Effect of dental bleaching on pulp oxygen saturation in maxillary central incisors - a randomized clinical trial.

Daniel De Almeida Decurcio,Carlos Estrela,Marco Antônio Zaiden Loureiro,Isabella Negro Favarão,Ana Helena Gonçalves De Alencar,Julio Almeida Silva,Fernando Branco Barletta,Lorena Ferreira Lima

doi:10.1590/1678-7757-2018-0442

Abstract

Objective To assess pulp oxygen saturation levels (SaO2) in maxillary central incisors after dental bleaching.Materials and Methods 80 participants (160 teeth) were randomly allocated to four groups: G1 In-office bleaching with two applications of 35% hydrogen peroxide (HP) (20 minutes), followed by at-home bleaching with 10% carbamide peroxide (CP) (2 hours/day for 16 days); G2 - Same protocol as G1, plus desensitizing toothpaste; G3 - In-office bleaching with 35% HP and one application of placebo gel (20 minutes), followed by at-home bleaching with 10% CP (2 hours/day for 16 days); and G4 - Same protocol as G3, plus desensitizing toothpaste. Pulp SaO2 levels were measured before (T0) and immediately after (T1) in-office bleaching; on the 5th (T2), 8th (T3), 12th (T4), and 16th days of at-home bleaching (T5); and on the 7th (T6) and 30th (T7) days. Mean (SD) pulp SaO2 levels were compared within groups by generalized estimating equations (GEE) and Student’s t-test (P<0.05).Results Mean pulp SaO2 at T0 was 84.29% in G1, 84.38% in G2, 84.79% in G3, and 85.83% in G4. At T1, these values decreased to 81.96%, 82.06%, 82.19%, and 81.15% in G1, G2, G3, and G4 respectively, with significant difference in G4 (P<0.05). During home bleaching, pulp SaO2 levels varied in all groups, with 86.55%, 86.60%, 85.71%, and 87.15% means at T7 for G1, G2, G3, and G4, respectively; G2 presented significant difference (P<0.05).Conclusions Pulp SaO2 level in maxillary central incisors was similar at baseline, reducing immediately after in-office bleaching, regardless of using desensitizing toothpaste and increasing at 30 days after dental bleaching.

Highlights

The search for a smile that conveys health and beauty is a common reason for seeking dental care
There are two types of dentist-supervised bleaching techniques: at-home or in-office bleaching,2 and both techniques usually employ products based on hydrogen peroxide or carbamide peroxide
Of the 80 subjects selected for this study, 21.25% withdrew during the clinical intervention period, and 2.5% were excluded due to severe tooth sensitivity (TS)

Summary

Introduction

The search for a smile that conveys health and beauty is a common reason for seeking dental care. Some authors have proposed a combined bleaching technique to combine the benefits of both techniques, such as the minimal adverse effects of at-home bleaching and the faster whitening potential of inoffice bleaching.. A recent multivariable logistic regression analysis reported a 51% probability of developing TS after home bleaching and 62.9% after in-office bleaching.. A recent multivariable logistic regression analysis reported a 51% probability of developing TS after home bleaching and 62.9% after in-office bleaching.1 Given this context, some authors have proposed changes in bleaching techniques, such as the reduction of contact time of bleaching gels in in-office procedures, the addition of substances to bleaching agents, and the use of desensitizing agents or dentifrices. Tooth sensitivity (TS) is a very common side effect of dental bleaching, causing discomfort in two-thirds of patients who undergo dental bleaching. A recent multivariable logistic regression analysis reported a 51% probability of developing TS after home bleaching and 62.9% after in-office bleaching. Given this context, some authors have proposed changes in bleaching techniques, such as the reduction of contact time of bleaching gels in in-office procedures, the addition of substances to bleaching agents, and the use of desensitizing agents or dentifrices.

Methods

Results

Conclusion