIE L *a *b * values were recorded and color differences (DeltaE) between baseline and each storage interval were calculated using a 2-way ANOVA with Bonferroni adjustment for multiple comparisons in conjunction with an overall alpha=.05.

Results: Results indicated the presence of strong interaction between material and storage solution regardless of the aspect of color considered (P<.0001 for DeltaE, DeltaL *, Deltaa *, and Deltab *). Coffee solution relative to saliva solution had the most significant impact on color change for Luxatemp, Protemp, and Temphase materials at 4 weeks, but the greatest overall color change for both coffee and saliva solutions was found for Provipont (DeltaE=9.40 coffee; 8.51 saliva) and the least overall color change for both solutions was found for Zeta CC (DeltaE=0.31 coffee; 0.23 saliva).

Conclusions: Under the conditions of this study, 12 provisional crown and fixed partial denture resins demonstrated varying tendency to discolor over a range of time periods when immersed in artificial saliva and artificial saliva-coffee solutions.