Metallic nanoparticles grown in the core of femtosecond laser micromachined waveguides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of simulated intraoral erosion and/or abrasion effects on etch-and-rinse bonding to enamel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aplicação de água ozonizada como agente sanitizante durante o processamento de café arábica

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Um estudo sobre o endurecimento, o processamento e propriedades mecânicas de uma liga de alumínio da série 3XXX tipo AA 3104 com adições de zinco

Modificações na composição química e no processamento termomecânico têm sido algumas das várias alternativas estudadas, para melhorar o desempenho de ligas de alumínio tradicionais. Neste trabalho foi modificada a composição de uma liga Al-Mn-Mg do tipo AA 3104, endurecível por deformação, adicionando-se diversos teores de zinco, transformando-a numa liga Al-Mn-Mg(Zn), endurecível por precipitação. O objetivo foi estudar e quantificar os efeitos do zinco sobre o processamento termomecânico e as propriedades mecânicas da liga modificada. Ligas com teores de zinco entre 0,03 a 1,52% foram fundidas e processadas obtendo-se um encruamento semelhante a condição H-19 industrial, denominada rota R. Ligas com teores de zinco entre 1,14 a 2,17% foram fundidas e processadas segundo três diferentes rotas: na rota S, o recozimento da rota R foi substituído por solubilização antes da laminação a frio; nas rotas E3H e E6H, as tiras laminadas a frio foram envelhecidas em dois estágios: 121°C por três horas para as duas rotas, mais três horas para a rota E3H e seis para a rota EH a 163°. A tensão de escoamento (SIGMA IND E) e a resistência à tração (SIGMA IND T) para a rota R aumentaram da ordem de 18% e 19% respectivamente, com o aumento do teor de zinco, enquanto o alongamento (E) permaneceu em torno de 4,5%. As propriedades mecânicas (SIGMA IND E SIGMA T E ) AUMENTARAM EM TORNO DE 25%, 31% E 27%, respectivamente, para a rota S. Considerando concentrações aproximadamente iguais de zinco, não foram verificadas diferenças significativas para (SIGMA E SIGMA T), entre as rotas R E S, no entanto, a rota S apresentou alongamento médio maior que a rota R da ordem 44%. Os menores valores de (SIGMA IND E SIGMA IND T) e os maiores valores de E foram obtidos para a rota E6H.

Does the Method of Caries Induction Influence the Bond Strength to Dentin of Primary Teeth?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Responses of dental pulp cells to a less invasive bleaching technique applied to adhesive restored teeth

To assess the cytotoxicity of 35% hydrogen peroxide (HP) bleaching gel applied for 15 min to sound or restored teeth with two-step self-etching adhesive systems and composite resin. Materials and Methods: Sound and restored enamel/dentin disks were stored in water for 24 h or 6 months + thermocycling. The disks were adapted to artificial pulp chambers and placed in compartments containing culture medium. Immediately after bleaching, the culture medium in contact with dentin was applied for 1 h to previously cultured odontoblast-like MDPC-23 cells. Thereafter, cell viability (MTT assay) and morphology (SEM) were assessed. Data were analyzed by two-way ANOVA and Tukey's test (a = 5%). Results: In comparison to the negative control group (no treatment), no significant cell viability reduction occurred in those groups in which sound teeth were bleached. However, a significant decrease in cell viability was observed in the adhesive-restored bleached groups compared to negative control. No significant difference among bleached groups was observed with respect to the presence of restoration and storage time. Conclusion: The application of 35% HP bleaching gel to sound teeth for 15 min does not cause toxic effects in pulp cells. When this bleaching protocol was performed in adhesive-restored teeth, a significant toxic effect occurred.

Effect of Er:YAG laser and diamond drill on hybrid layer morphology obtained with self-etch adhesive: analysis by SEM and confocal laser scanning microscopy (CLSM)

This study aimed to evaluate the effect of Er:YAG (L) and diamond drills (DD) on: 1) the microshear bond strength (MPa); 2) the adhesive interface of two-step (TS) – Adper Scotchbond Multipurpose and one-step (OS) adhesives – Adper EasyOne, both from 3M ESPE. Material and methods: According to the preparation condition and adhesives, the samples were divided into four groups: DD_TS (control); DD_OS; L_TS and L_OS. 60 bovine incisors were randomly divided into experimental and groups: 40 for microshear bond strength (n = 10) and 20 for the adhesive interface morphology [6 to measure the thickness of the hybrid layer (HL) and length of tags (t) by CLSM (n = 3); 12 to the adhesive interface morphology by SEM (n = 3) and 2 to illustrate the effect of the instruments on dentine by SEM (n = 1)]. To conduct the microshear bond strength test, four cylinders (0.7 mm in diameter and 1 mm in height with area of adhesion of 0.38 mm) were constructed with resin composite (Filtek Z350 XT – 3M ESPE) on each dentin surface treated by either L or DD and after adhesives application. Microshear bond strength was performed in universal testing machine (EMIC 2000) with load cell of 500 kgf and a crosshead speed of 0.5 mm / min. Adhesive interface was characterized by thickness of hybrid layer (HL) and length of tags (t) in nm, with the aid of UTHSCSA ImageTool software. Results: Microshear bond strength values were: L_TS 34.10 ± 19.07, DD_TS 24.26 ± 9.35, L_OS 33.18 ± 12.46, DD_OS 21.24 ± 13.96. Two-way ANOVA resulted in statistically significant differences only for instruments (p = 0.047). Mann-Whitney identified the instruments which determined significant differences for HL thickness and tag length (t). Concerning to the adhesive types, these differences were only observed for (t). Conclusion: It can be concluded that 1) laser Er:YAG results in higher microshear bond strength values regardless of the adhesive system (TS and OS); 2) the tags did not significant affect the microshear bond strength; 3) the adhesive interface was affected by both the instruments for cavity preparation and the type of adhesive system used.

Cuspal movement related to different polymerization protocols

Objective: The aim of this study to investigate the effects of different polymerization protocols on the cuspal movement in class II composite restorations. Materials and methods: Human premolar teeth were prepared with class II cavities and then restored with composite and three-step and two-step etch-and-rinse adhesive systems under different curing techniques (n = 10). It was used a lightemittingdiode curing unit and the mode of polymerization were: standard (exposure for 40 seconds at 700 mW/cm2), pulse-delay (initial exposure for 6 seconds at 350 mW/cm2 followed by a resting period of 3 minutes and a final exposure of 37 seconds at 700 mW/cm2) and soft-start curing (exposure 10 seconds at 350 mW/cm2 and 35 seconds at 700 mW/cm2). The cuspal distance (µm) was measured before and after the restorative procedure and the difference was recorded as cuspal movement. The data were submitted to two-way ANOVA and Bonferroni test (p < 0.05). Results: The type of adhesive system did not influenced the cuspal movement for all the curing methods. Standard protocol showed the highest values of cuspal movement and was statistically different from the pulse-delay and soft-start curing modes. Conclusion: Although the cuspal displacement was not completely avoided, alternative methods of photocuring should be considered to minimize the clinical consequences of composites contraction stress.

Clinical protocol for esthetic restoration using a self-etching adhesive

The advent of new adhesive systems is making techniques and clinical protocols to become faster and simpler, however it does not reduce the importance of knowledge of the properties, characteristics and interaction of dental materials with the tooth structure. Among the adhesives that have recently emerged, highlight the self-etching systems, especially the two-step selfetching, in which the acid primer is available in a separate bottle from the adhesive. These adhesives have shown good results for bond strength, microleakage and postoperative sensitivity, being an option for direct adhesive restorations in anterior teeth. This way, the present case report describes the step-by-step making of a class IV restoration in an upper right central incisor using atwo-step adhesive system, obtaining satisfactory results.

Effect of method of caries induction on aged resin-dentin bond of primary teeth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Responses of Dental Pulp Cells to a Less Invasive Bleaching Technique Applied to Adhesively Restored Teeth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlation between structural and catalytic properties of copper supported on porous alumina for the ethanol dehydrogenation reaction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic parameter estimates and principal component analysis on performance and carcass traits of a terminal pig sire line

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemopreventive effects of mate against mouse mammary and colon carcinogenesis

The present study evaluated the chemopreventive potential of mate tea-like intake on mammary and colon carcinogenesis initiated by 7,12-dimethylbenz(a)antracene (DMBA) and 1,2-dimethylhydrazine (DMH) in female Swiss mice. After the initiation period, the animals received basal diet and organic mate tea-like, conventional mate tea-like, or green tea (positive control) at 2.0% as the drinking fluid during 15 weeks. At week 20, colon and mammary gland were analyzed for preneoplastic and neoplastic lesions development. Colon and mammary gland complexes were processed for cell proliferation analysis, estimated by proliferating cell nuclear antigen labeling index (PCNA-LI%). Specially, organic mate tea-like reduced the values of PCNA-LI% in colonic crypts (p < .003) and in mammary glands (p < .05) in DMBA/DMH-initiated groups. A lower incidence of aberrant crypt foci (ACF) in colon (p = .03) and of hyperplastic and neoplastic lesions in mammary gland (p < .05 and p < .02, respectively) was observed in DMBA/DMH-initiated groups treated with organic mate tea-like. These results suggest that post-initiation treatment with organic mate tea-like inhibited the development of colon and mammary carcinogenesis in a two-step medium-term mouse carcinogenesis model.

Diffusion of hydroxyl ions from calcium hydroxide and Aloe vera pastes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)