Analysis of colour stability of selected provisional prosthetic materials: an in vitro study

Abstract

Prosthetic restorative materials (that are) used for temporary fixed dentures tend to exhibit variable discolouration over several weeks of use. The aim of this study was to perform a spectrophotometric analysis of the influence of selected discolouring factors on the colour stability of provisional prosthetic materials in vitro. In the study, the following prosthetic materials for short-term use in the oral cavity were evaluated: Luxatemp, Structur 2S.C., Protemp II, Zhermacryl STC and Dentalon Plus. Samples of these materials were immersed in coffee, tea and dark fruit juice for 60 h at different pH values. Colour was evaluated by determining the monochromatic coefficients of light reflected by the samples, using a spectrophotometric method. Results received in artificial light (illuminant A) were compared with those obtained in daylight (illuminant D65). Changes in colour and its parameters according to the CIE L*a*b* system were analysed. The analysis (of the colour and colour parameters) of the tested materials in two types of light showed that Structur displayed the greatest tendency to discolouration and that the least tendency to discolouration was exhibited by Dentalon Plus. The fact that colour parameters obtained in two types of light were not identical suggests that changes in the colour of the same material may be perceived differently, depending on the illuminant. Provisional prosthetic materials show variable colour stability under different conditions in the oral cavity. The colour of prosthetic materials may be perceived differently, depending on the illuminant and the effect of the environment in which they are used.

Comparison of color stability and fracture resistance of two temporary fiber-reinforced fixed partial denture materials

“…These important ingredients can penetrate deep into the prosthetic material through both absorption and adsorption. [17] The discoloring potential of the agent increases with an increase in its molecular weight. [18] Therefore, the color of coffee is considered strong and stable.…”

“…The staining mechanism of coffee in polymeric materials (polyethylene, polypropylene, polyester, and polyamides) is explained in two ways: the first explanation involves absorption of coffee pigments into the material and the second one involves an ionic interaction with amine groups. [17]…”