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Papers by LETÍCIA MACHADO GONÇALVES

Research paper thumbnail of Dietary Carbohydrates Modulate Candida albicans Biofilm Development on the Denture Surface

PLoS ONE, 2013

The purpose of this study was to investigate whether dietary carbohydrates can modulate the devel... more The purpose of this study was to investigate whether dietary carbohydrates can modulate the development of Candida albicans biofilms on the denture material surface. Poly (methyl methacrylate) acrylic resin discs were fabricated and had their surface roughness measured. Biofilms of C. albicans ATCC 90028 were developed on saliva-coated specimens in culture medium without (control) or with carbohydrate supplementation by starch, starch+sucrose, glucose, or sucrose for 72 h. The cell count, metabolic activity, biovolume, average thickness, and roughness coefficient were evaluated at the adhesion phase (1.5 h) and after 24, 48, and 72 h. The secretion of proteinases and phospholipases, cell surface energy, and production of extra/intracellular polysaccharides were analyzed after 72 h of biofilm development. Data were analyzed by one-and two-way ANOVA followed by Tukey's test at 5% significance level. In the early stages of colonization (adhesion and 24 h), the glucose group showed the highest cell counts and metabolic activity among the groups (p,0.05). After maturation (48 and 72 h), biofilms exposed to glucose, sucrose, or starch+sucrose showed higher cell counts and metabolic activity than the control and starch groups (p,0.001). Compared to the control group, biofilms developed on starch or starch+sucrose had more proteinase activity (p,0.001), whereas biofilms developed on glucose or sucrose had more phospholipase activity (p,0.05). Exposure to starch+sucrose increased the production of extracellular and intracellular polysaccharides (p,0.05). Biofilms developed on starch or without carbohydrate supplementation presented cells with more hydrophobic behavior compared to the other groups. Confocal images showed hyphae forms on biofilms exposed to starch or starch+sucrose. Within the conditions studied, it can be concluded that dietary carbohydrates can modulate biofilm development on the denture surface by affecting virulence factors and structural features.

Research paper thumbnail of Calcium Hydroxide Dressing Influences the Obturation of Simulated Lateral Canals

The journal of contemporary dental practice, 2015

The aim of this study was to investigate the influence of calcium hydroxide dressing on the filli... more The aim of this study was to investigate the influence of calcium hydroxide dressing on the filling of simulated lateral canals by different obturation techniques. Sixty single-root-premolars were instrumented. Simulated lateral canals were drilled on each third of the roots. The teeth were divided into four groups: no dressing and obturation by lateral condensation technique (G1), dressing with calcium hydroxide and obturation by lateral condensation technique (G2), no dressing and obturation by hybrid technique (G3) and, dressing with calcium hydroxide and obturation by hybrid technique (G4). The teeth were maintained at 37°C in 100% humidity for 7 days, and obturation techniques were performed. Radiographs were taken and filled or unfilled lateral canals were counted. Data were analyzed using analysis of variance (ANOVA) followed by Tukey's test (a = 5%). The hybrid technique filled large number of lateral canals as compared to lateral condensation technique, regardless the u...

Research paper thumbnail of Efficacy of calcium hydroxide paste prepared with different vehicles against salivary microbial infiltration of root canals

General dentistry

This in vitro study evaluated the efficacy of calcium hydroxide Ca(OH)2 pastes prepared with diff... more This in vitro study evaluated the efficacy of calcium hydroxide Ca(OH)2 pastes prepared with different vehicles in preventing bacterial infiltration in teeth exposed to human saliva. This study used 52 central incisors, of which 4 teeth were used as positive and negative controls (n = 2). The root canals were instrumented and filled with Ca(OH)2 paste prepared with different vehicles: saline solution (Group 1), polyethylene glycol (Group 2), or polyethylene glycol and camphorated paramonochlorophenol (Group 3). Only 6 teeth in Group 1 showed contamination. All teeth in Groups 2 and 3 were contaminated after 32 days of incubation. There were significant differences between Groups 1 and the other groups (P < 0.05) in terms of the mean time to contamination. By contrast, there was no such difference in terms of mean time to contamination between Groups 2 and 3 (P > 0.05). Based on the results, it was possible to conclude that calcium hydroxide paste prepared with saline solution ...

Research paper thumbnail of Dietary Carbohydrates Modulate Candida albicans Biofilm Development on the Denture Surface

PLoS ONE, 2013

The purpose of this study was to investigate whether dietary carbohydrates can modulate the devel... more The purpose of this study was to investigate whether dietary carbohydrates can modulate the development of Candida albicans biofilms on the denture material surface. Poly (methyl methacrylate) acrylic resin discs were fabricated and had their surface roughness measured. Biofilms of C. albicans ATCC 90028 were developed on saliva-coated specimens in culture medium without (control) or with carbohydrate supplementation by starch, starch+sucrose, glucose, or sucrose for 72 h. The cell count, metabolic activity, biovolume, average thickness, and roughness coefficient were evaluated at the adhesion phase (1.5 h) and after 24, 48, and 72 h. The secretion of proteinases and phospholipases, cell surface energy, and production of extra/intracellular polysaccharides were analyzed after 72 h of biofilm development. Data were analyzed by one-and two-way ANOVA followed by Tukey's test at 5% significance level. In the early stages of colonization (adhesion and 24 h), the glucose group showed the highest cell counts and metabolic activity among the groups (p,0.05). After maturation (48 and 72 h), biofilms exposed to glucose, sucrose, or starch+sucrose showed higher cell counts and metabolic activity than the control and starch groups (p,0.001). Compared to the control group, biofilms developed on starch or starch+sucrose had more proteinase activity (p,0.001), whereas biofilms developed on glucose or sucrose had more phospholipase activity (p,0.05). Exposure to starch+sucrose increased the production of extracellular and intracellular polysaccharides (p,0.05). Biofilms developed on starch or without carbohydrate supplementation presented cells with more hydrophobic behavior compared to the other groups. Confocal images showed hyphae forms on biofilms exposed to starch or starch+sucrose. Within the conditions studied, it can be concluded that dietary carbohydrates can modulate biofilm development on the denture surface by affecting virulence factors and structural features.

Research paper thumbnail of Calcium Hydroxide Dressing Influences the Obturation of Simulated Lateral Canals

The journal of contemporary dental practice, 2015

The aim of this study was to investigate the influence of calcium hydroxide dressing on the filli... more The aim of this study was to investigate the influence of calcium hydroxide dressing on the filling of simulated lateral canals by different obturation techniques. Sixty single-root-premolars were instrumented. Simulated lateral canals were drilled on each third of the roots. The teeth were divided into four groups: no dressing and obturation by lateral condensation technique (G1), dressing with calcium hydroxide and obturation by lateral condensation technique (G2), no dressing and obturation by hybrid technique (G3) and, dressing with calcium hydroxide and obturation by hybrid technique (G4). The teeth were maintained at 37°C in 100% humidity for 7 days, and obturation techniques were performed. Radiographs were taken and filled or unfilled lateral canals were counted. Data were analyzed using analysis of variance (ANOVA) followed by Tukey's test (a = 5%). The hybrid technique filled large number of lateral canals as compared to lateral condensation technique, regardless the u...

Research paper thumbnail of Efficacy of calcium hydroxide paste prepared with different vehicles against salivary microbial infiltration of root canals

General dentistry

This in vitro study evaluated the efficacy of calcium hydroxide Ca(OH)2 pastes prepared with diff... more This in vitro study evaluated the efficacy of calcium hydroxide Ca(OH)2 pastes prepared with different vehicles in preventing bacterial infiltration in teeth exposed to human saliva. This study used 52 central incisors, of which 4 teeth were used as positive and negative controls (n = 2). The root canals were instrumented and filled with Ca(OH)2 paste prepared with different vehicles: saline solution (Group 1), polyethylene glycol (Group 2), or polyethylene glycol and camphorated paramonochlorophenol (Group 3). Only 6 teeth in Group 1 showed contamination. All teeth in Groups 2 and 3 were contaminated after 32 days of incubation. There were significant differences between Groups 1 and the other groups (P < 0.05) in terms of the mean time to contamination. By contrast, there was no such difference in terms of mean time to contamination between Groups 2 and 3 (P > 0.05). Based on the results, it was possible to conclude that calcium hydroxide paste prepared with saline solution ...