Effect of Three Bleaching Protocols on Tooth Discoloration Caused by Hemoglobin

• Main Authors: Narges Panahandeh (Author), Shervin Sedighi (Author), Shervin Mohammadkhani (Author), Sogol Nejadkarimi (Author), Amir Ghasemi (Author)
• Format: Book
• Published: Tehran University of Medical Sciences, 2024-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.18502/fid.v21i29.16144; 2676-296X
• Keywords: Tooth Bleaching; Hemoglobins; Hydrogen Peroxide; Oxalic Acid; Sodium Hypochlorite; Dentistry; RK1-715
• Source: Frontiers in Dentistry, Vol 21 (2024)

Objectives: This study assessed the efficacy of different combinations of oxalic acid, 35% hydrogen peroxide, and 5.25% sodium hypochlorite (NaOCl) for bleaching of tooth discolorations caused by hemoglobin. Materials and Methods: In this in vitro study, 40 sound extracted human premolars were disinfected and decoronated. Their primary color parameters were measured (T1). The teeth were then centrifuged with human blood for 3 days, rinsed, polished, and their color parameters were measured again (T2). They were randomly divided into 4 groups (N=10) and treated as follows: Group A: in-office bleaching with Pola-Office Plus followed by 30 seconds of light-curing, group B: 0.24 M oxalic acid for 5 minutes followed by in-office bleaching, group C: 5.25% NaOCl for 5 minutes followed by in-office bleaching, and group D: 0.24 M oxalic acid (5 minutes) followed by 5.25% NaOCl (5 minutes) and subsequent application of in-office bleaching gel. The color parameters of the teeth were measured again (T3). Data were analyzed by one-way ANOVA and paired sample t-test (alpha=0.05). Results: T2-T3 ∆E in groups B and D was significantly higher than that in group A (P<0.05); the difference between groups B and D was not significant. The mean ∆E and ∆L in group C were not significantly different from those in group A (P>0.05). ∆L significantly and equally increased in groups B and D after bleaching. Conclusion: Application of oxalic acid followed by in-office bleaching gel is more effective than the bleaching gel alone for correction of tooth discolorations caused by hemoglobin.