International Journal of Dentistry

Research Article

Evaluation of the Pulp Oxygen Saturation Reading after Tooth Bleaching: A Randomized Clinical Trial

Table 5

The Spearman correlation value for SpO₂p data and color change (ΔE) data measured at different periods.


SaO₂p reading median (first/third quartiles)	Correlation (Spearman’s Rho test)	Color change (ΔE) median (first/third quartiles)
SaO₂p reading median (first/third quartiles)	Correlation (Spearman’s Rho test)	ΔE1 3.42 (2.90/4.43)	ΔE2 4.75 (3.89/6.54)	ΔE3 5.72 (4.85/6.94)	ΔE Final 5.67 (4.54/6.91)

After 1^st 98.33 (96.33/99.17)	Correlation coefficient Sig. (2-tailed)	0.334	0.406	0.281	0.410
After 1^st 98.33 (96.33/99.17)	Correlation coefficient Sig. (2-tailed)	0.111	0.049	0184	0.047
After 2^nd 99.33 (98.33/99.67)	Correlation coefficient Sig. (2-tailed)	0.346	0.299	0.345	0.332
After 2^nd 99.33 (98.33/99.67)	Correlation coefficient Sig. (2-tailed)	0.098	0.156	0.099	0.113
After 3^rd 99.00 (99.0/100)	Correlation coefficient Sig. (2-tailed)	−0.020	−0.010	−0.052	0.049
After 3^rd 99.00 (99.0/100)	Correlation coefficient Sig. (2-tailed)	0.926	0.963	0.810	0.818
Final 99.00 (98.33/99.33)	Correlation coefficient Sig. (2-tailed)	−0.200	−0.117	−0.285	−0.140
Final 99.00 (98.33/99.33)	Correlation coefficient Sig. (2-tailed)	0.348	0.586	0.177	0.514

The correlation is significant at the 0.05 level (2-tailed). ΔE means the change in teeth color value after each bleaching session (ΔE1: after 1^st; ΔE2: after 2^nd; ΔE3: after 3^rd; and ΔE Final: 1 week after the third bleaching session).