Composite Filtek Z350 XT Research Articles

Reliability of the color measurement of resin composites using images obtained using a stereoscopic loupe.

This study assessed the reliability of a color measurement method using images obtained from a charge-coupled device (CCD) camera and a stereoscopic loupe. Disc-shaped specimens were created using the composite Filtek Z350 XT (shades DA1, DA2, DA3, and DA4) (n = 3). CIELAB color coordinates of the specimens were measured using the spectrophotometer SP60 over white and black backgrounds. Images of the same specimens were taken using a CCD camera attached to a stereoscopic loupe. The color of the image was measured (red-green-blue [RGB]) using an image processing software and converted to CIELAB coordinates. For each color coordinate, data from images were adjusted using linear regressions predicting those values from SP60. The whiteness index for dentistry (WID) and translucency parameter (TP00) of the specimens as well as the color differences (ΔE00) among pairwise shades were calculated. Data were analyzed via repeated-measures analysis of variance and Tukey's post hoc test (α = 0.05). Images obtained using the loupe tended to be darker and redder than the actual color. Data adjustment resulted in similar WID, ΔE00, and TP00 values to those observed for the spectrophotometer. Differences were observed only for the WID of shade DA3 and ΔE00 for comparing DA1 and DA3 over the black background. However, these differences were not clinically relevant. The use of adjusted data from images taken using a stereoscopic loupe is considered a feasible method for color measurement.

Resistência à compressão de compósitos de preenchimento único

A new class of composite resins called single fill resins (Bulk-Fill) was proposed to simplify restorative procedures. They allow filling dental cavities in layers of approximately 4mm. This study aims to compare the compression strength of single fill composites with different polymerization times. Four Bulk-Fill composites were used Filtek Bulk-Fill, Filtek Bulk-Fill Flow, Tetric N-Ceram Bulk-Fill, and Tetric N-Flow Bulk-Fill, and also a conventional composite Filtek Z350 XT as a control group. One hundred cylinders were manufactured in a matrix with 4.7mm diameter and 4mm height for Bulk-Fill compounds, and 2mm height for the control group. Half of the specimens of each material was photopolymerized for 10 seconds and the other half for 20 seconds (n = 10). The samples were stored in distilled water for 48 hours at 37°C and subjected to compression testing in a universal test machine. Variance analysis was performed with t-test of multiple comparisons between groups and student t-test for the different polymerization times with significance index p=0.05. The results did not show statistically significant difference in relation to polymerization time. However, there was a statistically significant difference between the control and Filtek Bulk-Fill Flow groups, which presented higher strenght to compression than the Filltek Bulk-Fill, Tetric N-Ceram Bulk-Fill, and Tetric N-Flow Bulk-Fill groups. The type of resin can influence its resistance to fracture. The polymerization time did not have any influence in the materials strength.

3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching

This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n = 30) measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n = 10): subgroup A (Opalescence PF), subgroup B (Opalescence Boost in-office bleaching), and subgroup C (distilled water) serving as control. Samples were bleached according to the manufacturer's instructions for a period of two weeks. The Commission Internationale de L'Eclairage (CIE L *, a *, b *) system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM). Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤0.05. The three restorative materials showed significant color changes (ΔE); P ≤ 0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6) > Ketac Nano (2.97 ± 1.2) > Filtek Z350 XT (2.25 ± 1.0). However, none of the tested materials showed statistically significant changes in surface roughness; P > 0.05.