Efeito da microabrasão e do clareamento dental na rugosidade superficial e microdureza do esmalte dental: estudo longitudinal ‘in situ’

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

Estudo da dureza e da resistência à compressão de resinas compostas para dentes posteriores após a imersão em água destilada. Efeito da aplicação de selante superficial

Novos compósitos têm surgido no mercado especificamente destinados à confecção de restaurações estéticas posteriores. Entretanto, embora tais materiais apresentem resultados iniciais animadores, há a necessidade de comprovações adicionais para que possam ser utilizados com segurança. Resinas compostas posteriores são submetidas a estresses complexos de compressão e abrasão durante a mastigação e a aplicação de selantes superficiais tem sido relatada como forma de aumentar a resistência ao desgaste destes materiais. O presente trabalho teve como propósito avaliar a dureza e a resistência à compressão das resinas compostas Alert (Jeneric/Pentron), Ariston (Vivadent), Definite (Degussa), P60 (3M), Solitarie (Kulzer), Surefil (Dentsply) e Z100 (3M) após 90 dias de imersão em água destilada, recobertas com selante Protect It (Jeneric/Pentron) e submetidas à ciclagem mecânica (10.000 ciclos, 600N, 5Hz). Os ensaios de dureza (n=8) foram realizados em aparelho Wolpert, com diamante Vickers e peso de 50gf aplicado por 30 segundos, antes e após períodos de imersão de 30, 60 e 90 dias. Os ensaios de resistência à compressão (n=8) foram realizados somente após 90 dias, em corpos-de-prova cilíndricos medindo 8mm de altura por 4mm de diâmetro. Apenas os espécimes destinados à compressão foram ciclados mecanicamente. Os ensaios foram realizados em máquina MTS 810, equipada com célula de carga de 10kN (ciclagem) e 100kN (compressão) e velocidade de 0,5mm/min. Após análise de variância (p<0,05), os resultados mostraram, previamente à imersão, maiores valores de dureza para os materiais Z100 (74,253VHN) e Ariston (71,308VHN). A seguir, com valor semelhante à resina Ariston, mas inferior à resina Z100, apresentou-se o material Surefil (69,969VHN)...(Resumo completo, clicar acesso eletrônico abaixo)

Mapeamento geoestatístico da permeabilidade superficial no entorno do Ribeirão Claro: e simulação da possibilidade de sua contaminação

The evaluation of soil permeability throughout the weathering profile is one of the most important features to be considered in environmental studies. This study, developed from field testing and analysis of data obtained by geostatistical methods, aims at mapping the permeability around the Ribeirão Claro river. The intent is to simulate an accident with toxic liquids where soil permeability is of fundamental importance. Another purpose of the research was to determine the minimum time that, in the event of an accident, a possible contaminant to reach the water table level and be routed to the nearest drain, in this case, the Ribeirao V Claro river constitutes fundamental information. The studied area of approximately 4 km² is located within the UNESP-Rio Claro campus, consisting of colluvial soil from Fm. Rio Claro superimposed on residual soil of Fm. Corumbataí. The method used to determine the permeability is the concentric cylinders performed on a sampling grid with 64 points containing spacing of 5 meters EW and 10 meters NS. In the places of permeability tests were collected samples for laboratory determination of the percentage of fines. From particle size analysis was performed and analysis statistical and geostatistical on this data. The histogram was based on the statistical studies, and the semivariograms were based on geostatistical estimation methods. Based on the comparison between the maps and the data obtained, it was determined that the percentage of fines in colluvial surface soil has little influence on permeability, which the proximity to the Ribeirao Claro river, the eastern portion, a factor that influences the distribution of permeability values

Aplicação de técnicas alternativas para recuperação de foco eosivo em área rural situada no município de Álvares Machado – SP Presidente Prudente 2012

When handling soil conservation practices isn’t applied correctly, they cause problems at the level of structure, cohesion and fertility in soils and lack of water availability. In the case of this monograph, conducted in a rural property located at Álvares Machado City, identified that most areas are intended for use activities of beef cattle and dairy and subsistence agriculture, which historically addition to withdraw native flora, resulting in problems such as compaction and increase soil exposure to climatic agents, generating a serious frame of erosion problems. In the case of water from rainfall, the soil exposed, causes the “splash” effect and therefore when it becomes runoff carries the spalled particles mainly for low land areas. Without the vegetation, especially trees or shrubs species, the velocity of runoff increases, initiating the appearance of furrows, which consequently may become a kind of ravine erosion and gully, which makes invalid any area in your surroundings... (Complete abstract click electronic access below)

Carta geotécnica de suscetibilidade aos processos de dinâmica superficial na região do Bairro do Peão, Piracaia (SP)

This research presents the result of the engineering geological mapping in a 1:50.000 scale, in Bairro do Peão region, in Piracaia (SP), represented by means of homogeneous units which are susceptible to superficial dynamic processes. To serve as basis for the elaboration of a Chart of Susceptibility to Processes of Superficial Dynamic, a series of physical samples was collected, considering erosive processes and registers of information of usage and soil occupation. The procedure used for elaborating the geotechnical chart is based on Vedovello (2000), which suggests the physiographic compartimentation of the area through photointerpretation and further geotechnical characterization of the selected samples. The geotechnical characterization of the samples was made by identifying the features and properties of the material and forms of the physical environment determining the geotechnical conditions through geological-geotechnical profile descriptions typical of/ peculiar to each unit defined in the area. Thus, for each unit selected, the susceptibility level was established in very high, high, average and low, as well as the prevalent erosive processes.

Efeitos dos parâmetros de usinagem no acabamento superficial de materiais cerâmicos a verde

Pós-graduação em Engenharia Mecânica - FEB

Usinabilidade e integridade superficial de implantes dentários

Pós-graduação em Engenharia Mecânica - FEIS

Estudo da modificação superficial de fibras de carbono por meio de tratamentos a plasma para o aumento da adesão na interface de compósitos fibra de carbono/PPS

Pós-graduação em Engenharia Mecânica - FEG

Modificação superficial de nanopartículas de óxido de ferro por poli(ácido aspártico) reticulado

Pós-graduação em Química - IQ

Desgaste superficial do esmalte dental após microabrasão in vitro

The aim of this study was to investigate the enamel wear permanent teeth after plastic stick or low speed rubber cup microabrasion. Ten permanent molars were selected to evaluate enamel wear which were sectioned into mesial and distal halves. Each half of the molars was randomly assigned to one of two experimental groups (n = 10) according to the enamel microabrasion technique: plastic stick (GE) or rubber cup (GT). In both the groups, the enamel was submitted to 10 applications of an abrasive paste comprised of 35% phosphoric acid and pumice powder. The paste was applied for 20 seconds under a pressure of 30 g using the instrument defined for each group (plastic stick or rubber cup). The specimens were evaluated under a stereomicroscope connected to a computer. The enamel wear no was statistically different between GE and GT, which presented a mean wear of 304.74 µm (21.20%) and 338.35 µm (22.75%). In conclusion, superficial enamel wear was seen for both the groups, independent of the technique used for the accomplishment of the microabrasion.

Avaliação da aplicação de ondas de ultra-som sobre cimentos de ionômero de vidro: rugosidade superficial e dureza

The application of ultrasonic waves during the initial setting of the glass ionomer cements (GIC) has demonstrated increase of the cure speed, reduction of air bubbles and improves in some mechanical properties. The aim of this study was to evaluate the effect of the ultrasound on the microhardness and the superficial roughness in two GICs (FUJI IX GP (GC Corporation) and Ketac Molar EasyMix (3M ESPE)). Forty specimens were confectioned, twenty for evaluation of the superficial roughness and twenty for evaluation of the microhardness. Half of them received for thirty seconds the ultrasonic waves application. The readings of the roughness had been carried before and after the toothbrushing test. The twenty remaining specimens had been polished with abrasive sandpapers of decreasing granulations and submitted to the hardness test. The results, analyzed for the variance analysis (ANOVA) (p<0,05), had demonstrated increase of the hardness for all the groups with the application of ultrasonic waves, being bigger for the Ketac Molar EasyMix. The ultrasound application also caused significant reduction of the superficial roughness for the Ketac Molar EasyMix. After the toothbrushing test, this last property increased for all the materials. It could be concluded that the application of ultrasonic waves was effective in increasing the superficial hardness of the materials and that it improved the roughness of the Ketac Molar EasyMix before the toothbrushing test.

Desgaste e rugosidade superficial de um cimento de ionômero de vidro nanoparticulado

To compare the abrasion wear resistance and superficial roughness of different glass ionomer cements used as restorative materials, focusing on a new nanoparticulate material. Material and Method: Three glass ionomer cements were evaluated: Ketac Molar, Ketac N100 and Vitremer (3M ESPE, St. Paul, MN, USA), as well as the Filtek Z350 (3M ESPE, St. Paul, MN, USA). For each material were fabricated circular specimens (n=12), respecting the handling mode specified by the manufacturer, which were polished with sandpaper disks of decreasing grit. The wear was determined by the amount of mass (M) lost after brushing (10,000 cycles) and the roughness (Ra) using a surface roughness tester. The difference between the Minitial and Mfinal (ΔM) as well as beroughness of aesthetic restorative materials: an in vitro comparison. SADJ. 2001; 56(7): 316-20. 11. Yip HK, Peng D, Smales RJ. Effects of APF gel on the physical structure of compomers and glass ionomer cements. Oper. Dent. 2001; 26(3): 231-8. 12. Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on the surface characteristics and color of denture resins. J Prosthet Dent 1997; 77(2): 197-204. 13. International organization for standardization. Technical specification 14569-1. Dental Materials – guidance on testing of wear resistance – PART I: wear by tooth brushing. Switzerland: ISO; 1999. 14. Bollen CML, Lambrechts P, Quirynen M. Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: a review of the literature. Dent Mater.1997; 13(4): 258-9. 15. Kielbassa AM, Gillmann C, Zantner H, Meyer-Lueckel H, Hellwig E, Schulte-Mönting J. Profilometric and microradiographic studies on the effects of toothpaste and acidic gel abrasivity on sound and demineralized bovine dental enamel. Caries Res. 2005; 39(5): 380-6. 16. Tanoue N, Matsumara H, Atsuta M. Wear and surface roughness of current prosthetic composites after toothbrush/dentifrice abrasion. J Prosthet Dent. 2000; 84(1): 93-7. 17. Heath JR, Wilson HJ. Abrasion of restorative materials by toothpaste. J Oral Rehabil. 1976; 3(2): 121-38. 18. Frazier KB, Rueggeberg FA, Mettenburg DJ. Comparasion of wearresistance of class V restorative materials. J Esthet Dent. 1998; 10(6): 309-14. 19. Momoi Y, Hirosakil K, Kohmol A, McCabe JF. In vitro toothebrushdentifrrice abrasion of resin-modified glass ionomers. Dent Mater. 1997; 13(2): 82-8. 20. Turssi CP, Magalhães CS, Serra MC, Rodrigues Jr.AL. Surface roughness assessment of resin-based materials during brushing preceded by pHcycling simulations. Oper Dent. 2001; 26(6): 576-84. 21. Wang L, Cefaly DF, Dos Santos JL, Dos Santos JR, Lauris JR, Mondelli RF, et al. In vitro interactions between lactic acid solution and art glassionomer cements. J Appl Oral Sci. 2009; 17(4): 274-9. 22. Carvalho FG, Fucio SB, Paula AB, Correr GM, Sinhoreti MA, PuppinRontani RM. Child toothbrush abrasion effect on ionomeric materials. J Dent Child (Chic). 2008; 75(2): 112-6. 23. Coutinho E, Cardoso MV, De Munck J, Neves AA, Van Landuyt KL, Poitevin A, et al. Bonding effectiveness and interfacial characterization of a nano-filled resin-modified glass-ionomer. Dent Mater. 2009; 25(11): 1347-57. tween Rainitial and Rafinal (ΔRa) were also used for statistical analysis (α=0.05). Results: Except for the composite, significant loss of mass was observed for all glass ionomer cements and the ΔM was comparable for all of them. Significant increase in roughness was observed only for Vitremer and Ketac N100. At the end of the brushing cycle, just Vitremer presented surface roughness greater than the composite resin. Conclusion: All glass ionomer cements showed significant weight loss after 10,000 cycles of brushing. However, only Vitremer showed an increase of roughness greater than the Z350 resin, while the nanoparticulate cement Ketac N100 showed a smooth surface comparable to the composite.

Dureza e rugosidade superficial de cimentos de ionômero de vidro após ensaio de escovação

To evaluate the surface roughness and Vickers hardness of glass ionomer cements Ketac Molar® and Ketac Molar Easy Mix® (ESPE Dental AG) after brushing. Methods – After roughness and hardness tests of 14 specimens of each material, they were submitted to 30,000 brushing cycles and new analysis of roughness and hardness. Statistical analysis showed that there was no significant difference between the materials in relation to the initial roughness. Results – However, after brushing there was higher surface roughness for Ketac Molar Easy Mix®. For both materials, there was increase of hardness after brushing and the highest values were presented by Ketac Molar Easy Mix®. Conclusion – It can be concluded that, when choosing a glass ionomer cement for restoration it should be preferred to Ketac Molar, because it showed hardness similar to Ketac Molar Easy Mix, but it was less rough.

Efeitos de diferentes sistemas de clareamento dental sobre a rugosidade e morfologia superficial do esmalte e de uma resina composta restauradora

The aim of this study was to evaluate and compare the roughness and superficial morphology of enamel and a composite restorative resin after different bleaching techniques application. Material and Methods: Bovine incisors were selected and standardized cavities were prepared on the buccal surface, which were restored with composite resin. The teeth were distributed according to the following treatments: G1- bleaching with 10% carbamide peroxide (CP); G2 - bleaching with 38% hydrogen peroxide (HP); and G3 - bleaching with 38% of HP associated to light irradiation. For G1, the bleaching gel was applied for 8 hours daily during 21 days. For G2 and G3, 3 sessions were performed, consisting of 3 applications of 15 minutes each, with 7 days of intervals between the sessions. For G3, the LED (470nm) light was used to activate the bleaching agent for 6 minutes. The surface of enamel and composite resin were evaluated before and after the bleaching procedures using a roughness tester and an atomic force microscope. Results: The results showed significant differences in surface roughness of enamel after bleaching only for G1 (Wilcoxon, p<0.05). For composite resin, neither group showed a statistical difference compared to control (Mann-Whitney, p>0.05). Conclusion: It was concluded that the increase in the roughness of enamel occurred only after bleaching therapy using a gel with 10% of CP. The bleaching procedures evaluated in this investigation did not increase the roughness or cause changes in the superficial morphology of the composite resin.

Microdureza e rugosidade superficial do esmalte submetido ao clareamento: uma revisão de literatura

The increasing importance of aesthetic in the Dentistry for the patients and the consumers brought a constant rise in the number of products and procedures to facilitate the confection of the dental bleaching. Concomitantly, thone was a sudden increase in the number of research and publications, in vitro and in vivo, about its possible adverse reactions. Through literature revision this study aims to verify the possible morphologic alterations of the submitted enamel and dentine with different bleaching agents making critical analysis of the results of the current research with relation to the study of the microhardness and superficial roughness.