Table 2.

a ^∗ value and difference before and after the aging of silicone rubber specimens coated with nano-TiO₂ with different concentrations of silicon and aluminum (F = 20779.00, P < 0.05).

Chromatic aberration	Concentration
	0%	0.05%	0.10%	0.15%
Front	37.96 ± 0.30	29.30 ± 0.36	26.13 ± 0.26	16.94 ± 0.52
After	23.10 ± 0.23	26.62 ± 0.44	25.14 ± 0.24	15.69 ± 0.57
Δa∗	−14.86 ± 0.14	−2.69 ± 0.09	−0.99 ± 0.04	−1.25 ± 0.11