Changes in color and translucency of porcelain-repairing resin composites after thermocycling

Shade matching potential of one-shade resin composites used for restoration repair

To evaluate shade matching ability of one-shade composites used for repair of different resin-based restorative materials. Two one-shade composites or one layering composite of 1 mm thickness were placed over non-aged or aged 3 different base materials of 1 mm thickness to simulate repair. Two millimeters thick base samples were prepared and used for reference (n=12). Shade measurements of reference and repair groups were performed with dental spectrophotometer and color difference (ΔE₀₀) were calculated according to CIEDE2000. Data were analyzed using three-way ANOVA followed by Tukey's test (α=0.05). Regardless of aging and base materials, repairing with layering composite yielded lower ΔE₀₀ than repair of one-shade composites (p<0.05). Repair of non-aged and aged GrandioDisc with any repair composite led to higher ΔE₀₀ values than repair of other base materials (p<0.05). Shade matching performance of one-shade composites for repair of different non-aged or aged resin-based material was not clinically acceptable.

Translucency changes of direct esthetic restorative materials after curing, aging and treatment

The purpose of this article was to review the changes in translucency of direct esthetic restorative materials after curing, aging and treatment. As a criterion for the evaluation of clinical translucency changes, visual perceptibility threshold in translucency parameter difference (ΔTP) of 2 was used. Translucency changes after curing were perceivable depending on experimental methods and products (largest ΔTP in resin composites = 15.9). Translucency changes after aging were reported as either relatively stable or showed perceivable changes by aging protocols (largest ΔTP in resin composites = -3.8). Translucency changes after curing, aging and treatment were perceivable in several products and experimental methods. Therefore, shade matching of direct esthetic materials should be performed considering these instabilities of translucency in direct esthetic materials.

Difference in the color stability of direct and indirect resin composites

Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree