Objectives: The purpose of this study was to quantify the light transmission of different zirconia-ceramic framework materials.
Methods: Disk shaped specimens were fabricated in three clinical relevant thicknesses (0.3, 0.5, 1.0 mm) of various types of zirconia-ceramics with comparable color: ZPS) TZP-A porously sintered (Lava, 3M ESPE), ZHIP) TZP-A BioHIP (Metoxit), ZNAN) Nano Zr, ZACF) Zirluna (ACF). Light transmission through specimens (3/group) was determined in a spectrophotometer with an integrating Ulbricht sphere (Lamda35, UV-VIS, PerkinElmer) by measuring the transmission coefficient (tc) [%] for wavelengths from 400 to 700 nm. Overall tc was calculated by evaluating the integral ∫400-700 tc (l) dl [10-5].
Results: Given as mean values of overall tc (SD):
Thickness[mm]
| ZPS
| ZHIP
| ZNAN
| ZACF |
0.3
| 2897 (330)
| 2671 (42)
| 132 (17)
| 2618 (135) |
0.5
| 2326 (307)
| 1979 (91)
| 99 (10)
| 2566 (65) |
1.0
| 1515 (231)
| 643 (20)
| 6 (1)
| 1728 (275) |
ANOVA showed significant (p<0.05) differences among overall tc values depending on zirconia-ceramic type (p<0.001) and thickness (p<0.001). Post-hoc test indicated statistic differences between the 3 different thicknesses (Student-Newman-Keuls). Statistic differences were detected between ZNAN, ZHIP and ZACF/ZPS (Student-Newman-Keuls).
Conclusion: Especially Nano-Zirconia showed significantly lower translucency. Given to the high masking power ZNAN should be preferred in cases with severely discolored abutments.
This study was partially supported by 3M ESPE