Aim Venous blood derivatives (VBDs) have been suggested as substitutes for Fetal Bovine Serum (FBS) to improve the clinical transition of cell-based therapies. The literature is not clear about which is the best VBDs substitute. The present study aimed to evaluate the influence of VBDs on cell viability and describe a new method to seed these cells in a 3D Platelet-Rich Fibrin (PRF). Methods Blood was processed to obtain Platelet-Poor Plasma from PRF (P-PRF), Human Serum (HS), Platelet-Poor Plasma from PRP (P-PRP), activated-PRP (a-PRP), and Platelet lysate (PL). Cells were supplemented with each VBD at 10% and FBS at 10% was the control. Cell viability (fibroblast 3T3/NIH) test was evaluated with MTT assay in two ways: i) cell-seeded and expanded with VBD; ii) cell-seed with FBS and expanded with VBD. To seed the Fibrin construct, cells were suspended in PBS and dropped into the blood sample before performing Choukroun’s protocol for PRF. Constructs were cultured for 7 days in VBD supplements and FBS. Histological and Immunohistochemical analysis with vimentin was performed. Cell viability was analyzed by one-way ANOVA. Results VBD’s production time was very heterogeneous. Cells expanded in HS and a-PRP has grown faster. VBD-supplemented culture media provided cell culture highly sensible to trypsin/EDTA 0.25%. Cells seeded and expanded with VBD presented viability comparable to FBS in HS, a-PRP, and P-PRP (p>0.05) and lower in P-PRF and PL groups (p<0.05). The viability of cell seed with FBS and expanded with VBD was similar between P-PRF, a-PRP, PL, and FBS (p>0.05) and lower in HS and P-PRP (p<0.005). PRF-seeded cells showed a positive expression of vimentin and were able to maintain all cells supplemented with VBD. Conclusion VBD supplements were able to maintain fibroblast cells in 2D and 3D cultures. The new method of the fibrin-cell construct was efficient to insert the cells into the fibrin network. (VBDs (FBS cellbased based therapies substitute D PlateletRich Rich . (PRF) PlateletPoor Poor PPRF, PPRF P , (P-PRF) (HS) PPRP, PPRP (P-PRP) activatedPRP activated aPRP, aPRP (a-PRP) PL. (PL) 10 control 3T3/NIH 3T3NIH TNIH 3T3 NIH T ways i cellseeded ii cellseed Choukrouns Choukroun s performed oneway one way ANOVA heterogeneous faster VBDsupplemented trypsinEDTA trypsin EDTA 025 0 25 0.25% PRP, p>0.05 p005 p 05 (p>0.05 p<0.05. p<0.05 (p<0.05) PRF, p<0.005. p0005 p<0.005 005 (p<0.005) PRFseeded cultures fibrincell network (PRF (P-PRF (HS (P-PRP (a-PRP (PL 1 3T 02 2 0.25 p>0.0 p00 (p>0.0 p<0.0 (p<0.05 p000 p<0.00 00 (p<0.005 0.2 p>0. p0 (p>0. p<0. (p<0.0 (p<0.00 0. p>0 (p>0 p<0 (p<0. p> (p> p< (p<0 (p (p<

Abstract The present study aimed to investigate the contextual inequalities of specialized public dental care (SPDC) in Brazil. The outcome was the trajectory of dental specialized production in municipalities with SPDC (from 2015 to 2017) obtained by group-based trajectory modeling. A Poisson regression model was used to analyze the factors associated with the high trajectory of SPDC production. The inequality indicators for SPDC production were the slope index and the concentration index according to contextual factors. The study included 954 SPDC units distributed across 893 municipalities. Among the municipalities evaluated, 62.9% had a low trajectory of SPDC. Large-sized municipalities had the highest production (IRR = 2.84, 95%CI: 1.94–4.14) and the southern region had the lowest production (IRR = 0.73, 95%CI: 0.58–0.92). Municipalities presenting a very high human development index (HDI) showed the greatest SPDC production (IRR = 3.34, 95%CI: 1.09–10.24), as well as municipalities with the highest tertile of schooling rate (IRR = 1.23, 95%CI: 1.00–1.50). The absolute inequality was 52.1 percentage points for the average monthly wage (p < 0.001), 61.0 percentage points for the HDI (p < 0.001), -22.1 for infant mortality rate (p <0.001), and 14.8 for the schooling rate (p = 0.012). Thus, there are contextual inequalities in the Brazilian SPDC. Higher scores for social indicators were associated with better SPDC performance. (SPDC Brazil from 201 2017 groupbased group based modeling 95 89 evaluated 629 62 9 62.9 Largesized Large sized IRR 284 2 84 2.84 95%CI 95CI CI 1.94–4.14 194414 1 94 4 14 073 0 73 0.73 0.58–0.92. 058092 0.58–0.92 . 58 92 0.58–0.92) (HDI 334 3 34 3.34 1.09–10.24, 1091024 1.09–10.24 , 09 10 24 1.09–10.24) 123 23 1.23 1.00–1.50. 100150 1.00–1.50 00 50 1.00–1.50) 521 52 52. p 0.001, 0001 0.001 001 0.001) 610 61 61. 22.1 221 22 -22. <0.001, <0.001 <0.001) 148 8 14. 0.012. 0012 0.012 012 0.012) Thus performance 20 6 62. 28 2.8 1.94–4.1 19441 07 7 0.7 05809 0.58–0.9 5 33 3.3 109102 1.09–10.2 12 1.2 10015 1.00–1.5 000 0.00 22. -22 <0.00 0.01 01 2. 1.94–4. 1944 0. 0580 0.58–0. 3. 10910 1.09–10. 1. 1001 1.00–1. 0.0 -2 <0.0 1.94–4 194 058 0.58–0 1091 1.09–10 100 1.00–1 - <0. 1.94– 19 05 0.58– 109 1.09–1 1.00– <0 1.94 0.58 1.09– 1.00 1.9 0.5 1.09 1.0

Abstract This study developed and characterized a method for controlled deposition of thin films of hydroxyapatite on titanium surfaces. Thirty-three titanium cylinders were randomly divided: negative control/polished (A), acid etched (B) and coated by hydroxyapatite (C). Acid etch was performed in an aqueous solution of nitric acid. The cylinders were subjected to coating by a thin film of hydroxyapatite with dip-coating method. These cylinders were submitted to a pre-heat treatment 450°C/10 minutes and 800°C/2 hours. Scanning electron microscopy analysis demonstrated a homogeneous and smooth surface (A), an irregular and porous surface (B) and a crystalline deposition (C). The X-ray energy dispersive analysis showed characteristic elements of hydroxyapatite (C). Analysis by X-ray diffraction showed the presence of characteristic peaks of hydroxyapatite, corresponding to the structural composition of hydroxyapatite. Cell viability (MTT-assay in NIH-3T3-Cells) test demonstrated no differences between the groups. Titanium surfaces coated with a hydroxyapatite film by the dip-coating method suggest adequate control of deposition of thin films of hydroxyapatite and similar cell viability using mouse fibroblasts.

Resumo O objetivo da presente Scoping review foi investigar as possibilidades clínicas atuais e futuras das terapias regenerativas e sua capacidade de regenerar tecido ósseo, periodontal e polpar em humanos com confirmação histológica da natureza do tecido formado. Uma busca eletrônica foi realizada utilizando uma combinação entre as palavras-chave e termos MeSH nos bancos de dados PubMed, Scopus, ISI-web of Science e Cochrane library até janeiro de 2016. Dois revisores realizaram de forma independente o julgamento dos documentos. Os estudos selecionados foram lidos seguindo os critérios de inclusão predeterminados. Os estudos incluídos foram avaliados de acordo com a estrutura modificada de Arksey e O‘Malley. Dos 1349 artigos, 168 preencheram os critérios de inclusão. Várias células caracterizadas e não caracterizadas promoveram regeneração óssea utilizada em terapias celulares, demonstrando ganho ósseo em quantidade e qualidade, de forma rápida para regeneração óssea e periodontal. Os scaffolds sintéticos e naturais apresentaram boa manutenção celular, no entanto o poliglicol-polilácido apresentou uma reabsorção rápida e, consequentemente, pequeno ganho ósseo. A terapia mediada por fatores de crescimento foi capaz de regenerar tecido ósseo e todas as características de um tecido periodontal. Dentes submetidos à revascularização apresentaram aumento do comprimento e largura do canal radicular. No entanto, os tecidos formados não foram capazes de depositar dentina, caracterizando um tecido reparado. Tanto o PRP quanto o PRF parecem apresentar benefícios quando aplicados em terapias regenerativas sendo um bom scaffold natural. Portanto, a maioria dos estudos que aplicaram terapias regenerativas forneceram resultados promissores sendo possível regenerar tecido ósseo e periodontal com confirmação histológica. No entanto, não foi observada regeneração de polpa dental. Estes resultados devem ser interpretados com cautela.

Abstract The aim of presented systematic scoping review was to investigate the actual and future clinical possibilities of regenerative therapies and their ability to regenerate bone, periodontal and pulp with histological confirmation of the nature of formed tissue. Electronic search was conducted using a combination between Keywords and MeSH terms in PubMed, Scopus, ISI-Web of Science and Cochrane library databases up to January 2016. Two reviewers conducted independently the papers judgment. Screened studies were read following the predetermined inclusion criteria. The included studies were evaluated in accordance with Arksey and O’Malley’s modified framework. From 1349 papers, 168 completed inclusion criteria. Several characterized and uncharacterized cells used in Cell Therapy have provided bone regeneration, demonstrating bone gain in quantity and quality, even as accelerators for bone and periodontal regeneration. Synthetic and natural scaffolds presented good cell maintenance, however polyglycolid-polylactid presented faster resorption and consequently poor bone gain. The Growth Factor-Mediated Therapy was able to regenerate bone and all features of a periodontal tissue in bone defects. Teeth submitted to Revascularization presented an increase of length and width of root canal. However, formed tissues not seem able to deposit dentin, characterizing a repaired tissue. Both PRP and PRF presented benefits when applied in regenerative therapies as natural scaffolds. Therefore, most studies that applied regenerative therapies have provided promising results being possible to regenerate bone and periodontal tissue with histological confirmation. However, pulp regeneration was not reported. These results should be interpreted with caution due to the short follow-up periods.

Resumo Embora as propriedades biológicas das células-tronco mesenquimais (MSC) sejam bem caracterizadas in vitro, a aplicação clínica das MSC ainda está longe de ser alcançada, principalmente devido à necessidade de substâncias xenogênicas para expansão celular, como o soro fetal bovino (FBS). O FBS apresenta riscos quanto às transmissões de patógenos e à internalização de proteínas animais, o que pode desencadear respostas antigênicas em pacientes após a implantação das MSC. Uma vasta gama de derivados do sangue venoso (VBD) têm sido relatada como substitutos do FBS mostrando resultados promissores. Assim, o objetivo deste estudo foi conduzir uma revisão de escopo sistemática para analisar se VBD poderiam ser substitutos do FBS eficazes para expansão das MSC em condições ex vivo. A pesquisa foi realizada no SciVerse Scopus, PubMed, Web of Science, BIREME e biblioteca Cochrane até janeiro de 2016. As palavras-chave foram selecionadas usando MeSH e entre termos. Dois revisores independentes examinaram os registros obtidos considerando critérios de inclusão específicos. Os estudos incluídos foram avaliados de acordo com uma estrutura modificada de Arksey e O ‘Malley. Dos 184 estudos encontrados, 90 foram incluídos. As células-tronco da medula óssea (BMMSC) foram utilizadas na maior parte destes estudos. Em geral, o VBD permitiu tanto a manutenção da morfologia semelhante a fibroblastos das MCS, alta proliferação, alta capacidade de formação de colônias e manutenção de multipotêncialidade. Além disso, as MSC expandidas em suplementos derivados do sangue venoso apresentaram uma maior atividade mitogênica do que as expandidas em FBS. Os VBD parecem ser excelentes soro livres de agentes xenogênicos para expansão ex vivo de MSC. Entretanto, observou-se uma heterogeneidade acentuada entre os protocolos realizados para o isolamento VBD, não permitindo assim comparações diretas entre os estudos incluídos.

Abstract Although the biological properties of mesenchymal stem cells (MSC) are well-characterized in vitro, MSC clinical application is still far away to be achieved, mainly due to the need of xenogeneic substances for cell expansion, such as fetal bovine serum (FBS). FBS presents risks regarding pathogens transmissions and internalization of animal’s proteins, which can unleash antigenic responses in patients after MSC implantation. A wide range of venous blood derivatives (VBD) has been reported as FBS substitutes showing promising results. Thus, the aim of this study was to conduct a systematic scoping review to analyze whether VBD are effective FBS substitutes for MSC ex vivo expansion. The search was performed in SciVerse ScopusTM, PubMed, Web of ScienceTM, BIREME, Cochrane library up to January 2016. The keywords were selected using MeSH and entry terms. Two independent reviewers scrutinized the records obtained considering specific inclusion criteria. The included studies were evaluated in accordance with a modified Arksey and O’ Malley’s framework. From 184 found studies, 90 were included. Bone marrow mesenchymal stem cells (BMMSC) were presented in most of these studies. Overall, VBD allowed for either, maintenance of MCS’s fibroblast-like morphology, high proliferation, high colony-formation ability and maintenance of multipotency. Besides. MSC expanded in VBD supplements presented higher mitogen activity than FBS. VBD seems to be excellent xeno-free serum for ex vivo expansion of mesenchymal stem cells. However, an accentuated heterogeneity was observed between the carried out protocols for VBD isolation did not allowing for direct comparisons between the included studies.

Resumo Essa revisão sistemática avaliou se diferentes protocolos de criopreservação podem afetar as propriedades biológicas (taxa de sobrevivência celular, proliferação, diferenciação, manutenção dos marcadores de superfície) de células-tronco isoladas de tecidos dentais (DSC) após o descongelamento. Uma busca eletrônica foi realizada no PubMed e no ISI Web of Science utilizando palavras-chave específicas. Dois revisores independentes avaliaram os títulos e resumos de todos os estudos respeitando critérios de inclusão e exclusão previamente determinados. Os dados foram extraídos considerando as propriedades biológicas de DSC, e DSC isoladas de tecidos previamente criopreservados. DSC criopreservadas logo após seu isolamento apresentaram propriedades biológicas muito semelhantes às observadas em DSC não criopreservadas. Dimetil sulfóxido (DMSO) [10%] demonstrou bons resultados relacionados com a recuperação celular após descongelamento de células e tecidos, por períodos de até 2 anos. A criopreservação de DSC em freezer mecânico (-80 °C) permite a recuperação de células-tronco pós-descongelação. A utilização de freezer com campo magnético (MF), proporciona a utilização de uma menor concentração de crioprotector, mas a sua utilização não é dispensável. É possível isolar e criopreservar e criopreservar células-tronco da polpa dental (DPSC) de dentes vitais saudáveis e doentes. Criopreservação de tecidos dentais após o isolamento de DSC, combinados com MF, podem ser valiosas estratégias para reduzir custos e melhorar a logística no desenvolvimento de bancos de dentes.

Abstract This systematic review evaluated if different cryopreservation protocols could affect biological properties (Cell survival rate (CSR), proliferation, differentiation, maintenance of stem cell markers) of stem cells obtained from dental tissues (DSC) post-thaw. An electronic search was carried out within PubMed and ISI Web Science by using specific keyword. Two independent reviewers read the titles and abstracts of all reports respecting predetermined inclusion/exclusion criteria. Data were extracted considering the biological properties of previously cryopreserved DSCs and previously cryopreserved dental tissues. DSCs cryopreserved as soon as possible after their isolation presents a CSR quite similar to the non-cryopreserved DSC. Dimethyl sulfoxide (DMSO) [10%] showed good results related to cell recovery post-thaw to cryopreserve cells and tissues for periods of up to 2 years. The cryopreservation of DSC in a mechanical freezer (-80°C) allows the recovery of stem cells post-thaw. The facilities producing magnetic field (MF), demand a lower concentration of cryoprotectant, but their use is not dispensable. It is possible to isolate and cryopreserve dental pulp stem cell (DPSC) from healthy and diseased vital teeth. Cryopreservation of dental tissues for late DSC isolation, combined with MF dispensability, could be valuable to reduce costs and improve the logistics to develop teeth banks.

Este estudo avaliou o efeito do tempo de aplicação do chá verde na resistência de união do esmalte após o clareamento. Amostras de esmalte foram obtidas a partir de 70 terceiros molares e aleatoriamente divididas em 7 grupos experimentais (G1-G7) e um grupo sem tratamento (G8). Os 7 grupos experimentais foram tratados como segue: G1, clareado com peróxido de carbamida a 10% (PC); G2, PC + gel de ascorbato de sódio a 10% (AS) por 15 min; G3, PC + AS por 30 min; G4, PC + AS por 60 min; G5, PC + gel de chá verde a 10% (CV) por 15 min; G6, PC + CV por 30 min; G7, PC + CV por 60 min. O PC foi aplicado na superfície do esmalte por 8 h, durante 14 dias. O AS foi aplicado nos grupos 2, 3 e 4 e o CV foi aplicado nos grupos 5, 6 e 7 de acordo com os tempos de aplicação descritos acima. Imediatamente após o tratamento, foi realizado o procedimento adesivo utilizando Adper Single Bond 2 e Filtek Z350XT. Em seguida, as amostras foram preparadas para o teste de microtração. A análise do padrão de fratura foi realizada em lupa estereoscópica. Os dados foram analisados através de ANOVA (2 fatores), testes de Tukey e Dunnett (α=5%). As médias (desvio padrão) foram: G1: 23,29 (3,20); G2: 25,18 (3,95); G3: 26,41 (5,40); G4: 30,17 (4,46); G5: 26,63 (3,43); G6: 22,02 (5,41); G7: 31,40 (3,35); G8: 31,4 (3,2). Todos os grupos apresentaram maior porcentagem de falhas adesivas. Em conclusão, os valores de resistência de união foram maiores que os dos grupos clareados somente quando os antioxidantes foram aplicados por 60 min.

This study evaluated the effect of green tea application time on the bond strength of enamel after enamel bleaching. Enamel samples were obtained from 80 third molars and randomly divided into 7 experimental groups (G1-G7) and 1 group without treatment (G8): G1, bleached with 10% carbamide peroxide (CP); G2, CP + 10% sodium ascorbate gel (SA) for 15 min; G3, CP + SA for 30 min; G4, CP + SA for 60 min; G5, CP + 10% green tea gel (GT) for 15 min; G6, CP + GT for 30 min; G7, CP + GT for 60 min. The CP was applied onto the enamel surface for 8 h for 14 days. The SA was applied in groups 2, 3 and 4, and the GT was applied in groups 5-8 according to the above described application times. Immediately after treatment, the specimens were bonded with Adper Single Bond 2 and Filtek Z350XT. The specimens were prepared to microtensile bond strength analysis. Fracture mode analysis was performed using a stereoscopic loupe. The data were statistically analyzed by two-way analysis of variance, the Tukey's and Dunnett's tests (=5%). The means (standard deviation) were: G1, 23.3 (3.2); G2, 25.2 (3.9); G3, 26.4 (5.4); G4, 30.2 (4.5); G5, 26.6 (3.4); G6, 22.0 (5.4); G7, 31.4 (3.3); G8, 31.4 (3.2). All groups had a high percentage of adhesive failures. In conclusion, the bond strength values were higher than the value in the bleached group only when the antioxidants were applied for 60 min.

Objectives This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

OBJETIVO: O amálgama dentário tem servido como restaurador dentário a mais de 165 anos. Entretanto, alguns pacientes com estas restaurações têm demonstrado a ocorrência de lesões liquenóides orais (LLO). As LLO são reações de contato da mucosa oral crônicas ao amálgama dentário. Geralmente, o diagnóstico da lesão é feito pelo contato direto da mucosa afeta com a restauração de amalgama, pela aparência clínica, e a ausência de migrações. Um teste de contato para o mercúrio pode ser realizado para confirmar o diagnóstico. Assim, o objetivo deste trabalho foi discutir a ocorrência desta doença e suas possibilidades de diagnóstico diferencial existentes. DESCRIÇÃO DO CASO: Dois casos clínicos foram diagnosticados como LLO. Em ambos os casos, os pacientes relataram sofrer de sensação de queimação na mucosa oral adjacente às restaurações de amálgama. Para ambos pacientes, os tratamentos envolveram a substituição das restaurações de amálgama. Completa remissão da sintomatologia dolorosa foi observada após 17 dias em um caso e após 30 dias em outro, embora as lesões na mucosa intrabucal não tenham desaparecido completamente. CONCLUSÃO: Os cirurgiões-dentistas devem estar cientes da ocorrência da LLO relacionadas a restaurações de amálgama e devem saber como fazer o diagnóstico correto para assim recomendar a melhor forma de tratamento.

PURPOSE: Dental amalgam has been used as a dental restoration for more than 165 years. However, some patients with these restorations may present oral lichenoid lesions (OLL). OLL are chronic oral mucosal contact reactions to dental amalgam. Their diagnosis usually is based on the direct contact of the affected mucosa with the amalgam restorations, clinical appearance, and lack of migrations. A patch-test for mercury can be performed to confirm the diagnosis. Thus, the objective this work was to discuss the occurrence of this disease and your possibilities of existing differential diagnostic. CASE DESCRIPTION: Two clinical cases were diagnosed as related to OLL. In both cases, the patients complained of a burning sensation in the oral mucosa adjacent to the amalgam restorations. The treatment involved replacing the amalgam restorations by composite. A complete remission of the painful symptoms was observed after 17 days in one case and after one month in the other, although the lesions in the oral mucosa did not disappear completely. CONCLUSION: Dentists should be aware of OLL occurrence close to amalgam restorations and should be able to diagnose it and recommend the best treatment option.

O objetivo deste estudo foi avaliar a resistência de união (RU) de adesivos autocondicionantes com e sem HEMA à dentina. A superfície oclusal de 20 terceiros molares foi removida e a dentina abrasionada com lixa de carbeto de silício de granulação 600. Em seguida, os dentes foram divididos aleatoriamente em 4 grupos (n=5) e restaurados com os sistemas adesivos Go, Adper SE Plus, OptiBond All-In-One ed Clearfil 3S Bond e resina composta Filtek Z350. Após fotoativação (600 mW/cm²), eles foram armazenados em água destilada (37ºC/24 h) e secionados nas direções mésio-distal e vestíbulo-lingual, para obter corpos-de-prova em formato de palito (0,8 mm²). Os palitos foram tracionados em máquina de ensaio universal com velocidade de 0,5 mm/min, e os modos de fratura observados em microscópio eletrônico de varredura e classificados em adesiva, coesiva ou mista. Os dados de RU (em MPa) foram analisados estatisticamente por ANOVA a um critério e teste de Tukey com nível de significância de 5%. A menor RU foi observada para o adesivo GO (10,57 ± 3,72) (p=0,001). Adper SE Plus (29,08 ± 8,93), OptiBond All-In-One (28,36 ± 6,49) e Clearfil 3S Bond (28,62 ± 6,97) foram estatisticamente semelhantes entre si (p>0.05). Fraturas mistas predominaram nos grupos. Concluiu-se que a influência do HEMA na RU foi material-dependente.

This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n=5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite. After light curing (600 mW/cm²), the teeth were stored in distilled water at 37ºC for 24 h and were sectioned in the mesiodistal and buccolingual directions to obtain sticks (0.8 mm²). The sticks were subjected to tensile force using a universal testing machine (0.5 mm/min), and the modes of failure were analyzed by scanning electron microscopy and classified as adhesive, cohesive, or mixed. The BS data (in MPa) were treated using one-way ANOVA and Tukey’s tests at 5% significance. GO presented the lowest mean bond strength value (10.57 ± 3.72) and differed significantly from the other materials (p=0.001), which, in turn, presented statistically similar results (p>0.05) among themselves: Adper SE Plus (29.08 ± 8.93), OptiBond All-In-One (28.36 ± 6.49), and Clearfil 3S Bond (28.62 ± 6.97). Mixed fractures were the most prevalent. It was concluded that the influence of HEMA on BS to dentin was material dependent.

O objetivo do presente estudo foi avaliar se o conteúdo inorgânico exerce influência na resistência à flexão e no módulo de elasticidade de compósitos restauradores. Para determinar a resistência à flexão e o módulo de elasticidade foi realizado o teste de resistência à flexão por três pontos. Doze espécimes em formato de barra de cinco compósitos disponíveis comercialmente - Supreme (3M/ESPE), compósito universal nanoparticulado; Esthet-X (Dentsply), Z-250 (3M/ESPE), Charisma (Heraeus Kulzer), compósitos universais híbridos; e Helio Fill (Vigodent), compósito microparticulado - foram confeccionados conforme as especificações da ISO 4049/2000. Após 7 dias de armazenagem em água o teste foi realizado em uma máquina de ensaio universal com velocidade de carga de 1 mm/min. A avaliação do peso do conteúdo inorgânico foi determinada através da incineração da fase orgânica. Os dados obtidos referentes às propriedades mecânicas foram então submetidos à Análise de Variância e ao teste Tukey (p < 0,05). Para se determinar a correlação entre o conteúdo inorgânico e as propriedades mecânicas foi realizado o teste de correlação de Pearson. Uma fraca, porém significante correlação entre as propriedades mecânicas avaliadas e o peso do conteúdo inorgânico foi observada (p < 0,000). O compósito microparticulado apresentou menor conteúdo inorgânico e propriedades mecânicas mais baixas. Também foram observados valores de resistência à flexão e módulo de elasticidade estatisticamente diferentes entre os compósitos híbridos. O compósito nanoparticulado apresentou valores intermediários. Dentro das limitações deste estudo in vitro, pode-se concluir que o conteúdo inorgânico interfere significantemente na resistência à flexão e no módulo de elasticidade dos compósitos testados.

The aim of the study was to test whether the filler composition of resin composites influences their flexural strength and modulus of elasticity. Flexural strength and modulus of elasticity were obtained through a three-point bending test. Twelve bar shaped specimens of 5 commercially available composites - Supreme (3M/ESPE), a universal nanofilled composite; Esthet-X (Dentsply), Z-250 (3M/ESPE), Charisma (Heraeus Kulzer), universal hybrid composites; and Helio Fill (Vigodent), a microfine composite - were confectioned according to the ISO 4049/2000 specifications. The test was performed after a 7-days storage time using a universal test machine with a crosshead speed of 1 mm/min. The filler weight content was determined by the ashing technique. The data obtained on the mechanical properties were submitted to ANOVA and Tukey test (p < 0.05). Pearson's correlation test was used to determine the correlation between the filler content and the mechanical properties. A weak but significant correlation between the mechanical properties evaluated and the filler weight content was observed (p < 0.000). The microfine composite presented the lowest filler weight and the lowest mechanical properties. Statistically different flexural strength and modulus of elasticity results were observed among the universal hybrid composites. The nanofilled composite presented intermediary results. Within the limitations of this in vitro study, it could be concluded that the filler content significantly interfered in the flexural strength and modulus of elasticity of the composites tested.

O objetivo do presente estudo foi avaliar o estresse de contração de três resinas compostas sob diferentes métodos de fotoativação: fotoativação convencional halógena (G1), fotoativação "soft-start" halógena (G2) e fotoativação por LED (G3). As resinas compostas testadas foram a Filtek Z-100 (3M/ESPE), Filtek Z-250 (3M/ESPE) e Solitaire 2 (Heraeus Kulzer). Para G1, um aparelho fotoativador XL-3000 (3M/ESPE) com intensidade de 507 mW/cm² foi empregado. Em G2, o mesmo aparelho foi utilizado, mas com a intensidade reduzida nos primeiros 20 s (166 mW/cm²); em G3 foi utilizado um fotoativador LED Ultrablue I (DMC) com intensidade de 125 mW/cm². O teste foi realizado com uma máquina de ensaio universal DL 2000 (EMIC) e duas matrizes metálicas com um espaço de 1 mm entre elas. A resina composta foi inserida no espaço entre as matrizes e fotopolimerizada de acordo com o protocolo supracitado. O estresse foi registrado nos diferentes períodos de tempo: 10, 20, 40, 60, 90 e 120 s. Um aumento linear significante do estresse de contração em relação ao tempo foi observado, exceto para a Z-100 em G2. No geral, a fotoativação por LED (G3) reduziu o estresse gerado em comparação com a fotoativação convencional halógena (G1). Em G3, a resina com co-iniciador na sua composição apresentou menor estresse em comparação com as outras resinas testadas. A combinação entre resina composta e o método de fotoativação produziu diferentes padrões de comportamento do estresse. A polimerização com LED reduziu o estresse de contração inicial nos três materiais e foi influenciada pela presença de co-iniciadores nas resinas compostas.

The aim of this study was to evaluate the shrinkage stress of three composites under different polymerization methods: halogen conventional polymerization (G1), halogen "soft-start" polymerization (G2) and LED polymerization (G3). The composites tested were Filtek Z-100 (3M/ESPE), Filtek Z-250 (3M/ESPE) and Solitaire 2 (Heraeus Kulzer). For G1, an XL-3000 (3M/ESPE) curing unit with light intensity of 507 mW/cm² was employed. In G2, the same light unit was used, but with a reduced light intensity in the first 20 s (166 mW/cm²). In G3, an Ultrablue I (DMC) LED curing unit with light intensity of 125 mW/cm² was used. The test was performed with a DL 2000 (EMIC) universal testing machine and two metallic molds with a 1 mm space between them. The composites were inserted in the space between the molds and light cured according to the protocols mentioned above. Stress was registered in different periods of time: 10, 20, 40, 60, 90 and 120 s. A significant linear increase of the shrinkage stress over time was observed, except for Z-100 in G2. Generally, LED polymerization (G3) reduced the generated stress when compared to conventional halogen polymerization (G1). In G3, the composite with the additional co-initiatior presented lower stress when compared to the other composites tested. The combination between composite and polymerization method produced different patterns of stress behavior. LED polymerization reduced the initial shrinkage stress of the three materials and was influenced by the presence of co-initiators in the composites.