The aim of this study is to report a case of a nonvital, discolored, maxillary central incisor bleached by 35% hydrogen peroxide gel with the use of glass ionomer cement as a mechanical barrier in an attempt to minimize the undesirable side effects of intracoronal bleaching. The patient was a 13-year-old boy complaining of a discolored nonvital upper-right central incisor and was selected for this study from the pedodontic clinic in the Shibin Elkom teaching hospital in June 2013. After successful endodontic treatment, the Tooth was bleached by 35% hydrogen peroxide gel (Opalescence Xtra), activated by a standard curing light unit, and evaluated for any periapical changes by a periapical radiograph for a nine-months follow-up period. Radiographically, there was no evidence of cervical or apical resorption during the study period.

Objectives: The purpose was to investigate the effect of casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) paste, Remin Pro paste, and 0. 05% sodium fluoride (NaF) mouthwash on teeth discoloration after home bleaching. Materials and Methods: In this in-vitro study, 48 intact and unstained human incisors were divided into four groups (n=12): control (Group 1), CPP-ACPF paste (Group 2), Remin Pro paste (Group 3), and 0. 05% NaF mouthwash (Group 4). The specimens were bleached using 20% carbamide peroxide gel for 21 days and were subjected to pH cycling and surface treatment with remineralizing agents for one month. The color of the specimens was determined according to the CIELAB color space at baseline, after bleaching, and after surface treatment. Data were analyzed using one-way analysis of variance (ANOVA), post-hoc least significant difference (LSD) test, and one-sample t-test (P=0. 05). Results: ANOVA showed a significant difference in the mean Δ E of the four groups after surface treatment (P<0. 05). Post-hoc LSD test showed a significant difference between the mean Δ E of the control group and those of the treatment groups (P<0. 05) with no significant difference between the treatment groups, except for Remin Pro. The mean Δ E and Δ L of the Remin Pro group showed less change than those of the CPP-ACPF and NaF groups, indicating that Remin Pro has the lowest potential for post-bleaching Tooth discoloration. Conclusion: CPP-ACPF paste, Remin Pro paste, and 0. 05% NaF mouthwash cause noticeable teeth discoloration immediately after bleaching. Remin Pro has less effect on Tooth color than the other two products.

Background: bleaching treatments decrease shear bond strength between orthodontic brackets and teeth; although definite results have not been reported in this regard.Objectives: This study determined the effects of different bleaching protocols on the shear bond strength of orthodontic brackets to teeth.Materials and Methods: This experimental study was performed in Iran. Forty-eight extracted human premolars were randomly assigned into four groups. In the control group, no bleaching treatment was performed. In groups 2 - 4, the bleaching procedures were performed using carbamide peroxide 45%, carbamide peroxide 20% and diode laser, respectively. Two weeks later, brackets were bonded to teeth and thermocycled. The shear bond strengths of the brackets to the teeth were measured. Data was analyzed by one-way ANOVA and Dunnett post-hoc test.Results: Shear bond strength of the brackets to the teeth were 10.54±1.51, 6.37±0.92, 7.67±1.01 and 7.49±1.19 MPa, in groups 1 - 4, respectively. Significant differences were found between control group and all other groups (P<0.001); and also between groups 2 and 3 (P<0.05). No significant differences were found between the other groups.Conclusions: The bleaching procedures using 20% carbamide peroxide and 45% carbamide peroxide and diode laser significantly decreased shear bond strength of brackets to the teeth.45% carbamide peroxide had a more significant effect on bond strength compared to 20% carbamide peroxide. The difference in bond strength was not significant between laser group and either carbamide peroxide groups.