Fig. 6

NAC resulted in decreased levels of IL-8 secretion in saliva after bleaching in patients. Patients’ saliva samples were collected immediately before and after the bleaching procedures, as well as every two hours post-procedure for the first 10 h, and on daily bases for 5 days. The levels of IL-8 obtained at the pre-bleaching saliva samples were used as the baseline to calculate the fold-change of IL-8 secretion in subsequent time points. The mean fold-change values were plotted for both H2O and NAC-treated patients across all time points (a). A combined scatter plot, along with mean and standard deviation, from the 4-h post bleaching to day 3 post-bleaching was generated to examine the distribution of IL-8 changes. Control patients (n = 20) demonstrated higher IL-8 fold change values compared to NAC patients (n = 20), with a P-value of 0.038 (b)