Resumo

DORINI, Andréia Cristina Ramos et al. Influence of dental bleaching on marginal leakage of class V restorations. RGO, Rev. gaúch. odontol. (Online) [online]. 2010, vol.58, n.1, pp. 55-60. ISSN 1981-8637.

OBJECTIVE: Evaluate the in vitro effect of bleaching performed in the dental office and waiting time on the degree of microleakage in class V cavities with margins in enamel, restored with resin composite. METHODS: Forty-five human third molars were used, in which the vestibular faces were bleached with 35% hydrogen peroxide activated with LED and the palatine faces were not bleached (control). The teeth were randomly divided into 3 groups with 15 teeth in each: Group 1, restored immediately after bleaching; Group 2, seven days after bleaching; and Group 3, fourteen days after bleaching. After cavity preparation, 35% phosphoric acid, Adper Single Bond 2 adhesive (3M ESPE, St. Paul, Mn, USA), and resin composite Filtek Z250 (3M ESPE, St. Paul, MN, USA) were applied. The teeth were thermal cycled and sealed with red nail polish on the bleached faces and blue on the non bleached faces, except for 1mm around the restored region. The samples were classified according to the following scores: 0 = no leakage, 1 = minimum leakage (less than 1 / 3 the length of the wall), 2 = moderate leakage (1/3 to 2/3 of the wall) and 3 = extensive leakage (over 2/3 of the wall). The data were submitted to the Kruskal-Wallis test at a level of significance of 5%. RESULTS: The restorative procedure immediately after bleaching resulted in statistically higher microleakage values (p <0.05) than those in the non bleached group. In seven and fourteen days after bleaching, no statistically significant differences were found among the experimental groups (p>0.05). CONCLUSION: Based on the results, it is advisable to wait at least 7 days after bleaching to make the definitive restoration.

Palavras-chave : tooth bleaching; composite resins; dental restoration permanent.