Methods: 29 healthy volunteers in demand of tooth whitening participated in this study. Specified bleaching trays were built for maxilla and mandible. Two syringes containing hydrogen peroxide 9% gel were given to each participant to use for 30 min/night for 14 consecutive nights as instructed. To evaluate the oxidative-antioxdative status, the serum concentration of malondialdehyde (MDA) as marker of serum oxidative level, total antioxidant capacity (TAC), and prooxidant-antioxidant balance (PAB) were measured. Data were collected and analyzed in SPSS version 11.5 using the paired sample t-test. The confidence interval was set on 95%.
Results: 23 subjects completed the study. MDA, PAB, and TAC were increased significantly after bleaching period (P=0.001, 0.001 and 0.002, respectively). Although the magnitude of TAC change was not as big as MDA and PAB changes, the effect size of all measures was big (Eta square>0.16).
Conclusions: Results of the current study revealed that tooth whitening with dentist-supervised home bleaching technique could induce detectable oxidative stress in human serum, which must be considered as a serious safety concern.