Optical Properties of Veneer Materials

Objective: To evaluate translucency parameter (TP), Yellowness Index (YI, ASTM E313-73), Whiteness Index (WI, CIE Ganz 82), and Tappi Brightness (TB, T525 - 1986) of veneer materials. Materials and Methods:

Specimen preparation and positioning: Specimens (15 × 12 mm, 0.7-mm thick, n=5 per shade) were made. Shades A1, A2 and A3 of materials for veneers – 3M Paradigm (3M ESPE) and Vita Mark II (Vita Zahnfabrik) were used. TP was recorded three times for each specimen using a spectrophotometer using both the white and black background. Means and standard deviations were determined. The data was evaluated by analysis of variance. Fisher's PLSD interval for comparison of means was calculated at the 0.05 level of significance.

Results:

Table. Means (s.d.) of translucency parameter (TP). Yellowness Index (YI, ASTM E313-73), Whiteness Index (WI, CIE Ganz 82), and Tappi Brightness (TB, T525 - 1986)

Material	Shade	TP	YI	WI	TB
Paradigm	A1	23.7 (0.6)a	15.7 (0.2)	23.4 (0.4)	46.1 (0.5)
	A2	23.7 (0.4)a	22.8 (0.1)	2.6 (0.8)	42.2 (0.6)
	A3	23.4 (1.9)a	24.8 (0.4)	-4.4 (3.6)	40.3c (2.4)
Mark II	A1	19.7 (0.8)b	14.7 (0.2)	26.2 (0.8)	46.6d (1.0)
	A2	19.2 (0.4)b	20.3 (0.4)	13.4 (2.3)	45.5d (1.0)
	A3	19.3 (1.0)b	27.8 (0.6)	-8.2 (2.7)	40.8c (1.0)
Means marked with the same super-scripted letter are not statistically different.

Fishers PLSD critical differences are 0.8 for TP, 0.3 for YI, 2.0 for WI, and 1.1 for TB. p<0.0001.

Conclusion: Within the limitations of this study, Paradigm exhibited higher translucency than Mark II (p<0.0001)

Acknowledgment: Supported in part by 3M, Seefeld, Germany. Funded by NIH T32DE015355 and by UT Dental Branch at Houston Student Research Funds.