Table 3. Comparison of the oxidative stress index of saliva stored at -20°C and at -80°C at different time points.

Fresh saliva	9.71 ± 1.64
	Freezing at -20°C	Freezing at -80°C	p
15 Days	10.10 ± 1.53	10.50 ± 1.88	0.673
30 Days	10.24 ± 1.55	10.49 ± 1.78	0.233
45 Days	10.31 ± 1.94	10.30 ± 2.05	0.795
60 Days	10.30 ± 1.89	10.29 ± 1.83	0.581
90 Days	9.36 ± 1.18	10.77± 1.03	0.443
120 Days	9.65 ± 1.6	9.39 ± 1.23	0.445