Roughness and stability of compound resin color exposed to bleaching strips after surface treatment / Rugosidade e estabilidade de cor após clareamento caseiro

ABSTRACT Objective to analyze the surface roughness and color stability of the composite resin after surface treatment with the aluminum oxide discs and subsequent exposure to the Advanced Teeth Whitening Strips. Methods 20 specimens of the Filtek Z350XT restorer (3M®) were prepared and daily subjected to home bleaching for 30 minutes during 14 days. A precision rugosimeter was used in order to verify the roughness by means of 3 random readings in the same direction in each sample. For color stability the CIELAB system (L*, a*, b* values) was used through the spectrophotometer (MINOLTA CR -321, Japan). The means of the test specimens as well as the mean of each group were calculated using the random readings. Data statistical analysis were performed by ANOVA- analysis of variance. The level of significance was set at 5% (p ≤ 0.05). Results Roughness did not present great numerical variations. No statistically significant difference between the means obtained concerning the surface roughness of the composite resin with p = 0.44 was observed. However, it was found that there was a statistically significant difference between the means obtained in relation to the color stability of the composite resin, p=0. 007. Conclusion It was concluded that pre-contoured strips containing 6% hydrogen peroxide do not have a significant adverse effect on the roughness of Z350XT (3M®) resin. However, it was also concluded that according to the color stability analysis performed, there may be an indication of the restoration replacement after the bleaching treatment, due to their color change.

RESUMO Objetivo Analisar a rugosidade superficial e a estabilidade da cor da resina composta após tratamento de superfície com os discos de óxido de alumínio e posterior exposição à fita clareadora Advanced Teeth Whitening Strips. Métodos Foram confeccionados 20 corpos de prova do restaurador universal Filtek Z350XT (3M®), estes, foram submetidos ao clareamento caseiro por 30 minutos diários durante 14 dias. Utilizou-se um rugosímetro de precisão para verificação da rugosidade através de 3 leituras aleatórias no mesmo sentido em cada amostra, e para estabilidade de cor foi utilizado o sistema CIELAB (valores L*, a*, b*), através do espectofotômetro (MINOLTA CR-321, Japão). As leituras coletadas possibilitaram o cálculo das médias dos corpos de prova e a média de cada grupo. Em seguida, os dados foram submetidos a tratamento estatístico pela análise de variância ANOVA. O nível de significância estabelecido foi de 5% (p≤0,05). Resultados a rugosidade não sofreu grandes variações numéricas e também não houve diferença estatisticamente significantes entre as médias obtidas em relação a rugosidade superficial da resina composta (p=0,44). Contudo, verificou-se que houve diferenças estatisticamente significantes entre as medias obtidas em relação à estabilidade de cor da resina composta, com p= 0,007. Conclusão As fitas pré-contornadas contendo peróxido de hidrogênio a 6% não provocam efeito adverso significantes sobre a rugosidade da resina Z350XT (3M®). Contudo, também concluímos que, de acordo com a análise de estabilidade de cor realizada, poderá haver indicação da substituição das restaurações após o tratamento clareador devido à alteração na coloração das mesmas.

Tooth fragment re-attachment in fracture with biological width violation: case

ABSTRACT: Dento-alveolar traumas are one of the most frequent injuries to teeth, mainly affecting the upper incisors due to their exposed position in the dental arch. In such cases, esthetics, function and phonetics of anterior teeth may be compromised. Furthermore, when there is involvement of the biological width, there is often a poor prognosis. This case report describes the multidisciplinary approach to tooth fragment re-attachment in a fracture with biological width violation. The patient presented with an oblique crown fracture in the maxillary right lateral incisor, extending from the buccal to palatal side, as well as a biological width invasion. The re-establishment of the biological width was obtained by periodontal surgery to achieve clinical-crown lengthening and tooth fragment re-attachment with a glass fiber post to increase retention. After 3 years of follow-up, the rehabilitated lateral incisor remains in good condition, with satisfactory esthetic and periodontal health.