EFFECT OF REPRESSING ON THE COLOR AND TRANSLUENCY OF LITHIUM DISILICATE PRESSABLE CERAMIC MATERIAL

Abstract

as chemical composition and thickness. In clinical practice, pressable ceramics were found to be frequently subjected to repressing. Nonetheless, the effect of the repressing on the color stability and translucency have been unknown.OBJECTIVES: The aim of this study was to investigate the effect of repressing on the color and translucency of a lithium disilicate pressable ceramic material (e.max press).MATERIALS AND METHODS: twenty-four disc-shaped ceramic specimens (IPS e.max press ingots) 14 mm in diameter and 1.5 mm thick were divided into two parallel groups: press group and repress group. Each group had 12 specimens. Pressing was performed for e.max press ingots. Repressing was performed using the remaining material resulting from the pressing procedure. Color difference and translucency were measured using a portable spectrophotometer (VITA easy shade Advance). Translucency parameter (TP) was measured on black and white backgrounds. The resultant data were analyzed statistically using Kruskal-Wallis non-parametric test.RESULTS: There was a statistically significant difference in color change after repressing. (p=0.005). e.max pressed group produced color difference (ΔE) values of (3.88±1.12). This (ΔE) values was more than the selected clinical perceptible threshold selected for this study (ΔE=2.6). Moreover, e.max pressed group showed statistically significant decrease in translucency after repressing (p=0.002).CONCLUSIONS: The color of e.max press was affected by repressing with statistically significant decrease in translucency.