Colour comparison of two composite materials to natural tooth structure: an in vitro study
This in vitro study compares the ability of two composite materials Filtek Supreme XTE™ (3M, ESPE) and CeramX™ Duo (Dentsply) against extracted tooth structure using the modern two layering concept. Fifty six extracted anterior maxillary central incisor teeth were selected which were caries free, had no surface defects and within the colour range A3, B3, C3 or D2. The teeth were randomly divided into four colour groups (A3, B3, C3 and D2), each containing 14 teeth. A class IV cavity was prepared on all the teeth and the two composite materials were used alternately with no bonding agent to restore the cavity. The colour of both composites was assessed immediately after restoration, 24 hours and after two weeks using the SpectroShade™ (MHT) spectrophotometer. The MHT SpectroShade™ version 3.3 software was used with the CIE L*a*b* colour system to evaluate the colour of the teeth and restorations. The Kruskal-Wallis One- Way analysis of variance was used to compare the differences between the medians of the two composite materials. The significance was set at z>3.1237. The Spearman’s rank correlation coefficient was set at a significance of p<0.01 to evaluate colour change (_E*ab) in the restorations over three time intervals (immediate restoration, 24 hours and two weeks).