Dental bleaching agents with calcium and their effects on enamel microhardness and morphology

• Main Authors: Andréia Mara Andrade Pizani, Beatriz Tholt, Katia Regina Hostilio Cervantes Dias, Pedro Paulo Albuquerque Cavacanti de Albuquerque, Celso Silva Queiroz
• Format: Article
• Language: English
• Published: Universidade Estadual de Campinas 2015-07-01
• Series: Brazilian Journal of Oral Sciences
• Subjects: Bleaching agents; Calcium; Hydrogen peroxide; Dental enamel
• Online Access: https://periodicos.sbu.unicamp.br/ojs/index.php/bjos/article/view/8640831
• ISSN: 1677-3225

Aim: To evaluate enamel microhardness and morphology after bleaching with hydrogen peroxide containing calcium in different concentrations. Methods: One hundred specimens of human teeth were ground and polished and had the initial microhardness evaluated. The specimens were randomly assigned into five groups (n=20): Group 1 - Control group (no treatment); Group 2 - Home Peroxide 6% (without calcium); Group 3 - Home Peroxide 7.5% (without calcium); Group 4 - White Class 6% (with calcium); Group 5 - White Class 7.5% (with calcium). For each group, the bleaching was performed according to the manufacturer’s specifications. The specimens were bleached once a day for 5 days and subjected to pH cycling. Microhardness and scanning electron microscopy (SEM) analysis were performed before and after bleaching. Results: The results showed that groups submitted to bleaching treatment presented hardness loss compared to the control group. The group of 7.5% hydrogen peroxide with calcium showed a lower percentage of hardness loss in relation to other groups. Conclusion: Calcium in association with a higher hydrogen peroxide concentration may decrease microhardness changes on enamel.