Mudança de cor e rugosidade do esmalte clareado após tratamentos de superfície e pigmentação por uma bebida à base de cola

• Ano de defesa: 2016
• Autor(a) principal: Marcela Carolina Nunes de Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Pigmentação; Peróxido de Hidrogênio; Esmalte Dentário; Clareamento Dental; Esmalte dentário; Dentes Clareamento; Peróxido de hidrogênio
• Link de acesso: http://hdl.handle.net/1843/ODON-AH8FR4

Products containing pigments may affect the durability of dental bleaching. The aim of this study was to evaluate the effects of surface treatments and extrinsic staining on color change and roughness of bleached enamel, considering the elapsed time for contact with cola-based drink. An experimental in vitro study was conducted and it was outlined according to a randomized complete block design. The independent variables were: surface treatments (6 levels) and elapsed time for contact with cola-based drink (3 levels). The dependents variables were: color change (E, L*, a*, b*), evaluate with a spectrophotometer and surface roughness (Ra, Rz, Rq), measured using an 3D optical profilometer. Three measures for color parameters and surface roughness were performed (baseline, after bleaching and after staining). One hundred and eighty crowns of bovine teeth were divided into 6 groups (n=30), according to surface treatment: G1 - internal control (unbleached and without surface treatment), G2 - negative control (bleached and stored in distilled water), G3 - positive control (bleached and stored artificial saliva), G4 - bleached and treated with 2% neutral sodium fluoride for 4 min., G5 - bleached and treated with Serum Potencializador Regenerate Enamel Science for 3 min., G6 - bleached and polished with felt discs and polishing paste for 15 seconds. Bleaching was performed with 35% hydrogen peroxide and after surface treatments, the specimens were exposed to cola-based drink at different periods: immediate, 24 hours or a week. The effect of surface treatments and elapsed time were analyzed by tests Two-Way ANOVA, Kruskal-Wallis and Wilcoxon (p<0.05). Surface treatments (p>0.05) and elapsed time (p>0.05) were not relevant to maintain color after staining, considering the total color difference (Ep). The analyses of L*p parameter showed significant difference between G2 (86.99±3.86) / G3 (90.34±3.32) (p=0.005), G2 (86.99±3.86) / G4 (89.96±4.27) (p=0.018) and absence of difference statistics between the readings after bleaching and after the staining in G4 (91.58±4.00/89.96±4.27) (p=0.066). Roughness data showed a significant increase in G3 (Ra=0.042±0.016/0.057±0.022 - p=0.002; Rq=0.058±0.023/ 0.079±0.027 - p=0.001), G4 (Ra=0.044±0.020/ 0.064±0.022 - p=0.030; Rq=0.064±0.026/0.089±0.032 - p=0.039) e G6 (Rz=0.609±0.197/0.855±0.385 - p=0.007) after bleaching and in all experimental groups after immersion in cola-based drink (p<0.05), but there was no statistical difference between surface treatments. Surface treatments and elapsed time did not present significant influence in maintaining the color of bleached enamel. Neutral sodium fluoride has a protective effect on maintaining the luminosity after contact with cola-based drink. Enamel roughness was higher after bleaching and contact with cola-based drink. Surface treatments did not protect enamel against the erosive action of cola-based drink.