Effects of polyvinyl chloride film and oxygen-blocking gel on irradiance and depth of cure.

This study aimed to analyze the effects of polyvinyl chloride (PVC) film and oxygen-blocking gel (OBG) on the irradiance from an LED source and the depth of cure of a composite resin. Irradiance was measured with a curing radiometer, and curing depth was evaluated according to the methods described by the International Organization for Standardization (ISO 4049). Twelve experimental conditions were investigated in a 3 × 4 factorial design (n = 5 specimens per condition): no PVC film at the tip of the device, fitted PVC film, or misfit PVC film; and no OBG or a 1-, 2-, or 3-mm-thick layer of OBG. The data were analyzed using analysis of variance and Tukey tests (P < 0.05), and a linear regression test was performed between the variables (P < 0.05). The analyses showed that the variables under study influenced the irradiance (P < 0.05) but not the curing depth (P > 0.05). The 3 groups that did not have the PVC film and either did not have the OBG or had the OBG in a thickness of 1 or 2 mm were not significantly different from each other (P > 0.05) but presented the highest irradiance values among all the groups (P < 0.05). The use of the misfit PVC film with a 3-mm layer of OBG led to the lowest irradiance values (P < 0.05). The variables did not influence each other (P > 0.05). The results of this study indicated that the presence of PVC film, especially misfit film, reduced the irradiance. In addition, the greater the thickness of the OBG, the lower the irradiance. None of the PVC film barrier conditions or OBG thicknesses had an effect on the depth of cure.

Mechanical and surface properties analysis of restorative materials submitted to erosive challenges in situ.

OBJECTIVE: This study aims to evaluate the effect of acidic solutions (AS) on surface roughness (Ra) and microhardness of restorative materials (RM). MATERIALS AND METHODS: Eight volunteers wore intraoral palatal devices (IPD) containing samples of RM: Ketac Nano (KN); Ketac Nano + Biscover LV (KN-B); Esthet-X (EX); Esthet-X + Biscover LV (EX-B); Supreme XT (SXT); Supreme XT + Biscover LV (SXT-B); and bovine enamel. The samples were submitted to three phases: (1) immersion in 0.01M hydrochloric acid (HCl) - 10 min, three times/day (14 days); (2) immersion in soft drink (Sprite®) - 10 min, three times/day (14 days); and (3) keeping in saliva (14 days). Changes in Ra/microhardness were measured before/after the three phases. STATISTICAL ANALYSIS: ANOVA (α = 0.05) and Fisher's test. RESULTS: Materials sealed with Biscover LV (B) presented lowest values in all periods. KN glass ionomer cement showed highest Ra values after exposure in AS. Application of B did not reduce the Ra for the composites studied, except for EX after immersion in HCl. AS promoted changes in Ra/microhardness of RM, except for sealed materials. CONCLUSIONS: The acids used were able to change the Ra and microhardness of RM, except of the sealed materials. The resin-modified GIC showed the most significant changes after immersion in AS; and the composites sealed with B, even after immersion in acidic solutions (AS), showed the lowest Ra values and the least degradation in microhardness, especially when subjected to low pH solutions.

Effect of CPP-ACP on enamel eroded extrinsically: in vitro study / Efeito do CPP-ACP sobre o esmalte erodido extrinsecamente: estudo in vitro

ABSTRACT Objective: The aim of this study was to evaluate the remineralization effect of CPP-ACP on tooth enamel that is eroded extrinsically. Methods: Sixty freshly extracted bovine teeth were stored in a solution of thymol (0.1%), cut into enamel blocks (6x6mm), abraded with silicon carbide sandpaper (600, 800 and 1200 grit) and polished with felt. The specimens were randomly divided into 4 groups (n=15), varying the immersion medium , deionized water or citric acid, and the optional use of CPP-ACP. (G1: deionized water; G2: citric acid; G3: deionized water + CPP-ACP; G4: citric acid + CPP-ACP). The samples were subjected to 4 cycles of erosion every day, comprising 5 minutes immersion in one medium and 2 hours of immersion in artificial saliva, for 5 consecutive days. After each erosive cycle, 20 uL of the MI Paste was applied for 5 minutes on one half of the samples and washed with deionized water. Before and after the erosive cycling, the measurements of Vickers hardness and surface roughness were taken. Results: The results were evaluated through statistical testing. The final hardness and roughness values showed no statistically significant difference between G2 and G4. The paste in G4 did not promote an increase in hardness values nor a decrease in roughness values. Conclusion: It was concluded that CPP-ACP was unable to remineralize enamel subjected to extrinsic erosion, being ineffective in preventing erosion of enamel and in the remineralization of the eroded enamel.

RESUMO Objetivo: Avaliar o efeito de remineralização do CPP-ACP sobre o esmalte dentário erodido extrinsecamente. Métodos: Sessenta dentes bovinos recém-extraídos, foram armazenados em solução de timol 0,1%, cortados em blocos de esmalte (6x6mm), desgastados com lixas de carbeto de silício (600, 800 e 1200) e polidos com feltro. Os espécimes foram distribuídos aleatoriamente em 4 grupos (n=15), variando o meio de imersão, água deionizada ou ácido cítrico; e o uso ou não do CPP-ACP (G1: água deionizada; G2: ácido cítrico; G3: água deionizada + CPP-ACP; G4: ácido cítrico + CPP-ACP). As amostras foram submetidas a 4 ciclos erosivos diários de 5 minutos de imersão em um dos meios e 2 horas de imersão em saliva artificial, durante 5 dias consecutivos. Após cada ciclo erosivo, 20 µL da pasta MI Paste foram aplicadas por 5 minutos em metade das amostras e lavadas com água deionizada. Antes e após a ciclagem erosiva as mensurações de dureza Vickers e rugosidade de superfície foram realizadas. Resultados: Os resultados foram avaliados através de testes estatísticos. Os valores de microdureza e rugosidade final não apresentaram diferença estatisticamente significante entre os grupos G2 e G4. No G4 a pasta não promoveu aumento nos valores de microdureza e nem diminuição nos valores de rugosidade. Conclusão: Concluiu-se que o CPP-ACP não foi capaz de remineralizar o esmalte submetido a erosão extrínseca, sendo ineficaz na prevenção da erosão do esmalte e na remineralização do esmalte erodido.

Efeito de diferentes fotopolimerizadores e meio de imersão na rugosidade e na cor de um compósito nanoparticulado / Effect of different light curing units and immersion media on roughness and color of a nanofill composite

Introdução: O consumo excessivo de refrigerantes parece alterar as propriedades dos compósitos e essa alteração pode estar relacionada à unidade fotopolimerizadora. Objetivo Avaliar a alteração da rugosidade superficial (delta R) e da cor (delta E) de um compósito polimerizado por diferentes fotopolimerizadores, imerso em água destilada ou Coca-Cola®. Metodologia Sessenta amostras da resina nanoparticulada (FiltekMR Z350 XT, 3M) foram distribuídas de acordo com as diferentes unidades de fotopolimerização: a) luz halógena de quartzo-tungstênio-halogênio (QTH); b) Luz de Emissão Diodo - LED 1 com ponteira de polímero; c) LED 2 com ponteira de fibra ótica. Metade de cada grupo (n=10) foi mantida em água destilada ou imersa em Coca-Cola® 2×/dia por 20 minutos, durante 14 dias. Os dados foram submetidos aos testes Mann-Whitney e Kruskal-Wallis (p< =0,05). Resultado A ΔR não foi significante entre os grupos: em água: QTH = 0,006; LED 1 = 0,019; LED 2 = 0,010 (p=0,33); em refrigerante: QTH = 0,021; LED 1= 0,011; LED 2 = 0,030 (p=0,86). A delta E não foi significativa entre os fotopolimerizadores: em água: QTH = 1,40; LED 1 = 1,80; LED 2 = 1,60 (p=0,31); em refrigerante: QTH = 2,51; LED 1= 1,91; LED 2 = 2,61 (p=0,41), mas foi significante comparando os meios de imersão (p=0,01), exceto para LED 1 (p=0,54). Conclusão: As unidades fotopolimerizadoras não interferiram na rugosidade superficial e na cor da resina composta nanoparticulada. Os mergulhos diários em refrigerante não alteraram a lisura, mas alteraram a cor de modo visualmente perceptível, mas clinicamente aceitável, conforme os parâmetros da literatura científica.

Introduction: The excessive consumption of soft drinks seems to change the properties of composites and may be associated with the light curing unit. Objective: To evaluate changes in surface roughness (delta R) and color (delta E) of one composite polymerized with different light sources, immersed in distilled water or in Coca-Cola®. Methodology: Sixty samples of nanofilled resin (FiltekMR Z350 XT, 3M) were distributed into following light curing units: a) quartz-tungsten-halogen (QTH) light; b) light emitting diode (LED) with polymer tip (LED 1) and c) LED with optic fiber tip (LED 2). Half of each group (n=10) was kept in water or immersed in Coca-Cola® for 20 minutes 2x/day during 14 days. Data were submitted to the Mann-Whitney and Kruskal-Wallis tests (p<=0.05). Result: The delta R was not significant among groups: in water: QTH = 0.006; LED 1 = 0.019; LED 2 = 0.010 (p=0.33); in soft drink: QTH = 0.021; LED 1= 0.011; LED 2 = 0.030 (p=0.86). The delta E was not significant among light curing units: in water: QTH = 1.40; LED 1 = 1.80; LED 2 = 1.60 (p=0.31); in soft drink: QTH = 2.51; LED 1= 1.91; LED 2 = 2.61 (p=0.41), but was significant compared the immersion media (p=0.01), except for LED 1 (p=0.54). Conclusion The light curing lights did not interfere with the surface roughness and with color of nanofilled composite. Daily dives in soft drinks did not change smoothness, but the color changed to visually perceptible way, though clinically acceptable, according to the scientific literature parameters.

Effect of Fluoride-Releasing Adhesive Systems on the Mechanical Properties of Eroded Dentin.

The aim of the study was to evaluate the effect of erosive pH cycling with solutions that simulate dental erosion on Martens hardness (HMV) and elastic modulus (Eit) of dentin restored with fluoride-releasing adhesive systems. Twenty-seven bovine dentin slabs were restored with three adhesive systems: Adper Single Bond 2 total-etch adhesive system, One Up Bond F and Clearfil SE Protect fluoride-containing self-etching adhesive systems. The restorations were made with Filtek Z250. The HMV and Eit values at distances of 10, 30, 50 and 70 µm from the interface were evaluated using a dynamic ultra microhardness tester before and after immersion in deionized water, citric acid and hydrochloric acid (n=9). Data were submitted to repeated-measures ANOVA and Fisher's PLSD tests (=0.05). After erosive cycling, HMV values of dentin decreased in all groups. For dentin restored with Adper Single Bond 2, the lowest values were found closer to the hybrid layer, while for One Up Bond F and Clearfil SE Protect, the values remained unaltered at all distances. For dentin restored with fluoride-releasing adhesive systems, a decrease in Eit was found, but after 30 µm this difference was not significant. The acid substances were able to alter HMV and Eit of the underlying dentin. For fluoride-releasing adhesives, the greater the distance from bonded interface, the lower the Eit values. The fluoride in One Up Bond F and Clearfil SE Protect was able to protect the underlying dentin closer to the materials. In this way, the fluoride from adhesive systems could have some positive effect in the early stages of erosive lesions.

Effect of Fluoride-Releasing Adhesive Systems on the Mechanical Properties of Eroded Dentin

Abstract The aim of the study was to evaluate the effect of erosive pH cycling with solutions that simulate dental erosion on Martens hardness (HMV) and elastic modulus (Eit) of dentin restored with fluoride-releasing adhesive systems. Twenty-seven bovine dentin slabs were restored with three adhesive systems: Adper Single Bond 2 total-etch adhesive system, One Up Bond F and Clearfil SE Protect fluoride-containing self-etching adhesive systems. The restorations were made with Filtek Z250. The HMV and Eit values at distances of 10, 30, 50 and 70 µm from the interface were evaluated using a dynamic ultra microhardness tester before and after immersion in deionized water, citric acid and hydrochloric acid (n=9). Data were submitted to repeated-measures ANOVA and Fisher's PLSD tests (=0.05). After erosive cycling, HMV values of dentin decreased in all groups. For dentin restored with Adper Single Bond 2, the lowest values were found closer to the hybrid layer, while for One Up Bond F and Clearfil SE Protect, the values remained unaltered at all distances. For dentin restored with fluoride-releasing adhesive systems, a decrease in Eit was found, but after 30 µm this difference was not significant. The acid substances were able to alter HMV and Eit of the underlying dentin. For fluoride-releasing adhesives, the greater the distance from bonded interface, the lower the Eit values. The fluoride in One Up Bond F and Clearfil SE Protect was able to protect the underlying dentin closer to the materials. In this way, the fluoride from adhesive systems could have some positive effect in the early stages of erosive lesions.

Resumo O objetivo deste estudo foi avaliar o efeito da ciclagem de pH erosiva com soluções que simulam a erosão dental, na dureza Martens (HMV) e módulo de elasticidade (Eit) da dentina restaurada com sistemas adesivos contendo fluoretos. Vinte e sete blocos de dentina foram restaurados com três sistemas adesivos: sistema adesivo de condicionamento total Adper Single Bond 2 e sistemas adesivos autocondicionantes contendo fluoreto One Up Bond F e Clearfil SE Protect. As restaurações foram realizadas com resina Filtek Z250. Os valores de HMV e Eit nas distâncias de 10, 30, 50 e 70µm da interface foram avaliadas em ultramicrodurômetro dinâmico antes e após a imersão em água deionizada, ácido cítrico e ácido clorídrico (n=9). Dados foram submetidos à ANOVA para medidas repetidas e Fisher PLSD (α=0,05). Após a ciclagem erosiva, os valores de HMV da dentina diminuíram em todos os grupos. Para a dentina restaurada com Adper Single Bond 2, os menores valores foram encontrados próximo a camada híbrida enquanto que, para os sistemas adesivos One Up Bond F e Clearfil SE Protect, os valores permaneceram inalterados em todas as distâncias. Para a dentina restaurada com os materiais que liberam fluoretos, uma redução nos valores de Eit foi encontrada, mas após 30µm essa diferença não foi mais significante. As substâncias ácidas foram capazes de alterar a HMV e o Eit da dentina subjacente. Para os adesivos que liberam fluoretos, quanto maior a distância da interface adesiva, menor os valores de Eit. O fluoreto presente no One Up Bond F e Clearfil SE Protect foi capaz de proteger a dentina subjacente próxima aos materiais. Dessa maneira, a presença do flúor em sistemas adesivos pode ter algum efeito positivo em estágios iniciais de lesões erosivas.

Fluorescence intensity of composite layering combined with surface sealant submitted to staining solutions.

PURPOSE: The aim of this study was to evaluate the fluorescence intensity of a composite in different layering techniques combined to a surface sealant submitted to staining solutions. METHODS AND MATERIALS: One surface sealant and one composite resin (shades A2-0, A2, and YE) were tested. Specimens were carried out using layering with different shades of composite, and dental blocks (dentin/enamel) were obtained of human molars. Fluorescence intensity measurement performed using a spectrofluorophotometer, before and after storage in cola, orange juice, red wine, and distilled water. Data were subjected to analysis of variance and Fisher's test (α = 0.05). RESULTS: Initially, only A2-O + A2 layering showed fluorescence intensity statistically similar to the natural tooth. Overall, groups sealed showed the highest fluorescence intensity compared with unsealed groups. The aging decreased the fluorescence intensity compared with initial values. Red wine showed the highest decrease on the fluorescence intensity. CONCLUSION: The fluorescence of composite restorations is dependent of the layering technique and is affected by the diet. CLINICAL SIGNIFICANCE: The staining solutions decreased the fluorescence intensity, even when the composite resins were sealed. Different shades of the same composite showed distinct fluorescence values, so there should be greater standardization of this property for tooth reconstruction success by the layering technique with large tissue loss.

Effect of whitening and desensitizing dentifrices on composite surfaces treated with surface sealants.

OBJECTIVE: This study evaluated the effect of different dentifrices on the microhardness and surface roughness of composite surfaces covered by surface sealants. METHODS: Samples of Filtek P60 were made and divided into groups, in accordance with surface treatments: G1 - Fortify; G2 - Fortify Plus; G3 - control (none). For Knoop microhardness evaluation, the specimens were placed in a microdurometer, under a load of 50 g for 15 sec. The analyses of surface roughness were carried out individually in a profilometer. The specimens were submitted to toothbrushing using dentifrices: Colgate Maximum Protection Anti-caries, Colgate Whitening or Sensodyne, diluted in distilled water (1:3) for 30 000 cycles. RESULTS: The results showed that the control group (G3) presented the highest microhardness values. The control group presented, before toothbrushing, the lowest surface roughness values, and after toothbrushing there were no differences among the experimental groups. CONCLUSION: The maintenance of the lowest values of microhardness demonstrated the effectiveness of these sealant materials to support the abrasive wear.

Efeito da ciclagem de ph erosiva nas propriedades mecânicas da dentina utilizando diferentes materiais restauradores / Effect of erosive pH cycling on the mechanical properties of dentin using different restorative materials

O objetivo deste estudo in vitro foi avaliar o efeito da ciclagem de pH erosiva com soluções que simulam a erosão dental, provenientes de fatores extrínsecos ou intrínsecos, na dureza e módulo de elasticidade da dentina restaurada com materiais restauradores contendo fluoretos. Quarenta e cinco blocos de dentina medindo 6 x 6 mm foram restaurados com cinco materiais restauradores: sistema adesivo de condicionamento total Adper Single Bond 2 + resina composta Filtek Z250; sistema adesivo autocondicionante One Up Bond F + resina composta Filtek Z250; sistema adesivo autocondicionante Clearfil SE Protect + resina composta Filtek Z250; cimento de ionômero de vidro convencional Riva Self Cure; cimento de ionômero de vidro resinoso Riva Light Cure. Mensurações da dureza Martens e módulo de elasticidade da dentina subjacente à interface de união (10μm, 30μm, 50μm e 70μm) foram realizadas em ultramicrodurômetro digital antes e após a imersão em soluções de água deionizada, ácido cítrico ou ácido clorídrico. Após a ciclagem, os valores de dureza da dentina diminuíram para todos os materiais. Para a dentina restaurada com Adper Single Bond 2, os menores valores foram encontrados próximo a camada híbrida (10 μm) enquanto que para a dentina restaurada com os sistemas adesivos autocondicionantes (Clearfil SE Protect e One Up Bond F), esses valores foram mantidos em todas as distâncias avaliadas. Para os materiais Riva Self Cure e Riva Light Cure somente nas leituras iniciais a distância foi determinante na dureza, uma vez que quanto maior a distância da interface de união, maiores eram os valores encontrados. Com relação ao módulo de elasticidade, para a dentina restaurada com Adper Single Bond 2, não houve diferença significante em todas as distâncias avaliadas. Já na dentina restaurada com os sistemas adesivos autocondicionantes (Clearfil SE Protect e One Up Bond F) e cimentos ionoméricos (Riva Self Cure e Riva Light Cure) houve redução nos valores de módulo de...

The aim of this study was to evaluate the effect of erosive pH cycling with solutions that simulate dental erosion in the hardness and elastic modulus of dentin restored with fluoride-releasing restorative materials. Forty five bovine dentine slabs (6,0 mm x 6,0 mm) were restored with 5 restorative materials: Adper Single Bond 2 total-etch adhesive system + Filtek Z250 composite resin; One Up Bond F self-etching adhesive system + Filtek Z250 composite resin; Clearfil SE Protect self-etching adhesive system + Filtek Z250 composite resin; Riva Self Cure conventional glass ionomer cement and Riva Light Cure light curing glass ionomer cement. The values of hardness and elastic modulus of dentin (10μm, 30μm, 50μm e 70μm) were evaluated in digital ultramicrohardner tester before and after immersion in solutions of deionized water, citric acid and hydrochloric acid. After cycling, the hardness of dentin decreased for all materials. For dentin restored with Adper Single Bond 2, the lowest values were found close to hybrid layer (10 μm), while for the dentin restored with One Up Bond F and Clearfil SE Protect, the values remained unaltered in all the evaluated distances. For dentin restored with Riva Self Cure and Riva Light Cure only in the initial measurements, the distance had a significant effect in the hardness values, since the greater the distance to the bonding interface, higher values of hardness were found. For the elastic modulus analysis, dentin restored with Adper Single Bond 2 showed no significant difference when distances from bonding interface were compared. Dentin restored with self-etching adhesive system (One Up Bond F and Clearfil SE Protect) and glass ionomer cements (Riva Self Cure and Riva Light Cure) showed a reduction in the elastic modulus values from the bonding interface, but after 30 μm the difference was not significant

Efeito da ciclagem de ph erosiva nas propriedades mecânicas da dentina utilizando diferentes materiais restauradores / Effect of erosive pH cycling on the mechanical properties of dentin using different restorative materials

O objetivo deste estudo in vitro foi avaliar o efeito da ciclagem de pH erosiva com soluções que simulam a erosão dental, provenientes de fatores extrínsecos ou intrínsecos, na dureza e módulo de elasticidade da dentina restaurada com materiais restauradores contendo fluoretos. Quarenta e cinco blocos de dentina medindo 6 x 6 mm foram restaurados com cinco materiais restauradores: sistema adesivo de condicionamento total Adper Single Bond 2 + resina composta Filtek Z250; sistema adesivo autocondicionante One Up Bond F + resina composta Filtek Z250; sistema adesivo autocondicionante Clearfil SE Protect + resina composta Filtek Z250; cimento de ionômero de vidro convencional Riva Self Cure; cimento de ionômero de vidro resinoso Riva Light Cure. Mensurações da dureza Martens e módulo de elasticidade da dentina subjacente à interface de união (10μm, 30μm, 50μm e 70μm) foram realizadas em ultramicrodurômetro digital antes e após a imersão em soluções de água deionizada, ácido cítrico ou ácido clorídrico. Após a ciclagem, os valores de dureza da dentina diminuíram para todos os materiais. Para a dentina restaurada com Adper Single Bond 2, os menores valores foram encontrados próximo a camada híbrida (10 μm) enquanto que para a dentina restaurada com os sistemas adesivos autocondicionantes (Clearfil SE Protect e One Up Bond F), esses valores foram mantidos em todas as distâncias avaliadas. Para os materiais Riva Self Cure e Riva Light Cure somente nas leituras iniciais a distância foi determinante na dureza, uma vez que quanto maior a distância da interface de união, maiores eram os valores encontrados. Com relação ao módulo de elasticidade, para a dentina restaurada com Adper Single Bond 2, não houve diferença significante em todas as distâncias avaliadas. Já na dentina restaurada com os sistemas adesivos autocondicionantes (Clearfil SE Protect e One Up Bond F) e cimentos ionoméricos (Riva Self Cure e Riva Light Cure) houve redução nos valores de módulo de...

The aim of this study was to evaluate the effect of erosive pH cycling with solutions that simulate dental erosion in the hardness and elastic modulus of dentin restored with fluoride-releasing restorative materials. Forty five bovine dentine slabs (6,0 mm x 6,0 mm) were restored with 5 restorative materials: Adper Single Bond 2 total-etch adhesive system + Filtek Z250 composite resin; One Up Bond F self-etching adhesive system + Filtek Z250 composite resin; Clearfil SE Protect self-etching adhesive system + Filtek Z250 composite resin; Riva Self Cure conventional glass ionomer cement and Riva Light Cure light curing glass ionomer cement. The values of hardness and elastic modulus of dentin (10μm, 30μm, 50μm e 70μm) were evaluated in digital ultramicrohardner tester before and after immersion in solutions of deionized water, citric acid and hydrochloric acid. After cycling, the hardness of dentin decreased for all materials. For dentin restored with Adper Single Bond 2, the lowest values were found close to hybrid layer (10 μm), while for the dentin restored with One Up Bond F and Clearfil SE Protect, the values remained unaltered in all the evaluated distances. For dentin restored with Riva Self Cure and Riva Light Cure only in the initial measurements, the distance had a significant effect in the hardness values, since the greater the distance to the bonding interface, higher values of hardness were found. For the elastic modulus analysis, dentin restored with Adper Single Bond 2 showed no significant difference when distances from bonding interface were compared. Dentin restored with self-etching adhesive system (One Up Bond F and Clearfil SE Protect) and glass ionomer cements (Riva Self Cure and Riva Light Cure) showed a reduction in the elastic modulus values from the bonding interface, but after 30 μm the difference was not significant.

Effect of postpolymerization method on the color stability of composite resins submitted to ultraviolet aging.

The aim of this research was to evaluate the effect of postpolymerization method on the color stability of resin-based composites. Samples of direct and indirect restorative materials were polymerized with two photo-curing units (Visio photo-curing oven system and LED Elipar Freelight 2). All samples were submitted to an initial chromatic analysis using a spectrometer and submitted to ultraviolet-accelerated artificial aging. The direct material showed less color change than the indirect material, independent of the photo-activation method used. Samples photo cured with the LED system showed less change than those photo cured with the Visio system. The postpolymerization oven did not improve the color stability of direct and indirect resin-based composites.

Erosão dental e suas implicações sobre saúde bucal / Dental erosion and its implication on the oral health

Os conceitos de promoção de saude bucal e o aumento da espectativa de vida tem contribuído para a maior manutenção dos elementos dentais. Assim, com os novos hábitos alimentares e comportamentais, a perda irreversível de tecido dental duro de origem não cariosa tem aumentado substancialmente, sendo dividida em atrição, erosão e abrasão. A erosão dental é uma enfermidade crônica, definida como a perda superficial de tecido dental duro como resultado de um processo químico sem envolvimento de bactérias, causada por ácidos, que podem ter origem intrínseca, extrínseca ou idiopática, provocando a perda irreversível de tecido mineralizado e hipersensibilidade dentinária. O presente trabalho tem por objetivo apresentar uma revisão da literatura sobre os principais fatores que podem ocasionar as lesões de erosão, reunindo os diferentes aspectos relacionados à sua etiologia, classificação, diagnóstico, prevenção e tratamento

Erosão dental e suas implicações sobre a saúde bucal / Dental erosion and its implications on the oral health

Os conceitos de promoção de saúde bucal e o aumento da expectativa de vida têm contribuído para a maior manutenção dos elementos dentais. Assim, com os novos hábitos alimentares e comportamentais, a perda irreversível de tecido dental duro de origem não cariosa tem aumentado substancialmente, sendo dividida em atrição, erosão e abrasão. A erosão dental é uma enfermidade crônica, definida como a perda superficial de tecido dental duro como resultado de um processo químico sem envolvimento de bactérias, causada porácidos, que podem ter origem intrínseca, extrínseca ou idiopática, provocando a perda irreversível de tecido mineralizado e hipersensibilidade dentinária. O presente trabalho tem por objetivo apresentar uma revisão da literatura sobre os principais fatores que podem ocasionar as lesões de erosão, reunindo os diferentes aspectos relacionados à sua etiologia, classificação, diagnóstico, prevenção e tratamento.

Efeito de substâncias ácidas na rugosidade de superfície e dureza knoop de materiais restauradores: estudo in situ / In situ evaluation of surface roughness and microhardness of restorative materials submited to erosive challenges

O objetivo deste trabalho in situ foi avaliar o efeito de ácidos, presentes em refrigerantes e no suco gástrico, na rugosidade de superfície e microdureza de materiais restauradores. Cento e sessenta e oito corpos-de-prova foram divididos aletoriamente em 3 grupos de estudo com 8 voluntários. Cada voluntário utilizou o dispositivo intrabucal removível contendo 7 amostras (Ketac Nano, Ketac Nano + Biscover LV, Esthet-X, Esthet-X + Biscover LV, Supreme XT, Supreme XT + Biscover LV e esmalte bovino). O grupo I foi tratado com ácido clorídrico, o grupo II foi tratado com refrigerante de limão e o grupo III foi o controle, não recebendo nenhum tratamento ácido. As variáveis de respostas foram a medida de rugosidade superficial média (Ra) e a microdureza Knoop. A ANOVA e teste de Fisher PLSD (α = 0,05) demonstraram que a resina composta Supreme XT apresentou os maiores valores de microdureza antes e após os processos de envelhecimento com diferença significante para todos os outros materiais (p<0,0001). Os menores valores foram encontrados para os materiais selados com Biscover LV em todos os períodos analisados (p<0,0001). O ionômero de vidro Ketac Nano apresentou os maiores valores de rugosidade de superfície após a exposição nas soluções ácidas. A aplicação do selante de superfície não alterou os valores de rugosidade para as resinas compostas estudadas à exceção do Esthet-X após o desafio em ácido clorídrico (p<0.0001). As soluções ácidas foram capazes de alterar a microdureza e rugosidade de superfície dos materiais restauradores, exceto dos materiais selados

The aim of this study was to evaluate the effect of different acidics solutions on the microhardness and surface roughness of restorative materials. 168 specimens were randomly divided into 3 groups with 8 volunteers. The volunteers wore palatal device with 7 specimens (Ketac Nano, Ketac Nano + Biscover LV, Esthet-X, Esthet-X + Biscover LV, Supreme XT, Supreme XT + Biscover LV and bovine enamel). The group I was immersed in HCl; the group II was immersed in soft drink and the group III was subjected to saliva only. The microhardness and surface roughness data were analyzed by ANOVA and Fisher‟s test (α = 0.05). The Supreme XT showed the highest values of microhardness before and after aging with a significant difference for the other materials (p<0.0001). The lowest values were found for the materials sealed with Biscover LV in all periods analyzed (p<0.0001). The Ketac Nano glass-ionomer cement showed the highest values of surface roughness after exposure in acidic solutions. The application of the sealant did not reduce the roughness values for the composites studied except for Esthet-X after the challenge in hydrochloric acid. The acidic solutions promoted changes in microhardness and surface roughness of restorative materials, except for the sealed materials