Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles

Abstract

Objective:To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3).Materials and Methods:The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test.Results:There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances.Conclusion:It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

Effect of disinfection techniques on physical-mechanical properties of a microwave-activated acrylic resin

“…When a lower peracetic acid concentration (1%) with 30 minutes of immersion was evaluated, it did not affect the surface roughness [12] . The acrylic resin surfaces roughness is an important property, as an increased roughness can promote attachment of microorganisms and the colonization of the surface [4] .…”

“…In addition, complete dentures contaminated by Candida albicans are a potential source of infection and re-infection of the oral soft tissues, and its disinfection has been recommended as an adjuvant in the treatment of stomatitis and as an essential procedure for maintaining a healthy oral mucosa [7,8] . Many protocols for denture disinfection have been proposed, including immersion in chemical solutions such as glutaraldehyde [9] , sodium perborate [10] , sodium hypochlorite [11,12] , chlorhexidine digluconate [7] , peracetic acid [11,12] , and microwave irradiation [7,13] . Ideally, the choice of the disinfectant method should be made with regard to its effectiveness in inactivating microorganisms without detrimental effects on the acrylic resins.…”

“…However, only the effects on the hardness and flexural strength were verified with 1 minute of microwave irradiation exposure at high power [22] . Peracetic acid (C 2 H 4 O 3 ) has been suggested to be used for acrylic resins disinfection [11,12,25] , acting even at low concentrations with a broad antimicrobial spectrum and producing no harmful by products [25,26] . The disinfection efficacy of immersion in 0.2% peracetic acid-based disinfectant has been shown in the literature, including against Candida albicans [17,25] .…”

“…Likewise, immersion in a chemical solution may cause water sorption and polymer solubility, altering the polymer structure [9] . Despite color stability and surface roughness, its effect on the physical-mechanical properties of microwave-activated denture base acrylic resins have not been evaluated [11,12] . The aim of this study was to investigate the effects of two methods of disinfection, microwave irradiation at 840 W for 1 minute and immersion in 0.2% peracetic acid for 5 minutes, on the Knoop hardness, flexural strength, flexural modulus, Izod impact, water sorption and solubility, glass transition temperature, and degree of conversion of one type of microwave-activated denture base acrylic resin.…”

Avaliação dos efeitos adversos de soluções desinfetantes nas propriedades físicas e mecânicas de materiais para confecção de próteses totais

“…O método químico consiste na imersão da prótese em substâncias químicas com diferentes componentes e mecanismos de ação com objetivo de desorganizar o biofilme e causar a morte dos microrganismos. Vários são os estudos clínicos e laboratoriais que avaliam os efeitos dessas soluções sobre as propriedades físicas e mecânicas da resina acrílica de base, dentes artificiais, reembasadores para próteses totais e metais, bem como a capacidade de remoção de biofilme e atividade antimicrobiana (Davi et al, 2012;Pellizaro et al, 2012;Altieri et al, 2013;Rodrigues et al, 2013;Savabi et al, 2013;Vasconcellos et al, 2013;Al-Saadi, 2014;Amin et al, 2014;Freire et al, 2014;Kurtulmus-Yilmaz;Deniz, 2014;Oliveira et al, 2014;Paranhos et al, 2014;Salloum, 2014;Sczepanski et al, 2014;Tobouti et al, 2016;Yildirim-Bicer et al, 2014;Amin et al, 2015;Arruda et al, 2015;De Souza Porta et al, 2015;Gama et al, 2015;Haghi et al, 2015;Jeyapalan et al, 2015;Neppelenbroek et al, 2015;Panariello et al, 2015;Rodrigues Acosta et al, 2015;Salles et al, 2015;Sorgini et al, 2015;Badaró et al, 2016;Pero et al, 2016;Basavana et al, 2016;Matos et al, 2016). Porém, pode-se verificar a utilização de diferentes períodos de imersão diária e a avaliação dos efeitos destas soluções em um período curto de tempo, não representando a realidade clínica de uso das próteses.…”