Abstract
Intra-coronal bleaching is a treatment that whitens non-vital teeth from within the pulp chamber, a procedure by which oxygen and free radicals are released. This in vitro study analyzed and compares the oxygen expansion produced when different bleaching agents encounter dental tissues during this type of bleaching. Here, 120 lower incisors were included and prepared to achieve conditions as close as practicable to internal bleaching with the walking bleach technique. The access cavity of the lingual surface was prepared to seal glass tubes with oil inside them by adhesive restoration once the bleach was placed inside the pulp chamber. The following bleaching groups were used: hydrogen peroxide (HP) 30% (n = 30), sodium Perborate (SP) with distilled water (n = 30), a mixture of HP 30% with SP (n = 30) and a control group (n = 30). After 10 days, the oil displacement that took place through the tube due to oxygen release was measured daily. Displacement of the oil was observed in all groups except the control group. The final mean expansion at 10 days was 335.24 ± 76.85 mm for the HP 30% group, 8.40 ± 1.74 mm for the SP group and 183.07 ± 49.93 mm for the HP30% + SP mixture. Significant statistical differences were observed between the three groups using the Games–Howell post hoc test, where HP30% caused the greatest expansion and SP the least expansion. These results suggest that the higher the amount of HP in the sample, the more oxygen expansion is observed, so that temporary restoration must be performed more carefully to avoid displacement.
Highlights
Treatments that improve dental aesthetics increase the patient’s quality of life and psychological state, as a harmonious smile is positively related to high tests of social, intellectual and occupational competence [1–8].Dental dyschromias vary in aetiology, location and severity, and their origin may be related to extrinsic causes, intrinsic causes or a combination of both [9–13]
Carbamide peroxide (CP), which decomposes into hydrogen peroxide (HP) itself and urea, has been used
This study was designed and conducted in order to objectively measure and compare the expansion resulting from the reactions between hard dental tissues and HP 30%, sodium Perborate (SP) and HP 30% combined with SP during internal bleaching using the walking bleach technique
Summary
Treatments that improve dental aesthetics increase the patient’s quality of life and psychological state, as a harmonious smile is positively related to high tests of social, intellectual and occupational competence [1–8].Dental dyschromias vary in aetiology, location and severity, and their origin may be related to extrinsic causes, intrinsic causes or a combination of both [9–13]. A detailed study of the case must be carried out in order to make an accurate diagnosis, since the success of the treatment and the accuracy of the results will depend on it [9,14,15]. Cases in which only a single tooth in the anterior sector is affected are relatively frequent, and when this occurs the negative effect becomes even more pronounced because the color does not match the rest [2,5,16]. Internal or intra-coronal whitening is a therapeutic option that involves the application of an oxidizing chemical agent, which removes intrinsic stains via chromogenic degradation, and by breaking down the larger pigments into smaller ones the color of the teeth is lightened [17,18]. The most widely used bleaching agents for decades in this type of bleach for devitalized teeth were hydrogen peroxide (HP) and sodium perborate (SP). Carbamide peroxide (CP), which decomposes into HP itself and urea, has been used
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