Do different adhesives influence the color stability and fluorescence of composite restorations after aging?

Abstract This study aimed to evaluate the influence of dental adhesive color on the chromatic stability and fluorescence intensity of composite resin restorations of different thicknesses. Ninety bovine enamel samples were obtained and restored with resin composite varying thicknesses of restorative material and enamel (1.0 mm enamel and 1.0 mm composite; 1.5 mm enamel and 0.5 mm composite; 0.5 mm enamel and 1.5 mm composite). The restorations were made of composite resin (Opallis E-bleach H) using different types of dental adhesives: Ambar, Ambar APS, and Single Bond Universal (n=10). The samples were subjected to color measurement tests in a spectrophotometer using CIEDE2000 and fluorescence intensity measurements before and after aging in a red wine coloring solution. Data were subjected to analysis of variance (ANOVA) and Tukey's test (α = 0.05). There were no statistically significant changes in color stability or fluorescence intensity for restorations made of different materials or thicknesses (p>0.05). Single Bond Universal showed greater color stability at 0.5 mm thickness (ΔE00 = 4.4 ± 1.6) compared to other thicknesses of the same material (p=0.003), as well as a greater difference in fluorescence intensity after aging at 1.5 mm thickness (-414.9 ± 103.8) compared to other materials (p=0.0002). Overall, it was concluded that the different adhesive systems did not influence the color stability and fluorescence of restorations of different thicknesses.

Resumo O objetivo deste estudo foi avaliar a influência da cor do adesivo dental na estabilidade cromática e intensidade de fluorescência das restaurações de resina composta de diferentes espessuras. Foram obtidos noventa amostras de esmalte bovino que foram restaurados com resina composta, variando a espessura do material restaurador e do esmalte (1,0 mm de esmalte e 1,0 mm de compósito; 1,5 mm de esmalte e 0,5 mm de compósito; 0,5 mm de esmalte e 1,5 mm de compósito). As restaurações foram feitas de resina composta (Opallis E-bleach H) utilizando diferentes tipos de adesivos odontológicos: Ambar, Ambar APS, e Single Bond Universal (n=10). As amostras foram submetidas a testes de medição de cor em um espectrofotômetro usando CIEDE2000 e medições de intensidade de fluorescência antes e depois do envelhecimento em uma solução de coloração de vinho tinto. Os dados foram submetidos à análise de variância (ANOVA) e ao teste de Tukey (α = 0,05). Não houve mudanças estatisticamente significativas na estabilidade da cor ou intensidade de fluorescência para restaurações feitas de diferentes materiais ou espessuras (p>0,05). O Single Bond Universal mostrou maior estabilidade de cor a 0,5 mm de espessura (ΔE00 = 4,4 ± 1,6) em comparação com outras espessuras do mesmo material (p=0,03), bem como uma maior diferença na intensidade de fluorescência após o envelhecimento a 1,5 mm de espessura (-414,9 ± 103,8) em comparação com outros materiais (p=0,0002). Em geral, concluiu-se que os diferentes sistemas adesivos não influenciaram a estabilidade de cor e a intensidade de fluorescência das restaurações de diferentes espessuras.

Effects of different toothpastes on the prevention of erosion in composite resin and glass ionomer cement enamel and dentin restorations

Abstract Objective This study aimed to evaluate the effects of different toothpastes on the surface wear of enamel, dentin, composite resin (CR), and resin-modified glass ionomer cement (RMGIC), and to perform a topographic analysis of the surfaces, based on representative images generated by atomic force microscopy (AFM) after erosion-abrasion cycles. Methodology One hundred and forty bovine incisors were collected and divided into two groups: 72 enamel and 72 dentin blocks (4×4 mm). Half of the specimens were restored with CR (Filtek Z350 XT) and the other half with RMGIC (Fuji II LC). Then, samples were submitted to a demineralization cycle (5 days, 4×2 min/day, 1% citric acid, pH 3.2) and exposed to three different toothpastes (2×15 s/day): without fluoride (WF, n=12), sodium fluoride-based (NaF, n=12), and stannous fluoride-based (SnF2, n=12). Surface wear, as well as restoration interfaces wear, were investigated by profilometry of the dental substrates and restorative materials. All representative surfaces underwent AFM analysis. Data were analyzed by two-way analysis of variance and Tukey's tests (α=0.05). Results NaF-based toothpaste caused the greater dentin surface wear (p<0.05). Toothpastes affected only enamel-restoration interfaces. AFM analysis showed precipitate formation in dentinal tubules caused by the use of fluoride toothpastes. Conclusions NaF-based toothpastes had no protective effect on enamel adjacent to CR and RMGIC against erosion-abrasion challenges, nor on dentin adjacent to RMGIC material. SnF2-based toothpastes caused more damage to interfaces between enamel and RMGIC.

Influence of different types of light curing units and photoinitiators in microhardness and color of composite resins after immersion in wine / Influencia dos diferentes tipos de unidade fotoativadoras e fotoiniciadores na microdureza e cor de resinas compostas após imersão em vinho

Objective: the aim of this study is to evaluate the microhardness and color change (∆E) of composite resins, that were light-cured with different LEDs, after being immersed in a staining drink. Material and Methods: Two composite resins with Lucerin-TPO (Tetric N-Ceram/ Vit-l-escence) and camphorquinone (Filtek Z350) were selected. The specimens (n=120) were prepared and lightcured with LED of monowave or polywave lightemitting diode (LED) devices. Microhardness and color evaluations were measured before and after immersion in staining drink. Microhardness data were evaluated by Kruskal-Wallis test, MannWhitney and Wilcoxon tests. Color changes were evaluated by two-way analysis of variance (ANOVA) and Tukey test (p ≤ 0.05). Results: No statistically significant difference between the two generations of LEDs was found for microhardness data. Regarding the ∆E, a statistical difference between the two LEDs was observed for Tetric NCeram and Filtek Z350. Conclusion: The compostion of composites appears to have more influence on analyses than the type of LEDs used. A decreased microhardness occurred to Vit-lescence for monowave and to Filtek Z350 for both LED devices. A clinically perceptible color change was observed for Tetric-N Ceram and Filtek Z350 when polywave LED were used. (AU)

Objetivo: o objetivo deste estudo foi aviliar a microdureza e alteração de cor (∆E) de resinas compostas, fotoativadas com diferentes LEDs, imergidas em bebidas pigmetadas. Material e métodos: Duas resinas compostas com Lucerina-TPO (Tetric N-Ceram/ VIt-l-essence) e canforoquinona (Filtek Z350) foram selecionadas. Os espécimes (n=120) foram preparados. Os mesmos foram fotopolimerizados com LED monowave ou polywave. Microdureza e cor foram avaliadas antes e após a imersão em bebidas pigmentadas. Os dados de microdureza foram avaliados pelos testes de Kruskal-Wallis, Mann-Whitney e Wilcoxon. As alterações de cor foram avaliadas por análise de variância a dois critérios (ANOVA) e Tukey (p ≤ 0,05). Resultados: Não foi encontrada diferença estatística entre as duas gerações de LEDs, para os dados da microdureza. Quanto ao ∆E, foi encontrada diferença estatisticamente significante entre os dois LEDs, sendo observadas na Tetric N-Ceram na FIltek Z350. Conclusão: A composição das resinas compostas parece ter mais influencia nas análises do que o tipo de LEDs. Uma redução na microdureza ocorreu para Vit-lescence para monowave e para Filtek Z350 para ambos os dispositivos LED. Uma mudança de cor clinicamente perceptível foi observada em Tetric-N Ceram para polywave e Filtek Z350 para ambos os dispositivos LED. (AU)

Degree of conversion of resin cements polymerized under different thicknesses of feldspathic porcelain

Aim The aim of this study is to evaluate the degree of conversion (DC) of resin cements polymerized under different thicknesses of feldspathic dental ceramic. Methods: Forty samples of RelyX ARC and RelyX Veneer resin cements were polymerized under Starlight feldspathic ceramic discs (DeguDent Gmbh) with 0.5 mm, 1.2 mm, 1.8 mm, and 2.4 mm in thickness. The control group was cured without the interposition of ceramic. The DC measurements were performed 10 minutes, 1 hour, and 24 hours after the light-activation in a Nexus 670 FTIR spectrophotometer. Data were analyzed by two-way repeated measure ANOVA and Fisher PLSD test. Results: The RelyX ARC showed higher DC for all ceramic thicknesses. There was significant decrease in DC related to an increase in ceramic thickness. For RelyX ARC, the values of DC obtained after 1 hour and 24 hours did not differ statistically between them, but they were higher than those analyzed after 10 minutes. For RelyX Veneer cement, there was gradual increase in the DC up to 24 hours. Conclusion: The higher the thicknesses of ceramic, the lower DC of the resin cement

Microshear bond strength of conventional and self-adhesive resin cements to feldsphatic ceramic

Aim: The aim of this study was to verify the microshear bond strength of conventional and self-adhesive resin cements to feldsphatic ceramic. Methods: Twenty discs of Starlight ceramic (Degudent) were made (15mm x 2mm). The bonding procedure was accomplished by insertion of resin cements into tubes of 0.7mm internal diameter in contact with the ceramic. The resin cements used were: RelyX ARC (3M Espe), Panavia F (Kuraray), RelyX Unicem (3M Espe) and seT (SDI). Total of six tubes of each material on each ceramic disc. The specimens were tested for microshear in a universal testing machine, 24hours and 6months after bonding procedure. Values of microshear bonding strength (MPa) were subjected to ANOVA and Fisher PLSD test (p<0.05). Results: For 24hours analysis, RelyX ARC showed the highest microshear bonding strength without statistical difference to RelyX Unicem and seT. Panavia F showed the lowest values of microshear bonding strength in both periods. In the analysis after 6months there was a significant increase in the microshear bonding strength values for all cements compared to 24hours. Only for RelyX ARC, the increase was not statistically significant. Conclusion: In conclusion, the bond strength depends mainly on the type of resin cement used, and the self-adhesive cements behave similarly to conventional resin cement

Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial

Abstract Objective This study verified the occurrence of dental sensitivity in patients submitted to a 35% hydrogen peroxide based product (Whiteness HP Maxx 35% - FGM), skin cold sensation threshold (SCST) and its influence on dental sensitivity. Material and Methods Sixty volunteers were divided into 4 groups (n = 15), according to SCST (low: GI and GIII, and high: GII and IV) and bleaching treatment (hydrogen peroxide: GI and GII, and placebo: GIII and GIV). SCST was determined in the inner forearm for 6 different times using a neurosensory analyzer, the TSA II (Medoc Advanced Medical Systems, Ramat Yishai, Northern District, Israel). Dental sensitivity measurements were performed 10 different times using a thermal stimulus and an intraoral device attached to TSA II, positioned in the buccal surface of the upper right central incisor. Spontaneous dental sensitivity was also determined using the Visual Analogue Scale (VAS). Data were submitted to Student's t-test and Pearson's Correlation Test (α=0.05). SCST remained the same during bleaching treatment. Results Distinct responses of dental sensitivity were found in patients with low and high SCST during the first and third bleaching session (p≤0.05). The teeth submitted to the bleaching treatment became more sensitive to cold than those treated with placebo. Moreover, data obtained with TSA and VAS presented moderate correlation. Conclusions Bleaching treatment increased dental sensitivity and skin cold sensation threshold might represent a determining factor in this occurrence, since low and high SCST patients had different responses to the thermal stimulus in the teeth.

Neurosensory analysis of tooth sensitivity during at-home dental bleaching: a randomized clinical trial

Abstract Objective The objective of this study was to evaluate dental sensitivity using visual analogue scale, a Computerized Visual Analogue Scale (CoVAS) and a neurosensory analyzer (TSA II) during at-home bleaching with 10% carbamide peroxide, with and without potassium oxalate. Materials and Methods Power Bleaching 10% containing potassium oxalate was used on one maxillary hemi-arch of the 25 volunteers, and Opalescence 10% was used on the opposite hemi-arch. Bleaching agents were used daily for 3 weeks. Analysis was performed before treatment, 24 hours later, 7, 14, and 21 days after the start of the treatment, and 7 days after its conclusion. The spontaneous tooth sensitivity was evaluated using the visual analogue scale and the sensitivity caused by a continuous 0°C stimulus was analyzed using CoVAS. The cold sensation threshold was also analyzed using the TSA II. The temperatures obtained were statistically analyzed using ANOVA and Tukey's test (α=5%). Results The data obtained with the other methods were also analyzed. 24 hours, 7 and 14 days before the beginning of the treatment, over 20% of the teeth presented spontaneous sensitivity, the normal condition was restored after the end of the treatment. Regarding the cold sensation temperatures, both products sensitized the teeth (p<0.05) and no differences were detected between the products in each period (p>0.05). In addition, when they were compared using CoVAS, Power Bleaching caused the highest levels of sensitivity in all study periods, with the exception of the 14th day of treatment. Conclusion We concluded that the bleaching treatment sensitized the teeth and the product with potassium oxalate was not able to modulate tooth sensitivity.

Effect of Dental Pigmentation Intensity on the Transenamel and Transdentinal Penetration of Hydrogen Peroxide

Abastract This study aimed to evaluate the transenamel and transdentinal penetration of hydrogen peroxide (H202) applied to bovine teeth pigmented with black tea at different intensities. The following groups were formed DW: immersion in distilled water; BT100: immersion in an infusion of 1.6 g of black tea per 100 mL distilled water; BT10: immersion in an infusion of 1.6 g black tea per 10 mL distilled water. All groups were immersed for 6 days. To quantify the penetration of H202, the specimens were placed in artificial pulp chambers (APCs) and subjected to bleaching treatment with 38% H2O2 once per week for 3 weeks. After bleaching treatment, the acetate buffer solution of APCs with peroxidase enzyme was evaluated in a reflection spectrophotometer. The transenamel and transdentinal penetration of H2O2 and the L* values obtained at T1, T2 and T3 were subjected to Kruskal-Wallis and Friedman statistical tests. At T1, the H2O2 diffusion in DW was higher than that in BT100 and BT10. At the other evaluation times, the penetration values in BT100 and BT10 increased and remained similar. The L* values increased significantly in all groups at T1. At T2, the L* values were higher in DW, while the values in BT100 and BT10 were similar to each other. At the end of the experiment, BT10 showed the lowest L* values. The pigmentation level did not affect the penetration of H2O2 through the enamel and dentin and the bleaching agent effectively changed the color of the teeth.

Resumo Este estudo teve como objetivo avaliar a penetração trans-amelodentinária do peróxido de hidrogênio (H2O2) aplicados em dentes bovinos pigmentados com chá preto em diferentes intensidades. Divisão dos grupos: AD em água destilada; CP100 em uma infusão de 1,6 g de chá preto para 100 mL de água destilada; CP10 em uma infusão de 1,6 g de chá preto para 10 mL de água destilada. Todos os grupos foram imersos por 6 dias. Para quantificar a penetração de H2O2, as amostras foram colocadas em câmaras pulpares artificiais (CPAs) e submetidas a um tratamento clareador com PH a 38%, uma vez por semana durante 3 semanas. Após o tratamento clareador, a solução tampão de acetato das CPAs com a enzima da peroxidase, foi avaliada num espectrofotômetro de reflexão. A penetração trans-amelodentinária de PH e os valores de L* obtidos em T1, T2 e T3 foram submetidos ao teste estatístico de Kruskal-Wallis e Friedman. Em T1, a difusão de H2O2 no AD foi mais elevada do que em CP100 e CP10. Nos outros tempos de avaliação, os valores de penetração no CP100 e CP10 aumentaram e permaneceram semelhantes. Os valores L* aumentaram significativamente em todos os grupos no T1. No T2, os valores L* foram maiores no AD e os valores em CP100 e CP10 foram semelhantes entre si. No último tempo, o CP10 apresentou os menores valores de L*. Diferentes níveis de pigmentação não afetaram a penetração de H2O2 através do esmalte e dentina e o agente de clareador foi eficaz na alteração cromática.

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.

At-Home Bleaching: Color Alteration, Hydrogen Peroxide Diffusion and Cytotoxicity

This study evaluated the color change, cytotoxicity and hydrogen peroxide (HP) diffusion caused by different home bleaching protocols: 10% carbamide peroxide (CP) for 3 or 1.5 h, 6% hydrogen peroxide for 1.5 h or 45 min. To quantify the peroxide penetration, disks of bovine teeth were placed in artificial pulp chambers (APCs) containing acetate buffer, which was collected for evaluation in a spectrophotometer. For analysis of cytotoxicity, specimens were adapted in APCs containing culture medium, which subsequently was applied on MDPC-23 odontoblast-like cells for 1 h. Cellular metabolism was evaluated by methyl tetrazolium (MTT) assay and the color change of the specimens was analyzed using the CIE L * a * b * system. The data were submitted to ANOVA and Fisher test (α=5%). The treatment with 10% CP for 3 h was the most effective, and 6% HP for 45 min produced the lowest color change. The groups 10% CP for 1.5 h and 6% HP for 45 min had the lowest trans-enamel dentinal HP penetration, and the 6% HP for 1.5 h had the highest. None of the protocols affected cellular metabolism and morphology. In conclusion, reduced peroxide exposure time reduced the bleaching result; higher HP diffusion did not mean higher effectiveness.

Este estudo avaliou a alteração de cor, a citotoxicidade e a difusão de peroxido de hidrogênio ocorridos em diferentes protocolos clareadores caseiros: peróxido de carbamida (PC) 10% por 3 ou 1,5 h; peróxido de hidrogênio (PH) 6% por 1,5 h ou 45 min. Para a quantificação da penetração do peróxido, discos de dentes bovinos foram posicionados em câmaras pulpares artificiais (CPAs) contendo solução tampão de acetato, que foi coletada para avaliação em espectrofotômetro. Para análise da citotoxicidade, os espécimes foram adaptados nas CPAs contendo meio de cultura, que posteriormente foi aplicado sobre células odontoblastóides MDPC-23 por 1 h. O metabolismo celular foi avaliado pelo teste MTT e a alteração de cor dos espécimes foi analisada pelo sistema CIE L*a*b*. Os dados foram submetidos a ANOVA e teste de Fisher (α=5). O tratamento com PC10% por 3 horas foi o mais efetivo, enquanto que o tratamento com PH 6% por 45 min produziu a menor alteração cromática. Os grupos PC 10% por 1,5 h e PH 6% por 45 min causaram a menor penetração trans-amelodentinária do peróxido, e PH 6% por 1,5 h, a maior difusão. Nenhum tratamento alterou o metabolismo celular. A redução do tempo de exposição aos peróxidos comprometeu o resultado clareador; maior penetração de peroxido não significa maior efetividade clareadora.

Demineralization and Hydrogen Peroxide Penetration in Teeth with Incipient Lesions

The aim of this study was to evaluate the demineralization and hydrogen peroxide (HP) penetration in teeth with incipient lesions submitted to bleaching treatment. For analysis of HP penetration, sound and demineralized enamel/dentin discs were placed in artificial pulp chambers containing acetate buffer solution. After bleaching treatment, this solution was subjected for analysis of optical density by spectrophotometry and the disc surfaces were analyzed with scanning electron microscopy (SEM) and polarized light microscopy (PLM). The remaining discs were subjected for cross-sectional hardness analysis at different depths. Data were analyzed by repeated measures ANOVA and PLSD Fisher test (a=0.05). It was observed that previously demineralized teeth showed greater HP penetration (p<0.05). The bleaching treatment caused changes to a depth of 20 µm in sound enamel and up to 90 µm in demineralized enamel. SEM and PLM images revealed that the bleaching treatment caused superficial changes that were considerably more accentuated in previously demineralized teeth. It may be concluded that the enamel mineralization level influences HP penetration and the bleaching agent contributed to increase the demineralization depth.

O objetivo deste estudo foi avaliar a desmineralização e a penetração do peróxido de hidrogênio (HP) em dentes com lesões incipientes submetidos ao tratamento clareador. Para analisar a penetração do peróxido de hidrogênio, discos de esmalte/dentina hígidos e desmineralizados foram posicionados em câmaras pulpares artificiais contendo solução tampão de acetato. Após o tratamento clareador, esta solução foi submetida à análise da densidade óptica no espectrofotômetro e as superfícies dos discos foram analisadas por meio de microscopia eletrônica de varredura (MEV) e microscopia de luz polarizada (MLP). Os discos restantes foram submetidos à análise de microdureza transversal em diferentes profundidades. Os dados foram submetidos aos testes ANOVA e teste PLSD Fisher (= 5%). Observou-se que os dentes previamente desmineralizados mostraram maior penetração de HP (p<0,05). O tratamento clareador causou alterações em uma profundidade de 20 μm em esmalte hígido e até 90 μm em esmalte desmineralizado. As imagens obtidas em PLM e MEV mostraram que o tratamento clareador promove alterações superficiais no esmalte, sendo mais pronunciadas em dentes previamente desmineralizados. Foi concluído que o nível de mineralização do esmalte influencia a penetração do PH e que o agente clareador contribuiu para o aumento da profundidade de desmineralização.

Influência do tratamento de superfície da dentina radicular na resistência ao deslocamento de pino de fibra de vidro / Influence of root dentin surface treatment on bond strength of glass fiber post

Este trabalho avaliou a influência do tratamento de superfície na dentina radicular na resistência de união com pinos de fibra de vidro e cimento resinoso autoadesivo. Coletou-se 120 dentes incisivos inferiores bovinos dos quais 30 foram selecionados e tiveram suas coroas cortadas, permanecendo o remanescente radicular de 16 mm. Foi realizado o tratamento endodôntico e preparo intracanal para o pino, com profundidade de 8 mm para cimentação com cimento resinoso autoadesivo. As amostras foram divididas, randomicamente, em três grupos, segundo o tipo de tratamento de superfície, para limpeza intracanal após o preparo para cimentação: Grupo I - água destilada; Grupo II - EDTA 17% e Grupo III - clorexidina 0,12%. Os corpos de prova formados pelo conjunto dente-pino foram cortados no terço cervical, médio e apical, obtendo espécimes com 2,0 mm de espessura. Os espécimes foram levados à máquina de ensaios universal com velocidade de 0,5 mm/min para teste de resistência ao cisalhamento æpush-outÆ. A análise dos resultados foi feita com o teste ANOVA e Teste de Tukey (p<0,05). Os efeitos da água destilada, clorexidina 0,12% e EDTA 17% foram diferentes no tratamento superficial da dentina radicular, havendo diferença na resistência de união entre pinos de fibra de vidro e cimento resinoso autoadesivo nos terços cervical (p<0,013) e médio (p<0,026), sendo que o grupo da clorexidina 0,12% teve os melhores resultados. Isto permite sugerir novo protocolo de cimentação, com ação desinfetante (clorexidina), sem comprometer a resistência de união...

This study has evaluated the influence of different root canal dentin pre-treatments on the bond strength of radicular glass fiber posts. One hundred twenty bovine lower incisors were collecte. Thirty of them were selected and had their roots sectioned 16 mm from their apices. , Endodontic treatment and post space preparation to 8 mm deep were performed for cementation with self-adhesive resin cement. Samples were randomly divided into three according to surface treatments: Group I - irrigation with distilled water; Group II - irrigation with 17% EDTA; and Group III - irrigation with 0.12% chlorhexidine. Roots were then cut into 3 discs of 2 mm thick each and separated according to the region into cervical, medial and apical discs. A push-out bond strength test was performed by a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with one way analysis of variance (ANOVA) and Tuckey test (p<0.05). Mean bond strength values showed significant difference between the groups in the cervical region (p<0.013) and medial region (p<0.026), that suggest a new bond protocol with disinfectant effect using 0.12% chlorhexidine without negative impact on bond strength...

Flexural strength of composites: effects of the activationtechniques and fiber reinforcement / Resistência à flexão de compósitos: efeitos das técnicas de fotopolimerização e reforço de fibra

Objetivo: Avaliar a resistência à flexão de compósitos diretos (Charisma) e indiretos (Solidex), com ou sem reforços de fibra (Ribbond), polimerizados com LED ou Stroboscopic Xenon Light. Material e métodos: Barras de resina feitas com ou sem reforços de fibra,com 25 mm x 2 mm x 2 mm foram distribuídas emgrupos (n = 10): GDL- Resina Direta / LED; GDX ResinaDireta / Stroboscopic Xenon; GDFL- Resina Direta / Fibra / LED; GDFX- Resina Direta / Fibra /Stroboscopic Xenon; GIL- Resina Indireta / LED; GIXResinaIndireta / Stroboscopic Xenon; GIFL- Resina Indireta / Fibra / LED; GIFX- Resina Indireta / Fibra /Stroboscopic Xenon. Os espécimes foram conectados a uma máquina de teste universal e submetidos a uma carga de compressão (2 kN). Resultados: Os resultados obtidos foram submetidos ao teste de Análise de Variância (nível de significância de 5%) e teste de Tukey (p < 0,01). A resistência à flexão dos grupos que utilizaram reforço de fibra de polietileno(96,39) foi semelhante (p = 0,58) aos grupos sem reforço de fibras (92,47). Os compósitos diretos(107,79) mostraram maiores valores de resistência àflexão do que os compósitos indiretos (81,07), e a luze a polimerização com luz stroboscópica de xenônio(108,71) deu melhores resultados de resistência àflexão do que com LED (80,15), para ambos os tipos de compósitos estudados. Conclusão: O reforço de fibranão melhorou a resistência à flexão dos compósitos, compósitos diretos apresentaram maiores valores de resistência à flexão, e a luz estroboscópica de xenônio mostrou melhores resultados de resistência à flexão.

Objectives: To evaluate the flexural strength of direct(Charisma) and indirect (Solidex) composites, withor without fiber reinforcements (Ribbond), curedwith LED or Stroboscopic Xenon Light. Materialand Methods: Resin bars made with or withoutfiber reinforcements, with 25mm x 2mm x 2mmwere distributed in groups (n=10): GDL– DirectResin/LED; GDX–Direct Resin/Stroboscopic Xenon;GDFL– Direct Resin/Fiber/LED; GDFX– Direct Resin/Fiber/Stroboscopic Xenon; GIL– Indirect Resin/LED;GIX– Indirect Resin/Stroboscopic Xenon; GIFL–Indirect Resin/Fiber/LED; GIFX– Indirect Resin/Fiber/Stroboscopic Xenon. The specimens wereconnected to a universal test machine and submittedto a compression load (2 kN). Results: The obtainedresults were submitted to Analysis of Variance tests(p < 0.01), and Tukey (5% significance level)tests. The flexural strength of groups that usedpolyethylene fiber reinforcement (96.39) was similar(p = 0.58) to group without fiber reinforcement(92.47). Direct composites (107.79) showed highervalues of flexural strength than indirect composites(81.07), and stroboscopic xenon light curing(108.71) resulted in better flexural strength resultsthan LED (80.15), for both kinds of compositesexperimented. Conclusion: The fiber reinforcementdid not improve the composites’ flexural strength,direct composites showed higher flexural strengthvalues, and stroboscopic xenon light showed betterflexural strength results.

Radiant exposure effects on physical properties of methacrylate - and silorane-composites

AIM: To evaluate the effect of different radiant exposures on the degree of conversion (DC), Knoop hardness number (KHN), plasticization (P), water sorption (WS), and solubility (S) of different monomer resin-based composites. METHODS: Circular specimens (5 x 2 mm) were manufactured from methacrylate and silorane composite resins, and light-cured at 19.8, 27.8, 39.6, and 55.6 J/cm2, using second-generation LED at 1,390 mW/cm2. After 24 h, DC was obtained using a FT-Raman spectrometer equipped with a Nd:YAG laser, KHN was measured with 50-g load for 15 s, and P was evaluated on the top and bottom surfaces by the percentage of hardness reduction after 24 h immersed in absolute alcohol. WS and S were determined according to ISO 4049. Data were subjected to statistical analysis (α=0.05). RESULTS: Methacrylate material presented higher DC, KHN, P, and WS than silorane (p<0.05). There was no difference in the S values (p>0.05). The increased radiant exposures improved only the KHN (p<0.05). In general, top surfaces showed higher DC and KHN than bottom, for both materials (p<0.05). The increase of the radiant exposure did not improve most physical properties of the composites and were monomer-base dependent. CONCLUSIONS: Chemical composition of the composite resins resulted in different physical properties behavior and could affect the clinical longevity of dental restorations, but overall these properties were not influenced by the different radiant exposures evaluated in the study...

Surgical techniques for maxillary bone grafting - literature review / Técnicas cirúrgicas para a enxertia óssea dos maxilares - revisão da literatura

For oral rehabilitation with implant-supported prostheses, there are required procedures to create the bone volume needed for installation of the implants. Thus, bone grafts from intraoral or extraoral donor sites represent a very favorable opportunity. This study aimed to review the literature on the subject, seeking to discuss parameters for the indications, advantages and complications of techniques for autogenous bone grafts.

Para a reabilitação bucal com as próteses implantossuportadas é necessário a realização de procedimentos para criar o volume ósseo necessário para a instalação dos implantes. Com isso, os enxertos ósseos provenientes de áreas doadoras intrabucais ou extrabucais, representam uma possibilidade bastante favorável. O presente trabalho objetivou realizar uma revisão da literatura em que procurou discutir parâmetros para as indicações, as vantagens e complicações para as técnicas dos enxertos ósseos autógenos.

Confocal laser scanning microscopy investigation of bond interfaces involved in fiber glass post cementation / Avaliação de dentes restaurados com pinos de fibra de vidro e agentes cimentantes, empregando-se microscopia confocal

Objective: This confocal microscopy study evaluated the cement/dentin and cement/post interfaces along the root canal walls when fiber glass posts were bonded to dentin using different types of cements. Material & Methods: Thirty endodontically treated premolars were divided into 3 groups according to the adhesive materials used in the bonding procedure: Prime & Bond 2.1/Self Cure + Enforce, RelyX Unicem and RelyX Luting. Rhodamine B dye was incorporated in the luting materials for the cementation of the fiber glass posts (Exacto, Angelus) to dentin. Three transversal slices (apical, middle and coronal) were examined under confocal laser scanning microscopy. Statistical analysis was performed using the Kappa, Kruskal-Wallis and Dunnet tests, in a significance level of 5%. Results: The Prime & Bond 2.1/Self Cure + Enforce presented a uniform formation of tags in the dentin but gaps in the cement/dentin interface. The RelyX Unicem and RelyX Luting presented an adhesive interface with a fewer amount of gaps, but showed shorter tag formation than the Enforce system. All cements presented the same pattern of bubbles inside the cements. The RelyX Luting presented a greater amount of cracks inside the cement in comparison with the other cements in the coronal third, while no difference was observed between RelyX Unicem and Enforce. The RelyX Luting showed the lowest quantity of cement penetration into the post. Conclusion: In general, the quality of bonding interfaces of fiber posts luted to root canals was affected by both location and type of cement.

Objetivo: O objetivo deste trabalho foi avaliar as interfaces cimento/dentina e cimento/pino quando diferentes agentes cimentantes foram utilizados na cimentação de pinos de fibra de vidro. Material e Métodos: Trinta pré-molares humanos foram tratados endodonticamente e divididos em 3 grupos de acordo com o procedimento adesivo: Prime & Bond 2.1/Self Cure + Enforce, RelyX Unicem e RelyX Luting. Corante fluorescente Rodamina B foi incorporado aos agentes cimentantes para a cimentação dos pinos de fibra (Exacto, Angelus). Os dentes foram seccionados em três terços (apical, médio e coronário) e examinados ao microscópio confocal. Os dados foram submetidos aos testes Kappa, Kruskal-Wallis e Dunnet, a um nível de significância de 5%. Resultados: O grupo Prime & Bond 2.1 / Self Cure + Enforce apresentou uma formação uniforme de tags na dentina, porém fendas na interface cimento/dentina. Os cimentos RelyX Unicem e RelyX Luting apresentaram uma interface adesiva com pequena quantidade de fendas, mas mostrou pequena formação de tags se comparados ao sistema Enforce. Todos os cimentos apresentaram o mesmo padrão de bolhas em seu interior. O cimento RelyX Luting apresentou grande quantidade de trincas em seu interior se comparado com os outros cimentos no terço coronário, enquanto nenhuma diferença foi observada entre os cimentos RelyX Unicem e Enforce. O cimento RelyX Luting a menor quantidade de penetração de cimento dentro do pino. Conclusão: Em geral, a qualidade das interfaces adesivas dos cimentos foi afetada pela localização e tipo de cimento.

O impacto das próteses implantossuportadas na harmonia facial / The impact of implant-supported prostheses in facial harmony

Grande parte da população que procura atendimento odontológico deseja melhorar a estética facial e a do sorriso, para ser inserida na sociedade em que vive. Nos indivíduos usuários de próteses totais, a reabsorção fisiológica causa uma atrofia, principalmente da maxila, sendo necessária a realização de técnicas reconstrutoras e, às vezes, de movimentação das bases ósseas, para maior estabilidade oclusal e harmonia facial. O objetivo deste trabalho foi abordar as características relacionadas com a reabilitação dos pacientes edêntulos, com indicação para a reconstrução dos maxilares com enxerto ósseo e cirurgia ortognática, por meio de um caso clínico. Sendo que após a reabilitação com as próteses implantossuportadas, a paciente se mostrou amplamente satisfeita com o resultado estético-funcional alcançado e se recusou a submeter-se à cirurgia ortognática proposta no planejamento. Com isso, os profissionais devem apresentar as opções terapêuticas aos pacientes, porém, deve prevalecer a queixa principal dos mesmos, desde que seja uma modalidade de tratamento viável.

Many patients seeking dental care wish to improve facial and smile aesthetics to be accepted in modern day society. In denture wearers, the physiological resorption causes atrophy mainly in the maxilla, being necessary to carry out reconstruction techniques and sometimes orthognathic surgery to improve occlusal stability and facial harmony. The aim of this study is to discuss the features related to the rehabilitation of edentulous patients with indication for reconstruction of the maxilla using bone grafts and orthognathic surgery by means of a clinical case. In the present case, after the prosthetic rehabilitation, the patient was full satisfied with obtained results and dismissed the initially proposed surgical protocol. Therefore, professionals should provide therapeutic options but the patient’s opinion should prevail provided its clinical feasibility.

Registro do perfil de emergência para mimetização dos dentes naturais na região estética / Emergence profile registration to mimic natural teeth in the esthetic region

Introdução: o tratamento com implantes dentários para a reposição de dentes na região estética exige a utilização de materiais e técncias que permitam o máximo de naturalidade entre a restauração, os dentes vizinhos e to tecido gengival. Dessa forma, torna-se necessário criar o correto perfil de emergência para o dente, assim como a utilização de materiais com alto potencial estético. Objetivo: o objetivo do presente trabalho foi ilustrar, através de um caso clínico, a utilização de moldagem para a correta cópia do perfil de emergência do dente e sua transferência para o modelo de trabalho, tornando possível a confecção de uma restauração totalmente cerâmica, perfeitamente integrada ao tecido gengival. Caso clínico: paciente de 30 anos, procurou a clínica de prótese dentária com desejo de melhorar a estética dos dentes. Após diagnóstico e planejamento, foram confeccionadas 2 coroas totalmente cerâmcias sobre os dentes 12 e 21, e confecção de 1 coroa cerâmica sobre um pilar de zircônia após o estabelecimento e registro do perfil de emrgência do dente 11. Conclusão: após a conclusão do trtamento, observou-se naturalidade, estética e perfeita integração entre as restaurações, os dentes remanescentes e o tecido gengival.

Introduction: The treatment with dental implants for tooth replacement in esthetic regions requires the use of esthetic materials and techniques that allow natural restorations among the neighboring teeth and gingival tissue. Thus, it is necessary to create the proper emergence profile for the tooth, as well as the use of materials with high esthetic potential. Objective: The objective of this study was to illustrate through a clinical case using a impression technique for the correct copy of the emergence profile of the tooth, and its transfer to the working model, making possible the creation of an all-ceramic restoration perfectly integrated with the gingival tissue. Clinical case: The 30 years-old patient went to the dental clinic with the desire to improve the esthetics of her teeth. After diagnosis and planning were made two all-ceramic crowns on right lateral incisor (#12) and left central incisor (#21). Furthermore, it was made a ceramic crown on a zirconia based abutment after the creation and registration of the emergency profile of the right central incisor (#11). Conclusion: After finished the treatment it was observed naturalness, esthetics and seamless integration between the restorations, the remaining teeth and gingival tissue.

Effect of bleaching on sound enamel and with early artificial caries lesions using confocal laser microscopy

The aim of this study was to evaluate effect of bleaching agents on sound enamel (SE) and enamel with early artificial caries lesions (CL) using confocal laser scanning microscopy (CLSM). Eighty blocks (4 x 5 x 5 mm) of bovine enamel were used and half of them were submitted to a pH cycling model to induce CL. Eight experimental groups were obtained from the treatments and mineralization level of the enamel (SE or CL) (n=10). SE groups: G1 - unbleached (control); G2 - 4% hydrogen peroxide (4 HP); G3 - 4 HP containing 0.05% Ca (Ca); G4 - 7.5% hydrogen peroxide (7.5 HP) containing amorphous calcium phosphate (ACP). CL groups: G5 - unbleached; G6 - 4 HP; G7 - 4 HP containing Ca; G8 - 7.5 HP ACP. G2, G3, G6, G7 were treated with the bleaching agents for 8 h/day during 14 days, while G4 and G8 were exposed to the bleaching agents for 30 min twice a day during 14 days. The enamel blocks were stained with 0.1 mM rhodamine B solution and the demineralization was quantified using fluorescence intensity detected by CLSM. Data were analyzed using ANOVA and Fisher’s tests (α=0.05). For the SE groups, the bleaching treatments increased significantly the demineralization area when compared with the unbleached group. In the CL groups, no statistically significant difference was observed (p>0.05).The addition of ACP or Ca in the composition of the whitening products did not overcome the effects caused by bleaching treatments on SE and neither was able to promote remineralization of CL.

O objetivo deste estudo foi avaliar o efeito de agentes clareadores no esmalte sadio (ES) ou esmalte com lesão inicial de cárie artificial (LC), utilizando microscopia confocal laser de varredura (CLSM). Oitenta blocos (4 x 5 x 5 mm) de esmalte bovino foram usados, sendo que 40 destes foram desmineralizados com ciclagem de pH para induzir a LC. Oito grupos experimentais foram obtidos a partir dos tratamentos e condição do esmalte (ES ou LC), com n=10: Grupos ES: G1 - sem tratamento (controle); G2 - peróxido de hidrogênio 4% (PH4); G3: PH4 contendo 0,05% cálcio (Ca); G4 - peróxido de hidrogênio 7,5% (pH 7,5) contendo fosfato de cálcio amorfo (ACP). Grupos LC: G5 - não clareado; G6 - pH 4; G7 - pH 4 Ca; G8 - pH 7,5 ACP. Os grupos G2, G3, G6 e G7 foram tratados com o gel clareador por 8 h/dia durante 14 dias, enquanto as amostras dos grupos G4 e G8 foram submetidas ao agente clareador por 30 min/duas vezes ao dia, durante 14 dias. Os blocos de esmalte foram corados com solução de Rodamina B e a área fluorescente de desmineralização foi quantificada utilizando CLSM. Os dados foram submetidos a ANOVA e teste de Fisher (p<0,05). Para ES, os tratamentos clareadores aumentaram significativamente a área de desmineralização quando comparado com os grupos não clareados, entretanto, para LC não foi observado diferença estatística significante entre os grupos. A adição de ACP e Ca na composição dos géis clareadores não anulou os efeitos dos tratamentos clareadores no ES, assim como não teve capacidade de remineralizar o LC.

Reabilitação de maxila atrófica com enxerto de calota craniana e implantes / Atrophic maxilla rehabilitation with calvarial graft and implants

A utilização dos enxertos ósseos autógenos de calota craniana é uma das opções para as reconstruções de maxila atrófica. Possui diversas vantagens, sobretudo, devido a menor morbidade pós-operatória, quando comparado ao de crista ilíaca, além de apresentar o menor índice de reabsorção durante a incorporação. O presente trabalho teve como proposta discutir as vantagens da enxertia óssea autógena da calota craniana na reabilitação de maxila atrófica, por meio de um relato de caso clínico cirúrgico de uma paciente de 65 anos, pontuando todas as características envolvidas no planejamento, assim como da execução do tratamento proposto. Os resultados foram excelentes, com a obtenção de grande volume ósseo após o enxerto da maxila, o que proporcionou a instalação favorável dos implantes na maxila atrófica. As próteses protocolos trouxeram maior conforto para as funções mastigatórias e fonéticas, além de promoverem melhor assentamento dos tecidos moles da face.

The use of autogenous bone grafts for cranial vault is one of the options for the reconstruction of the atrophic maxilla. It has several advantages, mainly due to lower postoperative morbidity when compared to that obtained from the iliac crest, and lower resorption rate during graft incorporation. Thus, oral rehabilitation with dental implants has become a highly predictable treatment modality, particularly in large reconstructions. This work aims to discuss the advantages of autogenous bone graft from the skull in the rehabilitation of the atrophic maxilla by means of a clinical case report of a 65 years-old patient, detailing all the features involved in planning, as well as the execution of proposed treatment. The results showed an excellent prognosis for success, obtaining high bone volume after grafting of the maxilla, which provided a very favorable implant placement in the maxillary arch. The prostheses have brought greater comfort for mastication and phonetics, and promoted a better accomodation of the facial soft tissues