Effect of Water and Chlorhexidine with Different Pressures of Oral Irrigation Device on the Surface Roughness and Topography of Giomer

Abstract Objective: To evaluate the effect of different pressures of an oral irrigation device (OID) and the irrigation solution type on the surface roughness of the giomer restorative material. Material and Methods: In this in vitro study, disk-shaped giomer samples were fabricated and assigned to 5 groups (n=23): Group 1, storage in distilled water (control); Group 2, OID #7 pressure/ water; Group 3, OID #10 pressure/ water; Group 4, OID #7 pressure/ 0.05% CHX; Group 5, OID #10 pressure/ 0.05% CHX. The samples' treatment simulated a one-year application of OID. Surface roughness (Ra) and topography of the giomer were evaluated using profilometry and scanning electron microscopy. The data were analyzed with Paired t-test, Tukey, and ANOVA tests (α=0.05). Results: The Ra of the samples increased significantly after treatment with OID (p<0.001). The roughness increase in groups with a pressure of 10 was higher than those with a pressure of 7 (p<0.001). The effect of pressure on surface changes was significant (p<0.001). However, the solution type and the cumulative effect of these two factors were insignificant (p=0.08 and p=0.43, respectively). Conclusion: Oral irrigation device with both solutions significantly increased the surface roughness and topographic changes of the giomer. The severity of these changes was related to the device's pressure.

Does the combination of whitening toothpaste and hydrogen peroxide bleaching increase the surface roughness and change the morphology of a nanofilled composite?

Aim: To evaluate changes in the surface roughness and morphology of a nanofilled composite following toothbrushing with a whitening (WT) or regular toothpaste (RT), alone or combined with 35% hydrogen peroxide bleaching (HP). Methods: Seventy disc-shaped nanofilled composite (Filtek Z350XT) specimens were randomly divided into groups (n=10): WT, RT, TB (without toothpaste ­ control) or the combinations WT/ HP, RT/HP, TB/HP and HP. All groups underwent toothbrushing simulation (60,000 cycles) and bleaching treatment (4 sessions). Mean surface roughness (Ra, µm) was measured before (T0) and after treatments (TB). Surface morphology was assessed by scanning electron microscopy (SEM) at TB. Mean Ra was analyzed using general mixed models and multiple comparisons by the Tukey-Kramer test (α=5%). Results: HP caused no surface roughness changes on the nanofilled composite after treatment (p>0.05). RT toothbrushing, combined or not with HP, increased the surface roughness (p<0.05). WT and WT/ HP protocols had no effect on the surface roughness of the composite (p>0.05). The nanofilled composite submitted to RT toothbrushing combined with HP (RT/HP) presented substantial surface alterations under SEM, showing deep depressions and round-shaped defects. Toothbrushing with RT combined with the bleaching agent increased exposure of the inorganic fillers. Conclusion: WT toothbrushing, regardless of HP combination, or the single HP protocol had no effect on the surface roughness of the nanofilled composite. However, RT combined with HP negatively affected surface roughness and presented the most noticeable surface changes among groups

Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Color and surface roughness alterations of bulk-fill resin composites submitted to simulated toothbrushing with whitening dentifrices

Aim: To evaluate the surface roughness and color stability of bulk-fill resin composites after simulated toothbrushing with whitening dentifrices. The radioactive/relative dentin abrasion (RDA) and radioactive/relative enamel abrasion (REA) of dentifrices were also assessed. Methods: Specimens (n=10) of Tetric N Ceram Bulk Fill (TNCB), Filtek One Bulk Fill (FOB) resin composites, and Z100(Control) were prepared using a cylindrical Teflon matrix. Surface roughness (Ra, µm) was assessed by a roughness meter and the color evaluations (ΔEab , ΔE00 , WID ) were performed using a digital spectrophotometer based on the CIELAB system. Three measurements were performed per sample, before and after simulated toothbrushing with 3D Oral-B White Perfection (3DW) and Black is White (BW) dentifrices. The abrasivity (REA and RDA values) of the used dentifrices was also determined by the Hefferren abrasivity test. Results: The Ra values increased significantly in all resin composites after 3DW and BW toothbrushing. The acceptable threshold color varied among resin composites, and TNCB and Z100 presented the highest ΔEab and ΔE00 for BW dentifrice. The 3DW dentifrice was significantly more abrasive than BW dentifrice on enamel and dentin. Conclusions: simulated toothbrushing with tested whitening dentifrices increased the surface roughness at acceptable levels. The Tetric N Ceram Bulk-fill and Z100 composite showed the highest color alteration in BW. 3D White Perfection dentifrice was more abrasive on dentin and enamel than Black is White.

Avaliação antimicrobiana de uma resina Bulk Fill Fluida com inserção do xilitol / Antimicrobial evaluation of a Fluid Bulk Fill resin with xylitol insertion

Introdução: As resinas Bulk Fill apresentam uma boa procura pelos profissionais, pois o seu uso diminui o tempo clínico, como também a melhora qualidade das restaurações, porém não possuem atividade antibacteriana, sendo um dos fatores que ainda causam impacto negativo na vida das pessoas. A biomodificação com o xilitol tem o sentido de produzir ação microbiana e com isso aperfeiçoar as suas características clínicas. Objetivo: Avaliar a ação antimicrobiana de uma resina Bulk Fill flow após a inserção do xilitol. Metodologia: A resina Tetric® N-Flow Bulk Fill foi misturada às concentrações de xilitol (0% [Controle], 2,5% e 5% p/p). Amostras cilíndricas (n=5 do grupo controle e n=3 dos demais grupos experimentais) foram confeccionadas em moldes acrílicos de diâmetro de 2mm espessura, fotoativadas por 10s e armazenadas a 37ºC por 24h. Os espécimes foram esterilizados por luz ultravioleta por 20 minutos antes de serem acomodadas em uma placa de 48 poços estéril, sendo adicionado em cada poço 0,5mL de caldo Mueller Hinton. Então, adicionou-se 50µL do inóculo de S. mutans nos poços correspondentes. A placa foi incubada a 37 ± 1 ˚C durante 48 horas. Após o período de incubação, os espécimes foram gentilmente removidos e o crescimento microbiano foi indicado pela adição de 100µL da solução aquosa de resazurina (SigmaAldrich) a 0,01% com a posterior incubação a 37 ± 1 ˚C por duas horas. Micro-organismos viáveis reduzem o corante mudando sua coloração azul para rosa e a CIM foi definida como a menor concentração da substância que inibiu a mudança de coloração da resazurina. Em um poço contendo o grupo controle foi acrescentado clorexidina a 0,12% com o intuito de comparar o resultado gerado dos grupos testes. Resultado: Não houve inibição do crescimento bacteriano nos poços com inóculos que continham S. mutans e corpo de prova de resina acrescida de xilitol. Conclusão: Esse estudo mostrou que o acréscimo de 2,5% e 5% de Xilitol à resina Tetric® N-Flow Bulk Fill não apresentou inibição do crescimento bacteriano (AU).

Introduction: Bulk Fill resins are in good demand among professionals, as their use reduces clinical time and improves the quality of restorations, but they do not have antibacterial activity, which is one of the factors that still hurt people's lives. Biomodification with xylitol aims to improve its clinical characteristics. Objective: To evaluate the antimicrobial action of a Bulk Fill flow resin after inserting xylitol. Methodology: Tetric® N-Flow Bulk Fill resin was mixed with xylitol concentrations (0% [Control], 2.5% and 5% w/w). Cylindrical samples (n=5 from the control group and n=3 from the other groups) were made in acrylic molds with a diameter of 2 mm thick, light-cured for 10 s and stored at 37ºC for 24h. The specimens were sterilized by ultraviolet light for 20 minutes before being placed in a sterile 48-well plate, with 0.5 mL of Mueller Hinton broth added to each well. The plate was incubated at 37 ± 1 ˚C for 48 hours. After the incubation period, the specimens were gently removed, and microbial growth was indicated by adding 100 µL of 0.01% resazurin aqueous solution with subsequent incubation at 37 ± 1 ˚C for two hours. Viable microorganisms reduce the dye, changing its color from blue to pink. The MIC was defined as the lowest concentration of the substance that inhibited the color change of resazurin. In 0.12%, chlorhexidine was added to a well containing the control group to compare the results generated from the test groups. Result: There was no inhibition of bacterial growth in the wells with inocula containing S. mutans and the resin specimen with xylitol added. Conclusion: This study showed that adding 2.5% and 5% Xylitol to the Tetric® N-Flow Bulk Fill resin did not inhibit bacterial growth (AU).

Restauração transcirúrgica: inter-relação periodontia e dentística / Transsurgical restoration: interrelationship between periodontics and dentistry

Tendo em vista a importância da relação Dentística Restauradora e Periodontia na Odontologia atual, o presente estudo demonstrou o relato de um caso clínico realizado no Complexo Odontológico do Centro Universitário da Serra Gaúcha (FSG), retratando um procedimento de restauração transcirúrgica em um paciente cujo elemento 13 estava comprometido com uma cavidade subgengival disto-palatino, sendo a resina composta o material restaurador de escolha. Este estudo teve como objetivo apresentar um caso clínico demonstrando a técnica de restauração transcirúrgica e a integração do planejamento entre Periodontia e Dentística Restauradora realizado na Clínica de Odontologia do Centro Universitário da Serra Gaúcha -FSG. Este trabalho mostrou a importância da realização de uma técnica cirúrgica e restauradora correta por parte dos cirurgiões-dentistas, assim como na verificação de que os tecidos periodontais podem reagir de forma positiva à presença de materiais restauradores adesivos posicionados subgengivalmente(AU)

In view of the importance of the restorative dentistry and periodontics relationship in current dentistry, the present study demonstrated the report of a clinical case carried out in the Dental Complex of the Centro Universitário da Serra Gaúcha - FSG, portraying a transsurgical restoration procedure in a patient whose element 13 was compromised with a subgingival cavity of this-palatine, the composite resin being the restorative material of choice. This study aimed to present a clinical case demonstrating the technique of transsurgical restoration and the integration of planning between Periodontics and Restorative Dentistry carried out at the Dentistry Clinic of the University Centro Universitário da Serra Gaúcha - FSG. This study showed the importance of performing a correct surgical and restorative technique by dentists, as well as in verifying that periodontal tissues can react positively to the presence of adhesive restorative materials positioned subgingival(AU)

Envelhecimento bucal precoce e suas consequências para a cavidade oral com foco em reabilitação com resina composta: relato de caso / Early oral aging and its consequences for the oral cavity focusing on rehabilitation with composite resin: case report

O envelhecimento bucal precoce apresenta cada vez uma maior incidência nos consultórios odontológicos e sua degradação aos tecidos orais exige uma atenção por parte do cirurgiãodentista devido ao seu alto grau de complexidade. Esse envelhecimento precoce é causado principalmente por hábitos parafuncionais, dieta ou ambos. Suas consequências são desgastes patológicos dos tecidos dentários, extrusão passiva, perda de dimensão vertical e comprometimento estético e funcional. Por conta disso, o presente estudo teve como objetivo realizar um relato de caso clínico em um paciente jovem e com queixa estética como consequência de hábitos parafuncionais, aonde foram realizados uma reabilitação oral envolvendo aumento da dimensão vertical de oclusão através de Table Tops sem desgastes dentários e restaurações estéticas, ambas com resina composta. Essa reabilitação devolveu a DVO da paciente, trazendo conforto, contatos estáveis, guias de desoclusão e satisfação estética e funcional por parte da paciente(AU)

Early oral aging has an increasing incidence in dental offices and its degradation to oral tissues requires attention from the dentist due to its high degree of complexity. This premature aging is mainly caused by parafunctional habits, diet, or both. Its consequences are pathological wear of dental tissues, passive extrusion, loss of vertical dimension and aesthetic and functional impairment. Because of this, the present study aims to carry out a clinical case report in a young patient with an aesthetic complaint as a result of parafunctional habits, where an oral rehabilitation was carried out involving an increase in the vertical dimension of occlusion through Table Tops without dental wear and aesthetic restorations, both with composite resin. This rehabilitation returned the patient's OVD, bringing comfort, stable contacts, disocclusion guides and aesthetic and functional satisfaction on the part of the patient(AU)

Efeito da incorporação de xilitol na dureza de superfície de um compósito bulk fill fluido / Efeito da incorporação de xilitol na dureza de superfície de um compósito bulk fill fluido

Introdução: Frente à necessidade de maior longevidade das restaurações, o desenvolvimento de resinas antimicrobianas vem sendo necessário. O xilitol, um composto antimicrobiano natural e biocompatível, pode ser um aditivo em potencial para incluir esta propriedade em uma resina bulk fill fluida sem comprometer sua integridade. Objetivo: Avaliar a microdureza de superfície de uma resina antimicrobiana desenvolvida a partir da adição de xilitol (0% ou controle; 2,5%; 5%) em resina bulk fill fluida comercial (Tetric N-Flow Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein). Metodologia: 3 grupos (n=12) foram obtidos através da variação da concentração de xilitol (0% ou controle; 2,5%; 5%). Para obter as resinas experimentais, xilitol em pó foi incorporado à resina fluida por espatulação manual por 1 min em uma câmara escura. A partir de um molde de acrílico, discos de 5 mm de diâmetro foram confeccionados através da fotoativação de um incremento único com um aparelho de LED de irradiância 1400 mW/cm² (Bluephase, Ivoclar Vivadent) por 10 s. Os discos foram submetidos à análise de microdureza Vickers (HMV-2, Shimadzu, Tokyo, Japan) na face superior, com uma carga estática de 300g e em um tempo de 10 s, obtendo uma média após três indentações por amostra. A análise estatística foi realizada através da variância ANOVA a um fator e teste de Tukey para a comparação entre os grupos (p < 0,05). Resultados: O grupo xilitol 5% mostrou a menor média de microdureza de superfície quando comparado aos grupos 0% e 2,5%. Conclusão: O xilitol afetou negativamente à dureza da restauração, principalmente quando foi utilizada uma concentração de 5% (AU).

Introduction: In view of the need for improved longevity of restorations, the development of antimicrobial resins has become necessary. Xylitol, a natural and biocompatible antimicrobial compound, may be a potential additive to include this property in a flowable bulk fill resin without compromising its integrity. Objective: To evaluate the surface microhardness of an antimicrobial resin developed by adding xylitol (0% or control; 2.5%; 5%) to a commercial flowable bulk fill resin (Tetric N-Flow Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein). Methodology: 3 groups (n=12) were obtained by changing the xylitol concentration (0% or control; 2.5%; 5%). To obtain the experimental resins, xylitol powder was incorporated into the flowable resin by manual spatulation for 1 min in a darkroom. Based on an acrylic mold, 5 mm diameter disks were made by curing of a single increment with a 1400 mW/cm² irradiance LED device (Bluephase, Ivoclar Vivadent) for 10s. The disks were subjected to Vickers microhardness analysis (HMV-2, Shimadzu, Tokyo, Japan) on the upper face, with a static load of 300g and in a time of 10 s, obtaining an mean after three indentations for sample. Statistical analysis was performed using one-way ANOVA and Tukey's test for comparison between groups (p < 0.05). Results: The 5% xylitol group showed lower mean surface microhardness when compared to the 0% and 2.5% groups. Conclusion: Xylitol negatively affected restoration hardness mainly when a 5% concentration was used (p < 0.01) (AU).

Facetas diretas em resina composta utilizando o fluxo digital para planejamento: relato de caso / Direct facets in composite resin using digital flow for planning: case report / Facetas directas en resina compuesta utilizando flujo digital para planificación: reporte de caso

Introdução:O aprimoramento das resinas compostas nos últimosanos em associação com a difusão de informações nas redes sociais tornou as facetas diretas tratamentos populares na dentística restauradora. No entanto, são procedimentos que exigem ampla destreza manual e conhecimento técnico. O fluxo digital através doescaneamento, enceramento digital e prototipagem 3D para construção de guias tem se tornado uma excelente alternativa para aumentar a previsibilidade e aumentar a longevidade destes trabalhos. Objetivo:Descrever o protocolo de confecção de facetas diretas em resina composta, através de um relato de caso, utilizando como auxílio o planejamento digital para confecção de modelo 3D, guia de silicone e paredes palatinas. Descrição do Caso:Paciente do gênero masculino, 43 anos, queixava-se do formato dos seus dentes. Ao exame clínico percebeu-se desgaste dental nos incisivos centrais e linha do sorriso levemente invertida. Após duas sessões de clareamento de consultório com Peróxido de hidrogênio (35%) e mockup direto com resina composta, foi realizada a moldagem e escaneamento do modelo de gesso no laboratório. O enceramento digital foi aprovado, o modelo 3D foi impresso para confecção da guia de silicone. Com auxílio da guia foram executadas facetas diretas nos elementos 13, 12, 11, 21, 22 e 23. Conclusão:O fluxo digital pode ser uma alternativa viável para minimizar as falhas na confecção de facetas diretas em resina composta (AU).

Introduction:The improvement of composite resins in recent years, together with information disseminated on social media, has made direct veneers popular treatments in restorative dentistry. However, these procedures require significant manual dexterity and technical knowledge. Digital work flow using scanning, digital wax-up and 3D prototyping for the construction of guides has become an excellent alternative to increase predictability and the longevity of these procedures. Objective:Describe the manufacturing protocol for direct composite resin veneers, using a case report and digital to construct the 3D model, silicone guide and palatine walls. Case description:Male patient, 43 years old, complained of the shape of his teeth. Clinical examination revealed tooth wear on the central incisors and a slightly inverted smile line. After two whitening sessions with hydroigen peroxide (35%) and direct mockup with composite resin, the plaster model was molded and scanned in the laboratory. Digital wax-up was approved, and the 3D model was printed to manufacture the silicone guide. With the help of the guide, the direct veneers were applied to elements 13, 12, 11, 21, 22 and 23.Conclusions:Digital flow may be a feasible alternative to minimize manufacturing flaws in direct composite resin veneers (AU).

Introducción: La mejora de las resinas compuestas en los últimos años, y la difusión de información en las redes sociales, ha popularizado las facetas directas en los tratamientos en odontología restauradora. Sin embargo, son procedimientos que requieren demasiado destreza manual y conocimientos técnicos. El flujo digital usando escaneo, encerado digital y prototipado 3D para la construcción de guías se ha convertido en una excelente alternativa para aumentar la previsibilidad y la longevidad de estos procedimientos. Objetivo: Describir el protocolo para la realización de carillas directas en resina compuesta, a través de un reporte de caso, utilizando el planeo digital como ayuda para la realización de un modelo 3D, guía de silicona y paredes palatinas. Descripción del caso: Paciente masculino, 43 años, se quejó de la forma de sus dientes. El examen clínico reveló desgaste dental en los incisivos centrales y una línea de sonrisa levemente invertida. Después de dos sesiones de blanqueamiento en consultorio con peróxido de hidrógeno (35%) y maqueta directa con resina compuesta, el modelo de yeso fue moldeado y escaneado en el laboratorio. El encerado digital fue aprovado, el modelo 3D fue impreso para hacer la guía de silicona. Con la ayuda de la guía se realizaron carillas directas en los elementos 13, 12, 11, 21, 22 y 23. Conclusiones: El fluxo digital puede ser una alternativa viable para minimizar fallas en la fabricación de carillas directas en resina compuesta (AU).

Reabilitação estética e funcional com resina composta após trauma dentário: relato de caso / Aesthetic and functional rehabilitation with composite resin after dental trauma: case report

As lesões dentárias traumáticas são um problema de saúde pública mundial, dentre as quais a fratura dentária é a de maior ocorrência, envolvendo principalmente os dentes anteriores. A abordagem de grandes fraturas anteriores é um desafio para cirurgiões dentistas de qualquer nível pois, além da função, afetam diretamente a estética do paciente, fazendo-se necessário um planejamento que envolva diferentes especialidades na odontologia. Objetivo: Relatar um caso clínico de reabilitação funcional e estética de fratura dentária nos incisivos centrais superiores envolvendo tratamento endodôntico, instalação de pino de fibra de vidro e restauração direta em resina composta. Relato de Caso: O paciente de 17 anos sofreu fratura nos incisivos centrais superiores causada por uma queda de bicicleta. Devido à busca tardia por tratamento o elemento 21 foi diagnosticado com necrose pulpar e, portanto, foi submetido à tratamento endodôntico pela Técnica Crown Down e reabilitação com pino de fibra de vidro Splendor-SAP. Posteriormente, os elementos 11 e 21 foram restaurados com facetas diretas em resina composta pela técnica incremental. Conclusão: A reabilitação com instalação de pino de fibra de vidro associada à técnica de estratificação incremental em resina composta se mostra como uma boa opção para reabilitação estética pois permite dar forma anatômica ao dente com riqueza de detalhes na estratificação da dentina e esmalte, além de máxima preservação da estrutura dental. Os resultados obtidos reforçam o sucesso estético e funcional com significativo impacto na qualidade de vida do paciente(AU)

Traumatic dental injuries are a worldwide public health problem, among which dental fractures are the most frequent, mainly involving the anterior teeth. The approach of large anterior fractures is a challenge for dental surgeons of any level because, in addition to function, they directly affect the patient's esthetics, requiring a plan that involves different specialties in dentistry. Objective: Report a clinical case of functional and aesthetic rehabilitation of dental fractures in maxillary central incisors involving endodontic treatment, installation of a fiberglass post and direct restoration in composite resin. Case Report: The 17-year-old patient suffered a fracture in the upper central incisors caused by a fall from a bicycle. Due to the late search for treatment, element 21 was diagnosed with pulp necrosis and, therefore, underwent endodontic treatment using the Crown Down Technique and rehabilitation with a Splendor-SAP fiberglass pin. Later, elements 11 and 21 were restored with direct veneers in composite resin using the incremental technique. Conclusion: Rehabilitation with the installation of a fiberglass post associated with the incremental layering technique in composite resin is a good option for aesthetic rehabilitation as it allows the anatomical shape of the tooth with rich details in the layering of dentin and enamel, in addition to maximum preservation of the tooth structure. The results obtained reinforce the aesthetic and functional success with a significant impact on the patient's quality of life(AU)

Evidence-practice gap in treatment decisions about defective composite and amalgam restorations among Brazilian dentists

Better understanding of dentists' decision-making about defective restorations is needed to close the evidence-practice gap (EPG). This study aimed to quantify the EPG about defective restorations and identify dentist factors associated with this EPG. Methods: 216 dentists from São Paulo State, Brazil, completed a questionnaire about three clinical case scenarios involving defective composite restorations with cementum-dentin margins (case 1) and enamel margins (case 2), and an amalgam (case 3) restoration. Dentists were asked what treatment, if any, they would recommend, including preventive treatment, polishing, re-surfacing, or repairing the restoration, or replacing the entire restoration. Replacing the entire restoration in any of these three scenarios was classified as inconsistent with the evidence, comprising an EPG. Bivariate analyses using Chi-square, ANOVA, or multiple comparison tests were performed (p<.05). Results: for defective composite restorations, 49% and 55% of dentists chose to replace the entire restoration for cases 1 and 2, respectively. Twenty-nine percent of dentists chose to replace the entire amalgam restoration. Dentists were significantly more likely to choose to replace the defective amalgam restoration than the composite restoration with a defect at the cementum-dentin margins or the enamel margins (both at p < .001). Female dentists were more likely to choose a conservative treatment than male dentists for cases 1 (p=.034) and 2 (p=.009). Dentists with a higher percentage of patients interested in individualized caries prevention were also more conservative in case 1 (p=.045). Conclusion: a substantial EPG regarding treatment decisions for defective restorations exists, especially for composite restorations. This study adds to the international evidence that an EPG exists in this clinical area and that global strategies need to be developed to close the gap

Effect of time and dental substrate on the bond strength of a universal adhesive system: in vitro study / Efeito do tempo e do substrato dental na resistência de união de um sistema adesivo universal: estudo in vitro

Introduction: Dentin adhesives provide union between the dental substrate and composite resin, but this union can be influenced by the cleaning agent. Objective: Evaluate the use of ozonated water as a cavity cleaning solution. Material and method: 40 bovine dental crowns were selected, divided into four groups: AD (dentin cleaning with distilled water) and AO (dentin cleaning with ozonized distilled water). Each group was divided into two storage periods (24h and 30 days) kept at 37 °C. The selected universal system adhesive was employed according to the manufacturer's instructions and light cured for 20 seconds. At that time, three cylinders were made (Tygon matrix with an internal diameter of 2 mm and a height of 2 mm) of composite resin in the crowns in the cervical, médium, and incisal regions and light cured for 30 seconds. After storage, the bonding strength was tested by micro-shear, and fracture type analysis was performed. The data were submitted to statistical analysis using the Shapiro-Wilk test with a significance level of 95%, ANOVA, and Turkey. Result: There was a statistically significant difference between the bond strength values, only in the intergroup analysis for the time of 24 hours, between the middle third of the groups (LDAO24 = 2.70 (± 2.39); LDAO30 = 3.82 (± 2.31)). The predominant fracture type for both groups was an adhesive fracture, except in the medium and incisal thirds of the AD, which was a cohesive dentin fracture. Conclusion: The utilization of ozone did not change the bond strength adhesive.

Introdução: Os adesivos dentinários proporcionam união entre o substrato dental e resina composta, porém esta união pode ser influenciada pelo agente de limpeza. Objetivo: Avaliar a influência na resistência de união (RU) de um sistema adesivo universal associado à da água ozonizada como solução de limpeza cavitária. Material e método: Foram selecionadas 40 coroas de dentes anteriores bovinos divididos em 4 grupos: AD (limpeza dentinária com água destilada) e AO (limpeza dentinária com água destilada ozonizada). Cada grupo foi subdividido em outros dois grupos de acordo com o tempo de armazenamento (24h e 30 dias) armazenados a 37ºC. A limpeza dentinária foi realizada por meio de uma seringa de 60mL de cada solução e fricção por 10 segundos. O sistema adesivo universal selecionado foi aplicado de acordo com as instruções do fabricante e fotoativado por 20 segundos. Em seguida, foram confeccionados 3 cilindros (matriz Tygon com um diâmetro interno de 2 mm e 2 mm de altura) de resina composta nas coroas nas regiões cervical, média e incisal e fotoativados por 30 segundos. Após o armazenamento foi realizado o teste de RU por microcisalhamento e análise do tipo de fratura. Os dados coletados foram submetidos a análise estatística através do teste de Shapiro Wilk com nível de significância de 95%, ANOVA e Tukey. Resultado: Houve diferença estatística significativa entre os valores de RU apenas na análise intergrupos para o tempo de 24 horas, entre o terço médio dos grupos (LDAO24 = 2,70 (± 2,39); LDAO30 = 3,82 (± 2,31)). O tipo de fratura predominante para ambos os grupos em todos os tempos foi de fratura adesiva, com exceção ao terço médio e incisal do AD, que foi fratura coesiva de dentina. Conclusão: A utilização do ozônio não alterou a resistência de união adesiva.

Use of Restorative Materials in Primary Teeth - A Retrospective University-Based Study

ABSTRACT Objective: To investigate the types of restorative materials used for restorative treatment in primary teeth through a retrospective university-based study. Material and Methods: The sample consisted of all clinical records of children attended at the Pediatric Dentistry Clinic at the School of Dentistry of Ribeirão Preto at the University of São Paulo in Brazil. Inclusion criteria were primary anterior and posterior teeth that received dental restorations for treatment of dental caries lesions, dental trauma or dental development defects from 2013 to 2018. Restoration repairs and interim restorations during this period were also recorded. Descriptive analyzes were performed to assess the distribution according to the type of restorative material used over the years. Results: A total of 5,236 restorative procedures were performed in primary teeth, including restoration repair and interim restorations. Of those, 69% were done in posterior teeth and 31% in anterior teeth. Sixty percent of the procedures performed during this period were made of composite resin and a lower percentage of glass ionomer cement (18%) followed by silver amalgam (1%). The number of interim restorations was smaller but proportional to those of composite resin over the years. Conclusion: A tendency to carry out restorative treatment of primary teeth with composite resin during the 6 years of follow-up was observed.

Longitudinal analyses of composite resin restoration on erosive lesions: effect of dentin treatment with a chitosan nanoformulation containing green tea

Aim To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods The study was performed in a split-mouth, randomized and double-blinded model with 20 patients with 40 erosive lesions. The patient's teeth were randomized into two groups (n=20) according to the surface treatment: 1) Without biomodification (control), and 2) Biomodification with NanoCsQ solution (experimental). The lesions were restored with adhesive (Tetric N-bond, Ivoclar) and composite resin (IPS Empress Direct, Ivoclar). The restorations were polished and 7 days (baseline), 6 months, and 12 months later were evaluated according to the United States Public Health Service (USPHS) modified criteria, using clinical exam and photographics. Data were analyzed by Friedman's and Wilcoxon signed-rank tests. Results No significant differences were found between the control and experimental groups (p=0.423), and also among the follow-up periods (baseline, six months, and 12 months) (p=0.50). Regarding the retention criteria, 90% of the restoration had an alpha score in the control group. Only 10% of the restorations without biomodification (control) had a score charlie at the 12-month follow-up. None of the patients reported post-operatory sensitivity. Conclusion The NanoCsQ solution did not negatively affect the performance of the composite resin restorations after 12 months.

Comparison of shear bond strength and color reproduction of two different high-performance polymers veneered with two different thicknesses of resin composite: an in-vitro study / Comparação da resistência ao cisalhamento e reprodução de cor de dois diferentes polímeros de alto desempenho revestidos com duas diferentes espessuras de resina composta: um estudo in vitro

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)

Influence of two natural cross-linkers on microtensile bond strength durability ­ An in vitro study / Influência de dois reticuladores naturais na durabilidade da resistência de união à microtração ­ Um estudo in vitro

Objective: to investigate the effect of two natural cross-linkers on microtensile bond strength (µTBS) and evaluate their influence on the durability of the resin dentin bonds. Material and Methods: the Moringa oleifera and Centella asiatica plant extracts were qualitatively tested with high-performance thin layer chromatography (HPTLC) for the presence of phenols. The phenolic content ranged from 27 to 30 gallic acid equivalents (GAE), µg/mg of dry weight. After etching, two concentrations (5% and 1%) of these two extracts were prepared and used as pretreatment liners on dentin. They were applied for a min. After restoration with resin composite, dentin resin beams were prepared. The study groups were 5% Moringa, 1% Moringa 5% Centella 1% Centella, and control (without cross-linker application). For each group, half of the samples underwent µTBS testing after 24 hours, while the remaining half were immersed in artificial saliva to assess the bond's longevity after 6 months of ageing. Statistical analysis was performed using one-way ANOVA followed by Tukey's post hoc test. Results: both 5% and 1% Moringa showed a significant difference (p<0.05) compared to the other groups at both intervals. However, after ageing, the specimens in the control and 1% Centella groups resulted in a significant decrease in µTBS. Conclusion: overall, both concentrations of Moringa (5% and 1%) were effective in stabilising the bond during both intervals.(AU)

Objetivo: investigar o efeito de dois reticuladores naturais na resistência de união (µTBS) à microtração e avaliar sua influência na durabilidade da adesão da resina à dentina. Material e Métodos: extratos das plantas Moringa oleifera e Centella asiatica foram qualitativamente testados através de cromatografia em camada fina de alta performance (HPTLC) para a presença de fenóis. O conteúdo fenólico alcançou entre 27 a 30 equivalentes de ácido gálico (GAE), µg/mg de peso seco. Após o condicionamento, duas concentrações (5% e 1%) dos extratos foram preparadas e utilizadas como forros de pré-tratamento em dentina. Eles foram aplicados por um minuto. Após a restauração com resina composta, palitos de dentina e resina foram preparados. Os grupos foram 5% Moringa, 1% Moringa, 5% Centella, 1% Centella e controle (sem aplicação de reticulador). Para cada grupo, metade das amostras foram submetidas ao teste µTBS após 24 horas, enquanto a outra metade foi imersa em saliva artificial para avaliar a longevidade adesiva após 6 meses de envelhecimento. Foi realizada análise estatística através de ANOVA 1-fator, seguido do teste post hoc de Tukey. Resultados: ambas as concentrações de 5% e 1% de Moringa demonstraram diferença significativa (p<0.05) comparadas aos outros grupos em ambos os intervalos. No entanto, após o envelhecimento, os espécimes dos geupos controle e 1% de Centella resultaram em uma redução significativa de µTBS. Conclusão: no geral, ambas as concentrações de Moringa (5% e 1%) foram efetivas em estabelecer a adesão em ambos os intervalos (AU)

Influence of pH-cycling and abrasion wear on the mechanical properties of conventional and bulk fill resin composites

The objective of this study was to evaluate the effect of abrasion wear on surface roughness and microhardness of different commercially available resin composites simulating pH-challenges of the oral cavity. Methods: Three resin composites (RC) were used in this study: one conventional: Z250; and two bulk fill resin composites (BRC): Tetric N-Ceram (TNC) and Sonic Fill (SF). The RC was inserted in a prefabricated mold (15mm wide x 4mm thickness) in two layers, or in a single layer for BRC. Thirty samples were prepared and surface roughness (Ra) and Knoop microhardness (KHN) test were performed at three different time-points of evaluation: baseline (24h after sample preparation); partial (after pH cycling); and final (after simulated toothbrushing procedure). Two samples of each group were selected after different treatments and analyzed descriptively on a scanning electron microscopy (SEM). Data from Ra and KHN were analyzed by two-way repeated-measures ANOVA and Bonferroni's post-hoc test with a significance level set at 5%. Results: Ra increased for all groups (p<0.001), at the final time-point, Z250 and TNC groups present the highest values. Oppositely, KHN decreased for all groups (p<0.001), Z250 group showed the highest KHN values for all time-points (p<0.001). The SEM imagens showed a regular surface for samples cycled and irregular with inorganic particles exposed for samples toothbrushed. Conclusion: pH-cycling and simulated toothbrushing affected the superficial properties (roughness and Knoop microhardness), as observed at SEM imagens, with irregular surface with inorganic particles exposure

Potencial antibacteriano dos flavonoides e desenvolvimento de uma resina composta experimental a base de flavonoide / Antibacterial potential of flavonoids and development of an experimental flavonoid-based resin composite

Os flavonoides podem ser considerados substâncias fitofarmacêuticas, ou seja, são obtidas na natureza e possuem benefícios à saúde humana. Alguns desses benefícios estão relacionados ao sistema cardiovascular, doenças crônicas como diabetes e em desordens bucais como periodontite e cárie. Assim, os objetivos do presente estudo foram: analisar efeitos antibacterianos de diferentes flavonoides contra bactérias relacionadas à doença periodontal e à cárie dentária por meio de uma revisão de escopo; avaliar as propriedades físico-químicas de uma resina composta experimental adicionada de naringina. Para a revisão de escopo, 19 artigos foram incluídos, todos estudos in vitro. Para bactérias relacionadas à doença periodontal, proantocianidinas, isoliquiritigenina, liquiritigenina, galangina, quercitrina, taxifolina, crisina, diosmetina, quercetina, miricetina, naringina, apigenina, catequinas, luteolina, morina e rutina foram investigadas. Para bactérias relacionadas à cárie dentária, baicaleína, naringenina, catequina, isoliquiritigenina, liquiritigenina, miricetina, quercetina e kaempferol já foram investigados. Atividade bacteriostática, bactericida e antibiofilme foram predominantemente relatadas. Para o desenvolvimento de uma resina experimental, naringina foi adicionada em concentrações de 5, 10 e 15mM. Testes laboratoriais foram conduzidos para avaliar a resistência flexural e modulo de elasticidade, alteração de cor, sorção e solubilidade e a citotoxicidade dessas resinas, comparado ao controle sem adição do flavonoide. Os dados foram analisados quanto à normalidade e homoscedasticidade. A resistência à flexão, o módulo de flexão, a sorção de água, a solubilidade em água, os parâmetros a* e C* e a citotoxicidade de 24 horas foram analisados por ANOVA de uma via seguida pelo teste de Tukey. L*, b* e WID foram analisados por Welch ANOVA seguido pelo teste T3 de Dunnett, pois os dados eram heteroscedásticos. A citotoxicidade após 48h e 72h foi analisada pelo teste de Kruskal Wallis e Dunn porque os dados não foram normalmente distribuídos e heteroscedásticos. A revisão de escopo demonstrou um potencial de ação dos flavonoides nas bactérias relacionadas à carie e doença periodontal, sendo promissor quanto ao desenvolvimento de novas terapias e novos materiais restauradores. As resinas compostas experimentais adicionadas de naringina não apresentaram citotoxicidade e não demonstraram efeitos deletérios quanto as propriedades físico-químicas, apesar de promover uma alteração na cor final da resina.

Flavonoids can be considered phytopharmaceutical substances, that is, they are obtained in nature and have benefits to human health. Some of these benefits are related to the cardiovascular system, chronic diseases such as diabetes, and oral disorders as periodontitis and dental caries. Thus, the objectives of the present study were: to analyze the antibacterial effects of different flavonoids against bacteria related to periodontal disease and dental caries through a scoping review; to evaluate the physicalchemical properties of an experimental resin composite with naringin addition. For the scoping review, nineteen articles were included, all in vitro studies. For bacteria related to periodontal disease, proanthocyanidins isoliquiritigenin, liquiritigenin, galangin, quercetrin, taxifolin, chrysin, diosmetin, quercetin, myricetin, naringin, apigenin, catechins, luteolin, morin and rutin were investigated. For bacteria related to dental caries, baicalein, naringenin, catechin, isoliquiritigenin, liquiritigenin, myricetin, quercetin and kaempferol have been investigated. Bacteriostatic, bactericidal and antibiofilm activity were predominantly reported. For the development of an experimental composite, naringin was added in concentrations of 5, 10 and 15mM. Laboratory tests were conducted to evaluate the flexural strength and flexural modulus, color change, sorption and solubility, and the cytotoxicity of these composites, compared to the control group without flavonoids addition. Data were analyzed for normality and homoscedasticity. Flexural strength, flexural modulus, water sorption, water solubility, a* and C* parameters, and 24-hour cytotoxicity were analyzed by one-way ANOVA followed by Tukey's test. L*, b* and WID were analyzed by Welch ANOVA followed by Dunnett's T3 test, as the data were heteroscedastic. While the 48h and 72h cytotoxicity was analyzed by the Kruskal Wallis and Dunn test, because the data were not normally distributed and heteroskedastic. The scope review demonstrated a potential action of flavonoids on bacteria related to caries and periodontal disease, with potential development of new therapies and new restorative materials. The experimental composites with naringin addition did not show cytotoxicity and did not demonstrate deleterious effects in terms of physicochemical properties, despite promoting a change in the final color of the resin.

Avaliação das características de superfície e variação de massa de diferentes tipos de resina após escovação simulada / Evaluation of surface characteristics and mass variation of different types of resin after simulated toothbrushing

Introdução: O aumento da exigência estética pelos pacientes e o contínuo desenvolvimento de materiais - tais como resinas bulk fill de alta e baixa viscosidade e flow, demanda uma crescente necessidade de estudos nesta área para avaliar as propriedades dos materiais quando submetidos ao desgaste ocasionado pela escovação dentária ao longo do tempo. Objetivo: Avaliar as características superficiais de restaurações antes e após o processo de escovação simulada e comparar os resultados entre os mesmos. Materiais e métodos: Foram confeccionados ao total 80 corpos de prova (7x4mm), sendo 20 para cada tipo de resina utilizada, na cor A1: Bulk Fill One (3M/ESPE, St. Paul, MN, USA), Bulk Fill Flow (3M/ESPE, St. Paul, MN, USA), Z350XT (3M/ESPE St. Paul, MN, USA) e Z350XT Flow (3M/ESPE, St. Paul, MN, USA). Após a confecção, os corpos de prova permaneceram por 24 horas imersos em água destilada em estufa a 37°C, momento no qual foi realizado o acabamento e polimento com a sequência de discos de lixa Praxis (TDV, Brasil). Metade dos corpos de prova foi submetida a 60,000 ciclos de escovação simulada, enquanto a outra metade foi o grupo controle (n=10). A superfície das restaurações foi avaliada por meio do Microscópio Eletrônico de Varredura (MEV), rugosidade superficial (Ra) e variação de massa (através de pesagem) das restaurações antes e após o processo de escovação simulada. Para análise estatística, foi utilizada a análise de variância ANOVA dois fatores e pós teste de Tukey. Resultados: Na análise feita pelo MEV, em amplificação de 500x, foi observada a protuberância de partículas médias e pequenas em todas as resinas após a escovação simulada, com exceção da resina de tipo Z350 flow. Todos os materiais apresentaram aumento da Ra após a escovação simulada. Com relação a variação de massa, não houve diferença estatisticamente significativa. Conclusão: O processo abrasivo ocasionado pela escovação leva a mudanças na disposição das partículas, o que ocasiona mudanças na superfície do material e aumento na rugosidade. Por outro lado, não foi demonstrada diferença com relação a variação de massa (AU).

Introduction: The increasing of the aesthetic exigency by the patients and the continual development of materials ­ such as bulk fill and flow composites, demands a crescent need of studies on this area to evaluate the properties of the materials when submitted to the wear occasioned by toothbrushing abrasion over time. Objective: To evaluate the surface characteristics of restorations performed before and after the process of simulated toothbrushing and to compare the results between the composites. Materials and methods: In total, 80 samples were made (7x4mm), being 20 to each type of resin utilized, color A1: Bulk Fill One (3M/ESPE, St. Paul, MN, USA), Bulk Fill Flow (3M/ESPE, St. Paul, MN, USA), Z350XT (3M/ESPE St. Paul, MN, USA) and Z350XT Flow (3M/ESPE, St. Paul, MN, USA). After the confection of the specimens, the samples were immersed in distilled water for 24 hours and stored at 37°C in stove, moment that was performed the finishing and polishing with the sequence of sandpaper discs (TDV, Brasil). Half of the specimens was submitted to 60,000 cycles of simulated toothbrushing, meanwhile the other half was the control group (n=10). The surface of the restorations was evaluated through Scanning Electronic Microscopy (SEM), surface roughness (Ra), and weight loss (through measurements), in two moments: before and after the process of simulated toothbrushing. To the statistical analysis, it was used the variance analysis ANOVA two factors and Tukey's post test. Results: In the analysis performed by SEM, in amplification of 500x, it was observed the presence of medium and small protruding particles in all resins tested after simulated toothbrushing, with exception of the resin Z350 flow. All materials presented increasing on Ra after simulated toothbrushing. Regarding to mass variation, there was not any significant statistical difference. Conclusion: The abrasive process occasioned by toothbrushing leads to changes on the particles disposition, which causes changes on the surface and increase on the roughness. On the other hand, there was not any difference regarding to mass variation (AU).

Avaliação da resistência adesiva de restaurações indiretas em resina composta com ou sem uso de material forrador após remoção seletiva da dentina / Evaluation of the adhesive strength of indirect composite resin restorations with or without the use of linear material after selective removal of dentin

O objetivo deste estudo foi analisar a resistência de união de restaurações indiretas cimentadas em superfícies dentinárias desmineralizadas com simulação da remoção seletiva da dentina com e sem uso de material forrador. Foram utilizados 60 dentes bovinos com a superfície vestibular desgastada até dentina sadia e divididos em quatro grupos: dentina sadia (controle), dentina desmineralizada (des), dentina desmineralizada e selada com resina flow (des-flow) e dentina desmineralizada e coberta com cimento de inonômero de vidro (des-civ). Todos os espécimes receberam condicionamento com ácido fosfórico (37% Condac, FGM) previamente a hibridização com adesivo universal (Single Bond Universal; 3M). O grupo des-civ recebeu uma cobertura de cimento de ionômero de vidro previamente ao condicionamento e hibridização e o grupo des-flow recebeu um selamento com resina flow (Resina Filtek Z350 XT Supreme Flowable, 3M) após condicionamento e hibridização. Em sequência, foram cimentadas peças simulando restaurações indiretas em resina composta (Grandioso ­ VOCO) na região condicionada de cada amostra. O conjunto recebeu fotoativação por 60 segundos em cada face da peça cimentada. Após 48 horas da cimentação, os espécimes dos três primeiros grupos foram submetidos aos testes mecânicos de tração, com velocidade de 1 mm/min. E após 29 dias, o quarto grupo foi submetido ao mesmo teste. A análise do tipo de fratura foi realizada por estereomicroscopia e os dados foram convertidos em MPa. Os resultados apresentaram diferença estatística de acordo com o teste ANOVA a 1 fator (p=0,011). Para as comparações múltiplas, o teste de Tukey apontou que o grupo des-flow apresentou valores menores do que o grupo controle. Todas as outras comparações foram similares. Concluiu-se que o grupo des-flow, quando comparado ao grupo controle, apresentou uma adesão inferior e que os materiais forradores não diferiram entre si (AU)

The aim of this study was to analyze the bond strength of cemented indirect restorations on demineralized dentin surfaces by simulating selective dentin removal with and without the use of a liner material. Sixty bovine teeth were used with the buccal surface worn down to healthy dentin and divided into four groups: healthy dentin (control), demineralized dentin (des), demineralized dentin sealed with flow resin (desflow) and demineralized dentin covered with glass ionomer cement (des-civ). All specimens were etched with phosphoric acid (37% Condac, FGM) prior to hybridization with universal adhesive (Single Bond Universal; 3M). The des-civ group received a glass ionomer cement cover prior to etching and hybridization, and the desflow group received a flowable resin seal (Filtek Z350 XT Supreme Flowable Resin, 3M) after etching and hybridization. Subsequently, specimens simulating indirect composite resin restorations (Grandioso - VOCO) were cemented in the etched region of each sample. The set was photoactivated for 60 seconds on each side. 48 hours after cementation, the specimens from the first three groups were subjected to mechanical tensile testing at a speed of 1 mm/min. After 29 days, the fourth group was subjected to the same test. The analysis of the fracture type was performed by stereomicroscopy and the data were converted into MPa. The results showed statistical difference according to the one-way ANOVA (p=0.011). For multiple comparisons, the Tukey's test showed that the des-flow group presented lower values than the control group. All other comparisons were similar. It was concluded that the des-flow group, when compared to the control group, presented lower adhesion and that the liner materials did not differ among themselves.(AU)