Brenna Louise Cavalcanti Gondim

Avaliação microestrutural do esmalte bovino exposto a bebidas lácteas fermentadas e propriedades físico químicas

Resumen pt: Objetivo: Analisar o padrao de desmineralizacao do esmalte bovino submetido a acao de bebidas lacteas fermentadas frente a variacoes de tempo e avaliar ...

AVALIAÇÃO DO EFEITO EROSIVO EM MICROSCOPIA ELETRÔNICA DE VARREDURA E PROPRIEDADES FÍSICO-QUÍMICAS DE BEBIDAS GASEIFICADAS DE BAIXA CALORIA

Objective: To evaluate the pH, the amount of total soluble solids (°Brix), electrical conductivity and the surface of bovine enamel, by Scanning Electronic Microscopy (SEM), subjected to the action of low-calorie soft drinks. Materials and Methods: The products tested were: Aquarius® Fresh lemon, H2OH!® lemon, Aquazero® lemon, Viver Light® lemon, Coca- Cola® (positive control) and deionized water (negative control). The pH evaluation was performed by using digital pH meter. Electrical conductivity was determined by a workbench conductivimeter and for quantification of °Brix was used a specific refractometer of field. For each analysis were made three measurements and the arithmetic mean was calculated. The adamantine surface was made from the extraction of healthy maxillary incisors from bovine animals for slaughter, resulting in the end, in 3x3mm enamel blocks (n = 12), which were submitted to contact for 5 minutes with the drinks and then washed and stored for subsequent analysis by SEM. Results: The pH values †ranged from 2.56 (positive control) to 6.00 (negative control), while the remaining beverages showed pH bellow than 3.46. The results for electrical conductivity ranged from 001 mS.cm-1 (negative control) to 1071 mS.cm- (Coca-Cola®). Considering the TSS, all beverages had a value of 0° Brix, excepting Coca-Cola® (6.5° Brix). It was observed that the beverages analyzed proved to be potentially erosive. The enamel surface exposed to fizzy drinks had microstructural features indicative of erosion. Conclusion: Fizzy drinks analyzed have proved to be potentially erosive for the adamantine surface exposed for a short period of time to the action of those products, presenting no cariogenic potential. DESCRIPTORS Tooth Erosion. Carbonated Beverages. Drinking. Diet.

Atividade antimicrobiana de produtos naturais frente a bactérias formadoras do biofilme dentário

Resumen pt: Objeti vo: Verifi car, in vitro, o efeito anti microbiano do polen e dos extratos alcoolico e aquoso da propolis em suas formas pura e diluidas sobre cep...

Effect of chitosan nanoparticles on the inhibition of Candida spp. biofilm on denture base surface

OBJECTIVES Chitosan nanoparticles (ChNPs) have antifungal effects, however there is a lack of information about the effects of ChNPs against Candida biofilm on denture base surface. This study investigated the ChNPs effect against C. albicans biofilm adhesion and formation, and against Candida spp. biofilm on heat-cured acrylic resin. DESIGN The ChNPs were synthetized (3800 μg/mL) and characterized by infra-red spectrophotometry and transmission electron microscopy. The minimum inhibitory/fungicidal concentrations (MIC/MFC) against Candida spp. were determined. The time-kill assay and changes on C. albicans micromorphology were evaluated. The % inhibition of ChNPs on C. albicans biofilm formation and reduction were investigated using 1 min and 8 h exposure. Candida biofilm was developed on resin surfaces and ChNPs were applied every 8 h for 5 days. After, fungal cells were counted (CFU/mL) and the surface roughness (Ra) and vickers microhardness (HV) of resin were analysed. For all experiments, sodium hypochlorite (NaOCl) was used as control. Data were analyzed by ANOVA, Tukey and paired t-tests (α = 0.05). RESULTS The MIC80% of ChNPs was 30.1 μg/mL. ChNPs at 4 MIC showed complete inhibition in the time-kill assays. Blastoconidia cells were predominant after ChNPs application. The % inhibition ChNPs on C. albicans was proportional to its concentration, regardless of the exposure time. ChNPs decreased the CFU/mL of Candida spp. and showed lower alteration of HV and Ra values of resin surface compared to NaOCl. CONCLUSIONS The ChNPs inhibited C. albicans biofilm, reduced Candida biofilm on resin and caused small changes in roughness and hardness of acrylic resin surface.

Effects of erosive challenge on the morphology and surface properties of luting cements

Introduction Few studies investigated the surface properties of luting cements after erosive challenge. Objective To evaluate the surface roughness (Ra), Vickers hardness (VHN) and morphology of 4 luting cements after erosive challenge. Material and method Twenty specimens of each cement were prepared (4×2mm) and divided into experimental (erosive challenge) and control (artificial saliva) groups (n=10): Rely X U200 (U200); Rely X ARC (ARC); Ketac Cem Easy Mix (Ketac) and Zinc phosphate (ZnP). The erosive challenge was performed by four daily erosive cycles (90s) in a cola drink and 2 h in artificial saliva over 7 days. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was analyzed by scanning electron microscopy (SEM). ANOVA, Tukey and Student-T tests were used (α=0.05). Result After erosion, all luting cements had increase in Ra values and U200 and ZnP groups had the highest %VHN. After saliva immersion, only U200 and ZnP groups had significant increases in Ra values and there were no significant differences among the groups in %VHN. SEM analysis showed that Ketac and ZnP groups had rough and porous surfaces, and U200 group had higher resin matrix degradation than ARC group. Conclusion Erosive challenge with a cola drink affected the surface properties of all luting cements.

Social capital and self-perceived need for complete denture use or exchange

Purpose: to analyze self-perceived need for complete denture use or exchange in the population aged 35-44 and 65-74 years, as well as to carry out the association between that self-perception with social capital in the municipalities of Conde and Pedras de Fogo, Paraiba. Methods: a total of 134 adults and 54 elderlies participated in this sectional study. The outcome of interest was self-perceived need for complete denture use or exchange. Data were analyzed descriptively and association between variables was performed by means of statistical tests and regression models (=5%). Results: self-perception regarding the need for complete denture use or exchange was observed for 61.2% (n=82) of adults and 59.2% (n=32) of elderlies, and it was found to be statistically associated with dental prosthesis use (X² test; p-value<0.05). According to logistic regression, scholarity (OR=0.83, IC: 0.74-0.94), poor oral health self-perception (OR=19.22, IC: 1.29-286.45) and global use of dental prosthesis (OR=0.16, IC: 0.07-0.40) were found to be associated to the outcome. Conclusion: that self-perceived need for complete denture use or exchange was more frequent among adults that made use of dental prosthesis comparatively to the elderlies. In addition, individuals with lower scholarity level, unsatisfied with their oral health and users of dental prosthesis were more inclined to report needing for complete denture use or exchange.

AVALIAÇÃO DA ATIVIDADE ANTIBACTERIANA DAS TINTURAS DE HAMAMELIS VIRGINIANA L. E STRYPHNODENDRON ROTUNDIFOLIUM MART. FRENTE A BACTÉRIAS BUCAIS.

Objective: To evaluate the in vitro the antibacterial activity of the Hamamelis (Hamamelis virginiana L.) and Barbatimao (Stryphnodendron rotundifolium Mart.) tinctures against Streptococcus mutans (ATCC 25175), Streptococcus oralis (ATCC 10557) and Streptococcus salivarius (ATCC 9758). Material and Methods: Chlorhexidine (0.12%) was used as positive control. Distilled water and 70% alcohol were chosen as negative controls. The dilution of the tinctures was carried out from 1:1 (pure form) to 1:64 (D6) in 70% alcohol, which is found in the tinctures formula. The culture medium Brain Heart Infusion (BHI) was used, and microorganisms were inoculated on petri plates using swabs. Plates were incubated at 37 oC, in microaerophilia, for 48 hours. Tests were performed in duplicate and halos were measured using a manual caliper. Results: The positive control showed inhibition halos of 16, 15, and 16 mm on S. mutans, S. oralis and S. salivarius, respectively. None of the tinctures evaluated, in any form (diluted or pure), were found to show inhibition halos on these oral bacteria. Distilled water and 70% alcohol did not exhibit activity. Conclusion: The tinctures of Hamamelis and Barbatimao did not demonstrated antibacterial activity on S. mutans, S. oralis and S. salivarius. DESCRIPTORS: Phytotherapeutic Drugs. Microbiology. Products with Antimicrobial Action. Dental prophylaxis.