In Vitro and In Vivo Efficacy of New Composite for Direct Pulp Capping.

OBJECTIVES: To investigate physicochemical properties, dentin bonding, cytotoxicity, and in vivo pulp response of experimental self-adhesive composites tailored to direct pulp capping. MATERIALS AND METHODS: Experimental composites were prepared with beta-tricalcium phosphate and hydroxyapatite nanoparticles adsorbed with simvastatin and glutathione added at 0% (control resin), 1 wt% (Res 1%), and 10 wt% (Res 10%). A commercial light-curable calcium hydroxide (Ca(OH)2) (Ultra-Blend Plus) was used as control material. The physicochemical properties investigated were flexural strength and modulus, calcium release, and degree of conversion. Dentin bonding was assessed by the push-out test. Proliferation and cell counting assays were performed to evaluate in vitro cytotoxicity using fluorescence microscopy. In vivo pulp capping was performed on molars of Wistar rats, which were euthanized after 14 days and evaluated by histological analysis. RESULTS: No statistical difference was observed in flexural strength and cell viability (p > 0.05). Res 10% presented higher modulus than control resin and Ca(OH)2. Also, Res 10% attained statistically higher degree of conversion when compared to other experimental composites. Ca(OH)2 showed higher calcium release after 28 and 45 days of storage, with no statistical difference at 45 days to Res 10%. All experimental composites achieved significantly higher bond strength when compared to Ca(OH)2. While no significant difference was observed in the cell proliferation rates, resins at lower concentrations showed higher cell viability. In vivo evaluation of pulp response demonstrated no pulp damage with experimental composites. CONCLUSIONS: The experimental composite investigated in this study achieved adequate physicochemical properties with minor in vivo pulpal inflammation and proved to be a valuable alternative for direct pulp capping.

Microfiltración marginal de resinas de relleno masivo y nanohíbrida en molares deciduos / Marginal microleakage of bulk fill and nanohybrid resins in deciduous teeth

Introducción: En la atención odontológica a niños es crucial seleccionar materiales restaurativos con buen rendimiento clínico y corto tiempo de aplicación, especialmente en pacientes con capacidad de atención limitada. Las resinas compuestas, con el mejoramiento de sus propiedades físicas y mecánicas, constituyen hoy uno de los materiales de mayor elección por el odontopediatra. Las resinas de relleno masivo son una alternativa atractiva para las restauraciones en el sector posterior. Objetivo: Comparar el grado de microfiltración marginal de resinas de relleno masivo y nanohíbrida en molares deciduos. Métodos: Estudio experimental, in vitro, en cuarenta molares deciduos; exodonciados por motivos terapéuticos, divididos en dos grupos. Grupo I: resina nanohíbrida con técnica incremental (Tetric® N Ceram - Ivoclar Vivadent) y Grupo II: resina de relleno masivo con técnica monoincremental (Tetric® N Ceram bulk fill - Ivoclar Vivadent). Se realizó un proceso de termociclado manual de 500 ciclos, entre 5 ºC ± 2 ºC y 55 ºC ± 2 ºC. Las muestras fueron sumergidas en azul de metileno al 0,5 por ciento durante 24 horas a 37 ºC. Se analizaron con el microscopio estereoscópico de luz a 40X. Resultados: Todas las muestras presentaron microfiltración. Con el uso de resina nanohíbrida, el 25 presentó microfiltración leve; el 30 por ciento, moderada; y el 45 por ciento, severa. En el grupo de la resina de relleno masivo, el 30 por ciento presentó microfiltración leve; el 35 por ciento, moderada; y el 35 por ciento, severa. No se encontró diferencia significativa entre ambos grupos (p = 0,55). Conclusiones: Ambas resinas, de relleno masivo y nanohíbrida, presentaron similar microfiltración marginal in vitro, en molares deciduos; por lo que la técnica de relleno masivo, por su fácil y rápida aplicación en un solo tiempo, es una buena alternativa en la rehabilitación dental odontopediátrica(AU)

Introduction: In children's dental care it is crucial to select restorative materials of proven clinical quality and a short application period, particularly with patients of limited attention capacity. Due to their improved physical and mechanical properties, composite resins are currently one of the materials of choice for children's dental care. Bulk fill resins are an attractive alternative for posterior restorations. Objective: Compare the degree of marginal microleakage of bulk fill and nanohybrid resins in deciduous teeth. Methods: An experimental in vitro study was conducted of 40 deciduous teeth extracted for therapeutic reasons, which were divided into two groups. Group I: nanohybrid resin by incremental technique (Tetric® N Ceram - Ivoclar Vivadent) and Group II: bulk fill resin by monoincremental technique (Tetric® N Ceram bulk fill - Ivoclar Vivadent). A manual 500-cycle thermocycling procedure was performed at 5ºC ± 2ºC to 55ºC ± 2ºC. The samples were soaked in 0.5 percent methylene blue at 37ºC for 24 hours and analyzed under a light stereo microscope at 40X. Results: Microleakage was present in all the samples. In the nanohybrid resin group, microleakage was mild in 25 percent, moderate in 30 percent and severe in 45 percent. In the bulk fill resin group, microleakage was mild in 30 percent, moderate in 35 percent and severe in 35 percent. No significant difference was found between the groups (p = 0.55). Conclusions: Both resins, bulk fill and nanohybrid, presented similar in vitro marginal microleakage in deciduous molars. The bulk fill technique is therefore a good alternative for children's dental rehabilitation, due to its easy and fast application in a single session(AU)

Risk assessment of predicted serum concentrations of bisphenol A in children and adults following treatment with dental composite restoratives, dental sealants, or orthodontic adhesives using physiologically based pharmacokinetic modeling.

Bisphenol A (BPA) is a chemical used to manufacture bisphenol A glycidyl methacrylate (BisGMA). BisGMA has been used for decades in dental composite restoratives, sealants, and adhesives. Based on published studies, exposure to low concentrations of BPA are possible from dental and orthodontic devices. The serum BPA concentrations arising from such devices and oral doses were predicted using a PBPK model in children and adult females based on 1) published extraction data for cured and uncured 3M ESPE Filtek Supreme Ultra Flowable, 3M ESPE Filtek Bulk Fill Restorative, and 3M ESPE Clinpro Sealant and 2) published 20% ethanol/water and water rinsate data following orthodontic application with 3M ESPE Transbond MIP Primer and 3M ESPE Transbond XT Adhesive. Predicted oral exposure to BPA arising from these dental and orthodontic devices is low (median <10 ng/treatment) and predicted serum BPA concentrations were also low (<10-4 nM). Even the maximum predicted exposure in this study (533.2 ng/treatment) yields a margin of exposure of 7.5 relative to the EFSA t-TDI (4 µg/kg-day) and is only 2.8% of the daily BPA exposure for the US population in a 58-kg woman (15,660 ng/day). Therefore, the exposure to BPA arising from the 3M ESPE dental and orthodontic devices evaluated in this study is negligible relative to daily BPA exposure in the general population and these potential BPA sources do not constitute a risk to patients.

Efeito do polimento superficial a seco ou úmido sobre o brilho, rugosidade e desgaste de resina composta nanoparticulada antes e após envelhecimento artificial / Effect of dry or wet surface polishing on the gloss, roughness and wear of nanoparticulate composite resin before and after artificial aging

Este trabalho teve como objetivo investigar a rugosidade, o desgaste e o brilho superficial de uma resina composta nanoparticulada (Filtek Z350 XT - 3M ESPE), com diferentes sistemas de polimento a seco e lubrificado antes e após envelhecimento artificial. Foram confeccionados 100 espécimes de resina composta em forma de disco, divididos em: grupo controle (sem polimento) e em três sistemas de polimento (pontas de diamante de etapa única Dimanto - VOCO, discos de lixa Sof-Lex Pop-On - 3M ESPE - e escova de polimento com carbeto de silício nas cerdas Astrobrush - IVOCLAR VIVADENT). Os sistemas polidores foram empregados sem lubrificação, com água e com vaselina. Após a fase de envelhecimento por escovação, foi realizado o repolimento das amostras, exceto no grupo controle. Ao final de cada tempo do estudo (inicial, polimento, envelhecimento e repolimento), os grupos foram submetidos as leituras de rugosidade, desgaste e brilho, verificando assim a efetividade de cada sistema de polimento. Os dados referentes a cada avaliação quantitativa foram submetidos à análise estatística de variância de medidas repetidas. As comparações múltiplas foram realizadas por teste Pos-hoc de Tukey. Diferenças significantes foram determinadas por p < 0,05. Para as análises de brilho e rugosidade póspolimento o Dimanto não foi influenciado pelo uso ou não de lubrificantes. O Sof-Lex Pop-On obteve melhor desempenho sem utilização de lubrificante, enquanto a escova Astrobrush apresentou maiores valores de brilho e menor rugosidade quando lubrificada por água ou vaselina. Em relação ao desgaste superficial, o Dimanto foi melhor, quando associado a vaselina. O Sof-Lex PopOn apresentou menor desgaste, quando utilizado com água. A escova Astrobrush obteve o pior resultado quando lubrificada com vaselina. Portanto, o brilho, a rugosidade e o desgaste superficial dependem do polidor e da combinação com ou sem lubrificação(AU)

The aim of this study was to investigate the roughness, wear and surface gloss of a nanoparticulated resin composite (Filtek Z350 XT - 3M ESPE), with dry and lubricated polishing systems before and after artificial aging. One hundred resin composite specimens were fabricated in cylindrical shape, which was further divided into: control group (no polishing) and three polishing systems (One step diamond tips Dimanto -VOCO, Sof-Lex Pop-On -3M ESPE, and a silicon carbide polishing brush - Astrobrush -IVOCLAR VIVADENT). Polishing systems was used dry, with water or petroleum jelly. After aging by simulated tooth brushing, the samples' repolishing was carried out, except in the control group. After each study period (initial, polishing, aging and repolishing), the groups were subjected to roughness, wear and gloss, thus verifying the effectiveness of each polishing system. The data for each quantitative evaluation was submitted to repeated-measures analysis of variance. Multiple comparisons were performed by Tukey post-hoc test. Significant differences were determined by p <0.05. For post-polishing gloss and roughness analyzes, Dimanto was not influenced by the use or not of lubricants. Sof-Lex Pop-On achieved better performance without using lubricant, while the Astrobrush brush showed higher values of gloss and less roughness when lubricated by water or petroleum jelly. Regarding surface wear, Dimanto was better when associated with petroleum jelly. Sof-Lex Pop-On showed less wear when used with water. The Astrobrush brush obtained the worst result when lubricated with petroleum jelly. The brightness, roughness and surface wear depend on the polisher and the combination with or without lubrication(AU).

Efeito da elevação da margem gengival e do material restaurador no comportamento em fadiga e distribuição de tensão de molares restaurados com inlays mod / Effect of deep margin elevation and restorative material on the fatigue behavior and stress distribution of molars restored with MOD inlays

Este estudo avaliou o efeito da elevação da margem gengival (DME) e dos materiais restauradores (cerâmica vítrea reforçada por leucita [C] vs. resina composta indireta [R]) no comportamento de fadiga e distribuição de tensão de molares superiores com margens proximais com 2 mm de profundidade restauradas com inlays mesio-ocluso-distal (MOD). Para isso, 52 terceiros molares humanos extraídos foram distribuídos aleatoriamente em quatro grupos (n = 13): C; DME + C; R; e DME + R. Restaurações do tipo inlay foram confeccionados no CAD-CAM e cimentadas adesivamente em todos os dentes. O comportamento em fadiga foi avaliado com o ensaio de vida acelerada stepwise stress (10.000 ciclos/step; step=50 N; 20 Hz; carga inicial=200 N). As cargas e o número de ciclos de falha em fadiga foram analisados com ANOVA de 2 fatores e teste de Tukey (p <0,05), também foram realizados gráficos de sobrevivência de Kaplan-Meier. A distribuição de tensões foi avaliada utilizando a análise por elementos finitos. Os modelos foram considerados isotrópicos, lineares, homogêneos e apresentaram contatos colados. Uma carga axial (400 N) foi aplicada à superfície oclusal. A distribuição de tensões foi analisada com o critério de tensão principal máxima. Para o comportamento em fadiga, não houve diferença para o fator DME (p> 0,05). Para o fator material restaurador, a carga e o número de ciclos para falha foram estatisticamente maiores nos grupos R (p <0,05). A análise por elementos finitos mostrou que os inlays de resina composta concentraram mais tensões na estrutura do dente, enquanto os inlays de cerâmica concentraram mais tensões na restauração. Falhas não reparáveis foram mais frequentes nos grupos de inlays de resina composta. Foi possível concluir que a DME não foi prejudicial para o comportamento em fadiga e na distribuição de tensão. As inlays de resina composta foram mais resistentes ao teste de fadiga, embora o modo de falha tenha sido mais agressivo(AU)

Objectives: This study evaluated the effect of deep margin elevation (DME) and restorative materials (leucite-reinforced glass-ceramics [C] vs. indirect resin composite [R]) on the fatigue behavior and stress distribution of upper molars with 2-mm deep proximal margins restored with MOD-inlay. Methods: Fiftytwo extracted human third molars were randomly assigned into four groups (n=13): C; DME+C; R; and DME+R. Inlays were fabricated in CAD-CAM and bonded to all teeth. The fatigue behavior was assessed with the stepwise stress test (10,000 cycles/step; step=50N; 20 Hz; initial load=200 N). Fatigue failure loads and number of cycles were analyzed with 2-way ANOVA and Tukey's test (p<0.05) and Kaplan-Meier survival plots. The stress distribution was assessed with finite element analysis. The models were considered isotropic, linear, homogeneous, and presented bonded contacts. A tripod axial load (400 N) was applied to the occlusal surface. The stress distribution was analyzed with the maximum principal stress criterion. Results: For fatigue, there was no difference for DME factor (p>.05). For the material factor, the load and number of cycles for failure were statistically higher in the R groups (p<.05). The finite element analysis showed that resin composite inlays concentrated more stress in the tooth structure, while ceramic inlays concentrated more stress in the restoration. Non-reparable failures were more frequent in the resin composite inlays groups. Conclusions: DME was not negative for fatigue and biomechanical behaviors. Resin composite inlays were more resistant to the fatigue test, although the failure mode was more aggressive(AU)

Tratamiento Rehabilitador Estético-Oclusal con Resinas Compuestas en una Paciente con Mordida Profunda y Desgaste Severo / Aesthetic-Occlusal Rehabilitation Treatment with Composite Resins in a Patient with Deep Bite and Dental Wear

RESUMEN: La rehabilitación oral tradicional del paciente con mordida profunda y braquifacial puede ser muy compleja e invasiva, sin embargo, podría involucrar muchas especialidades para su resolución ideal. Un análisis integral estético-oclusal es necesario antes de empezar el tratamiento para hacer propuestas con el menor costo biológico, de tiempo y económico. La odontología adhesiva permite una propuesta aditiva y no invasiva como un tratamiento de mediano plazo o transitorio. Este artículo presenta un caso de una paciente de 46años de edad con mordida profunda anterior y desgaste dental severo en las caras palatinas de los dientes antero-superiores, sin disfunción temporomandibular, ni compromisos sistémicos. Se destaca la rehabilitación estética- oclusal con el mínimo compromiso biológico (ultra-conservadora), mediante restauraciones adhesivas semi-indirectas de resina compuesta con acompañamiento de 12meses. Esta propuesta rehabilitadora con resinas compuestas representa una alternativa de tratamiento para el manejo del paciente con mordida profunda anterior. El control a un año de tratamiento demostró que se siguió una secuencia y resolución que aseguró los principios de la rehabilitación oral, al mismo tiempo, se procedió de la manera menos invasiva posible.

ABSTRACT: The traditional oral rehabilitation of the patient with deep bite and brachifacial can be very complex and invasive, however, a number of treatments could be considered to improve rehabilitation. A comprehensive aesthetic-occlusal analysis is necessary prior to starting treatment in order to consider the best procedure, time involved, and economic cost. Adhesive dentistry allows an additive and non-invasive proposal as a medium-term or transitory treatment. A case of a 46-year-old patient is presented, with anterior deep bite and severe dental wear on palatal surfaces of the antero-superior teeth, without temporomandibular dysfunction, or systemic compromises. The objective was to emphasize the aesthetic and occlusal rehabilitation with the least biological commitment (ultraconservative), through semi-indirect adhesive restorations of composite resin with 12 months follow-up. This restorative proposal with composite resins represents an alternative treatment for patient management with anterior deep bite. Control at one year of treatment showed that a sequence and resolution was followed, that ensured adequate oral rehabilitation in the least invasive manner possible.

Avaliação in vitro de carga máxima de fratura em próteses fixas adesivas de resina composta indireta reforçadas com malha de sílica-nylon submetidas ao processo de envelhecimento / In vitro evaluation of maximum fracture load in resin-bonded fixed dental prostheses of indirect composite resin reinforced by silica-nylon mesh submitted to the aging process

O uso de próteses fixas adesivas é uma opção de tratamento reabilitador em casos de ausência dentária. A resina composta é um material com boas características mecânicas e estéticas, mas se faz necessário a utilização de reforços para proporcionar maior resistência ao conjunto. O presente estudo teve como objetivo avaliar a carga máxima de fratura quando da utilização de um sistema de reforço de sílica-nylon em próteses fixas adesivas confeccionadas em resina composta indireta. O estudo in vitro simulou uma prótese fixa adesiva de três elementos anterior (A) e posterior (P). Dessa forma, foram confeccionados 80 espécimes distribuídos em 8 grupos experimentais (n=10), tendo como variáveis a presença do sistema de reforço em sílica-nylon (R) e a ciclagem mecânica da peça protética (C). O processo de envelhecimento foi realizado através da ciclagem mecânica por 106 ciclos a 4 Hz (ERIOS ER-11000 Plus, São Paulo, Brasil). As amostras foram submetidas ao ensaio de resistência à carga máxima de fratura na máquina de ensaio universal (EMIC DL 1000, EMIC, Brasil) com uma célula de carga de 1000 Kgf e foram feitas análises das amostras após a fratura em estereomicroscópio (Discovery V20 CarlZeiss, Jena, Alemanha) e Microscopia Eletrônica de Varredura (Inspect S 50, FEI Company, Brno, República Tcheca). A análise estatística foi constituída pela análise de variância (ANOVA) e teste Tukey 5%. O estudo in silico foi realizado através da Análise em Elementos Finitos (FEA), onde os dentes pilares e as próteses foram escaneados (Ceramill Map 400, Amann Girrbach) e transferidos para o software CAD Rhinoceros (version 4.0SR8; McNeel North America, Seattle, WA), para elaboração do modelo volumétrico 3D e posteriormente a análise foi feita através do Software Ansys 19.3 (ANSYS, Inc. Southpointe, Canonsburg, EUA). Os resultados de resistência à carga máxima de fratura foram (N): A=163,55; AC=184,48; AR=198,81; ARC=192,24; P=539,99; PC=359,61; PR=541,74 e PRC=608,74. Foi constatado que houve diferença estatística na presença do reforço tanto nos grupos da região anterior (p=0,025), quanto da região posterior (p=0,001). Os resultados de tensão máxima principal, obtidos no FEA, foram (MPa): A=53,24/122,40; AR=55,07/117,70; P=33,28/36,18 e PR=28,06/42,87. Concluiu-se que a incorporação da malha de sílica-nylon aumentou a resistência à carga máxima de fratura das próteses fixas adesivas, independente da área em que se encontra, e os resultados obtidos no FEA corroboraram com os encontrados no teste in vitro o que permite concluir que houve validação do teste in silico(AU)

The use of resin-bonded fixed dental prostheses is a rehabilitative treatment option in cases of missing teeth. Composite resin is a material with good mechanical and aesthetic characteristics, but it is necessary to use reinforcements to provide greater resistance to the prosthesis. The present study aims to evaluate the maximum fracture load using a silica-nylon reinforcement system on resin-bonded fixed dental prostheses made of indirect composite resin. In vitro test simulated an anterior (A) and posterior (P) three-element resin-bonded fixed dental prostheses. Thus, 80 specimens were made in 8 experimental groups (n = 10), with variables the presence of the silica-nylon reinforcement system (R) and the mechanical cycling of the prosthesis (C). The aging process was performed through mechanical cycling for 106 cycles at 4 Hz (ERIOS ER-11000 Plus, São Paulo, Brazil). The samples were tested by maximum fracture load in the universal test machine (EMIC DL 1000, EMIC, Brazil) with a 1000 Kgf load cell and analyzed by stereomicroscope (Discovery V20 CarlZeiss, Jena, Germany) and Scanning Electron Microscopy (Inspect S 50, FEI Company, Brno, Czech Republic). Statistical analysis consisted of analysis of variance (ANOVA) and Tukey test 5%. In silico study was performed by Finite Element Analysis (FEA), where the abutment teeth and the prostheses were scanned (Ceramill Map 400, Amann Girrbach) and transferred to the CAD Rhinoceros (version 4.0SR8; McNeel North America, Seattle, WA) for the elaboration of the 3D volumetric model and the analysis test was made in the Ansys Software 19.3 (ANSYS, Canonsburg, PA, USA). The results of resistance to the maximum fracture load were (N): A=163,55; AC=184,48; AR=198,81; ARC=192,24; P=539,99; PC=359,61; PR=541,74 and PRC=608,74. It was found that there was a statistical difference in the presence of reinforcement in both the anterior region (p=0,025) and posterior region groups (p=0,001). The maximum main stress results obtained in the FEA were (MPa): A=53,24/122,40; AR=55,07/117,70; P=33,28/36,18 and PR=28,06/42,87. It was concluded that the incorporation of the silica-nylon mesh increased the resistance to maximum fracture load of the resin-bonded fixed dental prostheses regardless of the area it is located, and the results obtained in the FEA corroborated the results of in vitro test, which allows to conclude that the in silico test was validated(AU)

Accelerated aging effects on color, microhardness and microstructure of ICON resin infiltration.

OBJECTIVE: Infiltration resins provide an ideal treatment alternative for white spot lesions on teeth. The icon infiltrant has been widely used as a dental material for a few years, but there are some studies on the in vitro accelerated aging process and the change of hardness and microstructure on this material. The innovation of this work is to aim at investigating characteristics associated with this infiltrant resin and comparing the Icon infiltrant with universal Filtek Z350 and flowable Filtek Z350 resins when exposed to artificial accelerated aging. MATERIALS AND METHODS: Materials were prepared as disc-shaped specimens sized to 12 mm × 2.2 mm and were aged through exposure to 150 kJ/m2 in an artificial accelerated aging machine. Two-time points, 24 h after aging and 96 h after aging, were selected for evaluation in the following trials. The morphology was observed using a scanning electron microscopy. The standard CIEL*a*b* color system was employed for color measurements. Microhardness of all specimens was analyzed by a Knoop indenter. Chemical components were examined by Fourier transform infrared spectroscopy. RESULTS: Compared with universal Z350 and flowable Z350, the ICON infiltrant resin presented a uniform, slightly scratched surface before and after accelerated aging. The 24 h artificial accelerated aging of the three investigated materials resulted in acceptable color alterations, a ΔE* range of 2.52±0.63 for universal Z350, 2.43±0.59 for flowable Z350 and 3.31±0.32 for ICON. After 96 h aging, significant color changes were noted for universal Z350 (7.51±0.63) and ICON (4.70±0.69). The ICON infiltrant displayed reduced microhardness when compared to universal Z350 and flowable Z350. The absorption peaks of the chemical bonds were significantly altered after the accelerated aging process. CONCLUSIONS: Composed in a triethylene glycol dimethacrylate (TEGDMA) monomer-based network, the color stability and microhardness of the infiltrant resin provided suitable material for treating white spot lesions (WSLs), yet presented susceptibility under accelerated aging. Thus, osmotic resin therapy has strict limitations to be most effective.

Dentists' decisions regarding the need for cuspal coverage for endodontically treated and vital posterior teeth.

Objectives: Deciding when cuspal coverage is needed for posterior teeth is considered a challenge for dentists. The aims were to assess dentists' decision making regarding the need for cuspal coverage for vital teeth (VT) and endodontically treated teeth (ETT) with varying amounts of tooth structure loss and to identify clinical situations of dissimilarity and uncertainty in decision making. Materials and Methods: A random sample of 182 dentists were invited to participate in the survey. The survey included photos of 13 posterior teeth: six VT and seven ETT. The clinical situations selected were based on a hypothetical scale of typodont teeth with ascending amounts of tooth structure loss. A brief description of each situation was provided. Each dentist was asked to decide whether cuspal coverage is needed, not needed, or unsure. Descriptive analyses using SPSS were conducted. Seventy-five percent was chosen as a cutoff point for assessing similarity in decision making. The unsure answer reflected uncertainty. Associations were assessed using chi-square test. Results: One hundred twenty dentists participated (65.9% response rate, 70 females). Median for years of experience was 3.5 (interquartile range 1.1-10.8). Analyses revealed a similarity percentage of <75% in decision making among dentists for six clinical situations: four VT and two ETT. More similarity was observed for situations at both ends of the scale with minimal and severe amounts of tooth structure loss and more for ETT than for VT. The highest percentages of uncertainty were more for VT than for ETT. Clinical conditions of VT were more likely to receive the "not sure" decision compared with those of ETT (χ2, P < .001). No association was detected with gender (χ2, P = .509) or years of experience (χ2, P = .223). Conclusions: Dissimilarity and uncertainty in deciding when cuspal coverage is needed were observed especially for VT and teeth with a moderate amount of structure loss.

Investigations on the adhesion of new composites for restoring cervical lesions using energy dispersive X-ray analysis and scanning electron microscopy.

Restoration of noncarious cervical lesions with resin composites is one of the treatment options, but the retention of the restorations located at the crown-root junction is still a cause of clinical concern. The aim of this study was to evaluate the adhesive properties of three experimental resin composites and two commercial materials used to restore cavities prepared on extracted teeth as well as to determine the relative elemental composition of these materials. We tested the null hypothesis, which considered that the adhesive behaviours of different resin composites did not differ. The microleakage test using tracers showed that all tested materials exhibited some degree of dentinal microleakage, although they all had good dentinal adhesion. The results failed to reject the null hypothesis. The scanning electron microscopy revealed completely adapted adhesive interfaces underneath the restorations along with well-developed hybrid layers depending on the adhesive system. Energy dispersive X-ray analysis analyses showed that the restorative materials have similar chemical compositions, with some differences between the samples from the same material. The results support the implementation of experimental resins in clinical settings.

Avaliação do desempenho de duas resinas compostas e dois sistemas adesivos em um novo protocolo cirúrgico-restaurador para tratamento de lesões cervicais não-cariosas associadas à recessão gengival: estudo clínico controlado randomizado / Evaluation of two resin composites and two adhesives for a novel surgical-restorative protocol for the treatment of non-carious cervical lesions associated with gingival recession: a randomized controlled clinical trial

A recessão gengival está frequentemente associada à lesão cervical não-cariosa. Quando as duas lesões estão associadas, dão origem a uma lesão combinada (LC) que tem um prognóstico de tratamento diferente de quando as duas lesões se apresentam sozinhas. A literatura apresenta alguns estudos que avaliaram uma abordagem multidisciplinar para otimizar o tratamento dessa LC. No entanto, as abordagens propostas possuem limitações de técnicas e materiais, sem um protocolo clínico ideal estabelecido. Dessa forma, o objetivo do presente estudo foi avaliar um novo protocolo multidisciplinar, com duas resinas compostas e dois sistemas adesivos distintos através de estudo clínico randomizado. Foram selecionadas 80 lesões combinadas, alocadas aleatoriamente em um dos seguintes grupos: AC+NP (n=20) - restauração parcial da lesão cervical com resina nanoparticulada e sistema adesivo de condicionamento total em 2 passos e cirurgia para recobrimento radicular, AU+NP (n=20) - restauração parcial da lesão cervical com resina nanoparticulada e sistema adesivo autocondicionante e cirurgia para recobrimento radicular, AC+MH (n=20) - restauração parcial da lesão cervical com resina microhíbrida e sistema adesivo de condicionamento total em 2 passos e cirurgia para recobrimento radicular, AU+MH (n=20) - restauração parcial da lesão cervical com resina microhíbrida e sistema adesivo autocondicionante e cirurgia para recobrimento radicular. Foram realizadas avaliações das restaurações pelo método USPHS após 1 semana, 6 meses e 12 meses. A análise de sobrevivência das restaurações foi realizada através do teste de Kaplan-Meier. Os protocolos restauradores foram comparados para cada parâmetro pelo teste exato de Fisher, considerando tipo de adesivo e tipo de resina empregados. Teste de Qui-Quadrado foi utilizado para comparação das taxas após 6 e 12 meses entre os grupos testados. A avaliação da normalidade foi realizada pelo teste de Shapiro-Wilks. As medidas clínicas de RGR, PS, NIC, ETQ, ATQ, Hipersensibilidade Dentinária e Estética (VAS) foram comparadas tanto intra como intergrupo por teste de variância de medidas repetidas ANOVA de dois fatores e Tukey com teste post-hoc. IP, IS foram avaliados pelo teste de Qui-Quadrado. Os parâmetros de DC, Porcentagem de recobrimento e RecRed foram analisados pelo ANOVA 1 fator. Pôde-se observar uma taxa de sucesso geral cumulativo do tratamento de 98,7% aos 6 primeiros meses e 92,4% aos 12 meses de acompanhamento, sem diferença estatisticamente significativa entre os tempos e grupos avaliados. Todos os grupos apresentaram melhora estética e redução de hipersensibilidade significativa em relação ao baseline (p<0,001) após 6 meses. Houve redução significativa da recessão gengival relativa (p<0,05) após 12 meses de acompanhamento. Dentro dos limites do presente estudo, pode-se concluir que os materiais utilizados apresentaram desempenho clínico similares, sendo que as diferentes combinações de materiais restauradores adesivos estudados associados às técnicas cirúrgicas utilizadas podem ser empregadas no tratamento das lesões cervicais não-cariosas associadas a recessão gengival(AU)

Non-carious cervical lesion is frequently associated with gingival recession, resulting in a combined lesion (CL) that has a different treatment prognosis when the two lesions appear alone. The literature presents few studies that evaluate a multidisciplinary approach to optimize the treatment of this CL. The previously proposed approaches and materials have limitations and an optimal clinical protocol has not been established yet. Thus, the aim of this study was to evaluate a novel multidisciplinary protocol with two resin composites and two different adhesive systems by a randomized clinical. Eighty combined lesions were randomly assigned to one of the following groups: NP + TE (n = 20) - partial restoration of cervical lesions with nanofilled composite and total-etch adhesive system and periodontal surgery for root coverage, NP + UA (n =20) - partial restoration of cervical lesions with nanofilled composite and self-etching adhesive system and periodontal surgery for root coverage, MH + TE (n = 20) - partial restoration of cervical lesions with microhybrid composite and total-etch adhesive system and periodontal surgery for root coverage, MH + UA (n = 20) - partial restoration of cervical lesions with microhybrid composite and selfetching adhesive system and periodontal surgery for root coverage. Restorations were assessed using the USPHS criteria after one week, six months and twelve months. Survival rate was assessed by Kaplan-Meier test. Restorative protocols were compared for each parameter by Fisher's exact test, considering type of adhesive and type of composite used. Chi-square test was used to compare the rates at 6 and 12 months between the groups tested. Normality evaluation was assessed by Shapiro-Wilks test. Clinical measures of RGR, PS, NIC, KTW, KTH, Hipersensitivity and Esthetics (VAS) were compared both intra and inter-group by analysis of variance of repeated measures Two-Way ANOVA and Tukey posthoc test. IP, IS were evaluated by Chi-square test. CD parameter, Coverage percentage and RecRed were evaluated by One-Way ANOVA. It was observed a successful cumulative rate of 98.7 % at 6 months and 92.4 % at 12 months with no significant difference between groups. When compared to baseline, all groups presented significant improvement in esthetics and reduction of hipersensitivity at 6 months (p<0.001). Significant reduction of gingival recession was recorded after 12 months (p<0.05). It can be concluded that there is no difference between the tested materials, and different combinations of adhesive restorative materials associated with periodontal surgical techniques can be used to treat non-carious cervical lesions associated with gingival recession(AU)

SDR® vs traditional composite in class II restorations in primary molars.

This study aims to compare the clinical characteristics of a new flowable resin-based composite with those of a traditional composite when applied to deciduous molars for class II restorations. Twentyeight children between 6-12 years of age, with paired minimal Class II cavities present on their primary molars, were chosen. The paired cavities were restored with either a microhybrid composite or a new flowable resin-based composite. The composites were assigned to cavities in either the right or left side of the mouth, using random allocation tables. Each pair of restorations were clinically assessed at sixmonth intervals following the United States Public Health Service criteria. The prevalence of carious lesions was higher in maxillar molars (53.6%) compared to the mandibular molars (46.4%). At 24 months, Charlie or Delta scores in the paired groups were not seen in any patient, thus demonstrating a clinical success. The statistical analysis using Pearson’s chi-squared test did not reveal significant p-values for any parameter except the proximal contact showing significant p-values for this parameter. SDR appears to be the material of choice for the restoration of deciduous teeth due to its clinical features shown at 24 months as well as its ease and speed of application.

Qualitative analysis of the margins of restorations made with different filling resins.

PURPOSE: In this study the comparative results obtained from examinations of two different restorative composites with different cavities filling method are presented. Micro-CT was used for the evaluation of the marginal integrity and quality of composite fillings in connection with microstructural investigations made by both optical and scanning electron microscopy. MATERIALS AND METHODS: The examinations of dental tooth filings in bulk-fill technique were based on micro-CT and microscopy observations. Two different restorative composites were selected for the study, namely SonicFill- bulk fill and conventional Filtek Z550. RESULTS: The experiment has shown that micro-CT screening analysis for identification of individual components of tooth and fillings systems gives a high quality of images. Thanks to that it was possible to analyze and identify the porosity in the fillings. But the microscopy analysis has shown more information about the internal structure and quality of bonding between composite and enamel/dentin. The SonicFill gives better quality and bonding to structure of teeth than Filtek. CONCLUSIONS: SonicFill's filling have more homogenous structure than Filtec. It has a greater share of reinforcement in the form of polygonal particles, in Filtek particles have a shape close to spherical. Sonic Fill gives a better adhesion to tooth. CLINICAL RELEVANCE: The evaluation of clinical relevance in this research is crucial to simplify the transfer of knowledge from research by materials engineering into practice in dentistry.

Effect of Home Bleaching on the Color Matching of Composite Resin Restorations

Objective: To investigate the effect of home bleaching on color matching between the dental restoration and the adjacent tooth structure after the staining process. Material and Methods: Ten intact maxillary central incisors were used. After preparation (semimesial restoration of the specimens), the specimens were immersed in a colored solution for 14 days and then were washed and the bleaching process was there after performed. A spectrophotometer apparatus was used to determine the color of the specimens in the part of the tooth filled with restorative material three times, including before the staining process, fourteen days after the staining process and immediately after the bleaching process. Paired t-test was employed to compare the color of the intact tooth and the dental restoration before and after the staining and bleaching processes. The level of significance was set at 5%. Results: Pre-bleaching E color of the teeth was 68.1, which increased to 78.8% after bleaching, and this increase was also statistically significant (p<0.001). Pre and Post-bleaching E color of composite restorations was 65% and 77.6%, respectively. This increase was also statistically significant (p<0.001). Postbleaching E color of the tooth and composite material was 78.8% and 77.6%, respectively. This difference was not statistically significant (p=0.342). Conclusion: The staining and bleaching processes had a significant effect on the discoloration of the dental restoration and the tooth; however, the application of bleaching on the teeth and composite improved the tooth composite color-match.

Digital intraoral scanning technique for edentulous jaws.

Few studies have evaluated direct digital scans of edentulous jaws using intraoral scanners because it is difficult to scan edentulous sites that are smooth and devoid of features. A scanning technique is introduced for making direct digital scans of edentulous jaws with intraoral scanners in patients with a broad palate.

Efeito da termociclagem em diferentes soluções nas propriedades físicas e químicas dos materiais resinosos / Effect of thermocycling on different solutions on the physical and chemical properties of resinous materials

Os estudos em laboratório devem ser realizados para verificar e comprovar a eficácia destes novos materiais, equipamentos, técnicas e tecnologias, e sendo considerados aprovados, uma outra etapa in vivo deverá ser realizada. O advento da odontologia adesiva já causou profundas mudanças na prática da odontologia. A proposta deste trabalho foi avaliar in vitro, o efeito da termociclagem, em diferentes temperaturas (5°C, 55°C), soluções (água destilada, óleo mineral), quantidade de ciclos (500, 5.000, 10.000), utilizando um material restaurador universal nanohíbrido fotopolimerizável contendo carga inorgânica em uma matriz de metacrilato e um sistema de cimentação à base de resina composta de polimerização dual. A finalidade da termociclagem é o envelhecimento dos materiais pelo mecanismo do "choque térmico". O objetivo deste trabalho foi demonstrar se a termociclagem interfere ou não nas propriedades físicas e químicas destes materiais. Foram confeccionados 90 corpos de prova (cp) de cada material, cinco de cada grupo, (cpCRc = corpos de prova do cimento resinoso com YTZP, cpCRs= corpos de prova do cimento resinoso sem Y-TZP, e cpRC= corpos de prova da resina composta), que foram armazenados em água destilada, até o início da termociclagem. Estes espécimes receberam o tratamento térmico (nas distintas soluções) e após este evento foram realizadas as mensurações de massa, rugosidade, nanodureza e avaliações em MEV/ EDS, FTIR/UATR. Os dados obtidos foram submetidos ao teste Anova três fatores (α = 0,05). Os grupos cpCRc, cpCRs, cpRC não apresentaram alterações e ou modificações nas propriedades físicas e químicas dos materiais, independentemente do tipo de ciclagem, solução, temperatura e número de ciclos. Portanto, o uso da termociclagem, nas temperaturas de (5°C, 55°C), diferentes soluções (água destilada, óleo mineral), quantidade de ciclos (500, 5.000, 10.000) não foi observado o envelhecimento térmico para estes materiais(AU0

Laboratory studies should be performed to verify and prove the efficacy of these new materials, equipment, techniques and technologies, and being considered approved, another in vivo step should be performed. The advent of adhesive dentistry has already caused profound changes in the practice of dentistry. The determination of bond strength of dentin adhesives is a matter of great importance and interest in our profession. The purpose of this work is to evaluate in vitro the effect of thermocycling at different temperatures (5 °C, 55 °C), solvents (distilled water, mineral oil), number of cycles (500, 5.000, 10.000) and a universal nano-hybrid restorative light-curing material with contains inorganic fillers in a methacrylate matrix and a dual-curing composite-based luting system for permanent adhesive luting. The purpose of thermocycling is thermal and hydrolytic degradation; and the objective of this work is to demonstrate if the thermocycling interferes or not in the study in the physical and chemical properties. A metal matrix was produced to make the specimens (sp). A total of 90 (sp) from each material, five from each group, were prepared (BFX-C = YTZP with resin cement sp, BFX-S = YTZP without resin cement sp, and GRD = composite resin specimens) which were stored in distilled water until the beginning of the thermocycling. The sp received the thermal treatment (the different solvents) and after this event were reached the messages of mass, roughness, hardness. and evaluations in SEM / EDS, FTIR / UATR. Data were obtained from the Anova test (α = 0.05). The groups BFX-C, BFX-S, GRD are the parameters keys and physical properties of the materials, regardless of the type of cycling, solvent, temperature and number of cycles. Therefore, the use of thermocycling, at temperatures of 5 °C, 55 °C, different solvents, mineral oil, amount of heat (500, 5,000, 10,000) was not observed in the thermal heat for these materials(AU)

Influência da aplicação de um sistema adesivo na resistência de união entre resinas bulk fill flow e resina nanoparticulada em reparos / Adhesive system influence on bond strength between bulk fill flow and conventional nanoparticulated cover resin on a repair procedure

O objetivo desta pesquisa foi avaliar a influência da utilização ou não do bond do sistema adesivo Adper Scotchbond Multiuso(A) e o bond Gluma da Heraeus(G) na resistência de união entre as resinas do tipo flow Filtek Bulk Fill Flow(F) e X-tra base (X) como base e uma convencional nanoparticulada Z350 XT(Z)) como cobertura. Simulando assim seu uso em reparos de restaurações diretas em dentes posteriores. Foram confeccionados 120 espécimes em resina composta do tipo flow no formato tronco-cônico com as dimensões de 2mm base menor, 4mm de altura e 4 mm de base maior. 60 Filtek Bulk Fill(F) e 60 Xtra base (X). Metade de cada grupo (n=30) foi envelhecida por termociclagem 5.000 ciclos de 5°C a 55°C, (FE, XE), a outra metade não sofreu envelhecimento (FN e XN). Esses espécimes foram divididos em 3 subgrupos (n=10), sobre a base menor dessas 10 amostras foi aplicado o Bond de cada sistema adesivo após condicionadas pelos seus respectivos ácidos nos tempos preconizados pelos fabricantes. As outras 10 unidades de cada grupo não receberam qualquer sistema adesivo. Na simulação do reparo as duas primeiras metades em teflon foram invertidas ficando a área menor voltada pra cima. Sobre essa face foram colocadas outras duas metades em teflon com a área menor voltada para baixo. Foi inserida então a resina Z350 pela técnica incremental e fotopolimerizada por 20s a 800mw/cm². Após 24h de armazenamento em água destilada, em estufa bacteriológica os espécimes, agora com formato de ampulheta, foram tracionados na máquina de ensaios universais (EMIC). Todos os espécimes fraturados tiveram o tipo de falha analisados ao estereomicroscópio e também ao microscópio eletrônico de varredura (MEV). Os dados coletados no ensaio de tração foram analisados através de ANOVA 3- fatores e teste de Tukey (p<5%). Houve diferença significativa (p<5%) para a variável aplicação de sistema adesivo para a resina Filtek Bulk Fill flow que apresentou médias maiores (24,99 ± 4,3 MPa) quando comparadas ao grupo no qual não foi aplicado adesivo (18,20 ± 5,31 MPa). O mesmo não ocorreu com a resina X-tra base, na qual o fator adesivo não interferiu significantemente. Quando comparado o desempenho das resinas Filtek Bulk Fill flow e X-tra base (26,99 ± 6,11 MPa) sem aplicação de sistema adesivo, também se verificou diferença significativa, o que não ocorreu para a resina X-tra base quando comparados ambos os subgrupos. As falhas foram 100% adesivas para todos os grupos(AU)

The aim of our paper was to analyse the bonding influence of Adper Scotchbond Multipurpose Adhesive (A) and Heraeus Gluma universal bond (G), or no bond application, on bond strength between microhibrid Filtek Bulk Fill Flow (F) and nanohibrid X-tra base (X) as based composite resin and the conventional nanoparticulate Z350 XT (Z)) as cover. Simulating non-invasive repairs of direct restorations on posterior teeth. A total of 120 specimens were made from flow composite resin in the conical trunk format with the dimensions of 2x4x4, for 40s with Led-5 (N/S LD51803005) at 800mw/cm². Sixty Filtek bulk fill (F) and sixty X-tra base (X) were made. Half of each group (n=30) was aged by thermocycling 5,000 cycles from 5° C to 55° C, (FE, XE), the other half were not subjected to any aging procedure (FN, XN). These specimens were randomly divided into 3 subgroups (n = 10), on the smaller diameter of the 10 samples the Bond of each adhesive system were applied after conditioned by their respectively acids at the time recommended by the manufacturers. The other 10 units of each group did not receive any adhesive system. In the sequency of repair simulation the first two Teflon halves were turned up with the smaller diameter turned upwards. Above this face were placed two other halves in Teflon with the smaller diameter facing down. The Z350 repair composite resin were inserted by incremental technique and photopolymerized for 20s at 800mw/cm². After 24h of storage in distilled water in a bacteriological oven, the now hourglass-shaped specimens were drawn in the universal testing machine EMIC. All the fractured specimens had the type of failure analyzed in stereomicroscope. The most significant faulting specimens were evaluated with electronic microscope (MEV). The data collected at the traction test were analyzed through 3-factor ANOVA and Tukey's test (p <5%). There was a significant difference (p <5%) for the variable adhesive system application for Filtek Bulk Fill flow resin that presented averages (24.99 ± 4.3 MPa) when compared to the group in which no adhesive was applied (18.20 ± 5.31 MPa). The same did not occur with X-tra base resin, in which the adhesive factor did not interfere significantly. When comparing the performance of Filtek Bulk Fill Flow resins and X-tra base (26.99 ± 6.11 MPa) without application of adhesive system, a significant difference was also observed, which did not occur for X-tra base resin when compared both subgroups. Most of the failures were adhesive for all groups. Scanning electron microscopy images do not reveal any traces of discontinuity between the layers of the materials used (resin x resin or resin x adhesive)(AU)

Porosity of flowable resin composites is not influenced by applicator tip diameter.

PURPOSE: To assess the influence of applicator tip diameter on the inclusion of porosities in three different flowable resin composites. METHODS: The initial porosity of three syringes [Filtek Supreme XTE Flowable (XTE), Grandio Flow (GRF), Gradia Direct Flo (GDF)] was determined by 3D tomography. 25 samples per syringe, i.e. 75 samples in total, were prepared using five applicator tips of different diameters (n= 5). The porosity of the 75 samples was assessed by 3D tomography. RESULTS: For each of the materials, the applicator tips, irrespective of type, all generated an increase in the average porosity percentage compared to the initial porosity of the syringes. For XTE and GRF, the applicator tips, irrespective of type, all generated a decrease in the average porosity volume compared to the initial average porosity volume in their respective syringes. Conversely, for GDF the average porosity volume of the samples was increased. Furthermore, for each of the materials, varying the diameter of the applicator tips had no significant influence on the porosity percentage and volume. Using the present study conditions, the applicator tip generated a variation in the initial porosity of the materials; however, the diameter of the tip had no influence on said variation. CLINICAL SIGNIFICANCE: It appears that practitioners can choose an applicator tip with a diameter that best suits the size and shape of the cavity to be filled using a syringe of flowable resin composite without this having any impact on the percentage and volume of porosities in the final filling of the cavity.

Light Curing in Dentistry.

The ability to light cure resins 'on demand' in the mouth has revolutionized dentistry. However, there is a widespread lack of understanding of what is required for successful light curing in the mouth. Most instructions simply tell the user to 'light cure for xx seconds' without describing any of the nuances of how to successfully light cure a resin. This article provides a brief description of light curing. At the end, some recommendations are made to help when purchasing a curing light and how to improve the use of the curing light.

Release of fluoride from orthodontic adhesives and penetration into enamel.

OBJECTIVE: The purpose of this work was to compare fluoride release from three orthodontic adhesives and fluoride penetration into the enamel surface. MATERIALS AND METHODS: A total of 156 extracted human premolar teeth were randomly assigned to three experimental groups and one control group (without bonding) with 39 teeth per group. Brackets were bonded to teeth using Fuji Ortho LC®, Illuminate®, or Light Bond®. The amount of fluoride released (ppm) into artificial saliva was measured by a fluoride ion-selective electrode connected to an ion analyzer on days 1, 3, 7, and 30. Fluoride penetration was investigated after 1, 2, and 3 months; 13 teeth of each group were randomly selected at every period of study and sectioned across the center of the bracket. The surface of the cross-section was studied under the scanning electron microscope, and the fluoride concentration (weight%) at 1, 2, and 3 µm below the outer enamel surface was determined by energy-dispersive X-ray microanalysis. RESULTS: On days 1, 3, 7, and 30, the mean cumulative fluoride release from the three orthodontic adhesives were significantly different (p < 0.05). Illuminate® released the greatest fluoride, followed by Fuji Ortho LC® and Light Bond®. After 1, 2, and 3 months, fluoride penetration into enamel was only found from Fuji Ortho LC®. The fluoride concentration decreased with depth but there were no significant differences (p > 0.05) over time at all depths. CONCLUSIONS: The in vitro study indicated that fluoride release is a common property of the three fluoride-releasing orthodontic adhesives: Illuminate®, Fuji Ortho LC®, and Light Bond®. However, detectable fluoride penetration is a specific property of Fuji Ortho LC®. Further clinical studies should be undertaken to investigate the benefit of the two adhesives Illuminate® and Fuji Ortho LC® on protection of enamel demineralization.