Color Stability, Surface Roughness and Flexural Strength of an Acrylic Resin Submitted to Simulated Overnight Immersion in Denture Cleansers

Autor(es)

Helena de Freitas Oliveira Paranhos ^[1] ; Amanda Peracini ^[2] ; Marina Xavier Pisani ^[3] ; Viviane de Cássia Oliveira ^[4] ; Raphael Freitas de Souza ^[5] ; Cláudia Helena Silva-Lovato ^[6]

Afiliação do(s) autor(es)

^[1] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[2] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[3] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[4] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[5] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[6] USP - University of São Paulo. Ribeirão Preto Dental School. Department of Dental Materials and Prosthodontics - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Dental Journal; v. 24, n. 2, p. 152-156, 2013-04-00.

Resumo

This study evaluated color stability, surface roughness and flexural strength of acrylic resin specimens after immersion in alkaline peroxide and alkaline hypochlorite, simulating a period of one and a half year of use of overnight immersion. Sixty disc-shaped (16X4 mm) and 80 rectangular specimens (65X10X3.3 mm) were prepared from heat-polymerized acrylic resin (Lucitone 550) and distributed into 4 groups (n=20): C1: without immersion, C2: 8 h immersion in distilled water; AP: 8 h immersion in alkaline peroxide effervescent tablet; SH: 8 h immersion in 0.5% NaOCl solution. Properties were evaluated at baseline and after the immersion. Color data were also calculated according the National Bureau of Standards (NBS). Results were analyzed statistically by ANOVA and Tukey's HSD test (α=0.05). AP (2.34 ± 0.41) caused color alteration significantly higher than C2 (0.39 ± 0.30) and SH (1.73 ± 0.52). The mean ΔE values were classified as indicial for C2 (0.36 ± 0.29) and noticeable for AP (2.12 ± 0.39) and SH (1.59 ± 0.48). SH (0.0195 ± 0.0150) caused significantly higher ΔRa (p=0.000) than the C2 (0.0005 ± 0.0115) and PA (0.0005 ± 0.0157) groups. There was no statistically significant difference (p=0.063) among the solutions for flexural strength (C1: 105.43 ± 14.93, C2: 100.30 ± 12.43, PA: 97.61 ± 11.09, SH: 95.23 ± 10.18). In conclusion, overnight immersion in denture cleansing solutions simulating a year and a half of use did not alter the flexural strength of acrylic resin but caused noticeable color alterations, higher for alkaline peroxide. The 0.5% NaOCl solution caused increase in surface roughness. (AU)

• Processo FAPESP: 10/51544-2 - Avaliação de soluções higienizadoras de prótese totais (hipocloritos alcalinos e peróxidos alcalinos) quanto a propriedade de controle do biofilme e aos efeitos adversos sobre a resina acrílica termopolimerizável
• Beneficiário: Helena de Freitas Oliveira Paranhos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/51543-6 - Solucoes higienizadoras de protese total: avaliacao da remocao de biofilme e efeito sobre propriedades da resina acrilica termopolimerizavel.
• Beneficiário: Amanda Peracini
• Modalidade de apoio: Bolsas no Brasil - Doutorado