189 resultados para Surface Effects
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Purpose: To investigate the cumulative effects of brushing (B) or immersion (I), using different cleansing agents, on the surface roughness, hardness and color stability of a heat-polymerized denture resin, Lucitone 550 (L), and a hard chairside reline resin, Tokuyama Rebase Fast II (T). Methods: A total of 316 specimens (10 x 2 mm) were fabricated. The specimens (n= 9) were divided into brushing or immersion groups according to the following agents: dentifrice/distilled water (D), 1% sodium hypochlorite (Na0C1), Corega Tabs (Pb), 1% chlorhexidine gluconate (Chx), and 0.2% peracetic acid (Ac). Brushing and immersion were tested independently. Assays were performed after 1, 3, 21, 45 and 90 blushing cycles or immersion of 10 seconds each. Data were evaluated statistically by repeated measures ANOVA. Tukey's honestly significant difference (HSD) post-hoc test was used to determine differences between means (a= 0.05). Results: For L there was no statistically significant difference in roughness, except a significant decrease in roughness by brushing with D. T showed a significant effect on the roughness after 90 immersions with Ac. Hardness values decreased for L when specimens were immersed or brushed in Na0C1 and Pb. The hardness of T decreased with increases in the repetitions (immersion or brushing), regardless of the cleaning method. Values of color stability for L resin showed significant color change after brushing with and immersion in Ac and Pb. Brushing with D exhibited a higher incidence of color change. For T there were no significant differences between cleaning agents and repetitions in immersion. A color change was noted after three brushings with the Ac, Chx, and D. Brushing with dentifrice decreased roughness of L. Immersion in or brushing with Na0C1 and Pb decreased the hardness of L. For T, hardness decreased with increases in immersions or brushing. Color changes after the immersion in or brushing with cleaning agents were clinically acceptable according to National Bureau of Standards parameters for both resins.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Introduction: Antibiotic-containing polymer-based nanofibers (hereafter referred to as scaffolds) have demonstrated great potential for their use in regenerative endodontics from both an antimicrobial and cytocompatibility perspective. This study sought to evaluate in vitro the effects of ciprofloxacin (CIP)-containing polymer scaffolds against Enterococcus faecalis biofilms. Methods: Human mandibular incisors were longitudinally sectioned to prepare radicular dentin specimens. Sterile dentin specimens were distributed in 24-well plates and inoculated with E. faecalisfor biofilm formation. Infected dentin specimens were exposed to 3 groups of scaffolds, namely polydioxanone (PDS) (control), PDS + 5 wt% CIP, and PDS + 25 wt% CIP for 2 days. Colony-forming units (CFU/mL) (n = 10) and scanning electron microscopy (SEM) (n -= 2) were performed to quantitatively and qualitatively assess the antimicrobial effectiveness, respectively. Results: PDS scaffold containing CIP at 25 wt% showed maximum bacteria elimination with no microbial growth, differing statistically (P < .05) from the control (PDS) and from PDS scaffold containing CIP at 5 wt%. Statistical differences (P < .05) were also seen for the CFU/mL data between pure PDS (5.92-6.02 log CFU/mL) and the PDS scaffold containing CIP at 5 wt% (5.39 5.87 log CFU/mL). SEM images revealed a greater concentration of bacteria on the middle third of the dentin specimen. after 5 days of biofilm formation. On scaffold exposures, SEM images showed similar results when compared with the CFU/mL data. Dentin specimens exposed to PDS + 25 wt% CIP scaffolds displayed a practically bacteria-free surface. Conclusions: On the basis of the data presented, newly developed antibiotic-containing electrospun scaffolds hold promise as an intracanal medicament to eliminate biofilm/infection before regenerative procedures.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)