[Experimental study on the transparency of different all-ceramic materials and their color changes under different backgrounds].

OBJECTIVE: To evaluate the aesthetic outcomes of all-ceramic restorations by using four different porcelain materials on mimic-tetracycline pigmentation backgrounds.
METHODS: The translucency parameters (TP) of four different all-ceramic restorations (IPS e.max, Cercon, Lava, and Girrbach) were measured under white and black back grounds by using Datacolor 600, and the TP of each group (n = 8) was calculated. Five different mimic-tetracycline pigmentation teeth were printed with different colors by using a colorized printer as the prepared teeth backgrounds, under which the color parameters of each group were measured. The color differences with a standard 2M2 sample were calculated.
RESULTS: The TP values of the all-ceramic restorations were 15.67 +/- 0.58 for IPS e.max, 9.73 +/- 0.43 for Girrbach, 9.55 +/- 0.25 for Lava, and 7.56 +/- 0.43 for Cercon. The TP value of the IPS e.max group was significantly higher than those of the other three groups (P < 0.001). The deltaE of the IPS e.max group was 1.33 national bureau of standards (NBS) on the yellow background, and the deltaE of the Lava and Girrbach groups were 0.75 NBS to 1.47 NBS on the mimic-tetracycline pigmentation backgrounds of gray, dark gray, dark red, and light red.
CONCLUSION: The IPS e.max group has favorable TP. IPS e.max shows better aesthetic effects than the others when restoring mimic-tetracycline pigmentation teeth (on yellow background). Lava and Girrbach show better aesthetic effects on mimic-tetracycline pigmentation teeth (on gray, dark gray, dark red, and light red backgrounds).