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OBJECTIVE: To evaluate the effect of four different photoactivation protocols (according to "photoactivated faces" - mesial/distal, cervical/incisal or center - and "photoactivation time" - 6-3 s) of a high-power photo activator (Valo Cordless®-Ultradent) on the shear bond strength (SBS) between metal brackets and dental enamel and on the degree of conversion (DC) of an orthodontic resin. MATERIALS AND METHODS: 40 bovine incisor crowns were randomly assigned to 4 groups (n = 10). The brackets were bonded with Transbond XT® resin using 4 protocols according to the "photoactivation protocol" factor (which was subdivided into photoactivated faces and photoactivation time): V3C = 3 s + center; V6C = 6 s + center; V3M3D = 3 s on mesial + 3 s on distal; V3C3I = 3 s on cervical + 3 s on incisal. All the samples were stored for 4 months (water,37ºC) and then subjected to a SBS test (100KgF,1 mm/min). 40 resin discs were made to evaluate the monomer degree of conversion. Data from the SBS and DC were assessed by One-way ANOVA and Tukey's test (5%). Bond failures were analyzed according to the Adhesive Remnant Index (ARI) and evaluated by the Kruskal-Wallis test (5%). RESULTS: There was a statistically significant difference (p = 0.008) in the One-way ANOVA result for SBS values between all groups, but the protocols showed statistically similar results (p ≥ 0.05-Tukey's tests) concerning the photoactivated faces (V6C, V3M3D and V3C3I) and photoactivation time (V3C and V6C) factors individually. There was no statistically significant difference (p ≥ 0.05) in the One-way ANOVA result for DC values. CONCLUSION: The SBS and DC values will vary depending on the protocol applied. CLINICAL RELEVANCE: It is possible to maintain the bracket fixation quality with the use of a high-power LED photo activator associated with a shorter photoactivation time. However, it is assumed that not all types of protocols that might be applied will provide quality bonding, such as V3C, V3M3D and V3C3I, which may - depending on the SBS and DC values - affect the final treatment time, due to brackets debonding, or increase of possibility of damage to dental enamel during bracket removal. Clinical studies are suggested to confirm the hypotheses of this research.

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Aerosol emission by wind erosion in the arid and semi-arid areas of the world, is of environmental and health significance. Different methods have been used to mitigate aerosol emission among which the biological methods may be the most efficient ones. Although previously investigated, more research is essential to determine how the use of exopolysaccharide (biocrust)-producing cyanobacteria may affect soil physical properties. The objective was to investigate the effects of the cyanobacteria, Microcoleus vaginatus ATHK43 (identified and registered by the NCBI accession number MW433686), on soil physical properties of a sandy soil 15, 30, 60, and 90 d after inoculation. The effects of cyanobacterial biocrust on soil properties including shear strength, soil resistance, aggregate stability (mean weight diameter (MWD) and geometric mean diameter (GMD)), and wind erosion were determined in trays using a wind tunnel. Cyanobacterial inoculation significantly increased MWD (0-1 cm depth, from 0.12 mm to 0.47 mm) and GMD (from 0.3 to 0.5 mm) after a period of 90 d. Biocrust production significantly decreased soil erosion from 55.7 kgm- 2 to 0.3 kgm- 2 (wind rate of 50 kmh- 1), and from 116.42 kgm- 2 to 0.6 kgm- 2 (wind rate of 90 kmh- 1) after 90 d. In conclusion, cyanobacterial biocrust can significantly improve soil physical properties in different parts of the world including the deserts, and reduce aerosol emission by mitigating the destructive effects of wind erosion on soil physical properties.

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Objective: This in vitro study evaluates the shear bond strength (SBS) of yttria-stabilized tetragonal zirconia (Y-TZP) and resin cement after different surface treatments. Materials and methods: Forty-eight ceramic cubes were divided into four groups (n = 12): G1 (control) sandblasting with Al2O3; G2-sandblasting with silica-coated Al2O3 (Rocatec); G3-Rocatec + CO2 laser; and G4-CO2 laser + Rocatec. A metallic primer was applied to the pretreated ceramic. A rubber ring was adapted on the central area, and then, the resin cement was inserted into the matrix and photoactivated. The samples were evaluated regarding surface roughness (Ra), SBS, failure type, and qualitatively with scanning electron microscopy (SEM). The data were analyzed by one-way analysis of variance followed by Tukey's test (p < 0.05). Results: The mean values of Ra (µm) were as follows: G1-4.52a, G2-4.24a,b, G3-4.10a,b, and G4-2.90b and the mean values of SBS (MPa) were as follows: G1-7.84a , G2-4.41b , G3-4.61b and G4-6.14a,b. SEM analyses showed superficial irregularities for all groups, being more prominent for G1. The presence of silica deposits was observed for G2, G3, and G4, but in the last two groups there were some linear areas, promoted by the fusion of silica, due to the thermomechanical action of the CO2 laser. Conclusions: The surface treatment with CO2 laser + Rocatec, using one MDP-based cement, can be an alternative protocol for the adhesion cementation of Y-TZP ceramic since it was as effective as the conventional pretreatment with aluminum oxide sandblasting.

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Abstract The objective is to evaluate the effect of different surface treatments and storage on the shear strength of ultratranslucent zirconia. 36 blocks of ultra-translucent zirconia were fabricated (7x7x2mm) and sintered. Then, divided into 12 groups according to the "surface treatment" (C -Primer; Al -Sandblasting with Al2O3 + Primer; Si -Silicate + Primer; Gl -Glaze + HF + Primer; Z -Zirlink; Zp -Zirlink + Primer) and "storage" factors (ST-with 150 days/37º and without). After surface treatment, five cylinders (Ø=2mm; h=2.0mm) of resin cement (n=15) were constructed in each ceramic block; at the end, the shear strength test was performed (1mm/min, 50Kgf), and analysis of surface failures. 60 additional samples (2x2x2mm) were made for extras analysis (surface roughness, MEV, and EDS). Bond strength and surface roughness data were statistically evaluated by ANOVA (2 factors/1 factor), Tukey test (5%), and Weibull analysis, respectively. ANOVA (2-way) revealed that all factors were statistically significant for bond strength. The silicatization groups (SiST: 30.47AMPa; Si: 29.21AMPa) showed the highest bond strength values, regardless of storage (Tukey's test). While the groups treated with Zirlink (ZST: 2.76FMPa; Z: 5.27EFMPa) showed the lowest values, just similar to the GlST group (5.14EFMPa). The Weibull modulus (m) showed a statistical difference between groups (p=0.000). ANOVA (1 factor) revealed that the "surface treatment" factor (p=0.0000) was statistically significant for surface roughness. Therefore, the application of Zirlink and Glaze on pre-sintered zirconia did not promote efficient adhesion of the ultratranslucent zirconia to the resin cement, even when associated with a primer containing MDP.

Resumo O objetivo é avaliar o efeito de diferentes tratamentos superficiais e do envelhecimento na resistência ao cisalhamento da zircônia ultratranslúcida. Foram confeccionados 36 blocos de zircônia ultratranslúcida (7x7x2mm) e sinterizados. Em seguida, divididos em 12 grupos de acordo com o "tratamento de superfície" (C-Primer; Al-Jateamento com Al2O3+Primer; Si-Silicato+Primer; Gl -Glaze+HF+Primer; Z-Zirlink; Zp-Zirlink+Primer) e fatores de "armazenamento" (ST-com, 150 dias/37º e sem). Após o tratamento superficial, foram construídos cinco cilindros (Ø=2mm; h=2,0mm) de cimento resinoso (n=15) em cada bloco cerâmico; ao final foi realizado o ensaio de resistência ao cisalhamento (1mm/min, 50Kgf) e análise de falhas superficiais. Foram confeccionadas 60 amostras adicionais (2x2x2mm) para análises extras (rugosidade superficial, MEV e EDS). Os dados de resistência de união e rugosidade superficial foram avaliados estatisticamente por ANOVA (2 fatores/1fator), teste de Tukey (5%) e análise de Weibull, respectivamente. ANOVA (2 fatores) revelou que todos os fatores foram estatisticamente significativos para a resistência de união. Os grupos de silicatização (SiST: 30,47AMPa; Si: 29,21AMPa) apresentaram os maiores valores de resistência de união, independente do armazenamento (Tukey). Enquanto os grupos tratados com Zirlink (ZST: 2,76FMPa; Z: 5,27EFMPa) apresentaram os valores mais baixos, apenas semelhantes ao grupo GlST (5,14EFMPa). O módulo de Weibull (m) apresentou diferença estatística entre os grupos (p=0,000). A ANOVA (1 fator) revelou que o fator "tratamento superficial" (p=0,0000) foi estatisticamente significativo para rugosidade superficial. Portanto, a aplicação de Zirlink e do Glaze na zircônia pré-sinterizada não promoveu adesão eficiente da zircônia ultratranslúcida ao cimento resinoso, mesmo quando associada a primer contendo MDP.

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PURPOSE: This study evaluated the effect of coating traditional and translucent Y-TZP with an industrial nanometric colloidal silica or glaze before or after sintering on the adhesion of zirconia with various ytrria concentration. MATERIALS AND METHODS: Specimens of Y-TZP with 3% and 5% yttria were subdivided into 5 groups (n=10), according to the coating applied and moment of application (before or after Y-TZP sintering): Control (no coating), Colloidal Silica/Sintering, Sintering/Colloidal Silica, Glaze/Sintering, Sintering/ Glaze. Lithium disilicate (LD) was used as positive control. Except for Y-TZP controls, groups were conditioned with silane before cementation with a self-adhesive resin cement. After 24 hours, the shear bond strength and failure analysis were performed. Also, analysis of specimens' surface was accomplished with SEM-EDX. Kruskal-Wallis and Dunn tests were applied to analyze differences between groups (p⟨0.05). RESULTS: Overall, the worst and best values of shear bond strength test were control and glaze after sintering groups. Different morphological and chemical aspects were observed in SEM-EDX analysis. CONCLUSIONS: Coating Y-TZP with colloidal silica showed unsatisfactory results. In 3Y-TZP, the surface treatment associated with the best adhesion values was the application of glaze after zirconia sintering. However, in 5Y-TZP, glaze application can be performed before or after the zirconia sintering to optimize clinical steps.

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Dental fluorosis can cause changes in the enamel surface, conditioning its functionality and esthetics. The application of dental adhesives is a treatment option; however, their use on fluorotic teeth can result in limitations. The aim of this study was to compare the shear bond strength of two different adhesives, one with 10-MDP and one without 10-MDP, in different degrees of dental fluorosis.This is an in vitro study on dental enamel samples, a total of 180 samples with the inclusion criteria were treated, randomly divided into two groups of 90, according to the type of dental adhesive, where each group was again divided into three groups of 30 samples, representing different degrees of dental fluorosis according to the Thylstrup-Fejerskov index (Group I: TF1 and TF2; Group II: TF3; Group III: TF4). Normality tests, two-factor ANOVA, and post-hoc tests were used to determine differences between the groups, with a significance level of 95%. As results, a statistically significant difference was shown between the use of dental adhesive with 10-MDP and the three groups of dental fluorosis (p=0.011), in addition, a Tukey post-hoc test on the groups treated with 10-MDP adhesive revealed a statistically significant difference between group I versus group II, and group I versus group III, (p=<0.05). It is concluded that the use of adhesive systems with 10-MDP presents a better shear bond strength on enamel with dental fluorosis grades I and II in the Thylstrup-Fejerskov index.

La fluorosis dental puede ocasionar cambios en la superficie del esmalte, condicionando su funcionalidad y estética, la aplicación de adhesivos dentales es una opción de tratamiento, sin embargo, su uso en dientes fluoroticos puede resultar en limitaciones. El objetivo de este estudio consistió en comparar la fuerza de adhesión a la cizalladura de dos diferentes adhesivos, uno con 10-MDP y otro sin 10-MDP, en diferentes grados de fluorosis dental. Se trata de un estudio in vitro en muestras de esmalte dental, un total de 180 muestras con los criterios de inclusión fueron tratadas, aleatoriamente divididas en dos grupos de 90, de acuerdo al tipo de adhesivo dental, donde cada grupo fue dividido nuevamente en tres grupos de 30 muestras, representando diferentes grados de fluorosis dental según el índice de Thylstrup- Fejerskov (Grupo I: TF1 y TF2; Grupo II: TF3; Grupo III: TF4). Para determinar diferencias entre los grupos se utilizaron pruebas de normalidad, ANOVA de dos factores, y pruebas post-hoc, con un nivel de significancia de 95%. Como resultados, se mostró una diferencia estadísticamente significativa entre el uso de adhesivo dental con 10- MDP y los tres grupos de fluorosis dental (p=0.011), además, una prueba post hoc de Tukey sobre los grupos tratados con adhesivo 10-MDP revelaron una diferencia estadísticamente significativa entre el grupo I frente al grupo II, y el grupo I frente al grupo III, (p=<0.05) Se concluye que el uso de sistemas adhesivos con 10-MDP presentan una mejor resistencia de adhesión al cizallamiento en esmalte con grados de fluorosis dental I y II en el índice de Thylstrup-Fejerskov

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Introducción: La fijación de las restauraciones indirectas es uno de los pasos más importantes, para conseguir una adecuada retención y sellado de la interfase entre el material restaurador y el diente. Objetivo: Evaluar la resistencia de unión al cizallamiento de diferentes agentes de fijación a dos aleaciones metálicas utilizadas en odontología. Métodos: Estudio experimental in vitro. Cien especímenes de aleaciones de metales base, 50 de níquel-cromo y 50 de níquel-cromo-titanio fueron preparados y divididos de manera aleatoria en 5 grupos. Esta división se realizó acorde con el agente de fijación utilizado: sistema autograbante de dos pasos (Clearfil SE Bond; CSB), sistema adhesivo universal (Single Bond Universal; SBU), cemento resinoso autoadhesivo (Maxcem Elite; ME), ionómero de vidrio (IV) y fosfato de zinc (ZnPO). Posteriormente a la aplicación de cada agente de fijación, los especímenes tratados fueron almacenados en agua destilada por 24 h a 37 ºC y sometidos a un ensayo de resistencia de unión al cizallamiento. Resultados: La resistencia de unión al cizallamiento fue influenciada significativamente por el tipo de agente de fijación (p = 0,002) y el tipo de aleación utilizada (p < 0,001). La resistencia de unión al cizallamiento fue mayor, al utilizar el sistema Clearfil SE Bond, seguida de Single Bond Universal; las diferencias entre Maxcem Elite y el Fosfato de zinc no fueron significativas. Finalmente, el IV no mostró adhesión a ninguna de las aleaciones metálicas utilizadas. Conclusiones: El uso de Clearfil SE Bond aumentó la resistencia de unión de los cementos resinosos a las aleaciones metálicas(AU)

Introduction: The bonding of indirect restorations is one of the most important steps, in order to achieve adequate retention and sealing of the interface between the restorative material and the tooth. Objective: To evaluate the shear bond strength of different bonding agents to two metal alloys used in dentistry. Methods: In vitro experimental study. One hundred specimens of base metal alloys, 50 nickel-chromium and 50 nickel-chromium-titanium were prepared and randomly divided into 5 groups. This division was made according to the bonding agent used: two-step self-etching system (Clearfil SE Bond; CSB), universal adhesive system (Single Bond Universal; SBU), self-adhesive resin cement (Maxcem Elite; ME), glass ionomer (IV) and zinc phosphate (ZnPO). After the application of each bonding agent, the treated specimens were stored in distilled water for 24 hr at 37 ºC and subjected to a shear bond strength test. Results: Shear bond strength was significantly influenced by the type of bonding agent (p = 0.002) and the type of alloy used (p < 0.001). Shear bond strength was highest when using the Clearfil SE Bond system, followed by Single Bond Universal; the differences between Maxcem Elite and Zinc Phosphate were not significant. Finally, IV did not show adhesion to any of the metal alloys used. Conclusions: The use of Clearfil SE Bond increased the bond strength of resinous cements to metallic alloys(AU)

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Municipal solid waste (MSW) management is challenging as a whole. Global waste generation is expected to continue to increase in the coming years, and landfills are currently the primary destination. Therefore, the stability of these structures must be carefully evaluated to prevent failures and associated health and pollution risks, which implies the determination of waste properties using more reliable approaches. This paper presents a scoping review of field data from MSW landfills and outlines suggestions for future work. Studies published in the past twenty years were selected following a systematic search process in databases. Aspects discussed include (1) strength parameters and soil behavior type from in situ testing, (2) elastic moduli from seismic wave propagation, and (3) moisture content from geoelectrical measurements. Although the values of geotechnical parameters have varied due to waste heterogeneity and applied methods, the trends observed with depth and age could be compared. Research opportunities involve the spatial analysis of mechanical properties at a given site, seismic response of landfills with high organic content and saturation degree, interpretation of long-term resistivity monitoring, and combination of electrical properties to assess the degradation stages within the waste mass.

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A irradiação da dentina com o laser Nd:YAG mostra-se promissora para a qualidade da adesão, desde que aplicada sob parâmetros específicos e em etapas definidas. O objetivo deste estudo é avaliar de forma comparativa, o impacto da irradiação com laser de Nd:YAG sobre a formação e estabilidade da camada híbrida em dentina humana, pré-tratada com ácido e primer de sistema adesivo convencional, "in vitro". Setenta molares hígidos tiveram suas raízes e porções coronárias seccionadas horizontalmente, até completa exposição de dentina oclusal. As amostras foram divididas em: G1 (controle n=20); G2 (experimental n=20), sendo 10 dentes de cada grupo destinados ao microcisalhamento (MC) e 10 dentes à microscopia eletrônica de varredura (MEV). Nos 30 dentes restantes analisou-se: textura por Tomografia Computadorizada de Feixe Cônico (AT=15); e Espectroscopia de Infravermelho por Transformada de Fourier (FTIR=15) em 3 momentos: dentina controle; após tratamento com ácido + primer; e posterior à irradiação a laser. Estatisticamente, optou-se por ANOVA 1 fator, Qui Quadrado de Pearson, teste T e múltiplas comparações de Tukey com significância de 5%. A FTIR evidenciou redução dos níveis de fosfato e carbonato nos momentos primer e após irradiação laser, porém não havendo desnaturação do colágeno exposto. A análise de textura evidenciou uma tendência à formação de um tecido mais padronizado após o uso do laser. O teste de MC evidenciou valores médios de 36,5 e 35,2MPa para G1 e G2 respectivamente (p>0,05) e portanto, de forma imediata, o laser não mostrou efeitos deletérios ao processo adesivo. Além disso, observou-se maior penetrabilidade do adesivo na avaliação em MEV após a aplicação do laser. Novas pesquisas com avaliação longitudinal mostram-se necessárias para verificar se o efeito do laser pode ter sido protetor da degradação hidrolítica, visto que há uma redução do conteúdo de água local durante a formação da camada híbrida (AU).

Irradiation of dentin with the Nd:YAG laser shows promise for the quality of adhesion, as long as it is applied under specific parameters and in defined steps. The objective of this study is to comparatively evaluate the impact of irradiation with Nd:YAG laser on the formation and stability of the hybrid layer in human dentin, pretreated with acid and primer of conventional adhesive system, "in vitro". Seventy healthy molars had their roots and coronal portions horizontally sectioned, until complete exposure of occlusal dentin. The samples were divided into: G1 (control n=20); G2 (experimental n=20), with 10 teeth from each group destined for microshearing (MC) and 10 teeth for scanning electron microscopy (SEM). In the 30 remaining teeth analyzed: texture by Cone Beam Computed Tomography (AT=15); and Fourier Transform Infrared Spectroscopy (FTIR=15) in 3 moments: dentin control; after treatment with acid + primer; and after laser irradiation. Statistically, we opted for 1-way ANOVA, Pearson's Chi Square, T test and Tukey's multiple comparisons with a significance of 5%. FTIR showed a reduction in phosphate and carbonate levels in the primer moments and after laser irradiation, but there was no denaturation of the exposed collagen. The texture analysis evidenced a trend towards the formation of a more expressive tissue after the use of the laser. The CM test showed mean values of 36.5 and 35.2MPa for G1 and G2 respectively (p>0.05) and therefore, immediately, the laser showed no deleterious effects on the adhesive process. In addition, greater penetrability of the adhesive was observed in the SEM evaluation after laser application. New studies with longitudinal evaluation are necessary to verify if the laser effect could have been protected from hydrolytic degradation, since there is a reduction in the local water content during the formation of the hybrid layer (AU).

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Poliéter-éter-cetona (Polyetheretherketone - PEEK) é um polímero de excelentes propriedades mecânicas, o que o torna um potencial candidato para substituir ligas metálicas em diversas especialidades odontológicas. Quando utilizado como infraestrutura para confecção de próteses odontológicas, a adesão do PEEK ao material de revestimento estético é determinante para a longevidade do tratamento, embora a baixa energia de superfície e grande estabilidade química do polímero tornem essa adesão um desafio a ser superado. Objetivo: Responder à pergunta: "Outros tratamentos de superfície do PEEK geram resistências de união superiores ao adesivo comercial?" Métodos: A busca foi feita nas bases Pubmed, , LILACS, Scopus, Web of Science, EMBASE, ProQuest e Google Scholar em junho de 2023 e não houve restrição relativa ao idioma ou à data de publicação dos estudos. Foram utilizados os seguintes termos e operadores booleanos: "polyether ether ketone" [MH] OR "polyether ether ketone" OR "polyetheretherketone" OR "polyetherketoneketone" OR "PEEK" AND "shear strength" [MH] OR "shear strength" OR "shear bond strength" OR "tensile bond strength" OR "shear" OR "tensile" OR "microtensile" OR "microshear" OR "bonding" OR "bond strength" OR "microtensile strength" OR "microshear bond strength" OR "bond" OR "adhesion" OR "bond integrity" OR "bonded" OR "Bonding Strength" OR "Bonding Behavior" OR "Adhesive Performance" OR " surface bonding" OR "tensile strength" [MH] OR "tensile strength". Foram incluídos exclusivamente estudos in vitro. Resinas compostas e resinas acrílicas foram consideradas como materiais de revestimento para PEEK. A média e o desvio padrão expressos em MPa e obtidos a partir de testes de cisalhamento e tração foram utilizados para relatar a resistência de união entre o PEEK e os materiais de revestimento. As meta-análises foram realizadas e a ferramenta Cochrane Collaboration avaliou o risco de viés (RoBDEMAT). Resultados: Foram selecionados 23 estudos. A resistência de união entre PEEK e resina composta foi favorecida pelo uso do adesivo (P<0,00001), independentemente do tipo de adesivo. O pré-tratamento com jato de areia Al2O3 (P<0,00001), ácido sulfúrico (P<0,00001), plasma frio (P=0,0006) e laser (P<0,00001) mostrou-se eficiente, embora o condicionamento com solução piranha não tenha tido efeito estatisticamente significativo (P=0,47). Conclusão: A aplicação de ácido sulfúrico antes do adesivo apresentou melhores resultados de resistência de união em comparação ao uso isolado do adesivo.

Polyether-ether-ketone (Polyetheretherketone - PEEK) is a polymer with excellent mechanical properties, which makes it a potential candidate to replace metallic alloys in several dental specialties. When used as an infrastructure for the manufacture of dental prostheses, the adhesion of PEEK to the aesthetic coating material is decisive for the longevity of the treatment, although the low surface energy and great chemical stability of the polymer make this adhesion a challenge to be overcome. Objective: Answer the question: "Do other PEEK surface treatments generate bond strengths superior to commercial adhesive?" Methods: The search was carried out in the Pubmed, LILACS, Scopus, Web of Science, and EMBASE, ProQuest and Google Scholar databases in June 2023 and there were no restrictions regarding the language or publication date of the studies. The following terms and bolean operators were used: "polyether ether ketone" [MH] OR "polyether ether ketone" OR "polyetheretherketone" OR "polyetherketoneketone" OR "PEEK" AND "shear strength" [MH] OR "shear strength" OR " shear bond strength" OR "tensile bond strength" OR "shear" OR "tensile" OR "microtensile" OR "microshear" OR "bonding" OR "bond strength" OR "microtensile strength" OR "microshear bond strength" OR "bond" OR "adhesion" OR "bond integrity" OR "bonded" OR "Bonding Strength" OR "Bonding Behavior" OR "Adhesive Performance" OR "surface bonding" OR "tensile strength" [MH] OR "tensile strength". Only in vitro studies were included. Composite resins and acrylic resins were considered as coating materials for PEEK. The mean and standard deviation expressed in MPa and obtained from shear and tensile tests were used to report the bond strength between PEEK and coating materials. Meta-analyses were performed and the Cochrane Collaboration tool assessed the risk of bias (RoBDEMAT). Results: 23 studies were selected. The bond strength between PEEK and composite resin was favored by the use of the adhesive (P<0,00001), regardless of the type of adhesive. Pretreatment with Al2O3 sandblasting (P<0,00001), sulfuric acid (P<0,00001), cold plasma (P=0,0006) and laser (P<0,00001) proved to be efficient, although conditioning with piranha solution did not have a statistically significant effect (P=0,47). Conclusion: The application of sulfuric acid before the adhesive showed better results in bond strength compared to the use of the adhesive alone.

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Resumo OBJETIVO: Avaliar a resistência ao cisalhamento e o Índice de Remanescente Adesivo (IRA) de bráquetes metálicos colados com três diferentes fotopolimerizadores LED de alta potência, quando comparados ao LED convencional. MATERIAIS E MÉTODOS: 80 incisivos bovinos foram divididos aleatoriamente em 4 grupos (n=20), nos quais foram realizadas colagens dos bráquetes utilizando-se os seguintes LEDs de alta potência por 3s: Grupo 1 ­ LEDX ­ T 2400, Orthometric; Grupo 2 ­ Flashmax P4 PRO Ortho, Rock Moutain Orthodontics; Grupo 3 ­ VALO CORDLESS, Ultradent e Grupo 4 ­ LED convencional por 40s (controle) POLY-WIRELESS, Kavo. O teste de resistência ao cisalhamento foi realizado utilizando-se uma máquina de ensaio universal (AME-2kN, Oswaldo Filizola, São Paulo, Brasil) com velocidade de 0,5mm/min e célula de carga de 50N. A determinação da diferença estatística entre os grupos em relação ao cisalhamento foi realizada usando-se a análise de variância (ANOVA). Para avaliação do IRA, foi aplicado o teste Kruskal-Wallis. RESULTADOS: O grupo 2 apresentou resistência ao cisalhamento significativamente superior aos demais LEDs de alta potência e foi similar ao LED convencional. Em relação ao IRA, houve diferença estatisticamente significante entre os grupos e o único que não diferiu do grupo controle foi o 2, enquanto os demais LEDs de alta potência (Grupos 1 e 3) apresentaram mais falhas adesivas entre a resina e o esmalte. CONCLUSÃO: Houve diferença entre os três tipos de fotopolimerizadores LED de terceira geração, sendo que maior resistência ao cisalhamento e menos falhas adesivas foram observadas no LED que apresentou maior potência (AU)

Abstract OBJECTIVE: To evaluate shear strength and Adhesive Remnant Index (ARI) of metallic brackets bonded to three types of high-power LED light curing, when compared to conventional LED. MATERIALS AND METHODS: 80 bovine incisors were divided into 4 groups (n = 20), in which brackets were bonded using the following high-power LEDs for 3s: Group 1 ­ LEDX ­ T 2400, Orthometric; Group 2 ­ Flashmax P4 PRO Ortho, Rock Mountain Orthodontics; Group 3 ­ VALO CORDLESS, Ultradent; and Group 4 ­ conventional LED for 40s (control) POLY-WIRELESS, Kavo. The shear strength test was performed using a universal test machine (AME-2kN, Oswaldo Filizola, São Paulo, Brasil) with 0.5 mm/min speed and 50N load cell. The determination of statistical difference between the groups in relation to shear strength was performed using analysis of variance (ANOVA). The Kruskal-Wallis test was used to assess the IRA. RESULTS: Group 2 showed shear strength significantly higher than other high-power LEDs and was similar to conventional LED. Regarding ARI, there was a statistically significant difference between the groups and the only one that did not differ from the control group was 2, while the other high-power LEDs (Groups 1 and 3) had more adhesive failures between the resin and the enamel. CONCLUSION: There was a difference between the three types of third generation LED light curing agents, with greater shear strength and less adhesive failures observed in the LED that presented higher power. (AU)

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Resumo Objetivou-se avaliar in vitro a resistência ao cisalhamento (RUC) do bráquete ortodôntico associado ao elástico Guard como absorvedor de impactos e o índice de remanescente adesivo (IRA). Sessenta pré-molares humanos foram selecionados e distribuídos aleatoriamente em três grupos (n = 20): G1) sem elástico; G2) com elástico convencional (3M Unitek) e G3) com elástico Guard (3M Unitek). Os bráquetes Kirium Roth 0.22 (3M ESPE) foram fixados no terço médio da face vestibular do dente com resina Transbond XT (3M Unitek) e fotoativados por 3 segundos em cada face do bráquete com o dispositivo Valo (Ultradent). Após armazenamento por 24 horas, as amostras foram submetidas a uma velocidade de 1 mm/minuto. Os bráquetes foram retirados e o IRA avaliado em estereomicroscópio (Olympus) em aumento de 8x. Os dados do RUC foram submetidos à análise de variância e teste de Tukey (α = 0,05), e os dados ARI foram submetidos ao teste exato de Fisher. G3 mostrou valores RUC (20,1 ± 4,5) significativamente mais elevados do que o Grupo G1 sem elástico (15,3 ± 3,7) (P < 0,05). Não foi observada diferença estatística entre G2 (16,9 ± 6,0) e os demais grupos (P > 0,05). Não houve diferença significativa entre os grupos na avaliação do IRA (P = 0,3303). Em conclusão, a resistência ao cisalhamento do bráquete foi maior quando associado ao elástico Guard, sendo estatisticamente significante em relação aos bráquetes sem elástico. Menos da metade da resina permaneceu no dente em todos os grupos estudados para o IRA.(AU)

Abstract This in vitro study aimed to evaluate the shear bond strength (RUC) of the orthodontic bracket associated with the Guard elastic as an impact absorber and the remaining adhesive index (ARI). Sixty human premolars were selected and randomly distributed in three groups (n = 20): G1) without elastic; G2) with conventional elastic (3M Unitek); and G3) with Guard elastic (3M Unitek). Kirium Roth slot brackets 0.22 inch (3M ESPE) was fixed to the middle third of the buccal face of the tooth with Transbond XT resin (3M Unitek) and photoactivated for 3 seconds on each bracket face with the Valo (Ultradent) device. After storage for 24 hours, the samples were subjected to a speed of 1 mm/minute. The brackets were taken off, and the ARI was evaluated in a tereomicroscope (Olympus) in 8x magnification. The RUC data were subjected to analysis of variance and Tukey's test (α = 0.05), and ARI data were subjected to Fisher's exact test. G3 showed RUC values (20.1 ± 4.5) significantly higher than the group without elastic G1 (15.3 ± 3.7) (P < 0.05). No statistical difference was observed between G2 (16.9 ± 6.0) and the other groups (P > 0.05). There was no significant difference between groups in the assessment of ARI (P = 0.3303). In conclusion, completing the RUC of the Guard and the conventional elastic band was superior concerning the other groups. Less than half of the resin remained in the tooth in all groups studied for the ARI. (AU)

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Aim: This study assessed the effect of thermal aging on the interfacial strength of resin cements to surface-treated PEEK. Methods: Ninety-six PEEK blocks were allocated into 4 groups (n=24), according to following surface treatments: SB - sandblasting with aluminum oxide; SA - acid etched with 98% sulfuric acid; CA ­ coupling agent (Visio.link, Bredent) and CO - control group (untreated). Surface roughness (Ra) was measured and one cylinder (1-mm diameter and height) of Rely-X Ultimate - ULT (3M/ESPE) and another one of Panavia V5 - PAN (Kuraray) were constructed on the treated or untreated PEEK surfaces. Half of the samples of each group were thermal aged (1,000 cycles). Samples were tested at a crosshead speed of 1 mm/min in shear mode (µSBS). Ra and µSBS data were compared using one- and three-way ANOVA, respectively, and Tukey's tests. Results: SA and SB samples had the roughest surfaces, while CA the smoother (p<0.001). Thermal aging reduced µSBS regardless the surface treatment and resin cement used. There was interaction between surface treatment and resin cement (p <0.001), with ULT showing higher µSBS values than PAN. SA provided higher µSBS than SB for both resin cements, while for CA µSBS was higher (PAN) or lower than SB (ULT). Conclusion: Aging inadvertently reduces interfacial strength between PEEK and the resin cements. If ULT is the resin cement of choice, reliable interfacial strength is reached after any PEEK surface treatment. However, if PAN is going to be used only SA and CA are recommended as PEEK treatment

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Statement of problem: the bond strength between adhesive cement and root dentin can be affected by irrigation protocols. Purpose: therefore, the objective of this systematic review was to answer the following question: Do irrigation solutions used during root canal instrumentation influence the adhesion of glass fiber posts to root dentin? Material and Methods: this study followed the recommendations of PRISMA 2020 for writing. PubMed, Scopus, Web of Science, and LILACS databases were searched for articles published until 26 January, 2022. Grey literature and a manual search were also performed. The inclusion criteria were based on the PICO strategy: permanent human or animal teeth (P), which were irrigated during root canal instrumentation with endodontic substances (I) and compared to irrigation with sodium hypochlorite at various concentrations (C) to analyze the bond strength of glass fiber posts (O). Two authors independently performed data extraction and the risk of bias. Results: eight articles were included. Four articles were classified as having a high risk of bias, where the others as medium risk. Studies have reported conflicting results regarding the influence of irrigating solutions and the different concentrations of sodium hypochlorite on the adhesion of glass fiber posts to root dentin. Conclusion: the heterogeneity between studies did not allow the conclusion of a true estimate regarding this topic, and further well-designed studies are needed to clarify this issue. Register: CRD42020221835. (AU)

Definição do problema: a resistência de união entre o cimento adesivo e a dentina radicular pode ser afetada pelos protocolos de irrigação. Objetivo: portanto, o objetivo desta revisão sistemática foi responder à seguinte questão: As soluções de irrigação usadas durante a instrumentação do canal radicular influenciam a adesão de pinos de fibra de vidro à dentina radicular? Material e Métodos: este estudo seguiu as recomendações do PRISMA 2020 para sua redação. As bases de dados PubMed, Scopus, Web of Science e LILACS foram pesquisadas para artigos publicados até 26 de janeiro de 2022. A literatura cinza e uma pesquisa manual também foram realizadas. Os critérios de inclusão foram baseados na estratégia PICO: dentes humanos ou animais permanentes (P), que foram irrigados durante a instrumentação do canal radicular com substâncias endodônticas (I) e comparados à irrigação com hipoclorito de sódio em várias concentrações (C) para analisar a resistência de união de pinos de fibra de vidro (O). Dois autores realizaram independentemente a extração de dados e o risco de viés. Resultados:oito artigos foram incluídos. Quatro artigos foram classificados como de alto riscode viés, enquanto os demais como de médio risco. Estudos relataram resultados conflitantes sobre a influência de soluções irrigadoras e as diferentes concentrações de hipoclorito de sódio na adesão de pinos de fibra de vidro à dentina radicular. Conclusão: a heterogeneidade entre os estudos não permitiu a conclusão de uma estimativa verdadeira sobre este tópico, sendo necessários mais estudos bem delineados para esclarecer esta questão. Registo: CRD42020221835 (AU)

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Objective: to evaluate the effect of material type and veneer thickness on the final color and shear bond strength of PEEK bilayered restorations. Material and Methods: sixty-four square-shaped core specimens (7×7×2), were fabricated by CAD/CAM technology from two high-strength polymers, BioHPP (High-Performance Polymer, group B n=32), and Pekkton® ivory (PolyEtherKetoneKetone, group P n=32) then were veneered with resin composite (crea.lign dentin A3). Specimens from each group were divided (n=16) according to the veneer layer thickness (0.5 & 1 mm), then according to the test applied (n=8), either ΔE or shear bond strength (SBS). Specimen surfaces were treated according to the manufacturer's instructions. Specimens were veneered according to the manufacturer's instructions.The mode of failure was evaluated under a stereomicroscope at 40 x magnification after the shear bond strength test. Results: data showed parametric distribution and variance homogeneity and were analyzed using two-way ANOVA. The significance level was set at p<0.05 for all tests. Statistical analysis was performed with the R statistical analysis software version 4.3.1.Results of two-way ANOVA showed that material types and veneer thicknesses had an individual significant effect on the color change. For the shear bond strength, only the sample thickness (1mm) had a significant effect (p=0.033). The majority of samples in different groups presented a mixed failure mode with all the differences being not statistically significant (p>0.05). Conclusion: the thickness of the resin composite veneer can significantly affect the final esthetic outcome and shear bond strength of a bilayered restoration.(AU)

Objetivo: avaliar o efeito do tipo de material e da espessura do revestimento na cor final e na resistência ao cisalhamento de restaurações em duas camadas de PEEK. Material e Métodos: foram fabricados 64 espécimes com núcleo de formato quadrado (7x7x2) usando tecnologia CAD/CAM a partir de dois polímeros de alta resistência, BioHPP (Polímero de Alto Desempenho, grupo B n=32) e Pekkton ivory (Polieterecetona cetona, grupo P n=32), que foram então revestidos com resina composta (crea.lign dentin A3). Os espécimes de cada grupo foram divididos (n=16) de acordo com a espessura do revestimento (0,5 e 1 mm), e depois de acordo com o teste aplicado (n=8), seja ΔE ou resistência ao cisalhamento (SBS). As superfícies dos espécimes foram tratadas de acordo com as instruções do fabricante. Os espécimes foram revestidos de acordo com as instruções do fabricante. O modo de falha foi avaliado sob um estereomicroscópio com ampliação de 40x após o teste de resistência ao cisalhamento. Resultados: os dados apresentaram distribuição paramétrica e homogeneidade de variância e foram analisados por ANOVA de duas vias. O nível de significância foi estabelecido em p<0,05 para todos os testes. A análise estatística foi realizada com o software de análise estatística R, versão 4.3.1. Os resultados da ANOVA de duas vias mostraram que os tipos de materiais e as espessuras do revestimento tiveram um efeito significativo individual na mudança de cor. Para a resistência ao cisalhamento, apenas a espessura da amostra (1mm) teve um efeito significativo (p=0,033). A maioria das amostras em diferentes grupos apresentou um modo de falha misto, com todas as diferenças não sendo estatisticamente significativas (p>0,05). Conclusão:a espessura do revestimento de resina composta pode afetar significativamente o resultado estético final e a resistência ao cisalhamento de uma restauração em duas camadas.(AU)

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Objective: This study was conducted to evaluate the influence of the G-CEM ONE adhesive enhancing primer on the shear bond strength of self-adhesive resin cement (G-CEM ONE) to both tooth structure and two different CAD/CAM blocks (GC Initial LiSi and Cerasmart 270). Material and Methods: Forty specimens (cylindrical-shaped, 5 mm in diameter and height) were milled from both CAD/CAM blocks (20 specimens from each block type). Forty sound upper premolars were sectioned to the level of peripheral dentin, then randomly divided into four groups (n = 10): A1: GC Initial LiSi without adhesive enhancing primer; B1: Cerasmart 270 without adhesive enhancing primer; A2: GC Initial LiSi with adhesive enhancing primer; B2: Cerasmart 270 group with adhesive enhancing primer application. The CAD/CAM blocks were cemented on teeth using a self-adhesive resin cement (G-cem one). The shear bond strength was assessed using a computerized universal testing machine. A digital microscope was used to study the mode of failure. The shear bond strength values data were analyzed statistically using paired t-test and independent t-test at the significance level of (0.05). Results: A significant difference was shown in the shear bond strength values among groups (P =0.000). The highest shear bond strength value was revealed in group A2, while group B1 exhibited the lowest shear bond strength value. Conclusion: Using the adhesive enhancing primer on the tooth's surface improved the resin cement's bond strength to CAD/CAM blocks. Additionally, GC Initial LiSi exhibited higher bond strength than Cerasmart 270, with or without the primer (AU)

Objetivo: Este estudo foi conduzido para avaliar a influência do primer adesivo G-CEM ONE na resistência ao cisalhamento do cimento resinoso autoadesivo (G-CEM ONE) tanto na estrutura dentária quanto em dois diferentes blocos CAD/CAM (GC Initial LiSi e Cerasmart 270). Material e Métodos: Quarenta corpos de prova (formato cilíndrico, 5 mm de diâmetro e altura) foram fresados em blocos CAD/CAM (20 corpos de prova de cada tipo de bloco). Quarenta pré-molares superiores sadios foram seccionados até o nível da dentina mais externa e, em seguida, divididos aleatoriamente em quatro grupos (n = 10): A1: GC Initial LiSi sem primer adesivo; B1: Cerasmart 270 sem primer adesivo; A2: GC Initial LiSi com primer adesivo; B2: Grupo Cerasmart 270 com aplicação de primer adesivo. Os blocos CAD/CAM foram cimentados nos dentes com cimento resinoso autoadesivo (G-CEM ONE). A resistência ao cisalhamento foi avaliada utilizando uma máquina de ensaios universal computadorizada. Um microscópio digital foi utilizado para estudar o modo de falha. Os dados dos valores de resistência ao cisalhamento foram analisados estatisticamente por meio do teste t pareado e teste t independente ao nível de significância de (0,05). Resultados: Foi demonstrada diferença significativa nos valores de resistência ao cisalhamento entre os grupos (P =0,000). O maior valor de resistência ao cisalhamento foi revelado no grupo A2, enquanto o grupo B1 exibiu o menor valor de resistência ao cisalhamento. Conclusão:A utilização do primer adesivo na superfície dentária melhorou a resistência de união do cimento resinoso aos blocos CAD/CAM. Além disso, o GC Initial LiSi apresentou maior resistência de união que o Cerasmart 270, com ou sem primer.(AU)

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Aims: To verify the efficacy of Er,Cr:YSGG laser for debonding of lithium disilicate (LD) reinforced glass ceramic veneers of different thicknesses. Methods: Forty bovine teeth were prepared and randomly divided into four groups (n=10/group) according to the ceramic disc thickness: C0.5 (Control group) and L0.5 (Laser irradiated group) in which LD discs had a thickness of 0.5mm and 5mm diameter; C1 and L1 in which LD discs had a thickness of 1mm and 5mm diameter. The lithium disilcate discs (IPS E.max®, shade HTA2) were fabricated following the manufacturer's recommendations and cemented to the prepared tooth surface. The Er,Cr:YSGG laser was applied to the laser groups at 2.5W and 25Hz for 60seconds. Universal testing machine was used to evaluate the shear bond strength for all samples at a cross head speed of 1mm/min in an inciso-gingival direction parallel to the sample surface. After debonding, the samples were examined under stereoscope to evaluate the mode of failure according to the adhesive remnant index (ARI). Results: Laser irradiation significantly diminishes the shear bond strength from 10.868 MPa to 3.778 MPa for C0.5 and L0.5 groups respectively (p=0.00) and from 14.711 MPa to 4.992 MPa for C1 and L1 groups respectively (p=0.00). The shear bond strength required for debonding increased with increasing thickness of discs, but without significant difference (p=0.110). Higher ARI scores were seen in the laser groups (more cement remaining adhered to the tooth) when compared to the control groups. Conclusions: The Er,Cr:YSGG laser could be an effective and useful tool in debonding of lithium disilicate ceramic veneers as it decreases the shear bond strength required for veneer debonding

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PURPOSE: To evaluate in vitro the effect of gastroesophageal reflux, before and after bonding of metal brackets on composite resin surface. MATERIALS AND METHODS: Two hundred and ten resin discs were divided into 5 groups (n=42), according to the time and medium of storage: 24h, 7- and -30 days in artificial saliva (AS) and hydrochloric acid (HCL). Twelve samples from each group were submitted to surface roughness analysis (n=60). The other one hundred and fifty samples were divided into 3 groups (n=50) according to the bonding material: Transbond™ XT (TXT), 3M™ Filtek™ Z250 (Z250) and 3M™ Filtek™ Z350 XT (Z350). After bonding, the samples were subdivided, one more time, into 5 groups (n=10) according to the time (24h, 7, and 30 days) and medium storage (AS, HCL). Following, the shear bond strength (SBS) analysis was accomplished. Erosive challenge was performed for 7 or 30 days, before and after bonding of orthodontic brackets, for 1min, 4 times a day. SBS was performed in a universal testing machine (Instron) at 0.5mm/min. SBS data were subjected to two-way ANOVA and Tukey's test (α=0.05). RESULTS: TXT showed higher SBS values in all conditions (AS - 10.9±2.0 (24h); 10.5±4.9 (7 days); 9.4±2.2 (30 days); HCL - 11.5±3.7 (7 days); 8.0±2.1 (30 days)) - (P<0.0001). No statistical difference was detected in SBS between Z250 and Z350 composite resins (Z250 SBS: AS - 7.1±1.9 (24h), 5.2±1.8 (7 days), 4.5±1.5 (30 days); HCL - 5.2±2.3 (7 days), 5.0±2.5 (30 days)) - (P<=0.063)/Z350 SBS: AS - 7.4±1.0 (24h); 3.7±1.7 (7 days); 3.4±1.7 (30 days); HCL - 3.5±3.3 (7 days); 4.4±1.2 (30 days)) - (P<=0.167), respectively). Storage times and media did not statistically influence the SBS of TXT and Z250 composite resins (P>0.05), but did influence the Z350 SBS (P<0.05). CONCLUSION: Regardless of time and storage medium, TXT was the best composite resin for bonding brackets. Furthermore, the erosive challenge did not lead to surface changes in the Z250 resin at 7 and 30 days, unlike the Z350 resin.

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This study aimed to investigate the effect of two ceramic primers on the microshear bond strength (µSBS) of yttria-stabilized zirconia (Y-TZP) to two types of self-adhesive resin cement and one BisGMA-based resin cement. Zirconia specimens were sandblasted with 27-µm aluminum oxide and composite cylinders were cemented with resin cement with or without the prior use of ceramic primers. Nine groups (n=12) were randomly distributed according to the cement (self-adhesive RelyX U200/3M ESPE, self-adhesive Maxcem Elite/Kerr, and BisGMA-based dual-cure RelyX ARC/3M ESPE) and ceramic primer (Z-Primer Plus/Bisco and Porcelain Liner M/Sun Medical Co.). After luting, the specimens were stored in distilled water at 37°C for 24 hours and then submitted to the µSBS test. The data were analyzed with two-way ANOVA followed by the Scheffe post hoc test (p<0.05). There were significant differences between RelyX U200 and other groups. There were also significant differences between the RelyX U200 group without ceramic primer and other groups without ceramic primers (p<0.05). Self-adhesive resin cement (RelyX U200 and MaxCem) presented higher microshear bond strength (6.17 and 2.32 MPa) than the conventional resin cement (RelyX ARC) when a porcelain primer was not used (0.43 MPa). When using Porcelain Liner M, the results of RelyX ARC (2.94 MPa) were equivalent to the results of self-adhesive cement (3.93 and 2.11 MPa). When using Z-Prime Plus, the results of MaxCem (5.36 MPa) were lower than those of RelyX U200 (9.59 MPa) but equivalent to those of RelyX ARC (6.07 MPa). When using the RelyX ARC, the use of both ceramic primers improved bond strength to zirconia. When using self-adhesive resin cement, Z-Prime Plus improved microshear bond strength values. It can be concluded that, after 24 hours, the highest µSBS results were obtained when using Z-Prime Plus and RelyX U200 self-adhesive cement.

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This paper presents the characterization of municipal solid waste (MSW) randomly collected from two material recovery facilities in São Paulo city, before (input - recyclables) and after (output - rejects) the sorting processes. Geo-environmental and geotechnical tests were performed on shredded samples and a digestion method was applied to detect the metals As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations using an ICP OES. The objective was to assist future activities of integrated solid waste management and soil pollution. Results showed different particle sizes comparing the input (44.6%) and the output MSW (75.1%) passing through the 100-mm sieve. Organic matter and ash contents indicated the influence of inorganic carbon due to the plastics' presence, with values varying between 6 and 13%. The pH values obtained were neutral and the electrical conductivity of the MSW rejects suggested a higher amount of ions, with values above 1000 µS/cm. Metals analyses show that Cd, Cu, Ni, Pb, and Zn are present in high concentrations, depending on the types of the materials. Standard Proctor compaction curves yielded maximum dry unit weight varying from 6.6 to 10.0 kN/m3 and optimum moisture contents from 20 to 42%. Cohesion ranged from 1.3 to 31.3 kPa and friction angle from 3.2 to 42.9°. The results are comparable with those obtained for other countries using different MSW treatments and contribute to the data basis for MSW from the selective collection, aiming the integrated solid waste management, serving for other countries that adopt MSW sorting and recycling.

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