Abstract This study evaluated the effect of different firing protocols on the surface roughness and flexural strength of CAD/CAM lithium disilicate glass-ceramic (LD) after aging methods. Forty-two LD bars of 16 x 4 x 2 mm (IPS e-max CAD, Ivoclar) were randomly separated into two groups according to firing protocols: Single firing-Staining, glazing, and crystallization in a single step; Multiple firings-Crystallization+First staining+Firing+Second staining+Firing+Glazing+Firing. After protocols, initial surface roughness readings were taken (Surfcorder SE1700, Kosakalab). Samples were then randomly separated into three groups (n=7) according to the aging methods they were submitted: Thermomechanical cycling (TMC, ER System, Erios, 1,200,000 cycles, 0.3 MPa, 2 Hz and 5°C/37°C/55°C, 30 s swell time); Simulated toothbrushing (STB, Pepsodent, MAVTEC, 73,000 cycles), and Control (no aging). Final surface roughness readings were done, and samples were submitted to a three-point bending test (OM100, Odeme Dental Research) and fractographic analysis by scanning electron microscopy (EVO-MA10, ZEISS). Data were analyzed (2-way ANOVA, (α=.05). There was no difference (p>.05) in the flexural strength between the firing protocols, regardless of the aging method. STB decreased the flexural strength of samples submitted to multiple firings, different from control (p<.05). Without aging (Control), before TMC, and after STB, LD had lower surface roughness when submitted to multiple firings than to single firing (p<.05). The firing protocols did not affect the flexural strength or the surface roughness of the lithium disilicate glass-ceramic, even after aging. However, toothbrushing negatively affected the flexural strength and smoothed the surface of the ceramic submitted to multiple firings.

Resumo Este estudo avaliou o efeito de diferentes protocolos de queima na rugosidade de superfície e resistência à flexão de uma cerâmica vítrea de dissilicato de lítio (DL) para CAD/CAM, após métodos de envelhecimento. Quarenta e dois barras de DL (IPS e-max CAD, Ivoclar) de 16 x 4 x 2 mm foram separadas aleatoriamente em dois grupos de acordo com os protocolos de queima: Single firing-Pigmentação, glazeamento e cristalização em única etapa. Multiple firings-Cristalização+Primeira camada do pigmento+Queima+Segunda camada do pigmento+Queima+Glazeamento+Queima. Após os protocolos, foram realizadas leituras iniciais de rugosidade de superfície (Surfcorder SE1700, Kosakalab). As amostras foram então separadas aleatoriamente em três grupos (n=7) segundo o método de envelhecimento a que foram submetidas: Ciclagem termomecânica (CTM, Sistema ER, Erios, 1.200.000 ciclos, 0.3 MPa, 2 Hz e 5°C/37°C/55°C, 30 s de imersão), Escovação simulada (ES, Pepsodent, MAVTEC, 73.000 ciclos) e Controle (sem envelhecimento). Leituras finais de rugosidade foram realizadas, e as amostras foram submetidas ao ensaio de resistência à flexão em três pontos (OM100, Odeme Dental Research) e à análise fractográfica por microscopia eletrônica de varredura (EVO-MA10, ZEISS). Os dados foram analisados (ANOVA de dois fatores, (α=.05). Não houve diferença (p>.05) na resistência à flexão entre os protocolos de queima, independente do envelhecimento. ES diminuiu a resistência à flexão das amostras submetidas a multiple firings, diferente do controle (p<.05). Sem envelhecimento (Controle), antes da CTM e após ES, LD apresentou menor rugosidade de superfície quando submetido a multiple firings do que a single firing (p<.05). Os protocolos de queima não afetaram a resistência à flexão nem a rugosidade de superfície da cerâmica vítrea de dissilicato de lítio, mesmo após envelhecimento. No entanto, a escovação afetou negativamente a resistência à flexão e poliu a superfície da cerâmica submetida a multiple firings.

Abstract This study evaluated color stability (CS), anti-adherence effect (AAE), and cell viability of microorganisms on acrylic resin (AR) surface, treated associated or not with sodium percarbonate (SP). AR specimens were prepared, and color analysis was performed before and after the treatments and the CS was calculated. For analysis of AAE, the samples were sterilized by radiation in a microwave oven. Then samples were randomly distributed: phosphate-buffered saline (PBS - control), 0.5% sodium hypochlorite (SH), phytosphingosine (PHS), and phytosphingosine + SP (PHS+Na2CO3). The specimens remained in contact with solutions for 30 minutes and were later contaminated by Candida albicans. Aliquots were seeded in Petri dishes with Sabouraud Dextrose agar and incubated at 37°C for 24 hours. After the incubation, the number of colonies was counted. The cell viability of adhered microorganisms on the AR was evaluated and 20 fields were observed under an epifluorescence microscope, and the percentage of adhered viable cells was calculated. Data were compared (One-way ANOVA, Tukey, p<.05). As for CS, PHS+ Na2CO3 (0.4±0.1) resulted in less change than PBS (0.9±0.2), similar to the other groups (SH [1.0±0.3)]; PHS [0.9±0.2)]). There was no difference for all tested solutions regarding the ability to avoid microorganism adherence (p>0.05), but PHS (11.2±4.1) resulted in a smaller area of adhered viable cells, statistically different from SH (18.2±7.6) and PBS (26.4±10.8). It was concluded that PHS resulted in lower adhered viable cells and when associated with Na2CO3, also shows a lower effect on the CS of AR.

Resumo Este estudo avaliou estabilidade de cor (EC), efeito antiaderente (EAA) e viabilidade celular de microrganismos em superfície de resina acrílica (RA), tratada com solução de fitoesfingosina, associada ou não ao percarbonato de sódio (PS). Espécimes RA foram preparados e análise de cor foi realizada antes e após os tratamentos e EC foi calculada. Para análise de EAA, as amostras foram esterilizadas por radiação em forno de micro-ondas. Então foram distribuídas aleatoriamente: solução salina tamponada com fosfato (PBS - controle), hipoclorito de sódio 0,5% (SH), fitoesfingosina (PHS) e fitoesfingosina + SP (PHS+Na2CO3). Os espécimes permaneceram em contato com as soluções por 30 minutos e posteriormente foram contaminados por Candida albicans. Alíquotas foram semeadas em placas de Petri com ágar Sabouraud Dextrose e incubadas a 37°C por 24 horas. Após a incubação, o número de colônias foi contado. A viabilidade celular dos microorganismos aderidos na RA foi avaliada e 20 campos foram observados em microscópio de epifluorescência, e a porcentagem de células viáveis aderidas foi calculada. Os dados foram comparados (One-way ANOVA, Tukey, p<0,05). Quanto a EC, o PHS+ Na2CO3 [0,4 (0,1)] resultou em menor alteração que o PBS [0,9 (0,2)], semelhante aos demais grupos (SH [1,0 (0,3)]; PHS [0,9 (0,2)]). Não houve diferença para todas as soluções testadas quanto à capacidade de evitar a aderência de microorganismos (p>0,05), mas o PHS [11,2 (4,1)] resultou em uma área menor de células viáveis aderidas, estatisticamente diferente do SH [18,2 (7,6)] e PBS [26,4 (10,8)]. Concluiu-se que o PHS resultou em menor número de células viáveis aderidas e, quando associado ao Na2CO3, também apresenta menor efeito sobre o EC da RA.

Abstract This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey’s test; and Ra, by 2-way ANOVA, repeated measures, and Tukey’s test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

Resumo Este estudo avaliou o efeito da Fitoesfingosina (PHS) e da vitrocerâmica bioativa (Biosilicato) sobre o esmalte dental em termos de alteração de cor (ΔE), microdureza (KHN) e rugosidade superficial, quando submetido a desafio erosivo (DE). Sessenta espécimes de dentes bovinos (6×6×2mm) foram obtidos. Foram realizadas leituras de cor inicial (Easyshade, VITA), microdureza (HMV-2, Shimadzu) e rugosidade superfícial (SJ-201P, Mitutoyo). Os espécimes foram separados em grupos de acordo com os tratamentos: PHS, Biosilicato a 10%, PHS+Biosilicato a 10%, e saliva artificial (controle). Em seguida, foram submetidos a DE com Coca-Cola por 2 min. Esse ciclo foi repetido 4 vezes/dia por 15 dias. Entre os ciclos, as amostras foram mantidas em saliva artificial (2 h/37°C). Após os ciclos diários, os espécimes também foram armazenados em saliva artificial a 37ºC. Foram realizadas leituras finais de cor, microdureza e rugosidade superficial. Os dados de cor e microdureza foram analisados por ANOVA de uma via, teste de Tukey; e dados de rugosidade superficial, por ANOVA de duas vias, teste de Tukey (p<.05). A maior ΔE ocorreu em Saliva+DE (p<.05). Grupos tratados com PHS apresentaram menor alteração de cor do que Saliva+DE (p<.05). Biosilicate+DE demonstrou valores intermediários, similar (p>.05) aos outros grupos, exceto Saliva+DE. Todos os grupos presentaram média acima dos limites 50:50% de perceptibilidade (50:50%LP) e aceitabilidade (50:50%LA) exceto o controle que demonstrou média acima do 50:50%LA mas abaixo do 50:50%LP. Biosilicate+DE mostrou maior microdureza realativa do que Saliva+DE (p<.05), mas similar a PHS+DE e PHS+Biosilicato+DE. A rugosidade de superfície do esmalte aumentou para todos os grupos, exceto para o controle que presentou a menor alteração (p<.05). O Biosilicato apode prevenir perda mineral do esmalte indizido pela erosão melhor que a saliva. O PHS associado ou não ao Biosilicato demonstrou melhor estabilidade de cor que a saliva.

Abstract This study evaluated the efficacy of incorporating different concentrations of bioactive glass-ceramic (Biosilicate) into coconut oil on the remineralizing potential and surface roughness of white spot lesions. Fragments (6 x 6 x 2mm) of bovine teeth were sectioned and initial microhardness (KHN) and surface roughness (Ra) readings were obtained. The samples were submitted to cariogenic challenge to form white spot lesions and were separated into six groups (n=13): 1) Artificial Saliva (AS); 2) Coconut Oil (CO); 3) CO+2% Biosilicate (CO+2%Bio); 4) CO+5% Biosilicate (CO+5%Bio); 5) 2% Biosilicate Suspension (2% Bio) and 6) 5% Biosilicate Suspension (5% Bio). The treatments for 1 cycle/day were: immersion into the treatments for 5 minutes, rinsing in distilled water, and storage in artificial saliva at 37ºC. After 14 days, KHN and Ra readings were taken. The surface roughness alteration ((Ra) was analyzed (Kruskal-Wallis, Dunn’s post-test, p<0.05). CO+2%Bio had higher (p = 0.0013) (Ra followed by CO+5%Bio (p = 0.0244) than AS. The relative KHN and remineralization potential were analyzed (ANOVA, Tukey, p<0.05), and 5% Bio treatment presented a higher relative microhardness than all other groups (p>0.05). The remineralizing potential of all the treatments was similar (p > .05). When Biosilicate was added, the pH of the suspensions increased and the alkaline pH remained during the analysis. Biosilicate suspension is more efficient than the incorporation of particles into coconut oil at white spot lesion treatment. In addition to the benefits that coconut oil and Biosilicate present separately, their association can enhance the remineralizing potential of Biosilicate.

Resumo Este estudo avaliou a eficácia da incorporação de diferentes concentrações de vitrocerâmica bioativa (biosilicato) ao óleo de coco no potencial remineralizante e na rugosidade superficial de lesões de manchas brancas. Fragmentos (6 x 6 x 2mm) de dentes bovinos foram seccionados e as leituras iniciais de microdureza (KHN) e rugosidade superficial (Ra) foram obtidas. As amostras foram submetidas ao desafio cariogênico para formação de lesões de manchas brancas e foram separadas em seis grupos (n=13): 1) Saliva Artificial (AS); 2) Óleo de Coco (CO); 3) CO+2% Biosilicato (CO+2%Bio); 4) CO+5% Biosilicato (CO+5%Bio); 5) Suspensão de Biosilicato 2% (2% Bio) e 6) Suspensão de Biosilicato 5% (5% Bio). Os tratamentos de 1 ciclo/dia foram: imersão nos tratamentos por 5 minutos, enxágue em água destilada e armazenamento em saliva artificial a 37ºC. Após 14 dias, foram feitas as leituras de KHN e Ra. A alteração da rugosidade superficial ((Ra) foi analisada (Kruskal-Wallis, pós-teste de Dunn, p<0,05). CO+2%Bio apresentou maior (p = 0,0013) (Ra seguido de CO+5%Bio (p = 0,0244) do que AS. O KHN relativo e o potencial de remineralização foram analisados (ANOVA, Tukey, p<0,05), e o tratamento 5% Bio apresentou uma microdureza relativa maior do que todos os outros grupos (p>0,05). A suspensão de biosilicato é mais eficiente que a incorporação de partículas ao óleo de coco no tratamento de lesões de mancha branca. Além dos benefícios que o óleo de coco e o Biosilicato apresentam separadamente, sua associação pode amplificar o potencial remineralizante do Biosilicato.

Resumo O objetivo deste estudo foi avaliar o efeito de produtos clareadores naturais na cor, efeito clareador e propriedades superficiais do esmalte dentário. Setenta fragmentos de dente bovino foram obtidos (6mm x 6mm x 2mm). Foram realizadas leituras iniciais de rugosidade de superfície (Surfcorder SE1700, Kosakalab), microdureza (HMV-2, Shimadzu), cor (EasyShade, VITA) e brilho (Micro-Gloss 45º BYK, Gardner). As amostras foram separadas em cinco grupos (n=14), de acordo com os tratamentos utilizados: DC - dentifrício convencional (controle negativo); CA - carvão ativado; CM - cúrcuma; CB - casca de banana e PC16% - gel de peróxido de carbamida a 16% (controle positivo, 4h/dia por 14 dias), foram então escovadas por 560 ciclos (T1) e 1200 ciclos (T2), equivalente a 14 e 30 dias de escovação. Novas leituras foram realizadas após T1 e T2. A alteração do whiteness index for dentistry (∆WID) e perda de massa (Pm) foram calculadas. PC16% demonstrou a maior (p<0,05) alteração de cor (ΔE00) e ∆WID (2-way ANOVA, Bonferroni, p<0,05). A alteração de brilho foi menor para CM, PC16% e CB. DC e CA aumentaram a rugosidade de superfície (p<0,05). PC16% diminuiu a microdureza do esmalte. CA apresentou abrasividade média, e DC e CM, baixa abrasividade. Os produtos clareadores populares não foram eficientes para clareamento dental. Ademais, a escovação com carvão ativado aumentou a rugosidade de superfície do esmalte dentário, e com maior tempo PC16% diminuiu a microdureza do esmalte.

Abstract The objective of this study was to evaluate the effect of natural bleaching products on the color, whiteness, and superficial properties of dental enamel. Seventy fragments of bovine teeth were obtained (6mm x 6mm x 2mm). Initial surface roughness (Surfcorder SE1700, Kosakalab), microhardness (HMV-2, Shimadzu), color (EasyShade, VITA), and surface gloss (Micro-Gloss 45º BYK, Gardner) readings were done. Samples were separated into five groups (n=14) according to the treatments used: CT-conventional toothpaste (negative control); CH-charcoal; TU-turmeric; BP-banana peel, and CP16%-16% carbamide peroxide gel (positive control, 4 h/day for 14 days), and then brushed for 560 cycles (T1) and 1200 cycles (T2), equivalent to 14 and 30 days of brushing. New measurements were performed after T1 and T2. The whiteness index for dentistry change (∆WID) and Weight loss (Wl) were calculated. CP16% demonstrated the highest (p<.05) color change (ΔE00) and ∆WID (2-way ANOVA, Bonferroni, p<.05). Surface gloss alterations were lower for TU, CP16%, and BP. CT and CH increased surface roughness (p<.05). CP16% decreased enamel microhardness. CH presented medium abrasiveness, and CT and TU, low abrasiveness. The popular bleaching products were not efficient for tooth whitening. Furthermore, brushing with charcoal increased the enamel surface roughness, and CP16% decreased enamel microhardness over time

RESUMO Objetivo Avaliar o efeito de 0,2% de digluconato de clorexidina (CHX) no pré-tratamento de dois tipos de sistemas adesivos na estabilidade de cor de restaurações de resina composta. Métodos Quarenta dentes bovinos foram preparados (6x6x2mm) e foram divididos aleatoriamente em 4 grupos (n = 10): SB - adesivo total etch (Single Bond 2, 3M ESPE); SB + CHX - pré-tratamento da dentina com CHX (30 segundos) seguido pela aplicação de SB; Adh - adesivo auto condicionante (AdheSE, Ivoclar Vivadent); Adh + CHX - pré-tratamento da dentina com CHX (30 segundos) seguido pela aplicação de Adh. Os dentes foram restaurados com Filtek Z350XT (3M ESPE) e fotoativados por 40 segundos. As leituras de cor (EasyShade, VITA) foram realizadas seguindo a escala CIE Lab em baseline, 1 e 3 meses (água destilada/37°C). A variação de cor (?E) e as coordenadas (L*, a* e b*) foram analisadas estatisticamente (2-way ANOVA, medidas repetidas, Bonferroni, p <,05). Resultados Os resultados mostraram que houve avermelhamento e amarelamento na restauração após 3 meses, sendo diferente (p <,05) de 1 mês. Não houve diferença (p >,05) levando em consideração o tratamento com CHX. Conclusão O pré-tratamento adesivo com 0,2% CHX não produziu maiores alterações de cor nas restaurações em resina composta, independentemente do tipo de sistema adesivo utilizado. No entanto, o tempo teve efeito significativo sobre a alteração, independentemente do tratamento do substrato.

ABSTRACT Objective To evaluate the effect of 0.2% chlorhexidine digluconate (CHX) as a pretreatment of two types of adhesive systems on color stability of composite resin restorations. Methods Forty bovine teeth were prepared (6x6x2mm) and randomly divided into 4 groups (n=10): SB - total etch adhesive (Single Bond 2, 3M ESPE); SB + CHX - dentin pretreatment with CHX (30 seconds) followed by SB application; Adh - self-etch adhesive (AdheSE, Ivoclar Vivadent); Adh + CHX - pretreatment with CHX (30 seconds) + followed by Adh application. The teeth were restored with Filtek Z350XT (3M ESPE) and photoactivated for 40 seconds. Color measurements (EasyShade, VITA) were performed following the CIE Lab scale at baseline, 1 and 3 months (distilled water/37°C). The mean color change values (?E) and coordinates (L*, a* and b*) were statistically analyzed (2-way ANOVA, repeated measures, Bonferroni, p <.05). Results Results showed that there was a reddening and yellowing of the restorative material after 3 months, differing (p <.05) from 1 month. There was no difference (p >.05) regarding the treatment with CHX. Conclusions The 0.2% CHX adhesive pretreatment did not produce greater color changes in composite resin restorations irrespective of the type of adhesive system used. However, time had significant effect on the change, regardless of the substrate treatment.

Resumo O objetivo neste estudo foi avaliar a influência do pré-aquecimento, conteúdo de carga e espessura da cerâmica na espessura da película, resistência de união ao microcisalhamento, grau de conversão e alteração de cor na cimentação de cerâmicas. Dois compósitos experimentais foram preparados (Bis-GMA / UDMA / BisEMA / TEGDMA), com diferentes quantidades de carga (65% ou 50% em peso), simulando um compósito convencional e um fluido. O fluido (F) foi usado à temperatura ambiente e o convencional, à temperatura ambiente (C) ou pré-aquecido (CPH). Foram preparados discos de cerâmica com diferentes espessuras (0,4mm, 0,8mm, 1,5mm). A espessura da película foi avaliada de acordo com a ISO 4049 (n=10). A resistência de união ao microcisalhamento (n=10) foi avaliada em esmalte utilizando espécimes fotopolimerizados através da cerâmica. O grau de conversão foi avaliado usando espectroscopia Raman. A alteração de cor das restaurações cerâmicas (n=10) foi avaliada por espectrofotometria. Os resultados foram submetidos à ANOVA 2- fatores e ao teste post hoc de Tukey (a=5%). Para espessura de película foi utilizada a ANOVA 1-fator (a=5%). O grupo C apresentou maior espessura de película; o CPH produziu uma espessura semelhante ao F. Todos os compósitos mostraram resistência de união ao microcisalhamento similares. O grau de conversão do F foi maior que C e CPH. O grau de conversão dos compósitos fotoativados através 0,4 mm foi maior que dos compósitos fotoativados através de cerâmicas mais espessas. O grupo C apresentou a maior mudança de cor, enquanto o CPH apresentou mudança de cor semelhante ao F. Em conclusão, compósitos convencionais pré-aquecidos assim como compósitos fluídos, parecem ser uma alternativa em potencial para cimentar laminados cerâmicos.

Abstract The aim of this study was to evaluate of pre-heating, filler contents and ceramic thickness on film thickness, microshear bond strength, degree of conversion and color change on ceramic veneers. Two experimental composites were prepared (Bis-GMA/UDMA/BisEMA/ TEGDMA), with different amounts of filler (65% or 50%wt) simulating a conventional and a flowable composite. The flowable (F) was used at room temperature and, the conventional either at room temperature (C) or pre-heated (CPH). Disk-shaped ceramics with different thickness (0.4 mm, 0.8 mm, 1.5 mm) were prepared. The film thickness was evaluated according to the ISO 4049 (n=10). The microshear bond strength (n=10) was evaluated in enamel using tubing specimens light-cured through the ceramic veneer. The degree of conversion was evaluated using Raman spectroscopy. The color change of the ceramic restorations (n=10) was evaluated by spectrophotometry. The results were submitted to 2-way ANOVA and Tukey’s post hoc test (a=5%). For the film thickness 1-way ANOVA was used (a=5%). The C presented the thicker film thickness; the CPH produced a similar film thickness in comparison to the F. All composites showed similar microshear bond strength. The degree of conversion of the F was higher than the C and CPH. The degree of conversion of the composites photo-activated through a 0.4 mm was higher than the composites photo-activated through thicker ceramics. The C showed the highest color change, while the CPH showed similar color change to the F. In conclusion, pre-heated conventional composites seem to be a potential alternative to lute ceramic veneers such as the flowable composites.

Abstract The main of the study was quantify the effect of two ceramics with two underlying resin cements on apparent fluorescence levels. Buccal surfaces of two bovine incisors were ground flat producing one enamel and one dentin substrate. The veneers were fabricated (0.5 and 1.0 mm thickness) using two ceramics (IPSe.max Press and IPSe.max Zirpress, Ivoclar Vivadent). Veneers were cemented using either light-cured (Variolink II, Ivoclar Vivadent) or self-adhesive dual (Rely X U200, 3M ESPE) cement. The layered Control group materials had no cement application. Semi-quantitative fluorescence image analysis (Matlabs software, Matworks) involved processing the images as captured under each daylight (DL, Gretagmacbeth) and ultraviolet illuminants (UVA, Sylvania) within a neutral-gray lightbox (Macbeth Spectral Light). Statistical analysis of the quantitative fluorescence values was performed using two-way ANOVA and Tukey’s test (p < 0.05). The e.max Zirpress on the dentin substrate produced greater fluorescence (p < 0.05) when subjected to UV illumination and more fluorescence (p < 0.05) than e.max Press in both cement groups. Light-cured cement produced higher (p < 0.05) fluorescence than the dual-cement with e.max Press on enamel under UV illumination. The fluorescence for e.max Press on the dentin substrate was greater (p < 0.05) than for e.max Zirpress using dual self-adhesive cement subjected to daylight illumination. Thus, it is possible to conclude that the combination of ceramic and cement produce definite, significant effects on the apparent fluorescence, vital quality for restorative dentistry.

Resumo Este estudo avaliou o efeito de uma vitrocerâmica bioativa para o controle de lesões de erosão e cárie. Fragmentos (n=10) de esmalte bovino e dentina radicular receberam aplicação diária de diferentes tratamentos (Biosilicato; Fluoreto de Fosfato Acidulado - APF; não tratado - controle) durante a realização de ciclos erosivos. As superfícies foram analisadas com profilometria óptica 3D para quantificar a perda superficial em quatro períodos (1, 7, 14 e 21 dias), bem como a profundidade da lesão com microscopia confocal de varredura a laser. Para a avaliação da progressão de cárie, foi obtida a microdureza Knoop inicial de fragmentos de esmalte bovino. As lesões cariosas iniciais foram desenvolvidas e os espécimes foram divididos em três grupos (n =10), de acordo com a aplicação tópica diária (Biosilicato; APF; sem aplicação - controle) durante os ciclos de desmineralização por 14 dias. A microdureza final foi obtida para calcular a perda da microdureza superficial. A desmineralização sub-superficial foi analisada utilizando microdureza transversal (profundidades 10, 30, 50, 70, 90, 110 e 220 μm). Os dados foram testados utilizando ANOVA e teste de Tukey (α=5%). Os resultados da avaliação erosiva mostraram que o Biosilicato promoveu os menores valores (p <0,05) de perda superficial, independente do tempo, tanto para o esmalte como para a dentina; APF promoveu menor (p <0,05) perda de superfície do que controle; analisando os períodos de tempo, APF não mostrou diferença (p>0,05) entre 14 e 21 dias de desmineralização. Os resultados da avaliação da cárie no esmalte mostraram que o Biosilicato resultou em maiores (p<0,05) valores de microdureza superficial e subsuperficial do que as aplicações APF e controle. Pode-se concluir que a aplicação de Biosilicato apresentou maior potencial de redução da perda superficial e desenvolvimento de lesões de erosão e cárie.

Abstract This study evaluated the effect of a bioactive glass ceramic for the control of erosion and caries lesions. Fragments (n=10) of bovine enamel and root dentin received daily application of different treatments (Biosilicate; Acidulated Phosphate Fluoride- APF; Untreated - control) during the performance of erosive cycles. Surfaces were analyzed with 3D optical profilometry to quantify the superficial loss in four periods (1, 7, 14 and 21 days), as well as the lesion depth with confocal laser scanning microscopy. For caries progression assessment, initial Knoop microhardness was measured on enamel bovine fragments. Initial carious lesions were developed and specimens were divided into three groups (n=10), according to the daily topical application (Biosilicate; APF; no application - control), during the de-remineralization cycles for 14 days. Final microhardness was obtained to calculate the change of surface microhardness. Subsurface demineralization was analyzed using cross-sectional microhardness (depths 10, 30, 50, 70, 90, 110 and 220 µm). Data were tested using ANOVA and Tukey’s test (a=5%). Results of erosive evaluation showed that Biosilicate promoted the lowest (p<0.05) values of surface loss, regardless of time, for both enamel and dentin; APF promoted lower (p<0.05) surface loss than control; analyzing different periods of time, APF did not show difference (p>0.05) between 14 and 21 days of demineralization. Results of enamel caries assessment showed that Biosilicate resulted in higher (p<0.05) surface and subsurface microhardness than both APF and control-applications. It may be concluded that Biosilicate application showed a higher potential to reduce surface loss and development of erosion and caries lesions.

Resumo Biomateriais inovadores podem fornecer uma promissora nova direção para o tratamento de defeitos ósseos, estimulando um processo de reparo adequado, sem danos aos tecidos adjacentes. O objetivo deste estudo in vivo foi avaliar a biocompatibilidade e a capacidade osteoindutora de uma biomembrana e um scaffold compostos por colágeno e quitosana, contendo cimento de aluminato de cálcio. Dezoito coelhos (New Zealand White, Oryctolagus cuniculus) foram distribuídos de acordo com os períodos experimentais de análise (7, 15 e 30 dias). Quatro defeitos foram criados na calvaria dos coelhos, que foram individualmente preenchidos com a biomembrana, scaffold, coágulo (controle negativo) e osso autólogo (controle positivo). A avaliação histopatológica foi realizada em microscópio óptico em aumentos de 32´, 64´, 125´ e 320´. A resposta celular à inflamação e à formação de novo tecido ósseo foi quantificada utilizando um sistema de escore. O grupo da biomembrana apresentou maior resposta inflamatória no período de 15 dias, com diferença significativa para o grupo do osso autólogo (p<0,05). Não houve diferença estatística significante para a reação do tipo corpo estranho entre os grupos (p>0,05). Em relação à neoformação óssea, observou-se fechamento linear da área do defeito, que foi mais evidente no grupo em que se utilizou o osso autólogo. O grupo scaffold apresentou resultados semelhantes ao grupo do osso autólogo no período de 30 dias (p>0,05). Ambos os biomateriais testados apresentaram biocompatibilidade similar em comparação com os grupos controle. Além disso, a biomembrana e o scaffold apresentaram capacidade osteoindutora similar, estimulando o reparo ósseo ao longo dos intervalos de tempo experimentais.

Abstract Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Resumo O objetivo deste estudo foi avaliar a influência do envelhecimento artificial acelerado (EAA) sobre a estabilidade de cor de cimentos resinosos para fixação de laminados cerâmicos em diferentes espessuras. Oitenta molares humanos hígidos tiveram as faces oclusais planificadas. Laminados cerâmicos (IPS e-max Ceram, Ivoclar Vivadent) em duas espessuras (0,5 e 1,0mm) foram fixados com 3 tipos de cimentos: Fotoativado (Variolink II, Ivoclar/Vivadent), Dual convencional (Variolink II + catalisador, Ivoclar/Vivadent) ou Dual auto-adesivo (Rely-X Unicem, 3M ESPE). Dentes sem restaurações e amostras de cimentos (0,5mm) foram utilizados como controle. Após as leituras de cor iniciais (Vita EasyShade, VITA), as amostras foram submetidas a EAA por 580 horas. Em seguida, novas leituras de cor foram realizadas e os dados de estabilidade de cor (ΔE) e luminosidade (ΔL) foram analisados (ANOVA, dois fatores e Bonferroni, p<0,05). As maiores alterações de cor (p<0,05) ocorreram quando as restaurações de 0,5 mm foram fixadas com cimento fotoativado, e as menores quando restaurações de 1.0mm foram fixadas com cimento dual convencional. Não houve influência (p>0,05) da espessura da restauração quando utilizado o cimento dual autoadesivo. Quando as restaurações foram comparadas aos grupos controle (ANOVA um fator e Tukey, p<0.05), verificou-se que as amostras de cimento apresentaram as maiores alterações (p<0,05) em relação ao substrato e aos dentes restaurados. Conclui-se que a espessura da restauração influencia na alteração de cor e na luminosidade do cimento dual convencional e fotoativado. As alterações do cimento autoadesivo não dependem da espessura da restauração.

Abstract The aim of this study was to evaluate the influence of accelerated aging (AAA) on the color stability of resin cements for bonding ceramic laminate veneers of different thicknesses. The occlusal surfaces of 80 healthy human molars were flattened. Ceramic laminate veneers (IPS e-max Ceram) of two thicknesses (0.5 and 1.0 mm) were bonded with three types of luting agents: light-cured, conventional dual and self-adhesive dual cement. Teeth without restorations and cement samples (0.5 mm) were used as control. After initial color evaluations, the samples were subjected to AAA for 580 h. After this, new color readouts were made, and the color stability (ΔE) and luminosity (ΔL) data were analyzed. The greatest color changes (p<0.05) occurred when 0.5 mm veneers were fixed with light-cured cement and the lowest when 1.0 mm veneers were fixed with conventional dual cement. There was no influence of the restoration thickness when the self-adhesive dual cement was used. When veneers were compared with the control groups, it was verified that the cement samples presented the greatest alterations (p<0.05) in comparison with both substrates and restored teeth. Therefore, it was concluded that the thickness of the restoration influences color and luminosity changes for conventional dual and light-cured cements. The changes in self-adhesive cement do not depend on restoration thickness.

Abstract The aim of this clinical study was to evaluate tooth color changes (ΔE) and tooth sensitivity (TS) associated with whitening dentifrices. Sixty participants were selected according to inclusion and exclusion criteria and then allocated to three groups (n = 20): Colgate Luminous White (G1), Close Up White Now (G2) and Sorriso dentifrice (G3-control). The participants were instructed to use only the provided dentifrice and toothbrush in standardized oral hygiene procedures for 4 weeks. ΔE was assessed by spectrophotometry (CIELab System) whereas TS was determined by a visual analog scale at baseline and weekly using four assessment points. The data were analyzed by two-way ANOVA and Tukey’s post-hoc test and Friedman test (α = 0.05). ΔE (baseline-assessment point 4) showed no significant difference (p>0.05) across the groups: G1 (ΔE = 5.1), G2 (ΔE = 6.8), and G3 (ΔE = 4.4). Δb (baseline-assessment point 4) was significantly different (p < 0.05) in G2 (3.8) when compared to G1 (-0.2) and G3 (0.3). There was no significant difference (p > 0.05) in TS at baseline. Both the control and whitening dentifrices caused similar tooth color changes (ΔE). There was no significant TS during the study period.

Abstract Aim: To evaluate, in vitro, the effect of brushing with a Ricinus communis-based experimental toothpaste on color stability and surface roughness of artificial teeth. Methods: Ninety artificial teeth (maxillary central incisors) in different shades, light and dark (NatusDent Triple Pressing, Dentbras) were used. Initial color (Spectrophotometer Easyshade, VITA) and surface roughness (Rugosimeter Surfcorder SE 1700, Kosakalab) readouts were performed. After baseline measurements, samples were assigned to 10 groups (n=9) according to the artificial tooth shade and type of toothpaste used during the mechanical brushing test (Pepsodent, MAVTEC): Sorriso Dentes Brancos - SDB, Colgate Luminous White - CLW (Colgate-Palmolive), Close up White Now - CWN (Unilever), Trihydral - THL (Perland Pharmacos) and Ricinus communis - RCE (Experimental). After 29,200 cycles of brushing, corresponding to 2 years of brushing by a healthy individual, new color and roughness readouts of the specimens were performed. Data (before and after the tests) were statistically analyzed (2-way repeated measures ANOVA, Tukey, p<0.05). Results: RCE toothpaste produced the greatest color stability for dark tooth shade and the second best color stability for light tooth shade. For surface roughness alteration, there was no difference (p>0.05) for any tested toothpaste regardless of tooth shade. Conclusions: The experimental Ricinus communis toothpaste did not cause color and surface roughness alteration in the artificial teeth, and it may be considered a suitable option for denture cleaning.

Color alteration is still a disadvantage of acrylic resin teeth and this problem seems to be greater in smokers. The objective of this study was to evaluate the efficiency of polishing and brushing on removal of stains from artificial teeth submitted to cigarette smoke. Forty denture teeth of distinct shades (62 and 69) were selected. The teeth were divided into 4 groups (n= 10), according to the tooth shade and method of stain removal performed: Groups 1 and 2 were submitted to the smoke of 20 cigarettes, and after new color readouts, were submitted to polishing with pumice stone and Spanish white paste. Groups 3 and 4 were submitted to 4 cycles of 5 cigarettes interspersed with standardized manual brushing. The values of color stability (DE) were compared using 2-way ANOVA, Bonferroni test (p<0.05). For all the groups, color change occurred at clinically unacceptable levels (E>3.3). After exposure to 20 cigarettes, the greatest degree of color change occurred for teeth in shade 62. Polishing significantly reduced the color change for groups 1 and 2, however, without significant difference between them. For Groups 3 and 4 there was no difference between the teeth of shade 62 and 69. When the treatments for each tooth shade were compared alone, there was similarity between polishing and brushing irrespective of the shade of samples. Routine manual brushing and common clinical polishing methods were capable of removing a large portion of staining caused by cigarettes, and there was no difference between the methods.

La alteración del color sigue siendo una desventaja de los dientes de resina acrílica y este problema parece ser mayor en los fumadores. El objetivo de este estudio fue evaluar la eficacia de pulido y cepillado en la eliminación de manchas de los dientes artificiales presentados al humo del cigarrillo. Se seleccionaron cuarenta dientes de la dentadura de tonos diferentes (62 y 69). Los dientes fueron agrupados en 4 grupos (n= 10), de acuerdo con el color del diente y el método de eliminación de manchas realizado: Los grupos 1 y 2 fueron sometidos al humo de 20 cigarrillos, y después de nuevas lecturas de color, se pulieron con piedra pómez piedra y pasta blanca española. Los grupos 3 y 4 se sometieron a 4 ciclos de 5 cigarrillos intercalados con cepillado manual estandarizado. Los valores de estabilidad del color (Delta E) se compararon mediante las pruebas de ANOVA de dos vías y Bonferroni (p<0,05). Para todos los grupos, el cambio de color se produjo a niveles no aceptables clínicamente (DE>3,3). Después de la exposición a 20 cigarrillos, el mayor grado de cambio de color se produjo para los dientes de tono 62. El pulido redujo significativamente el cambio de color para los Grupos 1 y 2, sin diferencia significativa entre ellos. Para los Grupos 3 y 4 no hubo diferencia entre los dientes de tono 62 y 69. Cuando los tratamientos para cada color de diente se compararon individualmente, hubo similitud entre el pulido y el cepillado, independientemente del tono. El cepillado manual rutinario y los métodos comunes de pulido clínicos fueron capaces de eliminar una gran parte de manchas causadas por los cigarrillos, sin diferencia entre los métodos.

AbstractThe aim of this study was to manufacture a new zirconia implant (Y-TZP) and to evaluate the fracture strength and stresses generated after cyclic loading compared to titanium implants. Thirty-three zirconia and titanium implants were fabricated. The stress generated around the implants was observed by photoelastic analysis. The implants were then separated into groups (n = 10): Control (no treatment), mechanical fatigue and thermomechanical fatigue. All groups were submitted to a single cantilever flexure test to measure the material fracture strength. The results (2-way ANOVA, Bonferroni test, p <.05) showed no statistically significant difference in the stresses generated between the zirconia and titanium implants. Titanium implants showed higher fracture strength than the zirconia implants, a property that was not altered by fatigue applied. It was concluded that stress distribution was similar for Zr and Ti and mechanical and thermomechanical fatigue had no influence on the fracture strength of the implants tested.