Radiopacity and physical properties evaluation of infiltrants with Barium and Ytterbium addition

Abstract Radiopaque properties in the infiltrant should be interesting for clinicians to feel more confident to indicate this treatment. Thus, the aim of this study was to evaluate the effect of the incorporation of barium and ytterbium particles on the physical properties of resin infiltrants. Groups were divided according to the addition of ytterbium oxide (Y) alone (30 or 40%) or Y with barium (YB) (15/15% or 20/20% respectively) in the Icon commercial infiltrant and in the experimental infiltrant base. Digital radiography (n=5), Microradiography (n=5), Microtomography (n=3), degree of conversion (n=5), water sorption (n=16), solubility (n=16), contact angle (n=16), flexural strength (n=16), elastic modulus (n=16) and Energy dispersive X-ray Spectroscopy (n=10) were performed. Analyses were performed using the R program, with a significance level of 5%, and microradiography and Microtomography analyses were evaluated qualitatively. In groups with 30 or 40% of ytterbium, radiopacity was higher or equal to enamel. Microradiography and Microtomography appear to have more radiopacity in groups with 40% (Y). Among the groups with no particle addition, those of the experimental infiltrant presented a higher degree of conversion than those of Icon®. In most groups, there was solubility below the ISO-recommended levels. The addition of particles resulted in higher viscosity. Groups with Icon had higher flexural strength and elastic modulus than groups with experimental infiltrant. The addition of 40% (Y) improved polymerization, had low solubility, and had greater radiopacity than enamel, however negatively affected the viscosity increasing then. Experimental groups with the base showed a higher water sorption than Icon groups.

Resumo O objetivo desse estudo foi avaliar o efeito da incorporação de partículas de Bário e Itérbio nas propriedades físicas de infiltrantes resinosos. Os grupos foram divididos de acordo com a adição de Itérbio puro (30 ou 40%) ou Itérbio com Bário (15/15% ou 20/20% respectivamente) no infiltrante comercial Icon e no Infiltrante experimental base. Foram realizados os testes de: radiografia digital (n=5), microradiografia Transversa (n=5), microtomografia (n=3), grau de conversão (n=5), sorção (n=16), solubilidade (n=16), ângulo de contato (n=16), resistência flexural (n=16), modulo de elasticidade (n=16) e Espectroscopia por energia dispersiva (n=10). As análises foram realizadas utilizando o programa R, com nível de significância de 5%, e os testes de microradiografia e microtomografia foram analisados qualitativamente. Nos grupos com 30 ou 40% de Itérbio, a radiopacidade foi maior ou igual ao esmalte dentário. Na microradiografia e microtomografia parece ter maior radiopacidade nos grupos com 40% de itérbio. Dentre os grupos sem adição de partículas, os do infiltrante experimental apresentaram maior grau de conversão do que os do Icon e o grupo controle experimental e com 40% de itérbio apresentaram os melhores resultados. Na maioria dos grupos, a solubilidade foi abaixo dos níveis recomendados pela ISO. A adição de particulas resultou em maior viscosidade. Os grupos com Icon apresentaram maior resistência flexural e modulo de elasticidade do que os grupos com infiltrante experimental e a quantidade de partícula aumentou a resistência e o módulo de elasticidade. A adição de 40% de itérbio melhorou a polimerização, apresentou baixa solubilidade e maior radiopacidade do que o esmalte, porém afetou negativamente a viscosidade, aumentando-a.

Influence of bioactive particles and onium salt on the physicochemical properties of experimental infiltrants

Abstract This study evaluated physicochemical properties of experimental infiltrants after addition of hydroxyapatite nanoparticles (HAp) or 58S bioactive glass (BAG) and diphenyliodonium hexafluorophosphate (DPI). The resin matrix was composed of TEGDMA/Bis-EMA (3:1), 0.5 mol% CQ, and 1 mol% EDAB. The blends received or not 0.5 mol% DPI and 10% wt BAG or HAp. Icon was used as commercial control. The groups were characterized by XRD, FT-IR spectrometry, and SEM before and after simulated body fluid (SBF) immersion for up to 7 days. Polymerization kinetics (n =3 ), water sorption and solubility (n=10), and viscosity (n = 3) were surveyed. For polymerization kinetics, the samples were polymerized for 5 min and the data were obtained from 40 s and 5 min. Statistical analysis was made using ANOVA and Tukey's test (a = 0.05). After 7 days of SBF immersion, XRD and FT-IR showed that the HAp crystalline phase was present only in the HAp groups. A lower degree of conversion (DC) and polymerization rate were observed for the Icon and BAG groups, whereas HAp showed higher values. For the BAG group, DPI increased polymerization rate and DC in 40 s. After 5 min, all groups presented DC above 80%. In groups with particles, the HAp groups exhibited higher viscosity, whereas DPI groups showed a decrease in viscosity. Icon had the highest water sorption. To conclude, BAG neither improved the physicochemical properties studied, nor did it show bioactive properties. The addition of DPI reduced viscosity caused by particle addition and also attenuated the DC decrease caused by BAG addition. The addition of bioactive particles to infiltrants should be seen with caution because they increase viscosity and may not bring major clinical improvements that justify their use. DPI might be indicated only if any component is added to the infiltrant to act as a compensation mechanism.

A clinical evaluation of zirconia reinforced lithium silicate glass-ceramic CAD/CAM onlay: a two-year case report / Avaliação clínica de onlay cerâmica do tipo CAD / CAM de silicato de lítio reforçado com zircônia: um relato de caso de dois anos

ABSTRACT The CAD/CAM technology arose from the need to develop materials with better mechanical and optical properties that could be used for making monolithic restorations. Several materials have been used for milling indirect restorations in prefabricated blocks. Among them, lithium silicate reinforced with zirconia. Due to its recent introduction in the market, this case report aimed to present a detailed clinical protocol for the execution of a ceramic onlay of this material using CAD/CAM technology. A 57-year-old female patient sought care with extensive restoration in composite resin (BOMD) of tooth 15 maintained for almost two years. However, due to bruxism, constant dental tightening, the extension of the direct restoration and the need for improved esthetics, it was proposed to replace it with an indirect ceramic onlay restoration. Prophylaxis and choice of the color of the patient's dental substrate were performed. Afterwards, the dental preparation was made and polished. Subsequently, the molding was made with addition silicone and the provisional restoration confectioned. Once the stone model was obtained, it was scanned and the ceramic onlay restoration was milled using CAD/CAM technology. Finally, the restoration was stained and cemented over the preparation. After 2 years, the restoration remained stable, with no evidence of color mismatch, marginal discoloration, marginal cleft, caries or fracture, proving the effectiveness of the treatment in this time interval. The correct indication of the ceramic material combined with the use of CAD/CAM technology facilitated the restorative process, restoring function and the esthetics desired by the patient.

RESUMO A tecnologia CAD/CAM surgiu da necessidade de desenvolvimento de materiais com melhores propriedades mecânicas e ópticas que pudessem ser utilizados para confecção de restaurações monolíticas. Diversos materiais têm sido utilizados para fresagem de restaurações indiretas em blocos pré-fabricados. Dentre eles, o silicato de lítio reforçado com zircônia. Devido a sua recente introdução no mercado, este relato de caso objetivou apresentar um protocolo clínico detalhado para a execução de uma onlay cerâmica desse material utilizando a tecnologia CAD/CAM. Paciente, 57 anos, sexo feminino, procurou atendimento com extensa restauração em resina composta envolvendo as faces (MODV) do dente 15 mantida por quase dois anos. Contudo, em virtude do bruxismo, do apertamento dental constante, da extensão da restauração direta e da necessidade de melhora na estética, foi proposto a substituição por uma restauração indireta em cerâmica do tipo onlay. Foi realizada a profilaxia e escolha da cor do substrato dental da paciente. Em seguida o preparo dental foi confeccionado e polido. Posteriormente foi feita a moldagem com silicone de adição e a confecção do provisório. Com a obtenção do modelo, este foi escaneado e fresada a onlay cerâmica pela tecnologia CAD/CAM, que posteriormente foi maquiada e cimentada sobre o preparo. Após 2 anos, a restauração permaneceu estável, sem evidência de incompatibilidade de cor, descoloração marginal, fenda marginal, cárie ou fratura, comprovando a eficácia do tratamento neste intervalo de tempo. A correta indicação do material cerâmico aliada ao uso da tecnologia CAD-CAM facilitou o processo restaurador devolvendo função e a estética desejada pela paciente.

Effect of ceramic thicknesses and opacities on water sorption and solubility of a light-curing resin cement by different units

Aim: This study evaluated the water sorption and solubility of a light-cured resin cement, under four thicknesses and four opacities of a lithium disilicate ceramic, also considering three light-emitting diode (LED) units. Methods: A total of 288 specimens of a resin cement (AllCem Veneer Trans ­ FGM) were prepared, 96 samples were light-cured by each of the three light curing units (Valo ­ Ultradent / Radii-Cal ­ SDI / Bluephase II ­ Ivoclar Vivadent), divided into 16 experimental conditions, according to the opacities of the ceramic: High Opacity (HO), Medium Opacity (MO), Low Translucency (LT), High Translucency (HT), and thicknesses (0.3, 0.8, 1.5, and 2.0 mm) (n = 6). The specimens were weighed at three different times: Mass M1 (after making the specimens), M2 (after 7 days of storage in water), and M3 (after dissection cycle), for calculating water sorption and solubility. Results: The higher thickness of the ceramic (2.0 mm) significantly increased the values of water sorption (44.0± 4.0) and solubility (7.8±0.6), compared to lower thicknesses. Also, the ceramic of higher opacity (HO) generated the highest values of sorption and solubility when compared to the other opacities, regardless of the thickness tested (ANOVA-3 factors / Tukey's test, α = 0.05). There was no influence of light curing units. Conclusion: Higher thicknesses and opacities of the ceramic increased the water sorption and solubility of the tested light-cured resin cement

Conservative treatment of interproximal incipient caries lesions by resin infiltration

Minimally invasive dentistry is based on conservative techniques for the treatment of initial caries lesions, the so-called white spot lesions. One of the conservative maneuvers includes the use of enamel resin infiltrant: a low viscosity material that penetrates the enamel pores to stop lesion progression. Aim: Therefore, this case report aimed to describe the clinical case of a 28-year-old female patient under routine consultation, in which a radiographic examination showed the presence of two incipient caries lesions in the left upper premolars. Methods: The application of a resin infiltrating agent (Icon®, DMG ­ Hamburg, Germany) was chosen as treatment to stop caries lesions progression. Conclusion: The use of this conservative technique can be considered a promising approach for the prevention of dental tissue wear, and the resin infiltrant is considered an effective material

Repair Adhesive Strength of Conventional and Bulk Fill Resins Using Different Bonding Techniques / Resistência Adesiva de Reparo em Resinas Compostas Convencionais e 'Bulk-Fill' Utilizando Diferentes Técnicas de Adesão

This research aimed to evaluate the bond strength by micro tensile strength (µTBS), elastic modulus (EM) and flexural strength (FS) by the three-point test using three types of composite resins: Charisma Diamond, Filtek Z350 and Tetric N-Ceram Bulk Fill; and three adhesion techniques: adhesive, silane, silane and adhesive. The combinations of each resin with the adhesive technique resulted in nine groups (n = 12). Initially, with the composites, EM and FS tests were performed. Sequentially, each fragment was repaired with the different adhesive systems. All samples were subjected to µTBS testing on a universal assay machine. Data were subjected to the normality test and the parametric ANOVA test. Charisma resin showed the highest values in EM and RF compared to the other composite resins (p <0.05). The highest µTBS value was for silane + adhesive repaired Charisma resin. The lowest µTBS values were in Bulk Fill resin, regardless of adhesive system. The EM and FS results showed that Filtek Z350 resins had the best results, while bulk fill resins had lower results. It was concluded that Charisma and Filtek Z350 resins presented better results. However, in the bulk fill group, the lowest mean values of µTBS, FS and EM were obtained, as well as the lowest value in EM. (AU)

Esta pesquisa teve como objetivo avaliar a resistência de união (RU) por resistência à microtração, módulo de elasticidade (ME) e resistência à flexão (RF) pelo teste de três pontos, utilizando três tipos de resinas compostas: Charisma Diamond, Filtek Z350 e Tetric N-Ceram Bulk Fill; e três técnicas de adesão: adesivo, silano, silano e adesivo. As combinações de cada resina com a técnica adesiva resultaram nove grupos (n = 12). Inicialmente, com os compósitos foram realizados testes de ME e RF. Sequencialmente, cada fragmento foi reparado com os diferentes sistemas adesivos. Todas as amostras foram submetidas ao teste de RU por microtração em uma máquina de ensaio universal. Os dados foram submetidos ao teste de normalidade e ao teste paramétrico ANOVA. A resina Charisma apresentou os maiores valores no ME e RF em relação às demais resinas compostas (p <0,05). O maior valor de RU foi para a resina Charisma reparada com silano + adesivo. Os menores valores de RU foram na resina Bulk Fill, independentemente do sistema adesivo. Os resultados no ME e RF mostraram que as resinas Filtek Z350 obtiveram os melhores resultados, enquanto as resinas bulk fill obtiveram resultados inferiores. Conclui-se que as resinas Charisma e Filtek Z350 apresentaram melhores resultados. Entretanto, no grupo de bulk fill obteve-se as menores médias de RU, RF e ME, bem como o menor valor no ME. (AU)

Can composition and preheating improve infiltrant characteristics and penetrability in demineralized enamel?

Abstract The composition of infiltrants can influence their physical properties, viscosity and depth of penetration (DP). Strategies are used to increase the DP, such as the addition of diluents or the use of heat. This study aimed to evaluate the effect of preheating and composition on physical properties and DP of infiltrants in demineralized enamel. The groups were assigned, and the following experimental formulations were made: 25%BisEMA +75%TEGDMA; 25%BisEMA +65%TEGDMA +10%ethanol; 25%BisEMA +65%TEGDMA +10%HEMA; 100%TEGDMA; 90%TEGDMA +10%ethanol; 90%TEGDMA +10%HEMA. The samples were photoactivated at two temperatures (25°C and 55°C). Degree of conversion (DC) was performed using an infrared spectrophotometer. Elastic modulus (E), flexural strength (FS) and contact angle (CA) tests were also performed. The DP of an infiltrant in demineralized enamel was determined by confocal laser scanning microscopy (CLSM) using an indirect labeling technique. The data were analyzed by two-way ANOVA and Tukey's test. DC increased after preheating in all the groups; however, 90%TEGDMA+10%ethanol showed the lowest DC for both temperatures, and the lowest E. Preheating did not influence E or FS. The CA increased at 55°C for most groups, but decreased for groups containing HEMA. Temperature did not seem to influence DP, and Icon showed the lowest DP values. The 100%TEGDMA composition showed more homogeneous penetration, whereas Icon showed heterogeneous and superficial penetration. The preheating technique does not improve all properties in all the material compositions. The composition of a material can influence and improve its properties.

Conservative Substitution of Fractured Ceramic Onlays Using Self-Adhesive Cement: Case Report / Substituição Conservadora de Onlays Cerâmicas Fraturadas Utilizando Cimento Autoadesivo: Relato de Caso

The advances in bonding of ceramics and self-adhesive resin cements to tooth structure make this treatment a feasible alternative to restore posterior teeth. This case report described the removal of two fractured onlays and the fabrication of new lithium disilicate onlays cemented with self-adhesive resin cement. The rationale for various choices in this treatment protocol is detailed with reference to the pertinent literature. It is concluded that the clinical success of the technique depends on the correct identification of the case for which this treatment is appropriate and on the successful execution of the clinical steps involved. (AU)

Os avanços na adesão de cerâmicas e cimentos resinosos autoadesivos à estrutura dentária tornam este tratamento uma alternativa viável para restaurar os dentes posteriores. Ester relato de caso descreveu a remoção de duas onlays fraturadas e confecção de novas onlays de dissilicato de lítio cimentadas com cimento resinoso auto-adesivo. A justificativa para várias escolhas neste protocolo de tratamento é detalhada com referência à literatura pertinente. O sucesso clínico da técnica depende da correta identificação do caso para o qual este tratamento é adequado e da execução bem-sucedida das etapas clínicas envolvidas. (AU)

Conservative Esthetic Approach of Anterior Teeth Using Minimal Intervention and Preservation of all Sound Tooth Tissue: a Case Report / Abordagem Estética Conservadora dos Dentes Anteriores Utilizando Intervenção Mínima e Preservação de Todo o Tecido Dentário Sadio: Relato de Caso

This clinical case report describes a conservative approach to a smile harmony rehabilitation performing a gingivoplasty, dental bleaching and resin-based composites to finalize the case. This clinical article describes the case report of a patient in need of an esthetic and corrective solution for the anterior teeth, which presented a disharmonic smile, in its shape and color, besides the gingival smile. As a result, gingivoplasty, dental bleaching and restoration with composite resin were done. Gingivoplasty with bone preservation was possible because there was a large volume of soft tissue, and a distance ≥ 2 mm from the bone crest to the junction cementum enamel was confirmed. Bleaching was performed with the use of associated techniques: office (Whiteness HP 35%) and supervised at-home (Whiteness Perfect 10%) bleaching were performed, and then the "buccolingual technique" using a nanocomposite resin IPS was used from a diagnostic wax-up to perform the restorative procedure for the anterior teeth. The use of minimally invasive techniques is an effective alternative for the anterior teeth rehabilitation. As in this case, the gingivoplasty, dental bleaching with associated techniques, and restorations with nanocomposites allowed satisfactory esthetic results, even more so in relation to dental preservation, mainly in young patients. (AU)

Este relato de caso clínico descreve uma abordagem conservadora de uma reabilitação para harmonia do sorriso que foi realizado com gengivoplastia, clareamento dentário e resinas compostas para finalizar o caso. Este artigo clínico descreve o relato de caso de uma paciente com necessidade de solução estética e corretiva para os dentes anteriores, que apresentava um sorriso desarmônico, em sua forma e cor além do sorriso gengival. Como resultado, gengivoplastia, clareamento dental e restauração com resina composta foram realizados. A gengivoplastia com preservação óssea foi possível por apresentar grande volume de tecidos moles e uma distância ≥ 2 mm, desde a crista óssea até a junção do cemento esmalte. Clareamento com o uso de técnicas associadas: Clareamento de consultório (Whiteness HP 35%) e caseiro supervisionado (Whiteness Perfect 10%) foram realizados, e depois, a "técnica da barreira palatina" utilizando a resina IPS Empress direta foi realizada a partir de um enceramento diagnóstico para iniciar o procedimento restaurador dos dentes anteriores. O uso de técnicas minimamente invasivas é uma alternativa eficaz para reabilitação de dentes anteriores. Como no caso, a gengivoplastia, o clareamento dental com técnicas associadas e restaurações com nanocompósitos têm permitido resultados estéticos satisfatórios, ainda mais em relação à preservação dentária, principalmente em pacientes jovens. (AU)

The Use of Resinous Infiltrants for the Management of Incipient Carious Lesions: a Literature Review / Uso de Infiltrantes Resinosos para Tratamento de Lesões Cariosas Incipientes: uma Revisão da Literatura

The objective of this work was to analyze scientific evidence from a literature review pertaining to the effectiveness of resinous infiltrants for minimally invasive treatment of incipient carious lesions. Studies published between 2002 and 2019 were queried from the following databases: Capes, PubMed, Medline, BBO, Lilacs and SciELO. The search keywords included "Dental Caries", "Tooth Remineralization", "Dental Leakage". Most of the studies found resin-infiltrating treatment to be a viable option for the minimally invasive treatment of incipient carious lesions; this treatment was able to fulfill the primary expected effects: inhibition of carious progression and the lesions esthetic improvement. However, some issues need to be clarified to improve the safety of this treatment because it can be recommended in clinical practice. Inconclusion, the use of resinous infiltrants has been reported as promising for the treatment of incipient carious lesions. However, there is a need for long-term studies to confirm the effectiveness of this treatment to determine its applicability for clinical use. (AU)

O objetivo desse trabalho foi analisar evidências científicas, por meio de uma revisão de literatura, sobre a eficácia do uso de infiltrantes resinosos para o tratamento minimamente invasivo de lesões cariosas incipientes. A seleção do material literário utilizado foi realizada por pesquisa sobre o tema nas bases de dados: portal de periódicos Capes, PubMed, Medline, BBO, Lilacs e SciELO, abrangendo prioritariamente, o período de 2002 a 2019. Para busca nas bases de dados foram utilizadas palavras-chave como "Cárie Dentária", "Remineralização Dentária", "Infiltração Dentária", assim como suas correspondentes na língua inglesa. A maioria dos estudos encontrados aponta o tratamento infiltrante resinoso como uma opção viável para o tratamento minimamente invasivo de lesões cariosas incipien tes sendo capaz de cumprir os principais efeitos esperados: inibição da progressão cariosa e melhoria estética das lesões. Entretanto, alguns impasses necessitam ser esclarecidos para que o tratamento seja recomendado com mais segurança na prática clínica. Conclui-se que o uso de infiltrantes resinosos tem sido relatado como promissor para o tratamento de lesões cariosas incipientes, contudo há necessidade de novas pesquisas e estudos a longo prazo para confirmar sua eficácia em todos aspectos desejáveis para seu uso clínico. (AU)

Effect of iodonium salt and chitosan on the physical and antibacterial properties of experimental infiltrants

Abstract Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics.

Minimally invasive aesthetic rehabilitation in composite resin: report of two clinical cases / Reabilitação estética minimamente invasiva em resina composta: relato de dois casos clínicos

Patient demand looking for the perfect smile has been steadily growing in the last few years. Thus, these two case reports discuss some ultra-conservatives approach to achieve good esthetic results. In the first case the clinical protocol of a restorative approach is described, the cosmetic remodeling of the teeth and in the second case, the replacement of extensive unsatisfactory composite restorations. The treatment planning was based on diagnostic waxing and the making of mock-up in both cases. Teeth bleaching were also performed before restoration. To conclude, these conservative relative therapies with composite resin restorations provide an ultra-minimally invasive protocol with excellent esthetic appearances and fuction, especially for young people. (AU)

A demanda do paciente que procura o sorriso perfeito tem crescido constantemente nos últimos anos. Assim, esses dois relatos de casos clínicos discutem uma abordagem ultraconservadora para alcançar bons resultados estéticos. No primeiro caso é descrito o protocolo clínico de uma abordagem restauradora, a remodelação cosmética dos dentes e, no segundo caso, a substituição de restaurações compostas extensas insatisfatórias. O planejamento do tratamento baseouse em enceramento diagnóstico e a confecção de mock-up. O clareamento dos dentes foi realizado antes da restauração. Para concluir, essas terapias relativas conservadoras com restaurações de resina composta fornecem um protocolo ultra minimamenteinvasivo com excelentes aparências estéticas. (AU)

Effect of diphenyliodonium hexafluorphosphate in the yellowing and properties of experimental resin cements

Aim: The yellowing effect is undesirable and can occur in the dental restoration margins when light-cured resin cements containing camphorquinone as photoinitiator is used. This study aimed to evaluate the effect of diphenyliodonium hexafluorphosphate (DPI) in photoinitiator systems that contained different concentrations of camphorquinone (CQ) and dimethylamino ethyl benzoate (EDAB) on resin cements. Methods: A base (1:1) of bisphenol A diglycidyl methacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) was obtained, and 60wt% of glass fillers was added. Eight formulations were obtained: RC1 (0.5mol% CQ / 1mol% EDAB), RC2 (0.5mol% CQ / 2mol% EDAB), RC3 (1mol% CQ / 1mol% EDAB), RC4 (1mol% CQ / 2mol% EDAB), and RC5 to RC8, which contained the same bases plus 0.5mol% DPI. Experimental resin cements were evaluated by the degree of conversion (DC), L*a*b* color analysis, water sorption (WS) and solubility (S), flexural strength, and Elastic Modulus. The data were analyzed by three-way ANOVA, Tukey's and Mann-Whitney tests (α = 0.05). Results: The combination of DPI and 0.5mol% CQ increased DC in RC6 and L* in RC5 without increasing the WS and a* b* values. CQ at 1mol% showed higher values of b* and lower values of a*, except for RC3. Groups with 2mol% EDAB showed higher DC. Conclusion: The addition of DPI reduces CQ, generating a decreased yellowing effect, while maintaining adequate properties in the resin cements, especially with 2mol% EDAB

Treatment of non-carious lesions: diagnosis, restorative materials and techniques

Management of non-carious cervical lesions (NCCLs) still is a challenge in clinical practice. The diagnosis is the key to treat these lesions successfully. Aim/Case report: Therefore, the aim of this case report is to describe the diagnosis and treatment of generalized abfraction lesions associated to abrasion lesions of a 43 years old patient and to discuss considerations about the technique and materials to be used appropriately. After the diagnosis, a treatment plan with preventive and restorative approach was elaborated. The occlusal adjustment was performed to distribute the contact points and the patient was instructed in relation to tooth brushing habits. It was also recommended that the patient use a dentifrice with potassium nitrate for the control of sensitivity. For lesions over 1mm deep, the restorative treatment was performed using the self-etching adhesive system and nanohybrid composite by the stratification technique. Unsatisfactory restorations have been replaced. Occlusal splint was done and the patient was instructed to use the device every day overnight. One year after treatment, follow-up was performed. The appearance of new NCCLs was not observed. There was no progression of lesions smaller than 1 mm. There was no loss of restorations. All restorations were fully satisfactory and the patient reported absence of dentin hypersensitivity. Conclusion: The treatment performed besides being aesthetically satisfactory after 1 year resulted in the control of the disease, preventing the appearance of new lesions and guaranteeing a better quality of life to the patient

Minimally invasive approach to diastema closure using lithium disilicate porcelain veneers: clinical report / Abordagem minimamente invasiva para fechamento de diastema usando laminados cerâmicos de dissilicato de lítio: relato clínico

Objective: Numerous advances in dentistry techniques and material have allowed patients to have not only a functional but also an aesthetic smile in a conservative way. This case report describes a treatment with ceramic laminates to solve the aesthetic problems of an 18-year-old male dissatisfied with his smile. Following the correct protocols, using minimally invasive abrasions, ceramic laminates, and strong adhesion between porcelain and dental enamel can provide predictable results and clinical longevity through follow-up. (AU)

Objetivo: Devido aos inúmeros avanços das técnicas e materiais odontológicos tem sido possível proporcionar ao paciente não só a função, mas também a estética do sorriso de maneira minimamente invasiva. Esse relato de caso descreve o tratamento com laminados cerâmicos para resolver problemas de um paciente de 18 anos gênero masculino insatisfeito com o seu sorriso. Seguindo os protocolos corretamente, utilizando desgastes minimamente invasivos, laminados cerâmicos, e forte adesão entre a porcelana e o esmalte dental, é possível obter resultados previsíveis e longevidade clínica mediante acompanhamento. (AU)

Reconstrução estética do sorriso: a necessidade da abordagem multidisciplinar / Esthetic reconstruction of the smile: the need for a multidisciplinary approach

Atualmente a estética tem sido o principal motivo pelo qual diversos pacientes buscam o consultório odontológico. Em muitas situações, as cerâmicas são os materiais de escolha para a restauração dos dentes anteriores, no entanto diversos fatores devem ser avaliados na decisão do melhor protocolo a ser realizado. Uma visão ampla sobre o quadro apresentado também é necessária, observando-se a necessidade de realização não só de procedimentos restauradores, mas também ortodônticos e periodontais. Diante disso, o presente artigo demonstra a abordagem multidisciplinar na obtenção da estética dos dentes anteriores, através de cirurgia plástica periodontal e finalização do caso utilizando resinas compostas diretas. A combinação dessas técnicas permitiu devolver harmonia e naturalidade ao sorriso, restabelecendo as características da região anterior.

Currently, aesthetics has been the main reason why many patients seek the dental office. In many situations, ceramics is the material of choice for the restoration of anterior teeth. However, many factors must be evaluated when deciding the best protocol to be performed. A comprehensive view of the situation presented is also required, observing, not only, the need to perform restorative, but orthodontic and periodontal procedures. In view of this, the present article demonstrates a multidisciplinary approach in obtaining the aesthetics of anterior teeth through periodontal plastic surgery, finalizing the case using direct composite resins. The combination of these techniques made it possible to restore harmony and naturality to the smile, by restoring the characteristics of the anterior region.

Effect of pre- heating on hardness of methacrylate- and silorane- based composites

AIM: To evaluate the effect of composite pre-heating on the microhardness of different monomer resin-based. MATERIALS AND METHOD: Circular specimens of methacrylate- and silorane-based composite resins pre-heated at 23, 39, and 55˚ C were carried out, and cured using a halogen light-curing unit at 650 mW/cm². After 24 h, the specimens were polished and Knoop hardness number (KHN) was measured using a microhardness tester with 50-g load for 15 s. The data were analyzed with ANOVA and Tukey's tests (α = 0.05). RESULTS: Top surface presented higher KHN than bottom, methacrylate-based composite showed higher KHN compared to silorane, and pre-heating increased the KHN of the composites tested. CONCLUSION: Pre-heating can be used to improve the microhardness of methracrylate- and silorane-based composites.

Impact of light-curing time and aging on dentin bond strength of methacrylate- and silorane-based restorative systems

AIM: To evaluate the impact of different light-curing times on dentin microtensile bond strength of two restorative systems after 24 h and 6 months of water storage. METHODS: Standardized Class II preparations were performed in 56 freshly-extracted human molars (n = 7), restored with methacrylate- or silorane-based restorative systems, and light-cured using a light-emitting diode at 1390 mW/cm2 by the recommended manufacturers' time or double this time. After storage for 24 h at 37 oC, the teeth were sectioned to yield a series of 0.8-mm thick slices. Each slab was trimmed into an hourglass shape of approximately 0.64 mm2 area at the gingival dentin-resin interface. Specimens were tested using universal testing machine at crosshead speed of 0.5 mm/min until failure, after 24 h and 6 months of storage. Data were statistically analyzed by three-way ANOVA and Tukey's test (α = 0.05). RESULTS: The highest bond strength values were recorded for the groups restored with methacrylate system (p<0.001) as well as for extended light-curing time (p = 0.0034). There was no statistically significant difference between 24 h and 6 months storage on bond strength (p>0.05). CONCLUSIONS: Bond strength was influenced by the material and light-curing time, but the 6-month storage did not affect the bond strength of restorations...

Influence of different shades and LED irradiance on the degree of conversion of composite resins

The aim of this study was to evaluate the degree of conversion (DC) of two composite resins with different shades that were light cured by light-emitting diodes (LEDs) of different irradiances. Specimens (5 mm ' 2 mm) were prepared with a nanofilled (Filtek Supreme - A2E, A2D, and WE) or microhybrid resin (Opallis - A2E, A2D, and EBleach Low) and were randomly divided into 12 groups (n = 5 each) according to the composite resin and light-curing unit (Elipar FreeLight 2, 1250 mW/cm²; Ultralume 5, 850 mW/cm²). After 24 h, the DC was measured on two surfaces (top and bottom) with Fourier Transform infrared spectroscopy (FTIR). Data were statistically analyzed with two-way ANOVA and Tukey test (a = 0.05). Statistical differences among the surfaces were observed in all experimental conditions, with higher values on the top surface. The microhybrid resin presented the highest DCs for shades A2E and A2D on the top surface. The LED with higher irradiance promoted better DCs. Taken together, the data indicate that the shade of a composite resin and the irradiance of the light source affect the monomeric conversion of the restorative material.

Effect of chemical degradation followed by toothbrushing on the surface roughness of restorative composites

OBJECTIVES: The aim of the present study was to assess the effect of the exposure to food-simulating liquids prior to brushing simulation on the surface roughness of five composite materials (Quixfil, Filtek Supreme, Esthet-X, Filtek Z250, Tetric Ceram). Material and METHODS: Twenty cylinders (5 mm diameter and 4 mm height) of each composite were randomly allocated to 4 groups (n=5), according to the food-simulating liquid in which they were immersed for 7 days at 37°C: artificial saliva, heptane, citric acid, and ethanol. After this period, the top surface of composite cylinders was submitted to 7,500 brushing cycles (200 g load). Measurements of the surface roughness (Ra, »m) were carried out before and after the exposure to the chemicals/brushing simulation. Changes on the morphology of composite surfaces were observed through scanning electron microscopy (SEM). RESULTS: The statistical analysis (ANOVA with cofactor / Tukey's test, α=5 percent) detected a significant interaction between solutions and composite resins. Esthet-X, Filtek Z250 and Tetric Ceram were not affected by the food-simulating liquids/toothbrushing. Citric acid and ethanol increased the surface roughness of Quixfil and Filtek Supreme, respectively. SEM images corroborate the surface roughness findings, demonstrating the negative effect from chemical solutions and mechanical abrasion. CONCLUSIONS: The surface roughness of composite resin materials are differently affected by the food-simulating solutions, depending on the immersion media.