Resumo: O objetivo deste trabalho foi realizar avaliação da resistên - cia de união ao cisalhamento de reparos de resina compostas em restaurações com resina composta envelhecidas, em função de diferentes tratamentos superficiais. Foram confeccionados 60 corpos-de-prova de resina composta Z250 (3M) e levados a termociclagem para simular o envelhecimento da restauração, foram realizados 500 ciclos de 15 segundos cada, variando entre 5°e 55°C. Separados aleatoriamente em seis grupos que sofreram os seguintes tratamentos superficiais: nenhum tratamento (G1 - controle), desgaste com ponta diamantada (G2), jato de óxido de alumínio com partículas de 27,5æm (G3) por 10 segundos, laser de Er:YAG - 200mJ (G4), laser de Er:YAG - 300mJ (G4) e laser de Er:YAG - 400mJ (G6), os três últimos com freqüência de 10Hz por 10 segundo. Foi realizada microscopia eletrônica de varredura para observarmos o aspecto do material após os tratamentos terem sido executados. O reparo da restauração foi realizado utilizando-se a mesma resina. O teste de cisalhamento foi feito na Máquina de Ensaios Mecânicos MTS - 810. Analisando os resultados por ANOVA e pelo teste de Tukey não foram encontradas diferenças significativas (p-valor=0.5120). A análise dos valores medianos, mostrou que o tratamento superficial com jato de óxido de alumínio apresentou uma maior resistência da interface do reparo ao cisalhamento (8.91Mpa) enquanto que o laser de Er:YAG com 400mJ de potência, apresentou a menor (6.76Mpa). A análise dos tipos de fratura mostrou que 90% dos corpos-de-prova do grupo 3 (óxido de alumínio) sofreram fraturas coesivas. / Abstract: The aim of this work was to perform the evaluation of the shear bond strength of the composite resin repairs in old composite restorations, modifying the superficial treatment of the samples. Sixty samples of the composite resin Z250 (3M) were prepared and thermocycled for 500 cycles at 5° and 55°C with a dwelling time of 15 seconds. Speciments were randomly divided into six groups and subjected to different surface treatments as follows: No surface treatment (G1 - control), grinding with a diamond bur (G2), sandblasting with a microetcher for 10 seconds with 27,5æm Al2O3 particles (G3), treated with Er:YAG laser with an energy intensity of 200mJ (G4), 300mJ (G5), 400mJ (G6), frequency of 10Hz for 10 seconds. The speciments after surface treatment were observed using the scanning electron microscope. The repair of the old resin was done with the same material. The shear bond strength test was performed in a Mechanic Testing MTS - 810. Statistical treatment by ANOVA and Tukey's test showed no significant differences between the groups tested (p=0.5120). The highest shear bond strength values were achieved by sandblasting the surface with a microetcher with Al2O3 (8,91Mpa), whereas the lowest values were obtained with Er:YAG laser with energy intensity of 400mJ (6.76Mpa). Observing the rupture surface, G3 presented 90% of cohesive failures. / Orientador: José Roberto Cury Saad / Coorientador: Rosane F. Z. Lizarelli / Banca: Celso Luiz de Angelis Porto / Banca: Elda Pisaneschi / Mestre

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2018-05-08T18:50:19Z No. of bitstreams: 2 Dissertação - Alexandre Fausto da Veiga Jardim - 2018.pdf: 1979763 bytes, checksum: 0ef0698dbb58bc9423f5f8c180f2c6a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-09T11:29:00Z (GMT) No. of bitstreams: 2 Dissertação - Alexandre Fausto da Veiga Jardim - 2018.pdf: 1979763 bytes, checksum: 0ef0698dbb58bc9423f5f8c180f2c6a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-09T11:29:00Z (GMT). No. of bitstreams: 2 Dissertação - Alexandre Fausto da Veiga Jardim - 2018.pdf: 1979763 bytes, checksum: 0ef0698dbb58bc9423f5f8c180f2c6a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-02 / Objective: Evaluate the shear bond strength of the union of orthodontic tubes bonded to molar teeth with different bonding protocols. Material and Method: One hundred and twenty molar teeth, previously extracted from patients with age between 12 and 30 years were selected. Orthodontic molar tubes were bonded on the vestibular surface of these teeth with one of two types of adhesive (Transbond XT or Orthobond). Each of these groups were subsequently divided in 4 other groups: control and with the use of a resin reinforcement on the occlusal surface of the bonded tubes with one of three materials (Transbond XT, Tetric N Flow, Z 350 Flow). Shear bond strength and adhesive remnant index tests were performed to evaluate the bond strength and type of fracture of the tubes bonded with the different methods. Results: Tubes bonded with Transbond XT had superior bond strength than tubes bonded with Orthobond. The use of resin reinforcement with Transbond XT increased significantly the shear bond strength of tubes bonded with Transbond XT. All groups presented in most of their samples less than 50% of adhesive remnant in the vestibular surface after de shear bond test. Conclusion: The use of a resin reinforcement with Transbond XT increased the shear bond strength of orthodontic tubes bonded with Transbond XT. / Objetivo: Avaliar a resistência de união de tubos ortodônticos colados em molares com diferentes protocolos de colagem. Material e Método: Foram selecionados 120 molares humanos com coroas hígidas, previamente extraídos de pacientes com idade entre 12 e 30 anos. Tubos ortodônticos foram colados na superfície vestibular destes dentes com um de dois tipos de resinas (Transbond XT ou Orthobond). Cada grupo colado com um dos materiais foi subsequentemente dividido em 4 grupos: controle e com aplicação de um reforço de resina na superfície oclusal dos tubos com um de três materiais (Transbond XT, Tetric N Flow, Z 350 Flow). Testes de cisalhamento e de remanescente adesivo foram executados para avaliar a resistência e tipo de fratura dos tubos submetidos aos diferentes protocolos de colagem. Resultados: Tubos colados com a resina Transbond XT apresentaram resistência superior aos tubos colados com resina Orthobond. O uso de reforço resinoso com a resina Transbond XT aumentou de maneira significativa a resistência dos tubos ortodônticos colados com resina Transbond XT. O uso de resinas do tipo flow como reforço resinoso não resultou em aumento significativo da resistência ao cisalhamento. Todos os grupos em sua maioria apresentaram menos de 50% de remanescente resinoso na superfície vestibular após a fratura. Conclusão: O uso de um reforço resinoso com resina Transbond XT aumenta a resistência ao cisalhamento de tubos ortodônticos colados com resina Transbond XT.

Dental erosion is a result of the demineralization of enamel surface by the action of acids that soften it, and it may affect bracket adhesion to enamel. This research aimed to assess the effect of the application of aluminum oxide sandblasting and aluminum oxide discs on bond strength of metal brackets rebonded on artificially eroded enamel. Fifty-four crowns of bovine incisors were divided into group functions: Control (artificial saliva), Ox Al (aluminum oxide sandblasting), and SL (aluminum oxide discs Sof-Lex Pop On, 3M ESPE). The crowns were fixed in PVC tubes and enamel surface was flattened with carborundum discs (#320, 600, and 1200 Al2O3 discs; Buehler, Lake Bluff, IL, USA) in metallographic polisher (APL4, Arotec). Knoop microhardness was assessed for the standardization of enamel surfaces (HMV-2000; Shimadzu Corporation, Tokyo, Japan). Next, Ox Al and SL teeth were subjected to the erosive action, submerged in Coca-Cola™ for 1 minute, 3x a day for 7 days. Kirium metal brackets, specific for upper right central incisors, slot 022, Roth prescription (3M/Abzil, São José do Rio Preto, São Paulo, Brazil) were bonded on the buccal aspect of teeth. Shear strength was measured with a universal testing machine EMIC (DL200, EMIC, São José dos Pinhais, Paraná, Brazil) at speed of 0.5 mm/min. The Adhesive Remnant Index (ARI) was performed in samples after shear through a magnifying glass (10x). Kolmogorov-Smirnov, Levene, and homoscedasticity tests were used, as well as ANOVA, for the assessment of microhardness and shear strength. The three groups presented no significant differences for microhardness and shear, but the control group had the highest microhardness mean. There were no statistically significant differences among the three groups for shear bond strength (p=0.163). However, the Ox Al group showed higher values for bond strength. The assessment of ARI of groups showed statistically significant difference when comparing the Control group with Ox Al and SL groups. The ARI values showed the prevalence of ARI 3 (50%) for the control group, followed by ARI 4 (22%) and 5 (22%). For Ox Al and SL, ARI 1 and 2 prevailed. The use of aluminum oxide sandblasting and aluminum oxide discs did not increase bond strength of brackets when they were bonded on artificially eroded enamel. The Adhesive Remnant Index indicated that eroded teeth present higher resin adhesion to enamel. / O objetivo desta pesquisa foi avaliar o efeito da aplicação do microjateamento de óxido de alumínio e de discos de óxido de alumínio na resistência adesiva de braquetes metálicos recolados em esmalte erodido artificialmente. Cinquenta e quatro coroas de incisivos bovinos foram divididas em função dos grupos: Controle (Saliva Artificial), Ox Al (Microjateamento com óxido de alumínio) e SL (discos de óxido de alumínio (Sof-Lex Pop On, 3M ESPE). As coroas foram fixadas em tubos de PVC e a superfície do esmalte foi planificada com discos de carborundum (numerações 320, 600 e 1200 discos de Al2O3; Buehler, Lake Bluff, IL, USA), em Politriz Metalográfica (APL4, Arotec). A microdureza Knoop foi aferida para padronização das superfícies de esmalte (HMV-2000; Shimadzu Corporation, Tokyo, Japan). Após aferição os dentes de OxAl e SL foram submetidos ao desafio erosivo, submersos em Coca-Cola® por 1 minuto, 3X ao dia, por 7 dias. Foram colados braquetes metálicos Kirium específicos para incisivos centrais superiores direitos, slot 022”, prescrição Roth [(3M/Abzil, São José do Rio Preto, São Paulo, Brasil)] na face vestibular do dente. A força de cisalhamento foi mensurada por meio de uma máquina de teste universal EMIC (DL200, EMIC, São José dos Pinhais, Paraná) com velocidade 0,5mm/min. O Índice de Remanescente Adesivo (IRA) foi obtido nas amostras utilizando-se lupa (10X). Foram aplicados os testes de Kolmogorv-Smirnov, de Levene e a homocedasticidade e ANOVA para avaliação da microdureza e força de cisalhamento. Não houve diferenças estatisticamente significantes entre os três grupos quando avaliadas microdureza (p=0,163). Porém, ao avaliar o IRA entre grupos, houve diferença estatisticamente significativa ao comparar o grupo Controle com o OxAl e SL. Sendo a prevalência de IRA 3 (50%) para o grupo controle, seguido de IRA 4 (22%) e 5 (22%), respectivamente. Para OxAl e SL, IRA 1 e 2 prevaleceram. Concluiu-se que o uso de microjateamento de óxido de alumínio e discos de óxido de alumínio não aumentaram positivamente a resistência adesiva dos braquetes quando colados em esmalte erodido artificialmente. O índice de remanescente adesivo indicou que dentes erodidos apresentam uma maior adesão da resina ao esmalte.

Strong underwater bonds between polycarbonate sheet and various other substrates were achieved using ethyl 2-cyanoacrylate gel cured with an anionic photoinitiator (dibenzoylferrocene). The gel reacts quickly with water on contact and forms a protective polyethyl cyanoacrylate (PECA) skin. This provides a diffusion barrier that protects the inner monomer from further reaction with or polymerisation by water (hydroxide ions). The PECA skin is, however, permeable to water and the inner monomer slowly reacts as water diffuses through the PECA skin. The application procedure for this adhesive is critical because of the fast reaction with water. The adhesive should be applied at the centre of the bond area in such a way as to cover the smallest exposed surface area and that it should not be spread out over the entire surface area. The PECA skin will rupture when the substrates are pressed together, exposing unreacted monomer to the fresh new surface between the two substrates. The adhesive displaces water as it propagates towards the joint edges. In this way it is able to form a strong underwater bond. Without a photoinitiator, ethyl cyanoacrylate adhesives will form strong bonds to smooth underwater surfaces. The addition of a photoinitiator (dibenzoylferrocene), however, increases the rate at which the bond strength develops. Photo differential scanning calorimetric (photo-DSC) analysis was used to determine the optimum photoinitiator concentration. A concentration of between 0.3% (m/m) and 0.1% (m/m) was found to be optimum for adhesive films between 0.5 and 1.2 mm thick. Epoxy-based underwater adhesives have the disadvantage that the cure rate is very slow at low water temperatures. In contrast, the current system features a negative temperature dependence. Therefore, the curing rate is faster at lower water temperatures, making it highly suitable for very cold environmental conditions. The underwater bonding properties of cyanoacrylate adhesive were measured on a wide range of metallic and non-metallic materials. Bond strengths ranged from 1 to 5 MPa respectively. Bond strength (0.2 mm film thickness) develops in a very short time (less than a minute) using a 5 mW/cm2 blue LED light source as trigger for the photo initiator. Water temperatures between 1.5 and 40 °C did not influence the ultimate bond strength achieved following 50 seconds of illumination. The reduction in bond strength due to the ethyl cyanoacrylates reacting with water was measured in artificial sea water and potable water. A 20% reduction in bond strength was found after 10 minutes of water exposure. The underwater bond should therefore be made as soon as possible following exposure to water. Bond ageing studies on both steel and polycarbonate showed an initial decrease in bond strength (during the first 50 hours); thereafter the bond strength stabilises. / Dissertation (MEng)--University of Pretoria, 2011. / Chemical Engineering / unrestricted

Magister Scientiae Dentium - MSc(Dent) / The aim and objective of this study was to determine the bond strength of a twostep and a single-step dentin bonding agent and to determine the effect of repeated thermal-cycling from 50C and 550C on the bond strength values of these dentin bonding agents. / South Africa

Introduction: Orthodontic treatment may cause an increased accumulation of cariogenic bacteria. An orthodontic resin with antibacterial properties may inhibit bacterial growth around the brackets. The aims of this in-vitro study were to compare the antibacterial and mechanical properties of the newly introduced orthodontic resin containing selenium with a standard resin and a resin modified glass ionomer (RMGI). Methods: Three orthodontic materials were tested (SeLECTDefense; TransbondXT, Fuji Ortho-LC). The antibacterial properties of these materials were evaluated by studying the bacterial growth in liquid media (BG) and agar diffusion (AD) tests. In the BG testing, 100 adhesive discs (3mmx2mm) were created of each material. Five discs were then placed into each vial containing 0.5ml of brain-heart-infusion broth and 2.5µl of streptococcus mutans (MS)(n=20). Following incubation (37°C, 24hours), the vials were placed in a Spectrophotomoter (Genesys 20) at 600 nm to determine bacterial growth by measuring the optical density (OD). In the AG testing, agar plates were inoculated with 100µl of MS in brain heart infusion agar. Fifteen adhesive discs (6mmx2mm) of each material were prepared and placed into groups of five on 3 agar plates. Following incubation (37°C, 48 hours), the agar plates were visually inspected for zones of bacterial inhibition. The mechanical properties were evaluated using shear bond strength testing (SBS) and an adhesive remnant index scoring (ARI). Sixty human premolars were randomly assorted into groups of 20 for each material (n=20). The brackets were bonded following the manufacturers' instructions. Debonding was performed using a universal testing device (Instron)(crossheadspeed 5mm/min). The mode of failure was evaluated using a stereomicroscope (OlympusSZX7) and scored 0-to-3 for remaining adhesive on enamel. Results were statistically analyzed using Welsch's ANOVA, One way ANOVA, Tukey's Kramer and Tukey's HSD tests. Results: In BG, the resin containing selenium (SD) promoted more bacterial growth (OD=0.427) compared to the standard resin (XT) (OD= 0.222) and RMGI (OD=0.275). In AD, no zones of inhibition were observed which means that no antibacterial agent was released from any of the orthodontic adhesives. In SBS, SD (11.63±2.07MPa) showed statistically lower bond strength than XT (15.16±4.68MPa) but both resins were in the clinically acceptable range. RMGI (6.03±3.95MPa) showed a statistically lower bond strength at a clinically unacceptable degree. Debonding was mostly at the bracket-adhesive interface for SD (ARI=2&3) meaning that most of the adhesive remained on the enamel. In XT and RMGI groups, debonding occurred mostly at the adhesive-enamel interfaces (ARI=0&1). Conclusion: Within the limitations of this in vitro study, the resin containing selenium did not show any favorable antibacterial properties in comparison to the other materials. None of the materials, including fluoride-releasing RMGI, caused bacterial inhibition in their surroundings. The resin containing selenium showed clinically acceptable but statistically lower bond strength as compared to standard resin but its mode of failure was more favorable because most of the adhesive remained on enamel.

A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry. Objectives: To date, the literature has shown that a 10 second curing time is necessary to consistently achieve effective shear bond strengths (SBS) of greater than 10 MPa. Recently, several manufacturers have developed high power curing lights that claim only a 6 second cure time is needed. The purpose of this study was to evaluate the shear bond strength of orthodontic brackets when using two new high power LED curing lights after a 6 and 12 second light curing time. Methods: 120 extracted premolars were divided into 6 groups (n=20). Metallic brackets were bonded using Transbond XT (3M-Unitek) and cured for 6 or 12 seconds using two high power LED curing lights (Ortholux Luminous LED, 3M-Unitek; OrthoValo, Ultradent) and one control LED unit (Ortholux LED, 3M-Unitek). The samples were stored in distilled water for 24 hours at 37°C, thermocycled and then debonded using an Instron Universal Testing Machine at a crosshead speed of 5mm/min. Bond failure was evaluated under optical microscopy using a modified adhesive remnant index (ARI). Results: All sample groups produced mean SBS higher than 10MPa. Significant reductions in SBS were observed with the Ortholux LED when the curing time was reduced from 12 to 6 seconds. The OrthoValo had significantly higher SBS than the Ortholux LED and the Ortholux Luminous LED at 6 seconds. At 12 seconds, OrthoValo SBS were significantly higher than Ortholux LED only. A higher frequency of enamel damage occurred in the OrthoValo group (28.2%) compared to the Ortholux LED (12.5%) and Ortholux Luminous LED (7.5%). No significant correlation was found between ARI score and SBS. Conclusions: Higher SBS were obtained in the OrthoValo group. This coincided with a higher frequency of enamel damage.

Tendo em vista o importante papel desempenhado pelos selantes de fossas e fissuras na prevenção da cárie dental, o objetivo do presente estudo foi avaliar in vitro propriedades mecânicas, químicas e ntimicrobianas do selante isento de bisfenol A Embrace Wetbond™. Para os testes de resistência ao cisalhamento e microinfiltração foram selecionados 135 terceiros molares hígidos, extraídos de humanos, divididos aleatoriamente em 6 grupos: (I) selante Fluroshield® sem contaminação; (II) selante Embrace Wetbond™ sem contaminação; (III) selante Fluroshield® contaminado com saliva; (IV) selante Embrace Wetbond™ contaminado com saliva; (V) selante Fluroshield® contaminado com água; e (VI) selante Embrace Wetbond™ contaminado com água. No estudo de resistência ao cisalhamento os dentes foram seccionados no sentido vestíbulo-lingual, a porção radicular removida e as superfícies mesiais e distais foram embebidas em resina de poliéster. Após o condicionamento do esmalte, foi aplicado o selante com o auxílio de uma matriz de Teflon®. Os espécimes foram termociclados e submetidos ao teste de resistência ao cisalhamento com uma velocidade de 0,5mm/min e célula de carga de 50kgf. Os resultados foram comparados empregando a análise de variância (ANOVA) e pós-teste de Tukey. No estudo de microinfiltração, após o condicionamento do esmalte foi aplicado o selante. Os dentes foram termociclados, selados na região da câmara pulpar com resina composta, isolados, imersos em solução de rodamina B a 0,2%, incluídos em resina acrílica, seccionados, lixados, montados em lâminas, identificados e analisados em microscópio óptico para quantificação da microinfiltração. Os resultados foram comparados empregando o teste de Kruskal-Wallis e o pós-teste de Dunn. No estudo de liberação de fluoreto por meio de água aquecida e saliva artificial foram selecionados dois selantes resinosos contendo fluoreto (Embrace Wetbond™ e Fluroshield®), uma resina composta micro-híbrida (FiltekTM Z-250) e um cimento de ionômero de vidro (Vidrion R). As determinações de fluoreto foram realizadas por potenciometria direta, utilizando o eletrodo seletivo combinado de fluoreto. Para o teste de liberação de fluoreto em saliva artificial foram confeccionados 8 corpos de prova de cada material , os quais foram armazenados em tubos plásticos contendo saliva artificial, substituída diariamente. Após 15 dias, foi avaliada a quantidade de fluoreto liberado nas soluções. Os valores obtidos em mV foram convertidos em ppm (μg/ml). Os resultados foram comparados empregando a análise de variância (ANOVA) e o pós-teste de Tukey. No estudo da atividade antimicrobiana, efetuado por meio do teste de difusão em ágar pelo método do poço, foram selecionados dois selantes resinosos contendo fluoreto (Embrace Wetbond™ e Fluroshield®), um cimento de ionômero de vidro (Vidrion R), solução de digluconato de clorexidina a 1% e soro fisiológico. Foram utilizadas cepas de S. mutans (ATCC 25175 e cepa de campo), na densidade de 1-2 da escala de McFarland. Após o período de incubação, a zona de inibição do crescimento microbiano foi mensurada. Os resultados foram comparados empregando a análise de variância ANOVA e o pós-teste de Bonferroni. O nível de significância em todas as análises estatísticas foi de 5%. No estudo da dosagem de bisfenol A foram selecionados dois selantes resinosos (Embrace Wetbond™ e Fluroshield®), dispensados em recipientes contendo 3ml de metanol. Após homogeneização e filtragem, os extratos foram analisados utilizando um espectrômetro de massas por cromatografia gasosa. Foram realizados testes com as fórmulas moleculares do bisfenol A (C15H16O2) e do Bis-GMA (C29H36O8). Com base nos resultados obtidos pôde-se concluir que o selante Embrace Wetbond™ apresentou resistência ao cisalhamento próxima do mínimo aceitável e alta microinfiltração, quando utilizado de acordo com as indicações do fabricante, em condições de contaminação com umidade. Por outro lado, esse selante apresentou elevada liberação de fluoreto, tanto em água aquecida quanto em saliva artificial, apresentou elevada atividade antimicrobiana e não apresentou liberação de bisfenol A e de Bis- GMA. / Considering the important role of pit-and-fissure sealants on the prevention of dental caries, the purpose of this study was to evaluate in vitro the mechanical, chemical and antimicrobial properties of the bisphenol A-free pit-and-fissure sealant Embrace Wetbond™. For the shear bond strength and microleakage tests, 135 sound human third molars were selected and randomly assigned to 6 groups: (I) Fluroshield® sealant without contamination; (II) sealant Embrace Wetbond™ without contamination; (III) Fluroshield® sealant contaminated with saliva; (IV) Embrace Wetbond™ sealant contaminated with saliva; (V) Fluroshield® sealant contaminated with water; and (VI) Embrace Wetbond™ sealant contaminated with water. For the shear bond strength test, the teeth were sectioned in a buccolingual direction, the root portion was removed and the mesial and distal surfaces were embedded in polyester resin. The sealant was applied to the acid-etched enamel with the aid of Teflon® matrix. The specimens were thermocycled and subjected to a shearing force at a crosshead speed of 0.5mm/min with a 50kgf load cell. Data were analyzed statistically by analysis of variance (ANOVA) and Tukeys post-test. For the microleakage assay, after acid etching of enamel, the teeth were thermocycled, the pulp chamber was sealed with composite resin, and the teeth were rendered waterproof, immersed in 0.2% B rhodamine solution, embedded in acrylic resin, sectioned, ground, mounted on glass slides, identified and analyzed with an optical microscope for quantification of microleakage. The results were compared by the Kruskal-Wallis and Dunns post-test. Two fluoride-containing resin sealants (Embrace Wetbond™ and Fluroshield®), a microhybrid composite resin (FiltekTM Z-250) and a glass ionomer cement (Vidrion R) were selected for the fluoride release test in heated water and artificial saliva. Fluoride measurements were performed with a direct potentiometry using a fluoride ion selective electrode. For the test in saliva artificial, 8 specimens of each material were fabricated and stored in plastic tubes containing artificial saliva, which as daily renewed. The amount of fluoride released in the solutions after 15 days was analyzed, and the the values obtained in mV were converted into PPM (μg/mL). The results were compared by ANOVA and Tukeys post-test. Two fluoride-containing resin sealants (Embrace Wetbond™ and Fluroshield®), a glass ionomer cement (Vidrion R), 1% chlorhexidine digluconate solution and saline were selected for the analysis of the antimicrobial activity using the agar-well diffusion assay. Suspensions of S. mutans strains (ATCC 25175 and field strain) with density equivalent to the 1-2 McFarland scale were used. After incubation, the zones of microbial growth inhibition were measured. The results were compared by ANOVA and Bonferroni post-test. A significance level of 5% was set for all statistical analyses. For the analysis of bisphenol A dosage, two resin sealants (Embrace Wetbond™ and Fluroshield®) were delivered in receptacles containing 3ml of methanol. After homogenization and filtering, the extracts were analyzed under gas chromatography-mass spectroscopy and tests were performed with the molecular formulas of bisphenol A (C15H16O2) and Bis-GMA (C29H36O8). Based on the obtained results, it may be concluded that the sealant Embrace Wetbond™ presented shear bond strength near of the minimum acceptable and great microleakage when used according to the manufacturers instructions under moisture contamination conditions. On the other hand, this sealant presented high fluoride release in both heated water and artificial saliva, showed high activity antimicrobial and did not present release of bisphenol A or Bis-GMA.

O propósito deste estudo foi avaliar a resistência adesiva ao cisalhamento de um cimento resinoso à alumina densamente sinterizada testando o tratamento superficial feito pelo fabricante. O cimento utilizado foi o Multilink (Ivoclar Vivadent) e a alumina foi a Procera®Alumina (Nobel Biocare) constituída por 99,9 % de óxido de alumínio densamente sinterizado. Trinta e dois cilindros de alumina foram confeccionados pela Nobel Biocare, onde um dos extremos deste cilindro recebeu o tratamento superficial e o outro não. Para a aplicação do cimento resinoso sobre os cilindros de alumina, utilizou-se uma matriz de Teflon com um orifício central de 3,5mm de diâmetro por 3,0mm de profundidade. Foram determinados 4 grupos experimentais: Grupo 1 superfície sem tratamento; Grupo 2 superfície sem tratamento e com aplicação de adesivo; Grupo 3 - superfície com o tratamento realizado pelo fabricante; Grupo 4 superfície com tratamento realizado pelo fabricante e com adesivo. Após a aplicação do cimento nos 4 grupos, os espécimes foram armazenados em água deionizada a 37ºC durante 24h, sendo, em seguida, montados em uma máquina universal de ensaios para realização dos testes de resistência ao cisalhamento. Os resultados foram submetidos à análise de variância a dois critérios e ao teste de Tukey para comparação entre os grupos. A superfície tratada (grupo 3) apresentou valores significativamente maiores que todos os outros grupos. A presença do adesivo diminuiu a resistência adesiva quando aplicado na superfície tratada, mas não deu diferença significante quando aplicado na superfície sem tratamento. / The aim of this study was to investigate the shear bond strength between a resin cement and densely sintered alumina treated by the fabricant. The resin cement used was the Multilink (Ivoclar Vivadent) and the alumina the Procera®Alumina (Nobel Biocare) made with 99,9% of densely sintered aluminum oxide. Thirty two alumina cylinders were made by Nobel Biocare, and in one of the extremes was applied a own`s fabricant surface treatment. For the application of the cement, a Teflon matrix with a central hole (diameter of 3,5 mm and a height of 3,0 mm) was used. Four groups were created: Group 1 surface without treatment; Group 2 - surface without treatment and with adhesive; Group 3 surface with the own`s fabricant treatment; Group 4 - surface with the own`s fabricant treatment with adhesive. After the cement application, the specimens were stored in water at 37º C for 24 hours. Then the samples were placed in a universal testing machine for making the shear strength test. Statistical analysis was performed with two-way analysis of variance (ANOVA), and paired comparisons between groups were done with Tukey`s multiple comparison. Higher significant values were detected for Group 3 when compared with all the other groups. The adhesive decreased the shear bond strength when laid on the treated surface, and there were no difference when laid on the untreated surface.

A radioterapia (RT), quando aplicada na região de cabeça e pescoço, pode ocasionar alterações estruturais no esmalte e na dentina que poderiam influenciar o comportamento dos sistemas adesivos. O presente estudo teve como objetivo avaliar a influência da RT na adesão dos sistemas adesivos (Clearfil SE Bond e Adper&trade; Single Bond 2) ao esmalte (E) e à dentina (D) de dentes decíduos, em diferentes tempos (antes e após a RT). Foram utilizados 60 molares decíduos seccionados obtendo um total de 120 fragmentos de esmalte e 120 de dentina que, após o preparo da superfície, foram divididos aleatoriamente em 4 grupos (n=30/grupo): G1 (controle) - esmalte/dentina sem irradiação + procedimento restaurador; G2 - procedimento restaurador realizado antes da RT, G3 - procedimento restaurador realizado após a RT; e G4 - procedimento restaurador realizado 6 meses após a RT. Cada um dos grupos foi dividido em 2 subgrupos, sendo no subgrupo A empregado o sistema adesivo etch-rinse Adper&trade; Single Bond 2; e no subgrupo B o adesivo self-etch Clearfil SE Bond. Os espécimes foram irradiados com fração de dose de 2 Gy, por 5 dias consecutivos, até atingir a dose total de 60 Gy, com um total de 30 frações, durante 6 semanas. O procedimento restaurador foi realizado com resina Z350, e para padronização da restauração foi utilizada uma matriz, de forma que os espécimes apresentasse 4 mm de altura e 2 mm de diâmetro. Os corpos de prova foram submetidos ao teste de resistência ao cisalhamento (célula de carga 50 kgf e velocidade 0,5 mm/minuto) obtendo-se o resultado em N, o qual foi transformado em MPa. A análise do padrão de fratura foi realizada em microscopia confocal (MC). Foram selecionados 5 espécimes de esmalte e 5 espécimes de dentina, para realização da análise morfológica da superfície dental por meio de microscopia confocal, sendo estes avaliados a cada 10 Gy. Para a análise da interface adesiva foram selecionados 3 espécimes de cada grupo e estes foram preparados para análise em microscopia eletrônica de varredura (MEV). O esmalte e a dentina foram analisados separadamente, sendo os dados analisados por ANOVA a 2 critérios e pós- teste de tukey (p<0,05). O nível de significância adotado foi 5%. Pode-se observar que, para ambos os substratos, o Clearfil SE Bond (E: 20,19 MPa; D: 17,61 MPa) apresentou adesão estatisticamente superior ao Single Bond (E: 17,21 MPa; D: 15,45 MPa) (p<0,05). Quanto ao momento da realização da restauração, tanto no esmalte quanto na dentina, o grupo 2 apresentou os menores valores. Na comparação fator irradiação observou-se que a irradiação afetou negativamente a adesão do esmalte e da dentina (p<0,05), no entanto no grupo 4 não observou-se alteração (p>0,05). O tipo de fratura predominante foi adesiva, que aumentou a predominância com a irradiação. Na análise em MC houve alterações morfológicas em esmalte e dentina após a dose cumulativa de 40 Gy. Em MEV observou-se a alterações na formação de tags e de camada híbrida. Pôde-se concluir que a radioterapia alterou a morfologia da superfície do esmalte e da dentina, e afetou a adesão dos sistemas adesivos, sendo necessário esperar pelo menos 6 meses para a realização dos procedimentos restauradores, tendo o sistema Clearfil SE Bond menos influenciado. / When radiotherapy (RT) is performed in the head and neck region, it could lead to structural alteration in enamel and dentin that could influence the behavior of the bonding agents. The present study aimed to evaluate whether the RT interferes in the bonding o two adhesive systems (Clearfil SE Bond e AdperTM Single Bond 2) to enamel (E) and dentin (D) of primary teeth, in different times (before and after RT). Sixty primary molars were cut in a total of 120 fragments of enamel and 120 of dentin, which after the surface polishing were randomly divided into 4 groups (n=30/group): G1 (control) - enamel and dentin without RT + restorative procedures; G2 - restorative procedures performed before RT; G3 - restorative procedures performed after RT; and G4 - restorative procedures performed 6 months after RT. Each one of the groups was then divided into 2 subgroups: subgroup A using the etch-rinse Adper&trade; Single Bond 2; and subgroup B using the self-etch Clearfil SE Bond. The specimens were irradiated in dose fractions of 2 Gy, for 5 consecutive days, until reaching the final dose of 60Gy, in a total of 30 fractions, during 6 weeks. The restorative procedures were done using the Z350 composite, and for standardization of the restorations a matrix was used, so the specimens all presented 4 mm height and 2 mm of diameter. The specimens were submitted to the shear bond strength test (load of 50 kgf and speed of 0.5 mm/minute), the result was obtained in N and then transformed to Mpa. The fracture pattern was analyzed in a confocal microscopy (MC). Five specimens of enamel and 5 of dentin were chosen to the morphological analyzes also by MC, those specimens were evaluated every 10 Gy. As for the bonding interface 3 specimens of each group were chosen, and prepared for scanning electron microscopy (SEM). Enamel and dentin were evaluated separately, data was analyzed by the ANOVA and Post Test Tukey (p<0.05). Significance level was 5%. It could be observed that for both substrates the Clearfil SE Bond (E: 20.19 MPa; D: 17.61 MPa) was statically superior than Single Bond (E: 17.21 MPa; D: 15.45 MPa) (p<0.05). As for the time of restoration, group 2 had the worst results, in both enamel and dentin. It was observed that that radiation affected negatively the bonding in enamel and dentin (p<0.05), however, in the group 4 no alterations were observed (p<0.05). The predominant fracture pattern was the adhesive, which had raised its prevalence according to the radiation. In the MC analyses there were morphological alteration in enamel and dentin after the cumulative doses of 40 Gy. It was observed, by SEM, tags formations and alterations on the hybrid layer. It could be concluded that RT had affected the morphological surface of enamel and dentin, and that it affected the adhesion of the bonding systems, indicating that it should be waited at least 6 months after RT to perform restorative procedures, in which the Clearfil SE Bond was less affected.