Flexural strength and Vickers hardness of milled and 3D-printed resins for provisional dental restorations

Various forms of temporary resins are offered on the market; however, the properties of temporary resins obtained by milling and 3D printing have not been fully examined. This study aimed to compare the flexural strength and Vickers hardness of milled and 3D-printed resins. Methods: Three resins were tested: Evolux PMMA (milled resin), Cosmos Temp (3D-printed resin), and Structur 2 SC (bis-acrylic resin, group control). Specimens were prepared with rectangular shapes (n = 12) for flexural strength measurements and disc shapes (n = 9) for Vickers hardness tests. Flexural strength tests were performed at a crosshead speed of 0.75 mm/min, and the Vickers hardness was measured under a load of 20 N for 10 s. The obtained data were subjected to the Kruskal­Wallis test. Results: A significant difference (p < 0.05) in flexural strength was observed among the three sample groups: Evolux PMMA (111.76 MPa), Structur 2 SC (87.34 MPa), and Cosmos Temp (56.83 MPa). No significant difference (p < 0.05) was observed between the Vickers hardness values of Structur 2 SC (33.37 VHN) and Evolux PMMA (29.11 VHN); however, both materials were statistically superior to Cosmos Temp (10.90 VHN). Conclusion: While the mechanical properties of the milled resin were superior or similar to those of the bisacrylic resin, the 3D-printed resin was statistically inferior to both the milled and bis-acrylic resins

Factors associated with decision-making for replacing the temporary coronal restoration after endodontic treatment

Aim: This study aimed to evaluate the decision-making by patients to replace temporary restorations with permanent restorations after endodontic treatment and to verify the associated factors and evaluate the quality/integrity of the temporary restorative material within one month. Methods: This is a cross-sectional study using non-probabilistic sampling which analyzed patients after one month of endodontic treatment. The self-administered questionnaire contained sociodemographic, treatment decision-making and endodontic treatment questions. The restoration present in the mouth was evaluated in the clinical oral examination. The Poisson Regression test was used to verify the prevalence ratio. Results: The prevalence failure to perform permanent restorations was 61.1% of patients, and 42.7% reported not having adhered. The reasons are lack of time and not knowing the importance of replacing the restoration with a definitive one. The glass ionomer temporary restorative frequency was higher among those who chose not to replace the temporary restoration with a permanent one (PR=5.19; 95%CI 2.10-12.33). In addition, there was an association between the quality of the restorative material and the type of material, and the best clinical quality of the restoration was statistically associated with glass ionomer and composite resin. Conclusions: The findings show the importance of guidance by the dental surgeon in helping patients decide to replace their temporary restoration

Influence of different separating mediums applied on the immediate dentin sealing in the tensile strength of temporary restorations / Influência de diferentes agentes isolantes aplicados sobre o selamento dentinário imediato na resistência à tração de restaurações provisórias

Objective: To evaluate the ability of different separating mediums to prevent adhesion between provisional restorations and hybridized dentin surfaces when used with the Immediate Dentin Sealing technique (IDS). Material and Methods: 120 extracted human teeth ­ 40 premolars and 80 molars ­ were selected to integrate acrylics samples separated into 4 different groups (n=10) according to the separating medium used for IDS protection. Forty samples were made of three teeth mounted in a self-cure acrylic resin block (Jet, Classic, São Paulo, Brazil) arranged side by side, simulating the positioning and proximal contacts present in the dental arch between the second premolar, first molar and second molar. A standard dental preparation for ultra-thin occlusal veneer was performed and complete occlusal dentin exposure was achieved by selective removal of the occlusal enamel with a high-speed conical round burr (Code: 1801.4138 FG, KG Sorensen, Medical Burs Ind. e Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brazil). Dentin hybridization were performed on the control group and 3 different groups of separating mediums (n=10): PC­commercial provisional separating agent (Pro-V Coat, Bisco, Schaumburg, USA); GG­glycerin gel (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brazil); PJ­petroleum jelly (Rioquímica, São Paulo, Brazil). Provisionalization were manufactured on the prepared teeth. After 2 weeks, the tensile test was performed, and the analysis of the failure pattern was performed by 3D laser confocal microscopy and Scanning Electron Microscopy (SEM). The data were analyzed with the 1-way ANOVA and the Tukey test (α = 0.05). Results: Significantly lower tensile strength values were found for the commercial provisional separating agent (30.39 ± 10.01 N) compared to others (p < 0.05). Conclusion: The commercial provisional separating agent showed greater effectiveness on protecting hybridized dentin against the provisional restorations (AU)

Objetivo: Avaliar a capacidade de diferentes agentes isolantes em prevenir a adesão entre as restaurações provisórias e a superfícies de dentina hibridizadas quando usados com a técnica do Selamento Dentinário Imediato (IDS). Material e Métodos: 120 dentes humanos extraídos - 40 pré-molares e 80 molares - foram selecionados para integrar as amostras de acrílico divididas em 4 grupos diferentes (n = 10) de acordo com o meio de separação usado para proteção IDS. Foram confeccionadas 40 amostras de três dentes montados em um bloco de resina acrílica autopolimerizável (Jet, Classic, São Paulo, Brasil) dispostos lado a lado, simulando o posicionamento e os contatos proximais presentes na arcada dentária entre o segundo pré-molar, primeiro molar e segundo molar. Um preparo dentário padrão para laminado oclusal ultrafino foi realizado e a exposição completa da dentina oclusal foi obtida pela remoção seletiva do esmalte oclusal com uma broca cônica arredondada de alta rotação (Código: 1801.4138 FG, KG Sorensen, Medical Burs Ind. E Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brasil). A hibridização da dentina foi realizada no grupo controle e em 3 grupos diferentes de agentes isolantes (n = 10): PC - agente de separação provisório comercial (Pro-V Coat, Bisco, Schaumburg, EUA); GG ­ gel de glicerina (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brasil); PJ ­ vaselina (Rioquímica, São Paulo, Brasil). As restaurações provisórias foram fabricadas nos dentes preparados. Após 2 semanas, foi realizado o teste de tração, e a análise do padrão de falha foi realizada por microscopia confocal a laser 3D e Microscopia Eletrônica de Varredura (MEV). Os dados foram analisados com a ANOVA de 1 fator e o teste de Tukey (α = 0,05). Resultados: Valores de resistência à tração significativamente menores foram encontrados para o agente separador provisório comercial (30,39 ± 10,01 N) em comparação com os demais (p < 0,05). Conclusão: O agente separador provisório comercial mostrou maior eficácia para a proteção da dentina hibridizada contra as restaurações provisórias (AU)

Color and surface gloss stability of bis-acryl and resin composite after exposure to cigarette smoke / Estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas após exposição por fumaça de cigarro

Objective: To evaluate color and surface gloss stability of bis-acryl resins and resin composites, submitted to artificial staining with cigarette smoke. Material and Methods: Specimens of each material were prepared (n=15). Two resin composites (GrandioSO [RCG], Filtek Supreme [RCZ]) and five bis-acryl resins (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] and Yprov [BisYPR]) were tested. Initial color was assessed using a spectrophotometer and surface gloss with a glossmeter. Samples were submitted to smoke exposure (10 cigarettes under 8 minutes per cycle). After 3 and 6 cycles, color and gloss were reassessed. Final readings were performed after brush prophylaxis. Data were analyzed using two-way repeated ANOVA and Tukey's test (p<0.05). Results: Differences and interaction of factors (p<0.01) were detected for both color and gloss readings. Resin composites were the least affected by aging, with gloss reduction after prophylaxis. Differences were detected among bis-acryl resins, with better results for BisLUX and BisPRO. BisPRO and BisSTR, showed reduction in gloss after 60 cigarettes, while BisYPR gloss decreased at all evaluated periods. Conclusion: Resin composites are less susceptible to changes after smoke exposure, while bis-acryl resins results are brand-dependent. Prophylaxis negatively influenced the surface gloss of most of the tested materials (AU)

Objetivo: Avaliar a estabilidade de cor e brilho superficial de resinas compostas e bisacrílicas, submetidos ao manchamento artificial por fumaça de cigarro. Material e Métodos: Foram preparados espécimes de cada material (n=15). Duas resinas compostas (GrandioSO [RCG], Filtek Supreme [RCZ]) e cinco resinas bisacrílicas (Luxatemp Star [BisLUX], Protemp4 [BisPRO], Structor3 [BisSTR], Visalys Temp [BisVIS] e Yprov [BisYPR]) foram testados. A cor inicial foi avaliada usando um espectrofotômetro e o brilho de superfície com um medidor de brilho. As amostras foram submetidas à exposição de fumaça de cigarro (10 cigarros com até 8 minutos por ciclo). Após 3 e 6 ciclos, a cor e o brilho foram reavaliados. As leituras finais foram realizadas após a profilaxia escova de robinson. Os dados foram analisados usando de medidas repetidas e teste de Tukey (p<0,05). Resultados: Foram detectadas diferenças e interação de fatores (p<0,01) tanto para leituras de cor quanto para leituras de brilho. As resinas compostas foram as menos afetados pelo envelhecimento, com redução do brilho após a profilaxia. Foram detectadas diferenças entre as resinas bisacrílicas, com melhores resultados para BisLUX e BisPRO. BisPRO e BisSTR, mostraram redução de brilho após 60 cigarros, enquanto que o brilho da BisYPR diminuiu em todos os períodos avaliados. Conclusão: As resinas compostas são as menos suscetíveis a mudanças após a exposição à fumaça, enquanto os resultados das resinas bisacrílicas são dependentes da marca. A profilaxia influenciou negativamente o brilho de superfície da maioria dos materiais testados.(AU)

SAT: Sistematización Adhesiva Temporaria. Integración estético-oclusal predecible en rehabilitación conservadora. Informe de caso y revisión bibliográfica / TAS: Temporary Adhesive Systematization. Predictable aesthetic-occlusal integration in conservative rehabilitation. Case report and bibliographic review

Objetivos: Realizar una revisión de la literatura sobre métodos de rehabilitación mínimamente invasivos, y presentar un caso clínico acerca de un nuevo procedimiento denominado sistematización adhesiva temporaria (SAT), destinado a pacientes que presentan pérdida de sustancia dentaria y que se caracteriza como un abordaje terapéutico predecible para transferir el proyecto rehabilitador (encerado) a la boca del paciente mediante 3 pasos bien definidos y con objetivos específicos. Caso clínico: Un paciente adulto joven de sexo masculino con desgastes severos por bruxismo es rehabilitado temporalmente con resinas compuestas (SAT) para devolver la anatomía perdida en forma adhesiva y conservadora, siguiendo un protocolo de abordaje terapéutico predecible denominado EGOP (estéticamente guiado y oclusalmente protegido). Este procedimiento, que es considerado muchas veces de transición previo a las restauraciones finales, nos permite evaluar la estética, la oclusión y mejorar la comunicación entre el equipo de trabajo para poder realizar el cambio por restauraciones cerámicas en forma gradual. En aquellos pacientes que necesitan rehabilitaciones totales producto del desgaste dentario severo, la SAT puede ser una herramienta que facilite al odontólogo la posibilidad de restablecer los patrones oclusales y estéticos perdidos sin la necesidad de realizar desgastes dentarios y provisionales como se hacía clásicamente (AU)

Aims: To carry out a literature review on minimally-invasive rehabilitation methods and to present a clinical case on a new procedure called Temporary Adhesive Systemization (TAS), intended for patients that show a considerable loss of dental substance, characterized by a predictable therapeutic approach to transfer the rehabilitation diagnosis wax-up through 3 well defined steps and with specific objectives to the patient´s dentition. Clinical case: A young adult male patient with severe wear due to bruxism is temporarily rehabilitated with composite resins (TAS) to return the lost anatomy in a conservative way, following a predictable therapeutic approach protocol called EGOP (aesthetically guided and occlusally protected). This procedure, which is often considered transitional prior to final restorations, allows us to evaluate aesthetics, occlusion, improve communication between the working team and to be able to gradually change for ceramic restorations. In patients that need full rehabilitation due to severe dental erosion, TAS is a predictable procedure that helps the dentist to re-establish the loss of aesthetical and occlusal patterns, without the need of preparing the teeth for the classic provisional restorations (AU)

Percepción de estudiantes respecto al recambio de restauraciones / Students' perception regarding the replacement of restorations

Introducción: El reemplazo de restauraciones defectuosas representa la mayor parte de la práctica del odontólogo, lo que lleva a una perdida mayor del remanente dentario ante cada reemplazo. Objetivo: Determinar si existe variación del criterio clínico en alumnos frente a la decisión de recambio en restauraciones de resina compuesta previo y posterior al reacondicionamiento. Material y Métodos: Estudio analítico transversal. Se contó con una muestra de 40 estudiantes de quinto año de un universo de 72. Se utilizó un set fotográfico, que contaba con restauraciones defectuosas, en uno o más parámetros según los criterios RYGE/USPHS, las cuales posteriormente se reacondicionaron, por lo que se contaba con las fotografías del antes y del después del tratamiento conservador. Se realizó una encuesta a partir de las fotografías mostradas en la cual debían indicar la elección de tratamiento. Resultados: Se observó que hay una gran variación de elección de tratamiento previo a ser reparadas con tratamientos conservadores: 38 por ciento y no conservador de 62 por ciento y frente a la misma restauración de resina posterior a haber sido intervenida la elección de tratamiento conservador fue de 83 por ciento y no conservador 17 por ciento. Mediante el Test de McNemar se obtuvo un p<0.0001 entre elección de tratamiento conservador por sobre el no conservador posterior a haber sido realizada el reacondicionamiento de la restauración. Conclusiones: Existe un cambio en la percepción sobre la indicación de tratamiento de restauraciones defectuosas, a favor de una alternativa conservadora, después de que han sido intervenidas con procedimientos mínimamente invasivos(AU)

Introduction: The replacement of defective restorations, which leads to a greater loss of the dental remnant before each replacement, represents the large majority of the dentist's practice. Objective: To determine if there is any variation in students´ clinical criterion in relation to the decision of replacement of composite resin restorations prior to and following reconditioning. Material and Methods: A cross-sectional analytical study was conducted. The sample was composed of 40 fifth-year students in a universe of 72. A set of photographs showing defective restorations in one or more parameters evaluated according to RYGE / USPHS criteria was used. They were later reconditioned, so there were photographs prior to and following conservative treatment. Based on the photographs shown, a survey in which they had to indicate the choice of treatment was performed. Results: We observed that there is a great variation in the choice of treatment prior to the repair with conservative treatments (38 percent) and non-conservative ones (62 percent), compared to the same resin restoration after the choice of conservative treatment (83 percent) and non-conservative one (17 percent). Using the McNemar Test, p<0.0001 was obtained between the choice of conservative treatment over the non-conservative one after the restoration reconditioning had been performed. Conclusions: There is a change in perception of the indication of treatment to repair defective restorations towards a conservative alternative after they have undergone minimally invasive procedures(AU)

Influence of viscosity and chemical composition of composite resins in non-carious cervical restorations: 12-month randomized clinical trial / Influência da viscosidade e composição química das resina compostas em restaurações de lesões cervicais não-cariosas: resultados de 12 meses de uma pesquisa clínica randomizada

Objective: The objective of this double-blind, randomized controlled clinical trial was to evaluate the clinical performance of two methacrylate-based flowable composite and ormocer-based flowable composite in non-carious cervical lesions (NCCLs) of adult patients. Material and Methods: 183 restorations were performed on NCCLs using the Futurabond U adhesive system, applied in the selective enamel etching mode in all cavities. After the adhesive application, the cavities were restored with one out of the three evaluated flowable composites (n = 61 per group): ormocer-based flowable composite (Admira Fusion Flow, ORM), low viscosity methacrylate-based composite (GrandioSO Flow, LV) and high viscosity methacrylate-based composite (GrandioSO Heavy Flow, HV). After 12 months of clinical performance, these restorations were evaluated according to FDI and USPHS criteria in the following items: retention/fracture, marginal adaptation, marginal staining, postoperative sensitivity and caries recurrence. Results: eight restorations were lost/fractured after 12 months of clinical evaluation (1 in the ORM and 7 in the HV group). The retention rates for 12- months (95% confidence interval) were 98.4% (91.3%-99.7%) for the ORM group, 100% (94.5%-100%) for the LV group and 88.5% (78.1%-94.3%) for the HV group, with no statistical difference identified between any pair of groups (p > 0.05). Five restorations presented small marginal adaptation defects at the 12-months evaluation recall, and all of them were considered clinically acceptable. Conclusion: The clinical performance of the universal adhesive associated to ormocer-based or methacrylate-based flowable composite were found to be promising after 12-month of clinical evaluation (AU)

Objetivo: O objetivo deste estudo clínico duplo-cego randomizado foi comparar as taxas de retenção de um compósito fluido à base de Ormocer versus dois compósitos fluidos à base de metacrilato quando utilizados em lesões cervicais não cariosas (LCNCs) de pacientes adultos. Material e Métodos: 183 restaurações foram realizadas em LCNCs utilizando o sistema adesivo Futurabond U, aplicado no modo de condicionamento seletivo do esmalte em todas as cavidades. Após a aplicação do adesivo, as cavidades foram restauradas com um dos três compósitos fluidos avaliados (n = 61 por grupo): compósito fluido à base de ormocer (Admira Fusion Flow, ORM), compósito à base de metacrilato de baixa viscosidade (GrandioSO Flow, LV) e compósito à base de metacrilato de alta viscosidade (GrandioSO Heavy Flow, HV). Após 12 meses de desempenho clínico, essas restaurações foram avaliadas de acordo com os critérios FDI e USPHS nos seguintes itens: retenção / fratura, adaptação marginal, coloração marginal, sensibilidade pós-operatória e recorrência de cárie. Resultados: oito restaurações foram perdidas / fraturadas após 12 meses de avaliação clínica (1 no grupo ORM e 7 no grupo HV). As taxas de retenção por 12 meses (intervalo de confiança de 95%) foram 98,4% (91,3% -99,7%) para o grupo ORM, 100% (94,5% -100%) para o grupo LV e 88,5% (78,1% -94,3%) para o grupo HV, sem diferença estatística identificada entre nenhum par de grupos (p> 0,05). Cinco restaurações apresentaram pequenos defeitos de adaptação marginais no período de avaliação de 12 meses, e todas foram consideradas clinicamente aceitáveis. Conclusão: O desempenho clínico do adesivo universal associado ao compósito fluido à base de ormocer ou metacrilato mostrou-se promissor após 12 meses de avaliação clínica(AU)

Resistência flexural e adaptação marginal dos materiais restauradores provisórios utilizados em dentes tratados endodonticamente / Flexural strength and marginal adaptation of temporary restorative materials used in endodontically treated teeth

Avaliar a resistência flexural e a adaptação marginal dos materiais restauradores provisórios Clip F (CF),Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) e Provi Master F (PF), na dentina da coroa dentária de dentes tratados endodonticamente. Métodos: Inicial-mente, foram confeccionados dez espécimes de cada um dos materiais restauradores, que foram individualmente submetidos ao teste de resistência flexural, na máquina de ensaio eletromecânica. Para avaliar a adaptação marginal,a câmara pulpar de cinquenta pré-molares superiores foi restaurada com um dos materiais avaliados (n=10). Após sete dias, a interface entre a dentina e o material restaurador, no terço médio da coroa dentária, foi submetida à análise em microscopia eletrônica de varredura. A extensão de desadaptação dos materiais e os gaps formados com a dentina foram mensurados com o software Image J.Resultados: CF e BT demonstraram o maior e o menor valor de resistência flexural, respectivamente (p<0,05).Os valores demonstrados por SO, FT e PF foram similares entre si (p>0,05). Por outro lado, CF demonstrou a menor extensão de desadaptação marginal (em porcentagem)e extensão de gaps (em µm) (p<0,05) na interface com a dentina. BT apresentou valor intermediário, mas menor do que os dos SO, FT e PF (p<0,05) que, por sua vez, foram similares entre si (p>0,05). Conclusões: O CF demonstrou o maior índice de resistência flexural e menor extensão de desadaptação marginal e gaps, em comparação aos demais materiais restauradores provisórios (AU).

Objectve: This study evaluated the flexural strength and marginal adaptation of Clip F (CF), Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) and Provi Master F (PF) in endodontically-treated coronal dentin. Methods: Firstly, ten specimens of each restorative material were prepared, and submitted to flexural strength test using eletromechanical testing machine. Then, the pulp chamber of 50 maxillary premolar were restored using one of the provisional restorative materials (n = 10) in order to evaluate the marginal desadaptation extension. After 7 days, the interface between dentin and temporary restorative material, in crown middle third, was subjected to scanning electron microscopy (500X). Marginal desadaptation and gaps extensions in dentin-temporary restorations interface were measured using Image J software. Results: CF and BT presented the highest and the lowest flexural strength values, respectively (p <0.05). SO, FT and PF showed similar values (p> 0.05). In relation to marginal desadaptation (%) and gap extensions (µm), CF presented the lowest marginal desadaptation and gaps incidence values (p < 0.05). BT showed intermediate values, but lower than SO, FT e PF (p < 0.05), which were similar among them (p > 0.05). Conclusion: CF presented the best flexural strength and the lowest marginal desadaptation and gaps extension (AU).

Effect of Ions Released and pH of Two Glass Ionomer Cements in Human Gingival Fibroblasts / Efecto de la liberación de iones y pH de dos cementos de ionómero de vidrio en fibroblastos gingivales humanos

Abstract 20. Conventional glass ionomer cements are used as dental provisional restorative materials, which present several advantages such as adhesion to the tooth mineral phase among others. On the other hand, the knowledge about biological property of glass ionomers shows various approaches and results. In this work, it was studied the in vitro biological response of human gingival fibroblasts in contact with commercial cements of glass ionomer: Mirafil® and Ionglass® and with their extracts, according to ISO 10993. The extracts of the cements, in which the cells were cultured, were adjusted at different concentrations ranging 0.1% to 100%. The cellular metabolic activity of gingival fibroblasts was measured using the Alamar Blue® reagent. The results showed a significant effect on the cellular metabolic activity correlated with the concentration of liberated ions (Al³+ and Ca²+) for both ionomers, as well as the pH variations of the culture media. This could mean that the cellular metabolic activity is substantially influenced by ions and pH of the cell culture.

Resumen 24. Los cementos de ionómero de vidrio convencionales se utilizan como materiales de restauración provisional para uso dental, los cuales presentan varias ventajas como la adhesión a la fase mineral de los dientes. Por otro lado, las propiedades biológicas de los ionómeros de vidrio muestran diversos enfoques y resultados. En éste trabajo se estudió la respuesta biológica in vitro de fibroblastos gingivales humanos en contacto con cementos comerciales de ionómero de vidrio: Mirafil® e Ionglass® y con sus respectivos extractos según la norma ISO 10993. Los extractos de los cementos en los que se cultivaron las células estaban en diferentes concentraciones: de 0.1% a 100%. La actividad metabólica celular se midió usando el reactivo Alamar Blue®. Los resultados mostraron un efecto significativo sobre la actividad metabólica celular correlacionada con la concentración de iones liberados (Al³+ y Ca²+) para ambos ionómeros, así como las variaciones de pH de los medios de cultivo. Ello podria explicar la influencia por los iones y el pH del cultivo celular en la actividad metabólica celular.

Tendências atuais no tratamento endodôntico por cirurgiões dentistas no Brasil / Current trends in endodontic treatment by dental surgeons in Brazil

Objetivo: conhecer as principais práticas adotadas atualmente por cirurgiões dentistas, clínicos gerais e endodontistas na realização do tratamento endodôntico. Material e Métodos: um questionário contendo 21 perguntas de múltipla escolha foi enviado para os profissionais, nas cinco regiões do país. As perguntas abordaram o tempo de experiência, tipos de técnicas, materiais e recursos auxiliares. Resultados: a maior parte dos respondentes são do Sudeste e Sul, endodontistas há menos de 10 anos. Realizam até 20 tratamentos/mês, utilizam localizador apical, instrumentação manual com limas de aço inoxidável associada a brocas gates glidden/largo, lupa e isolamento absoluto. O hipoclorito de sódio (2,5 a 5%) e o EDTA são os irrigantes mais utilizados juntamente com o ultrassom. O tratamento é feito em sessão única, porém o diagnóstico pulpar pode alterar o número de sessões. Quando é necessário o uso de medicação intracanal, o hidróxido de cálcio associado a outras formulações é a primeira escolha. Para obturação do sistema de canais radiculares é utilizada a técnica de condensação lateral e o cimento à base de óxido de zinco e eugenol. O selamento coronário entre sessões é feito com coltosol e com cimento de ionômero de vidro ao término do tratamento, quando os pacientes são encaminhados a outro profissional para restauração final. Atualizam-se através de artigos científicos e mostram abertura para testar novos produtos. Conclusão: a maioria dos participantes aderem a práticas atuais com uso de novas tecnologias durante o tratamento e se atualizam através da leitura de artigos científicos

Objective: to be aware of the main practices currently adopted by general dentists and endodontists when performing endodontic treatments. Material and methods: a questionnaire containing 21 multiple-choice questions was sent to professionals in the five regions of Brazil. These questions covered experience time, techniques, materials and auxiliary resources. Results: most participants are from the Southeast and South regions of Brazil and have been specialized in endodontic for less than 10 years. They perform up to 20 treatments per month, use apex locator, manual instrumentation with stainless steel files associated with gates-glidden or largo burs, magnifying loupes and absolute isolation. Sodium hypochlorite (2.5 to 5.0%) and EDTA are the most used substances for irrigation associated with ultrasound. The treatment is done in a single visit, but pulp diagnosis might alter the number of visits. When intracanal medication is required, calcium hydroxide associated with other formulations is the first choice. For root canal filling, lateral condensation technique, zinc oxide and eugenol based sealers are used. Coronal sealing between sessions is done with Coltosol® and glass ionomer cement at the end of treatment, when patients are referred to another professional for final restoration. These professionals update their knowledge with scientific articles and show availability to test new products. Conclusion: most participants have been adhering to current practices (new technologies) during treatment and has kept updated by reading scientific articles

Adaptación marginal y resistencia a la tracción de coronas provisionales cementadas con dos tipos de cemento provisional / Marginal adaptation and tensile strength of interim crowns with two types of cemented provisional cement / Adaptação marginal e resistência à tração de coroas provisórias cimentadas com dois tipos de cimento provisório

Entre los requerimientos que debe cumplir una restauración provisional, destacan la adaptación marginal precisa y el sellado adecuado del agente cementante temporal. Objetivo: Comparar la adaptación marginal y resistencia a la tracción de coronas provisionales fabricadas con acrílico de termocurado y resina, cementadas con dos tipos de biomaterial. Me-todología: Estudio in vitro. 40 premolares superiores fueron tallados para recibir una corona completa que se confeccionó con dos tipos de biomaterial provisional (n=20): acrílico de termocurado Veracril® y resina Temp Basic® - CAD/CAM. Las coronas fueron cementadas con dos agentes cementantes temporales (Dycal® y TempBond NE®), se observó la adapta-ción marginal por medio de un estéreo microscopio; después, fueron sometidas a termociclado por 2.500 ciclos y luego se realizó una segunda observación y medición, finalmente se realizaron pruebas de tracción. Resultados: Mediante Kruskal Wallis se encontró diferencias significativas entre los grupos en ambos tiempos de estudio. Los grupos cementados con Dycal® presentaron mejor sellado marginal antes y después del termociclado y mayor resistencia a la tracción que los ce-mentados con TempBond NE® (p= <0,05). En todos los grupos la adaptación marginal fue menor después del termocicla-do (p= <0,05). Por medio del coeficiente de Pearson se determinó una correlación negativa (- 0.97) entre la desadaptación marginal y la resistencia a la tracción. Conclusiones: La desadaptación marginal tiene relación con el cemento utilizado, las coronas provisionales cementadas con Dycal® presentaron estadísticamente menor discrepancia marginal y mayores fuerzas de retención con relación al TempBond NE. El proceso de termociclado influyó en el aumento de la desadaptación marginal en todos los grupos. Cuando la desadaptación fue mayor disminuyó la resistencia a la tracción.

Among the requirements that must be carried out by a provisional restoration, the precise marginal adaptation and ade-quate sealing of the temporary cementing agent stand out. Objective: To compare the marginal adaptation and tensile strength of temporary crowns made of thermo-curing acrylic and resin, cemented with two types of biomaterial. Meth-odology: In vitro study. 40 upper premolars were carved to receive a complete crown that was made with two types of provisional biomaterial (n = 20): Veracril® thermosetting acrylic and Temp Basic® resin - CAD / CAM. The crowns were cemented with two temporary cementing agents (Dycal® and TempBond NE®), marginal adaptation was observed by means of a stereo microscope; then, they were subjected to thermocycling for 2,500 cycles and then a second observation and measurement was performed, finally tensile tests were performed. Results: Kruskal Wallis found significant differences between the groups in both study times. The groups cemented with Dycal® presented better marginal sealing before and after thermocycling and greater tensile strength than those cemented with TempBond NE® (p = <0.05). In all groups the marginal adaptation was lower after thermocycling (p = <0.05). By means of the Pearson coefficient, a negative correlation (- 0.97) was determined between marginal maladjustment and tensile strength. Conclusions: The marginal microleakage is related to the cement used, the provisional crowns cemented with Dycal® presented statistically lower marginal dis-crepancy and greater retention forces in relation to TempBond NE. The thermocycling process influenced the increase in marginal maladjustment in all groups. When the maladjustment was higher, the tensile strength decreased.

Entre os requisitos que uma restauração provisória deve atender, destacam-se a adaptação marginal precisa e o selamen-to adequado do agente de cimentação temporário. Objetivo: Comparar a adaptação marginal e resistência à tração de coroas temporárias de acrílico e resina de termopolimerização, cimentadas com dois tipos de biomateriais. Metodologia: Estudo in vitro. 40 pré-molares superiores foram preparados para receber uma coroa completa confeccionada com dois tipos de biomaterial provisório (n = 20): acrílico de termopolimerização Veracril® e resina Temp Basic® - CAD / CAM. As coroas foram cimentadas com dois agentes de cimentação temporários (Dycal® e TempBond NE®); a adaptação margi-nal foi observada por meio de estéreo microscópio; depois, foram submetidos a termociclagem por 2.500 ciclos térmicos e, em seguida, uma segunda observação e medição foi realizada; finalmente, testes de tração foram realizados. Resulta-dos: no teste Kruskal Wallis encontrou-se diferenças significativas entre os grupos nos dois tempos de estudo. Os grupos cimentados com Dycal® apresentaram melhor selamento marginal antes e depois da termociclagem e maior resistência à tração do que os cimentados com TempBond NE® (p = <0,05). Em todos os grupos, a adaptação marginal foi menor após da termociclagem (p = <0,05). Por meio do coeficiente de Pearson, foi determinada uma correlação negativa (- 0,97) entre discrepância marginal e resistência à tração. Conclusões: A perda da adaptação marginal está relacionada ao cimento utilizado, as coroas provisórias cimentadas com Dycal® apresentaram discrepância marginal menor estatisticamente significativa e maiores forças de retenção em relação ao TempBond® NE. O processo de termociclagem influenciou o au-mento da desadaptação marginal em todos os grupos. Quando a desadaptação foi maior, a resistência à tração diminuiu.

Marginal adaptation of provisional crowns made of acrylic and bisacrylic resins using different impression materials

Aim: To evaluate the marginal adaptation of provisional crowns made of acrylic and bisacrylic resins using different impression materials. Methods: a metal die and a matrix applied through a direct technique were used to fabricate the specimens. The impression materials used as a matrix were divided into four groups: Irreversible hydrocolloid(IH), laboratory silicone (LS), condensation silicone (CS), and addition silicone (AS). After the impression procedures, each matrix was loaded with the provisional prosthetic materials, Alike, Duralay, Protemp 4, and Structur 3 (n = 12). Marginal discrepancy was evaluated using a stereomicroscope at ×45 magnification. The images obtained were transferred to the Corel Draw X7 program, and the distances from the cervical margins of the specimen to the reference lines at the metal die were measured vertically. The data were analyzed by using 2-way ANOVA followed by the Tukey test (α=.05). Results: the acrylic resins had higher values ​​of marginal discrepancy compared to the bisacrylic resins. A statistically significant difference was found between all impression materials, and the irreversible hydrocolloid presented higher values of discrepancy (303.28­613.31 µm), whereas addition silicone had the lowest (48.61­190.06 µm). Conclusions: the bisacrylic resins had a better marginal adaptation compared to the acrylic resins. The addition silicone promoted a better marginal adaptation of the provisional prosthetic materials tested, followed by condensation silicone, laboratory silicone, and irreversible hydrocolloid

Development and characterization of a novel bulk-fill elastomeric temporary restorative composite

Abstract Objectives: This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM). Material and Methods: Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans' biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%). Results: The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs. Conclusions: The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

Evaluation of the marginal accuracy of provisional restorations made of acrylic resins

Aim: To evaluate the marginal accuracy of provisional crowns made with acrylics resins and to identify the surface(s) with the highest marginal discrepancy. Methods: A direct technique was used to fabricate 96 provisional restorations with 8 materials: Dencrilay, Dencôrlay, Dencôr, Vipicor, Duralay, Resinlay Speed, Refine Bright and Alike (n=12). The provisional crowns were made on a prepared molar-shaped metal die with a vinyl polysiloxane impression as a matrix. Marginal discrepancy of provisional restorations was analyzed at buccal, lingual, mesial and distal surfaces of metal die finish line in a stereomicroscope lupe at 100X. The images obtained were transferred to the Corel Draw X7 program and the distances from the cervical margins of the specimen to the reference lines were measured vertically. Comparisons were made with 1-way analysis of variance and the Tukey test (p <0.05). Results: The Alike resin exhibited the lowest marginal discrepancy (0.018 mm) and was significantly different from the Dencôrlay (0.037 mm), Filter Bright (0.034 mm), Duralay (0.033 mm) and Vipicor (0.032) resins. The buccal surface showed the highest marginal discrepancy (0.040 mm) compared to those of other surfaces (distal 0.029mm, lingual 0.028mm and mesial 0.024mm). Conclusion: The marginal adaptation of all materials and surfaces tested in this study were within a clinical acceptable limit. The Alike resin showed the best performance compared to Dencôrlay, Refine Bright, Duralay, and Vipicor resins. The buccal surface showed the highest marginal discrepancy than those of the other tested surfaces

Comparação da exotermia de resinas durante a restauração provisória direta / Comparison of resin exotherm during direct provisional restoration

Resumo Introdução As resinas de polimetilmetacrilato e as bisacrílicas são materiais amplamente utilizados para a confecção de restaurações provisórias; no entanto, ambas apresentam uma característica de exotermia durante a polimerização que deve ser investigada por causa de possíveis interferências no sucesso clínico. Objetivo Avaliar a variação de temperatura de polimerização da resina bisacrílica e de uma resina acrílica quimicamente ativada, em preparos classe V, pelo método direto. Material e método Para isso, vinte dentes incisivos inferiores bovinos foram divididos em dois grupos: RA (N=10) com dentes restaurados com resina acrílica e RB (N=10) com dentes restaurados com resina bisacrílica. As mensurações das variações térmicas foram realizadas através de termopares tipo J, ligados a um termômetro óptico, e analisadas por um computador equipado com o software específico. Os dados obtidos foram analisados e submetidos à análise de médias comparadas pelo teste de Tukey (significância de 5%). Resultado Foi possível observar que não houve diferença estatística significante entre ambos os grupos experimentais (p=0,0739), mesmo que aumento de temperatura de RA tenha apresentado média maior (0,52 °C) do que RB (0,44 °C). Conclusão Não existe diferença significativa experimental entre o calor emitido pela resina acrílica e pela resina bisacrílica durante seus processos de polimerização, não definindo a característica de escolha de uma destas para as restaurações provisórias diretas.

Abstract Introduction Polymethyl methacrylate and bis-acryl resins are materials widely used for temporary restorations, however, both have a characteristic of polymerization exotermia that should be investigated because of possible interferences in clinical success. Objective to evaluate the variation of the polymerization temperature of bis-acryl resin and a chemically activated acrylic resin in the temporary restoration by the direct method. Material and method Twenty bovine mandibular incisor teeth were divided into two groups: AR (N = 10) teeth restored with acrylic resin and BR (N = 10) teeth restored with bis-acryl resin. Measurements of thermal variations were performed using type J thermocouples, connected to an optical thermometer and analyzed by a computer equipped with specific software. The obtained data were analyzed and submitted to the analysis of means compared by Tukey test (significance of 5%). Result It was observed that there was no statistically significant difference between both experimental groups (p = 0.0739), even though AR temperature increase presented higher average (0.52ºC) than BR (0.44ºC). Conclusion There is no significant experimental difference between the heat emitted by acrylic resin and bis-acryl resin during their polymerization processes, not defining the factor that characterizes a choice of a material for temporary restorations.

Restauraciones transicionales de resina mediante la técnica de matriz transparente / Transitional resin restorations with the transparent matrix technique

La colocación de restauraciones directas a base de resina en el área de premolares y molares permite realizar tratamientos complejos en pacientes afectados por atrición dental severa y/o bruxismo. Hoy en día gracias a la técnica de grabado ácido, la fuerza de adhesión de la resina al esmalte disminuye la microfi ltración y sensibilidad postoperatoria. El objetivo de este artículo es describir la rehabilitación provisional mediante restauraciones adhesivas de resina compuesta en un paciente con atrición dental severa, el cual recibirá posteriormente tratamiento de ortodoncia por discrepancia de las arcadas. Al término de este tratamiento se colocarán restauraciones onlay de disilicato de litio (AU)

The placement of resin-based direct restorations in the area of premolars and molars allows the treatment of complex cases in patients aff ected by dental attrition and/or bruxism. Nowadays, due to the acid etching technique, the bond strength of the resin to the enamel will reduce the micro-leakage and post-operative sensitivity. The aim of this article is to describe the provisional rehabilitation with resin adhesive restorations, in a patient with a severe dental attrition, which will receive orthodontic treatment due to discrepancies in the arches. At the end of this treatment, ceramic restorations will be placed (AU)

Effect of colorant solutions on the color stability of provisional prosthetic materials

Aim: To evaluate the color stability of acrylic and bis-acrylic resins after immersion in 3 staining solutions. Methods: Forty-eight samples (10 x 2 mm) of each provisional restorative material (Duralay, Dencrilay, Structur 2 and Protemp 4) were fabricated and distributed into four groups (n = 12): G1 ­ distilled water (control group); G2 ­ a cola flavored soft drink; G3 ­ wine and G4 ­ coffee. The specimens were immersed for seven days at 37°C in the solutions, which were changed every 24 hours. The color of all specimens was measured with a spectrophotometer (VITA Easyshade Advance) before (T0) and after immersion (T1), and the color changes (ΔE) were calculated. Nonparametric Kruskal-Wallis tests were used, followed by Dunn's test with a significance level of 5%. Results: For the acrylic resins (Duralay and Dencrilay), the largest color change values were obtained in group G4 ­ coffee, whereas in the bis-acrylic resins (Protemp 4 and Structur 2), the largest color difference was observed in groups G3 ­ wine and G4 ­ coffee. The acrylic resins showed statistically significantly less color change than the bis-acrylic resins. Conclusions: The coffee and the wine promoted larger color changes in the provisional prosthetic materials tested in this study. The acrylic resins showed more color stability than the bis-acrylic resins

Evaluación in vitro de la dureza superficial en amalgamas y coronas de acero cromado / Avaliação in vitro da dureza superficial em amálgamas e coroas de aço / In vitro evaluation of micro-hardness of amalgam and stainless-steel crowns

Introducción: la elección del material restaurador es uno de los puntos críticos cuando se va a restaurar un diente temporal. Tradicionalmente, la corona de acero cromado ha sido empleada en dientes con extensa destrucción coronal o posterior a un tratamiento pulpar; no obstante, la amalgama también ha sido muy utilizada. Existen estudios que miden el porcentaje de éxito a nivel clínico de dichos materiales, sin embargo, no hay investigaciones que midan y comparen las propiedades físicas. Objetivo: evaluar la dureza superficial en amalgamas y coronas de acero cromado. Materiales y método: se confeccionaron 15 cuerpos de prueba de amalgama SDI tipo GS80, y 15 cuerpos de prueba con un trozo de corona de acero cromado marca 3M. Los cuerpos de prueba se elaboraron en dos tiempos diferentes, unos fueron alma-1. DDS, Especialista en Odontopediatría. Profesora de Odontopediatría, Facultad de Odontología, Universidad de Costa Rica, San José, Costa Rica. 2. DDS, MSc. Profesora, Facultada de Odontología, ULACIT Universidad Latinoamericana de Ciencia y Tecnología, San José, Costa Rica. cenados por 4 años y los otros por 3 días al 100% de humedad relativa. A cada cuerpo de prueba se le hicieron 2 indentaciones con el microdurómetro Micromet 2001 para determinar la dureza superficial. Los resultados obtenidos fueron evaluados por el test ANOVA (p≤0,05) Resultados: se comprobó que la media de la dureza superficial de la corona de acero cromado es significativamente mayor que la media de la amalgama (p=0,000). La dureza superficial de la amalgama aumenta de forma significativa con el tiempo de almacenamiento (p=0,000). Conclusiones: el material que presentó mayor dureza superficial fue la corona de acero cromado. Los valores de microdureza de la amalgama son tiempo-dependientes, no así los valores registrados con las coronas de acero cromado.

Introdução: a seleção do material restaurador é um ponto crítico no momento da restauração de dentes decíduos.Tradicionalmente, a coroa de aço tem sido utilizada em dentes com muita destruição coronária ou após tratamento endodôntico, porém o amálgama pode também ser utilizado nesses casos. Existem estudos que determinam a porcentagem de sucesso a nível clínico desses materiais, no entanto, poucas pesquisas medem e comparam as propriedades físicas. Objetivo: avaliar a dureza superficial em amálgamas dentais e coroas de aço. Materiais e método: foram elaborados 15 corpos de prova de amálgama SDI tipo GS80, e 15 corpos de prova com um fragmento de coroa de aço marca 3M. A fabricação dos corpos de prova ocorreu em dois tempos distintos, sendo alguns armazenados por 4 anos e outros por 3 dias a 100% de umidade relativa. A dureza superficial foi determinada a partir de duas endentações feitas com o microdurômetro Micromet 2001 em cada corpo de prova. Os resultados foram avaliados com o teste de ANOVA (p≤0,05). Resultados: a média da dureza superficial da coroa de aço foi significativamente maior que a média da dureza do amálgama (p=0,000). A dureza superficial do amálgama aumenta significativamente conforme o tempo de armazenamento (p=0,000). Conclusões: a coroa de aço foi o material que apresentou maior dureza superficial. Os valores da microdureza do amálgama são tempo-dependentes, diferentemente dos valores da coroa de aço.

Introduction: the choice of the restorative material is critical for the restoration of primary teeth. Traditionally, stainless-steel crowns have been used in teeth with extensive crown destruction or after pulp treatment; however amalgam can be used too. There are studies that have measured the clinical success of these materials; however, there are no reports that have measured and compared the physical properties between them. Aim: evaluate the micro-hardness of dental amalgam and stainless steel crown. Method and materials: test objects of SDI amalgam type GS80 (15) and 3M stainless-steel crown (15) were made in two different times, some were stored for 4 years and the others for 3 days at 100% relative humidity. Two indentations were made to each test object with the Micromet 2001 microdurometer to determine the micro-hardness. The results obtained were evaluated by the ANOVA test (p≤0.05). Results: the average of the microhardness stainless steel crown was significantly higher than the average of the amalgam (p=0.000). The micro-hardness of the amalgam increases significantly with the storage time (p=0.000). Conclusions: the stainless-steel crown was the material with the highest micro-hardness. The micro-hardness values of the amalgam are time-dependent.