Mauricio Neves Gomes1, Flávia Pires Rodrigues2,3, Nick Silikas4, Carlos Eduardo Francci5. 1. Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo, SP, 05508-900, Brazil. maungomes@gmail.com. 2. Post-graduate Programme in Dentistry, School of Dentistry, Paulista University-UNIP, Av. Dr Bacelar 1212, Vila Clementino, São Paulo, SP, 04026-002, Brazil. 3. Department of Restorative Dentistry School of Dentistry Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, R. Gilberto Studart, 770/901, Cocó, Fortaleza, CE, 60190-750, Brazil. 4. Biomaterials Science Research Group, School of Dentistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. 5. Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, Av. Prof. Lineu Prestes, 2227, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
Abstract
OBJECTIVES: The objective of the present study is to evaluate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on bleached enamel. MATERIALS AND METHODS: A bleaching agent (35% hydrogen peroxide) was applied, 4 × 8 min on premolar teeth (n = 8). A CPP-ACP paste was applied for 7 days. Prior and post-treatment, microtomography images were obtained and 3D regions of interest (ROIs) were selected, from outer enamel, extending to 110.2-μm depth. CT parameters of structure: thickness (St.Th), separation (St.Sp), and fragmentation index (Fr.I.) were calculated for each (ROI). Data was submitted to paired t tests at a 95% confidence level. The samples were evaluated at 3000 to 100,000 magnification. Quantitative analysis of enamel mineral content was also determined by SEM EDX. RESULTS: There was a significant increase in structure thickness and calcium content. The phosphorus content increased after bleaching. There was also a decreased separation and fragmentation index on the outer enamel to a depth of 56.2 μm (p < 0.05). There were no changes at 110.2-μm depth for the bleaching CPP-ACP association. A covering layer and decreased spaces between the hydroxyapatite crystals appeared around the enamel prisms, 7 days after the CPP-ACP application. CONCLUSIONS: The application of a CPP-ACP provides a compact structure on the enamel's outer surface, for 7 days, due to calcium deposition. CT parameters seem to be a useful tool for mineralizing and remineralizing future studies. CLINICAL RELEVANCE: CPP-ACP neutralizes any adverse effects on enamel surface when applied during a week after bleaching and minimizes any side effects of the bleaching treatment due to a more compact structure.
OBJECTIVES: The objective of the present study is to evaluate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on bleached enamel. MATERIALS AND METHODS: A bleaching agent (35% hydrogen peroxide) was applied, 4 × 8 min on premolar teeth (n = 8). A CPP-ACP paste was applied for 7 days. Prior and post-treatment, microtomography images were obtained and 3D regions of interest (ROIs) were selected, from outer enamel, extending to 110.2-μm depth. CT parameters of structure: thickness (St.Th), separation (St.Sp), and fragmentation index (Fr.I.) were calculated for each (ROI). Data was submitted to paired t tests at a 95% confidence level. The samples were evaluated at 3000 to 100,000 magnification. Quantitative analysis of enamel mineral content was also determined by SEM EDX. RESULTS: There was a significant increase in structure thickness and calcium content. The phosphorus content increased after bleaching. There was also a decreased separation and fragmentation index on the outer enamel to a depth of 56.2 μm (p < 0.05). There were no changes at 110.2-μm depth for the bleaching CPP-ACP association. A covering layer and decreased spaces between the hydroxyapatite crystals appeared around the enamel prisms, 7 days after the CPP-ACP application. CONCLUSIONS: The application of a CPP-ACP provides a compact structure on the enamel's outer surface, for 7 days, due to calcium deposition. CT parameters seem to be a useful tool for mineralizing and remineralizing future studies. CLINICAL RELEVANCE: CPP-ACP neutralizes any adverse effects on enamel surface when applied during a week after bleaching and minimizes any side effects of the bleaching treatment due to a more compact structure.
Entities:
Keywords:
35% hydrogen peroxide; Bleaching; CPP-ACP; Color change; Micro-CT; Remineralization