ABSTRACT
PURPOSE: The objective of this study was to evaluate the effect of different immersion times in denture cleansers on surface roughness (SR) of two resilient denture liners (RDL) after the cleanliness of Candida albicans biofilm. METHODS: Poly(methyl methacrylate) (PMMA) resin discs (10x1.5 mm) were relined with a 1.5 mm layer of RDL (PMMA or silicone-based). The initial SR of each specimen was measured and C. albicans biofilm was developed for 48 h. Subsequently, the discs were randomly assigned for one of four cleansing treatments (n=8): two alkaline peroxide (soaking for 3 or 15 min), 0.5 percent sodium hypochlorite (10 min) or distilled water as control (15 min). After the treatments, the SR was measured again. Data were analyzed by ANOVA and the Tukey post-hoc test (α=0.05) RESULTS: No differences were found between the cleansing treatments evaluated (P>0.05). The PMMA-based liner exhibited higher SR than silicon-based (P<0.001); however, both liners showed higher SR after the reatments compared with the baseline values (P<0.001). CONCLUSION: Within limitations of this study, it can be concluded that the surface roughness of RDL increased after the immersion in denture cleansers, independently of the time of immersion.
OBJETIVO: O objetivo deste estudo foi avaliar o efeito de diferentes tempos de imersão em limpadores químicos sobre a rugosidade de superfície ( RS)de reembasadores resilientes após a simulação da limpeza de biofilmes de Candida albicans. METODOLOGIA: Discos (10x1,5 mm) de poli(metilmetacrilato) (PMMA) foram cobertos com uma camada de 1,5 mm de reembasador resiliente (a base de PMMA ou silicone). A RS inicial de cada espécime foi mensurada e biofilmes de C. albicans desenvolvidos por 48 h. Em seguida, os espécimes foram submetidos aleatoriamente a um dos tratamentos (n=8): duas soluções alcalinas a base de peróxido (imersão por 3 ou 15 min), hipoclorito de sódio a 0.5 por cento (10 min) ou água destilada como grupo controle (15 min). Após o tratamento, a RS foi mensurada novamente. Os resultados foram analisados por ANOVA e teste Tukey (α=0,05). RESULTADOS: Não houve diferença estatística entre os tratamentos (P>0,05). O reembasador a base de PMMA apresentou maior RS que os de silicone (P<0,001); entretanto, ambos apresentaram um aumento da RS após os tratamentos (P<0,001). CONCLUSÃO: Dentro das limitações deste estudo, conclui-se que a RS dos reembasadores resilientes aumenta após a imersão em limpadores químicos, independentemente do tempo de imersão.
Subject(s)
Disinfection , Denture Cleansers/adverse effects , Denture Liners , Surface PropertiesABSTRACT
This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate)-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min), 0.5 percent sodium hypochlorite (10 min) or distilled water (control; 15 min). After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL). Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p < 0.001), and it could be observed by SEM. However, no significant difference (p > 0.05) was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001). Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.