Efecto del tratamiento de la morfología oclusal con materiales para restauraciones preventivas / Effect of treating occlusal morphology with materials for preventive restorations

Introducción: las fosas y fisuras son áreas formadas por delgadas irregularidades de la capa del esmalte de la superficie oclusal. La compleja morfología en dientes posteriores es un determinante biológico asociado al desarrollo de caries. Objetivo: evaluar el efecto de diversas formas de tratar la morfología oclusal en la adaptación y penetración de materiales utilizados en restauraciones preventivas. Material y métodos: diseño experimental e in vitro. Sesenta terceros molares fueron distribuidos aleatoriamente en dos grupos: surco sin ameloplastia y con ameloplastia; además, contaban con acondicionamiento del esmalte que se subdividió en tres subgrupos: 1) sellador de fosas y fisuras, 2) adhesivo/sellador de fosas y fisuras y 3) adhesivo/ resina Flow. Resultados: los subgrupos adhesivo/sellador y adhesivo/ Flow alcanzaron mayores valores de adaptación íntima a las paredes del surco. Las diferencias fueron significativas entre los materiales (p = 0.0009). Las mayores zonas de desadaptación resultaron para el sellador sin y con ameloplastia. La penetración de los materiales fue mayor en los surcos con ameloplastia. En los surcos tratados con ameloplastia, el adhesivo/Flow reveló el mayor porcentaje de penetración y la mejor adaptación a las paredes del surco. Conclusiones: la penetración del material está positivamente correlacionada con la profundidad del surco. El sellador con y sin ameloplastia mostró pobre adaptación a las paredes del surco (AU)

Introduction: pits and fissures are areas formed by fine irregularities in the enamel layer of the occlusal surface. The complex morphology in posterior teeth are biological determinants associated with the development of caries. Objective: to evaluate the effect of various ways of treating occlusal morphology on the adaptation and penetration of materials used in preventive restorations. Material and methods: experimental design, in vitro. Sixty third molars were randomly distributed into two groups: groove without ameloplasty and with ameloplasty, with enamel conditioning with three subgroups: 1) pit and fissure sealer, 2) adhesive/pit and fissure sealer, 3) adhesive/resin flow. Results: the adhesive/sealant and adhesive/flow subgroups reached higher values of intimate adaptation to the furrow walls. The differences were significant between the materials (p = 0.0009). The largest areas of maladjustment were found for the sealant without and with ameloplasty. The penetration of the materials was greater in the grooves with ameloplasty. In the grooves treated with ameloplasty, the adhesive/flow revealed the highest percentage of penetration and the best adaptation to the walls of the groove. Conclusions: the penetration of the material is positively correlated with the depth of the furrow. The sealant with and without ameloplasty showed poor adaptation to the sulcus walls (AU)

Uso efectivo de los adhesivos de octava generación / Effective use of eighth generation adhesives

Introducción: se realizó una revisión bibliográfica con el objetivo de conocer, analizar y comparar los diferentes tipos de adhesivos de octava generación que se encuentran en el mercado y la diferencia que existe entre cada uno. Los adhesivos universales han demostrado mejoras en su resistencia, sobre todo en las técnicas de aplicación y en las propiedades de estos materiales, al mejorar la fuerza adhesiva para que el odontólogo pueda brindar tratamientos restaurativos exitosos. Objetivo: conocer, analizar y comparar los diferentes tipos de adhe- sivos de la octava generación empleados en odontología. Material y métodos: se realizó una búsqueda en las bases de datos electrónicas PubMed, BVS, Redalyc y ScienceDirect. Se utilizaron 32 artículos que cumplieron con los criterios predeterminados y la especificidad reque- rida para la pregunta de investigación. Conclusiones: se demostró que la tecnología cada día avanza, sobre todo en el área de los adhesivos, ya que éstos son de mucha utilidad en el día a día del odontólogo; es importante conocer cada uno de éstos, puesto que es un poco complejo seleccionar el correcto, mas no el uso. En la actualidad, existen diversas opciones por las que el odontólogo puede optar, es por ello que el pro- fesional debe estar capacitado sobre cada una de las diferentes marcas existentes y, de acuerdo al tratamiento, debe elegir cuál es mejor utilizar en una rehabilitación. Es importante para el odontólogo conocer estos materiales, ya que esto lo beneficiará al momento de llevar un plan de tratamiento restaurador (AU)

Introduction: a bibliographic review was carried out to learn about, analyze, and compare the different types of eighth-generation adhesives on the market and the difference between each one. Universal adhesives have demonstrated improvements in their resistance, especially in the application techniques and properties of these materials, improving the adhesive strength so that the dentist can provide successful restorative treatments. Objective: to know, analyze and compare the different types of eighth-generation adhesives used in dentistry. Material and methods: a search was made of the following electronic databases: PubMed, BVS, Redalyc, ScienceDirect. Finally, 32 articles that met the predetermined criteria and the specificity required for the research question were used. Conclusions: it was demonstrated that technology is advancing every day, especially in the area of adhesives since these are very useful in the daily life of the dentist. It is important to know each one of these since it is a little complex at the moment of selecting the correct one, but not the use. Currently, there are several options that the dentist can choose, which is why the professional must be trained on each of the various existing brands and according to the treatment which is the best to use at the time of rehabilitation. The dentist needs to know these materials since they will benefit him/her when carrying out a restorative treatment plan (AU)

Adhesión a dentina parte I: características del sustrato y sistemas adhesivos / Dentin bonding part I: substrate characteristics and bonding systems

La Odontología Restauradora contemporánea no puede concebirse sin la adhesión de los materiales restauradores a las estructuras dentarias. En mu-chos procedimientos restauradores, no sólo el esmal-te sino también la dentina se encuentra involucrada, por lo tanto, la adhesión a esta última juega un rol cla-ve en el éxito clínico. No obstante, todavía supone un gran desafío lograr una adhesión estable y predeci-ble en el tiempo. El propósito del presente artículo es analizar las características principales de la dentina como sustrato adhesivo y describir los sistemas ad-hesivos actuales y sus mecanismos de acción (AU)

Contemporary Restorative Dentistry cannot be conceived without the adhesion of restorative materials to dental structures. In many restorative procedures not only the enamel, but also the dentin is involved, therefore dentin bonding plays a key role in their success. However, it is still a great challenge to achieve stable and predictable dentin bonding over time. The aim of this article is to analyze the main characteristics of dentin as an adhesive substrate and to describe current adhesive systems and their bonding mechanisms (AU)

Adhesión a dentina part II: estrategias para optimizar la adhesión a dentina y protocolos adhesivos / Dentin bonding part II: strategies to optimize dentin bonding and adhesive protocols

La adhesión a dentina con sistemas adhesivos polimé-ricos representa un desafío que surge de la necesi-dad de vincular un sustrato dentario heterogéneo y variable con materiales que presentan todavía cier-tos aspectos a atender para poder conseguir el máxi-mo desempeño. El propósito del presente artículo es evaluar algunas de las estrategias propuestas para mejorar la adhesión a dentina, y sugerir un protocolo de trabajo con los diferentes tipos de sistemas adhesivos (AU)

Dentin bonding with polymeric adhesive systems represents a challenge that arises from the need to link a heterogeneous and variable dental substrate with materials that still have certain aspects to be addressed in order to achieve maximum performance. The aim of this article is to evaluate some of the proposed strategies to improve dentin bonding and to suggest a protocol for each different type of bonding systems (AU)

Tratamiento de la fractura corono-radicular no complicada de la corona: caso clínico / Treatment of non-complicated crown-root fracture: a clinical case

El trauma dentoalveolar se define como aquella lesión de extensión e intensidad variable y de ori- gen accidental o intencional, causada por fuerzas que actúan sobre el órgano dentario y los tejidos que lo rodean. Se puede diagnosticar a simple vista o con ayuda de la radiografía, se debe tratar sin demora para preservar la vitalidad de la pulpa, sobre todo en casos de niños y adolescentes, to- mando en cuenta la formación radicular. El trau- ma dental es motivo de urgencia por el dolor que provocan en los pacientes, la prevalencia varia del 26 al 76% de las lesiones dentales en dentición permanente (AU)

Sistemas adesivos universais ­ há 10 anos no Brasil: revisão de literatura / Universal adhesive systems ­ 10 years in Brasil: literature review

Objetivo: analisar, a partir da literatura publicada, os sistemas adesivos universais, conceituando sobre seu desempenho nos diferentes substratos, assim como potenciais estudos executados com eles após 10 anos no Brasil. Materiais e métodos: para esta revisão narrativa, foram pesquisados artigos na língua inglesa nas bases de dados eletrônicas PubMed/Medline, SciELO e Scopus, publicados de 2012 a 2022, período considerado por ser a última década, além dos 10 anos da chegada do sistema adesivo universal ao Brasil. Utilizaram-se os seguintes descritores: universal adhesives (adesivos universais) OR universal adhesive system (sistemas adesivos universais). Realizou-se a inclusão de estudos laboratoriais (in vitro), ensaios clínicos, revisões de literatura e sistemáticas com meta-análise. Resultados: após análise meticulosa, foram selecionados 56 estudos. Os adesivos universais são considerados mais "amigáveis" ao usuário, pois permitem ao clínico a utilização no modo condicione e lave e autocondicionante, principalmente devido à inclusão do monômero MDP ou de monômeros similares. No esmalte, o condicionamento ácido seletivo antes da aplicação do adesivo é recomendado. Permite ser utilizado com uma diversidade de substratos, a aplicação de forma ativa do adesivo melhora a resistência de união. Conclusão: os sistemas adesivos universais foram lançados para tornar os procedimentos de adesão mais simples. Entretanto, mais ensaios clínicos com maiores tempos de acompanhamento são necessários, para avaliar adequadamente a efetividade desse material.(AU)

Objective: To evaluate, from published literature, the universal adhesive systems, conceptualizing their performance, as well as potential studies performed using this material. MATERIAL AND METHODS: This narrative review considered articles in the English language searched on Pubmed/ Medline, Scielo and Scopus from 2012 to 2022, considered period to be the last decade, besides ten years of the universal adhesive system arrived in Brazil. The descriptors "universal adhesive" or "universal adhesive systems" were used. Laboratorial studies (in vitro), clinical trials, literature review and systematic review with meta-analysis were included. RESULTS: 56 studies were included. The universal adhesives are considered more user-friendly, allowing for etch & rinse and self-etch modes, mostly due to MDP monomer or similar monomers inclusion. In enamel selective acid etching before adhesive application is recommended. The system can be used with great amount of substrates and results in superior bond strength when applied through active mode. CONCLUSION: Universal adhesive systems were launched to simplify the adhesion procedure, however more clinical trials with longer follow-ups are required using this material, with adequate evaluation of their effectiveness.(AU)

Effect of grape seed extract-containing phosphoric acid formulations on bonding to enamel and dentin

Abstract The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

Deproteinization of primary enamel with sodium hypochlorite before phosphoric acid etching

The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group AAcid Etching with 37% H3PO4 gel for 15 s; Group B5% NaOCl for 60 s + Acid Etching with 37% H3PO4for 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by KolgomorvSmirnov test and the nonparametric unpaired MannWhitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern (AU)

El objetivo del estudio fue evaluar la desproteinización del esmalte primario a través de los tipos de patrones de grabado, con y sin NaOCl 5% utilizado antes del grabado ácido con H3PO4 37%. Quince dientes primarios humanos extraídos se seleccionaron al azar para el presente estudio in vitro, se prepararon bloques de 1mm x 1 mm y se dividieron en dos grupos (n = 21). Estos grupos se trataron de la siguiente manera: Grupo A: Grabado ácido con H3PO4 37% en gel durante 15 segundos; Grupo B: NaOCl 5% durante 60 segundos + Grabado ácido con H3PO4 37% durante 15 segundos. Las muestras se prepararon para el análisis de microscopía electrónica de barrido. Las imágenes obtenidas se evaluaron principalmente por la calidad de los grabados tipo I y II de la superficie del esmalte primario, utilizando el software Image J. Los datos se analizaron en cuanto a su normalidad mediante la prueba de KolgomorvSmirnov, se utilizó pruebas no paramétricas: Prueba de MannWhitney no pareada. Como resultado, se encontró que el área de superficie media de los valores de patrón de grabado de tipo I y II para el Grupo A era 1922,314 µm2 y el Grupo B era 3840,473 µm2. Finalmente, llegamos a la conclusión de que se puede usar la desproteinización con NaOCl 5% antes del grabado ácido para aumentar el área de adhesión y la calidad del patrón de grabado (AU)

Adhesion to a lithium disilicate glass ceramic etched with hydrofluoric acid at distinct concentrations

Abstract This study evaluated the effect of different hydrofluoric acid (HF) concentrations on the bond strength between a lithium disilicate-based glass ceramic and a resin cement. Eighty ceramic-blocks (12×7×2 mm) of IPS e.Max CAD (Ivoclar Vivadent) were produced and randomly assigned to 8 groups, considering 2 study factors: HF concentration in 4 levels, i.e., 1% (HF1), 3% (HF3), 5% (HF5), and 10% (HF10), and storage in 2 levels, i.e., baseline (tests were performed 24 h after cementation), and aged (storage for 150 days + 12,000 thermal-cycles at 5°C and 55°C). Acid etching (20 s) was performed, followed by washing, drying, and silanization. Four resin cement cylinders (ϕ= 0.96 mm) were built-up from starch matrices on each ceramic sample (n= 40). Additional ceramic samples were etched and analyzed for contact angle, micro-morphology, and roughness. In baseline condition (without aging), the HF3, HF5, and HF10 groups showed similar bond strength values (13.9 - 15.9 MPa), and HF1 (11.2 MPa) presented lower values than HF5, being that statistically different (p= 0.012). After aging, all the mean bond strengths statistically decreased, being that HF3, HF5, and HF10 (7.8 - 11 MPa) were similar and higher than HF1 (1.8 MPa) (p= 0.0001). For contact angle, HF3, HF5, and HF10 presented similar values (7.8 - 10.4°), lower than HF1 and CTRL groups. HF5 and HF10 presented rougher surfaces than other conditions. For better bond strength results, the tested ceramic may be etched by HF acid in concentrations of 3%, 5%, and 10%.

Resumo Este estudo avaliou o efeito de diferentes concentrações de ácido fluorídrico (HF) na resistência de união entre uma cerâmica vítrea à base de dissilicato de lítio e um cimento resinoso. Oitenta blocos cerâmicos (12×7×2 mm) de IPS e.Max CAD (Ivoclar Vivadent) foram produzidos e distribuídos aleatoriamente em 8 grupos, considerando 2 fatores de estudo: concentração de HF em 4 níveis, isto é, 1% (HF1), 3% (HF3), 5% (HF5), e 10% (HF10), e armazenamento em 2 níveis, isto é, condição inicial (testes foram realizados 24 h após a cimentação), e envelhecidos (150 dias de armazenamento + 12.000 ciclos térmicos a 5°C e 55°C). Condicionamento ácido (20 s) foi realizado, seguido por lavagem, secagem e silanização. Quatro cilindros de cimento resinoso (ϕ= 0.96 mm) foram construídos a partir de matrizes de amido em cada amostra cerâmica (n= 40). Amostras cerâmicas adicionais foram condicionadas e analisadas quanto ao ângulo de contato, micro-morfologia e rugosidade. Na condição inicial (sem envelhecimento), os grupos HF3, HF5, e HF10 mostraram valores de resistência de união similares (13.9 - 15.9 MPa), e HF1 apresentou valores menores que HF5, sendo estatisticamente diferente (p= 0.012). Após o envelhecimento, todas as médias de resistência de união diminuíram estatisticamente, sendo que HF3, HF5 e HF10 foram similares e maiores que HF1 (p= 0.0001). Para o ângulo de contato, HF3, HF5 e HF10 apresentaram valores similares (7.8 - 10.4°), menores que os grupos HF1 e CTRL. HF5 e HF10 apresentaram superfícies mais rugosas que as outras condições. Para melhores resultados de resistência de união, a cerâmica testada pode ser condicionada com ácido fluorídrico nas concentrações de 3%, 5% e 10%.

Tratamentos superficiais de sistemas cerâmicos para união a cimentos resinosos / Surface treatments of ceramic systems for bonding to resin cements

Objetivo: apresentar uma revisão de literatura sobreos tipos de tratamentos de superfície disponíveis paracimentação adesiva a sistemas cerâmicos. Revisãode literatura: ainda que haja certo consenso na uniãoadesiva às vitrocerâmicas, ainda não há uma unanimidadequanto à adesão de cerâmicas policristalinasde alta resistência. Com base na literatura disponível,para vitrocerâmicas, o tratamento preferencial ainda é ocondicionamento com ácido hidrofluorídrico (HF), emconcentração e tempo correspondentes a seu conteúdocristalino, seguido de silanização. Para as policristalinasà base de zircônia, métodos como condicionamentoseletivo por infiltração ou revestimento triboquímicocom sílica, seguidos de silanização e utilização de primersou cimentos resinosos contendo monômero MDP,resultaram em altos valores de resistência de união.Considerações finais: vitrocerâmicas são adequadamentetratadas por meio de condicionamento com HF,seguido de silanização. Maiores valores de resistênciade união para as cerâmicas policristalinas foram obtidosapós tratamento com condicionamento seletivopor infiltração ou silicatização, seguido de silanização,além da utilização de primers ou cimentos resinososcontendo monômero MDP. Porém, são necessários estudosin vitro adicionais para definir a melhor opção detratamento para tais materiais. (AU)

Objective: this study presents a review of the literature on the types of surface treatment available for bonding cement to ceramic systems. Literature review: although there is some consensus on the adhesive bonding to glass-ceramics, there is still no unanimity regarding the adhesion of high-resistance polycrystalline ceramics. Based on the literature available, the preferential treatment for glass ceramics is still hydrofluoric acid (HF) etching, at concentration and time corresponding to its crystalline content, followed by silanization. For polycrystalline ceramics, methods such as selective conditioning by infiltration or tribochemical coating with silica followed by silanization and the use of primers or resin cement containing MDP monomer resulted in high bond strength values. Final considerations: glass ceramics are suitably treated by HF etching followed by silanization. Higher bond strength values for polycrystalline ceramics were obtained after treatment with selective conditioning by infiltration or silicatization followed by silanization, in addition to the use of primers or resin cement containing MDP monomer. However, additional in vitro studies are needed to define the best treatment option for such materials. (AU)

Influence of ethanol-wet dentin, adhesive mode of application, and aging on bond strength of universal adhesive

Abstract The aim of this study was to evaluate the effect of ethanol on the bond longevity of a universal adhesive system to bovine dentin, under different modes of adhesive application and artificial aging. Bovine dentin was exposed, and the smear layer was standardized by sandpaper polishing. Specimens were randomly divided into 2 groups: ethanol (E) and non-ethanol (N). Groups were subdivided according to adhesive mode of application into etch-and-rinse (Er) and self-etching (S). Resin blocks were built onto the treated surface, and the specimens were stored in deionized water at 37°C for 48 h. Half of the specimens (n = 10) were subjected to thermomechanical aging (A for aged and Na for non-aged). Resin/dentin beams were obtained and subjected to microtensile test in a universal testing machine. Data were analyzed using a three-way ANOVA and Tukey's tests (α = 5%). There was interaction among the three factors (p=0.0003). The use of ethanol resulted in higher values, except for the Er and Na groups (E_Er_Na = N_Er_Na). The mode of application was similar, except for the N and A groups (N_S_A > N_Er_A). For the A groups, the values were lower, except in the cases using ethanol, in which the results were not affected. The study concluded that the use of ethanol resulted in higher microtensile bond strength values, even after aging. The mode of adhesive application did not influence the results.

Effect of different bonding protocols on degree of monomer conversion and bond strength between orthodontic brackets and enamel

Abstract The objective of the present study was to evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A: Phosphoric Acid; ATxt: Phosphoric Acid + Transbond XT Primer®; Tse: Transbond Plus Self Etching Primer®; and SBU: Scotchbond Universal®) and "polymerization" factor (R20: Radii-Cal®/20 seconds; V20: Valo Cordless®/20 seconds; and V3: Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). For the SBS, the factors "polymerization" (R20 = 8.1B; V20 = 13.2A; V3 = 5.2C, p = 0.0001) and "surface treatment" (A = 3.1C; ATxt = 13.6A; Tse = 12.3A; SBU = 6.3B, p = 0.0001) were statistically significant among groups. The highest adhesion value were found for the ATxt/V20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p = 1.0). Regarding DC, the factors "polymerization" (R20 = 66.6A; V20 = 58.4B; V3 = 45.1C, p = 0.0001) and "surface treatment" (A = 52B, ATxt = 59.7A, Tse = 51.4B, SBU = 63.8A, p = 0.0001) were statistically significant. Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion.

The effect of silver nanoparticles on composite shear bond strength to dentin with different adhesion protocols

Abstract In Dentistry, restorative materials and oral bacteria are believed to be responsible for restoration failure. To make long-lasting restorations, antibacterial agents should be made. Inorganic nanoparticles and their nano composites are applied as good antibacterial agents. Objective The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Material and Methods Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Results Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (p≤0.05). Conclusions Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching.

Profundidad de curado e interfaces en medios cementantes para incrustaciones de resina / Curing depth and interphases in luting agents for resin inlays

Los medios de fijación a base de resinas compuestas para cementado, no son más que una resina compuesta fluida, que contiene un menor porcentaje de relleno inorgánico. Es por esto que en la actualidad, algunos autores plantean el uso de resina compuesta de restauración como medio de fijación de restauraciones indirectas (inlay fabricado en cerómero). Dicha resina debe ser fluidificada con calor (50ºC), para posteriormente ser fotoactivada por un tiempo adecuado. Asimismo, como se trata de un material cuya reacción de polimerización sólo es activada por luz, surge la pregunta de si será capaz de ser fotoactivada eficazmente como para polimerizar correctamente, en especial en las zonas más profundas de la preparación cavitaria. El presente estudio busca analizar si existen diferencias en el grado de sellado marginal y en la profundidad de curado de restauraciones cementadas con un medio de fijación a base de resina, previa técnica de grabado y colocación de adhesivo y con una resina compuesta a través de la técnica fluidificada.

The fixing means based on composite resins for cementing, are nothing more than a fluid composite resin, which contains a lower percentage of inorganic filler. This is why, at present, some authors propose the use of composite resin restoration as a means of fixing indirect restorations (inlay made of ceramics). Said resin must be fluidized with heat (50 ° C), to be photoactivated for a suitable time. Also, since it is a material whose polymerization reaction is only activated by light, the question arises whether it will be able to be effectively photoactivated to properly polymerize, especially in the deeper areas of the cavity preparation. The present study aims to analyze if there are differences in the degree of marginal sealing and in the depth of cure of cemented restorations with a resin-based fixing medium, prior to etching and adhesive placement and with a composite resin through the fluidized technique.

Restauración postendodóncica: técnica con postes accesorios de fibra de vidrio / Postendodontic restoration: a technique with accessory fiber glass posts

Utilizar esta técnica implica grandes ventajas, ya que se reduce el volumen de cemento de resina, lo que disminuye la probabilidad de contracción, formación de burbujas y vacíos internos, los cuales representanáreas de debilidad en la restauración postendodóncica. Esta técnica ya ha sido propuesta y debidamente investigada por algunos autores. Se aplica en dientes con conductos radiculares amplios que han sido debilitados por restauraciones defi cientes, desmineralización de la dentina, fi ltraciones en la corona y poste radicular o simplementeconductos amplios en pacientes de corta edad. Tenemos la firme convicciónde que no podemos garantizar la permanencia de un órgano dentalen la cavidad oral, pero sí podemos intentar prolongar su permanenciaen el alvéolo el mayor tiempo posible. La técnica que se describe en elpresente artículo consiste en colocar postes accesorios de fi bra de vidriodespués del poste principal, logrando reducir el espesor de película delagente cementante a un grado ideal.

The use of this technique, shows significant advantages, as the thicknessof the resin cement is reduced, in consequence, the contraction ratio,bubble formation, and internal voids are reduced, which represent areasof weakness in the post-endodontic restoration, this technique has beenalready proposed and properly investigated by certain authors. Thisis applied on teeth with enlarged canals, that have been weakened byineffi cient restorations, dentin demineralization, bacterial fi ltration ofcrown and post, or simply wide canals in young patients. We have afi rm conviction, that we can´t guarantee the permanence of a dentalorgan in the oral cavity, but we can try to lengthen its permanency onthe alveolus as much as possible. The technique that´s described in thisarticle, consists in placing accessory posts of fi ber glass after placingthe main post, achieving a reduction of the cement fi lm thickness toideal thicknesses.

Bond Strength Evaluation of Two Adhesive Systems in Fiberglass Posts Cementation

Objective: To compare the bond strength of three-step and self-etch adhesive systems with and without prior acid etching on bonding of fiberglass posts in root canals. Material and Methods: Experiments were conducted on roots of five upper molars without curvature and sectioned in a cervical-apical direction. With the aid of a highspeed turbine and diamond tips, cylindrical cavities 7 mm in depth and 1.4 mm in diameter were made in the dentine. The roots of the same tooth were used, where the retainers were cemented, thus generating three groups: Group A: Adper Scotchbond Multipurpose Plus (SBMP) + Rely X ARC; Group B: Single Bond Universal (SBU-1) + Rely X ARC, with acid etching prior to adhesive insertion; Group C: Single Bond Universal (SBU-2) + Rely X ARC. The samples were stored in a bacteriological incubator at 37ºC with 100% humidity for 48h and were subsequently cross-sectioned to obtain 3 dentine discs 1mm in thickness. Forty-five specimens were subjected to the push-out test. Results: Through the analysis of variance and Tukey's test, it was found that SBMP showed, with statistical significance (p<0.05), highest bond strength when compared with the SBU-1 and SBU-2 systems. The observed difference in the discs was located in the cervical portion. Conclusion: The three-step adhesive system had higher bond strength with the substrate than the self-etching adhesive only in the disc in the cervical portion; further, statistically, the prior application of phosphoric acid in SBU-1 did not affect its bond strength significantly.

Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts

Abstract This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.

Avaliação do recobrimento radicular pela técnica de enxerto conjuntivo subepitelial e condicionamento radicular com ácido cítrico associado à tetraciclina ou terapia fotodinâmica antimicrobiana - ensaio clínico randomizado / Analysis of root coverage by subepithelial connective tissue graft associated to root conditioning with citric acid plus tetracycline or antimicrobial photodynamic therapy ­ a randomized clinical trial

Este estudo teve o objetivo de comparar os efeitos da biomodificação radicular por ácido cítrico associado à tetraciclina (AC) ou terapia fotodinâmica antimicrobiana (aPDT) no recobrimento de recessões gengivais pela técnica do enxerto de tecido conjuntivo subepitelial (ETCS). Para o estudo paralelo foram selecionados 60 sítios em 17 pacientes com recessões de classe I e II de Miller de 2 a 5 mm, múltiplas e isoladas, as quais foram divididas em 3 grupos: grupo controle (C) - apenas raspagem, grupo AC ­ raspagem e, aplicação de gel de ácido cítrico associado à tetraciclina (90s) e o grupo aPDT - raspagem e aplicação da terapia fotodinâmica antimicrobiana (Azul de toluidina O 100µg/ml + laser vermelho). Os parâmetros clínicos profundidade de sondagem (PS), nível clínico de inserção (NCI), altura da recessão (AR), largura mucosa ceratinizada (LMC), espessura de mucosa ceratinizada (EMC), índice de sangramento à sondagem (ISS), índice de placa (IPI) e porcentagem de recobrimento radicular (%REC) foram avaliados por um examinador cego e calibrado no baseline e 3, 6 e 12 meses de pós-operatório. Avaliou-se a hiperestesia dentinária (HIPER) e a percepção estética (EST) do paciente através de escala analógica visual no baseline e após 7 e 14 dias e 1, 3, 6 e 12 meses. A análise estatística dos dados de NCI foi feita pelo teste ANOVA complementado por Tukey. O teste de Friedman complementado por Wilcoxon foi aplicado para análise intra-grupos. O teste de Kruskal-Wallis foi aplicado para as diferenças entre os grupos, complementado por comparações múltiplas entre os três grupos. Para a %REC foi realizado o teste de Kruskal-Wallis complementado por Dunnet (p<0,05). Observou-se ganho do NCI em todos os grupos, mas este ganho foi maior para os grupos AC (0,55±1,68) e aPDT (0,80±2,11) em relação ao C (2,50±1,99) (p<0,05). Houve redução na AR em todos os grupos, porém o grupo AC (0,40±0,62) teve maior redução quando comparado C (1,15±1,04) (p<0,05). Houve aumento na LMC em todos os grupos e aumento na EMC também em todos os grupos, sendo que a EMC nos grupos aPDT (2,80±0,733) e AC (2,33±0,60) foram iguais com melhores resultados que o C (1,99±0,65) (p<0,05). Para a PS não foram observadas diferenças significantes entre os grupos e nem entre os períodos (p>0,05). A %REC foi maior nos grupos AC (82%±30%) e aPDT (82%±28%) do que no grupo C (58%±40%) (p<0,05). De maneira geral C, AC e aPDT foram semelhantes entre si e entre eles ao longo do tempo para o ISS e IPI (p>0,05). Houve redução significante da HIPER ao longo do tempo e entre os grupos, sendo que em AC (1,20±2,23) e aPDT (0,70±1,15) a diminuição da sensibilidade foi maior do que em C (2,63±2,22) (p<0,05). Houve melhora na EST ao longo do tempo e para o grupo AC (9,40±0,96) foi maior do que o C (8,58±1,07) (p<0,05), sendo que o grupo aPDT foi igual ao C. Concluiu-se que o uso de biomodificadores radiculares, como o AC e aPDT favorecem o recobrimento de recessões, resultando em redução da hipersensibilidade dentinária, maior porcentagem de recobrimento radicular e mais sítios com recobrimento completo, mantendo os resultados a longo prazo. (AU)

The aim of this study was to compare root biomodification by a combination of citric acid with tetracycline (CA) or antimicrobial photodynamic therapy (aPDT) on root coverage by subepithelial connective tissue graft (SCTG). Sixty sites with Miller's class I or II recessions were divided in three groups: Control (C) ­ scaling only, CA ­ scaling and root conditioning with a combination of citric acid and tetracycline (gel ­ 90s), aPDT ­ scaling and antimicrobial photodynamic therapy (toluidine blue O 100 µg/ml and red laser). Periodontal clinical parameters as probing depth (PD), clinical attachment level (CAL), recession height (RH), keratinized mucosa height (KMH), keratinized mucosa width (KMW), bleeding on probing (BOP), plaque index (PI) and percentage of root coverage (%RC) were evaluated by a blinded calibrated examiner at baseline, 3, 6, 12 months. Dentinal hyperestesia (HYPER) and patient esthetic perception (EST) were recorded in a visual analogic scale at baseline, 7 and 14 days, 1, 3, 6,and 12 months. Statistical analysis of CAL values was done with ANOVA complemented by Tukey. Friedman's complemented by Wilcoxon's test evaluated intragroup data, while Kruskal-Wallis was applied for intergroup data. Comparison for %RC was done by Kruskal-Wallis complemented by Dunnet (p<0.05). Reduction in CAL was observed in all groups, with higher numbers for CA (0.55±1.68) and aPDT (0.80±2.11) in relation to C (2.50±1.99) (p<0.05). A higher reduction in RH was observed for CA (0.40±0.62) compared to C (1.15±1.04) (p<0.05). There was an improvement of KMH and KMW for all groups, but with higher values of KMW for aPDT (2.80±0.733) and CA (2.33±0.60) in relation to C (1.99±0.65) (p<0.05). There were no differences for PD (p>0.05). There was a significant higher %RC for CA (82%±30%) and aPDT (82%±28%) in relation to C (58%±40%) (p<0.05). In general, BOP and PI were similar for all groups and periods (p>0.05). There was a significant reduction in hyperestesia along time, but for CA (1.20±2.23) and aPDT (0.70±1.15) the reduction was higher than C (2.63±2.22) (p<0.05). Esthetic perception was improved along time with higher values for CA (9.40±0.96) than C (9.40±0.96) (p<0.05). In conclusion, root biomodification agents as CA and aPDT favored recession coverage by STCG, resulting in reduction of dentin hypersensitivity, higher percentage of root coverage and more sites with total coverage. Additionally, these results had a long-term stability. (AU)

Bonding of the Polymer Polyetheretherketone (PEEK) to Human Dentin: Effect of Surface Treatments

Abstract Polyetheretherketone (PEEK) is a material suitable for frameworks of fixed dental prostheses. The effect of different surface treatments on the bond strength of PEEK bonded to human dentin was evaluated. One hundred PEEK cylinders (3 mm×3 mm) were divided into five groups according to surface treatment: silica coating, sandblasting with 45 μm Al2O3 particles, etching with 98% sulfuric acid for 5, 30 and for 60 s. These cylinders were luted with resin cement onto 50 human molars. First, each tooth was embedded in epoxy resin and the buccal dentin surface was exposed. Then, two delimited dentin areas (Æ:3 mm) per tooth were etched with 35% phosphoric acid and bonded with a two-step self-priming adhesive system. After the luting procedure the specimens were stored in water (24 h/37 °C). Shear bond strength (SBS) was tested using a universal testing machine (crosshead speed 0.5 mm/min; load cell 50 kgf) and failure types were assessed. Stress data (MPa) were analyzed using the Kruskal-Wallis test. Comparison of the proportions of different failure types was performed using the Bonferroni method (p<0.05). Kruskal-Wallis demonstrated that differences among groups were not significant (p=0.187). Mean SBS were as follows: silica coating, 2.12±1.12 MPa; sandblasting, 2.37±0.86 MPa; sulfuric acid 5 s, 2.28±1.75 MPa; sulfuric acid 30 s, 1.80±0.85 MPa; sulfuric acid 60 s, 1.67±0.94 MPa. Adhesive and mixed failures were predominant in all groups. Both physical and chemical surface treatments produced adhesion between PEEK, resin cement and dentin.

Resumo O poli-éter-éter-cetona (PEEK) é um material indicado para as estruturas de próteses parciais fixas. O efeito de diferentes tratamentos de superfície na resistência de união entre PEEK e dentina humana foi avaliado. Cem cilindros de PEEK (3 mm×3 mm) foram divididos em cinco grupos de acordo com tratamento de superfície: silicatização, jateamento com partículas de Al2O3 45 µm, condicionamento com ácido sulfúrico 98% por 5, 30 e 60 s. Esses cilindros foram cimentados com cimento resinoso em cinquenta molares humanos. Primeiro, cada dente foi incluído em resina epóxica e a superfície dentinária vestibular foi exposta. Depois, duas áreas (Æ:3 mm) em dentina/por dente foram delimitadas, condicionadas com ácido fosfórico a 35% e receberam aplicação de um sistema adesivo de dois passos. Após o procedimento de cimentação, as amostras foram armazenadas em água (24 h/37 °C). A resistência da união ao cisalhamento (SBS) foi testada em uma máquina universal de ensaios (velocidade 0,5 mm/min; célula de carga 50 kgf), e foram avaliados os tipos de falha. Os dados de tensão (MPa) foram analisados pelo teste de Kruskal-Wallis. A comparação das percentagens de diferentes tipos de falha foi realizada utilizando o método de Bonferroni (p<0,05). O teste de Kruskal-Wallis demonstrou que as diferenças entre os grupos não foram significantes (p=0,187). As médias de SBS foram: silicatização, 2,12±1,12 MPa; jateamento, 2,37±0,86 MPa; ácido sulfúrico por 5 s, de 2,28±1,75 MPa; ácido sulfúrico por 30 s, 1,80±0,85 MPa, ácido sulfúrico por 60 s, 1,67±0,94 MPa. Falhas adesivas e mistas foram predominantes em todos os grupos. Ambos tratamentos de superfície, físicos e químicos, promoveram adesão entre PEEK, cimento resinoso e dentina.

Effect of Acid Etching, Silane and Thermal Cycling on the Bond Strength of Metallic Brackets to Ceramic

Abstract The aim of this study was to evaluate the effect of silanes, thermal cycling and acid etching on the shear bond strength (SBS) of metallic brackets to feldspathic ceramic. Feldspathic ceramic cylinders (Groups 1, 2, 5 and 6) were etched for 60 s with 10% hydrofluoric acid and Groups 3, 4, 7 and 8, without acid etching. Two layers of silane Clearfil Ceramic Primer (CCP, Groups 1 to 4) and two layers of RelyX Ceramic Primer (RCP, groups 5 to 8) were applied and dried for 60 s. Brackets were bonded to the cylinders with Transbond XT and light-activated for 40 s with Bluephase G2. All specimens were stored in deionized water at 37 °C for 24 h, and the specimens of groups 1, 3, 5 and 7 were submitted to 7,000 thermal cycles (5 °C/55 °C). After storage, the SBS test was performed at a crosshead speed of 1 mm/min. Data were subjected to three-way ANOVA and Tukey's post hoc test (α=0.05). The adhesive remnant index (ARI) was evaluated at 8x magnification. The SBS of CCP was significantly greater than of RCP (p<0.05), with or without thermal cycling. Thermal cycling significantly reduced the SBS (p<0.05). The groups submitted to acid etching showed significantly higher SBS than those without acid etching (p<0.05). In conclusion, thermal cycling reduced SBS for all groups. The best ceramic surface treatment for bracket bonding was achieved by acid etching and CCP silane. The ARI results showed predominance of score 0 for all groups.

Resumo O objetivo neste estudo foi avaliar o efeito de diferentes silanos, ciclagem térmica e condicionamento ácido na resistência da união ao cisalhamento (RUC) de bráquetes metálicos a cerâmica feldspática. Cilindros da cerâmica feldspática (Grupos 1, 2, 5 e 6) foram condicionados por 60 s com ácido hidrofluorídrico a 10% e os Grupos 3, 4, 7 e 8 sem condicionamento ácido. Duas camadas do silano Clearfil Ceramic Primer (CCP, Grupos 1 a 4) e duas camadas do RelyX Ceramic Primer (RCP, Grupos 5 a 8) foram aplicadas e secas por 60 s. Bráquetes foram fixados aos cilindros cerâmicos usando Transbond XT e fotoativado por 40 s com Bluephase G2. Todas as amostras foram armazenadas em água deionizada a 37 °C por 24 h, sendo as amostras dos grupos 1, 3, 5 e 7 submetidas a 7.000 ciclos térmicos (5 °C/55 °C). Após a armazenagem, a RUC foi verificada a velocidade de 1 mm/min. Os dados foram submetidos à ANOVA 3 fatores e teste de Tukey post hoc (α=0,05). O Índice de Remanescente do Adesivo (IRA) foi avaliado com aumento de 8x. A RUC do CCP foi significantemente maior do que o RCP (p<0,05), com ou sem ciclagem térmica. A ciclagem térmica reduziu significantemente a RUC (p<0,05). Os grupos submetidos ao condicionamento ácido mostraram valores de RUC significantemente maiores em relação os grupos sem condicionamento ácido (p<0,05). Concluindo, a ciclagem térmica reduziu a RUC para todos os grupos. O melhor tratamento de superfície da cerâmica para colagem de bráquetes foi obtido pelo condicionamento ácido e pelo silano CCP. O IRA mostrou predominância de escore 0 para todos os grupos.