Irritation on marginal gengiva and dentin hypersensitivity after dental bleaching

Dentin hypersensitivity (DH) and irritation on marginal gengiva (IM) are collateral effects which could occur during sound-teeth bleaching. Objectives: to compare DH levels and to observe the incidence of IM in 36 volunteers submitted to bleaching in dental office (OF) with 37% carbamide peroxide (P37) and/or “at home” bleaching (AH) with 10% carbamide peroxide (P10) or a placebo gel of Carbopol 934P (PG). Methods: the volunteers were divided into four groups according to the technique and the bleaching agent: G1: OF+P37 and AH+P10; G2: OF+P37 and AH+PG; G3: OF+PG and AH+P10; and G4: OF+PG and AH+PG. Three sessions of OF and 21 assays of AH were carried out in three weeks. All volunteers filled a questionnaire in about the presence of IM or DH. In addition, they classified the DH as light (LH), moderate (MH) or severe (SH) through a visual analog scale (VAS). Results: considering IM, G1 presented a prevalence of 67%, G2 33%, G3 67% and G4 0%. DH values were submitted to the Kruscal Wallis test. No statistically significant differences were observed among DH severity considering G1, G2 and G3. However, these groups showed statistically significant differences (p<0.05) when compared to G4 (0% of DH). G1 presented 11% of LH, 44% of MH and 22% of SH, while G2 presented 33% of LH, 44% of MH and 0% of SH and G3 presented 33% of LH, 44% of MH and 11% of SH. Conclusion: there is no difference among the DH severity induced by the different bleaching techniques, but the AH bleaching caused higher prevalence of IM.