Evaluación de la respuesta inflamatoria en ratas Wistar a TheraCalTM LC implantado vía subcutánea / Evaluation of the inflammatory response in Wistar rats to TheraCalTM LC implanted subcutaneously

El Theracal TM LC es un cemento silicato de calcio (Ca) modificado con resina (SMCR) que ha demostrado ser un material ideal para el tratamiento dentino-pulpar por su alta tasa de formación de calcio. Los biomateriales por su contenido de Ca tienden a tener un aumento en su biodisponibilidad, estimulando la formación del puente dentario atreves de las células involucradas en la formación de tejidos mineralizados, promoviendo la diferenciación de fibroblastos en odontoblastos y aumentando la actividad de la enzima pirofostasa responsable en la mineralización de la dentina. El presente estudio con el objetivo de evaluar la respuesta inflamatoria a Theracal TM LC subcutáneamente en ratas Wistar. Fueron usados seis ratas cepa Wistar en las cuales se realizaron cuatro bolsillos quirúrgicos subcutáneos. Cada uno de estos bolsillos se determinó como cuadrante distinto, conteniendo los siguientes implantes: 1 Theracal TM LC en tubo polietileno, 2 tubo de polietileno, 3 Theracal TM LC directo y 4 como control. Las muestras histológicas se procesaron y se evaluaron distintos tipos celulares mediante conteo a microscopio de luz a 100X utilizando las tinciones H&E y AT pH 2.3. Los resultados mostraron que existen diferencias significativas en todos los tipos celulares observados durante los diferentes tiempos de exposición. Las diferencias en los tipos celulares observados podrían ser debido al tiempo de exposición al Theracal TM LC, al tubo polietileno y a ambos. El tejido evaluado del implante del tubo polietileno y al tubo polietileno con Theracal TM LC, presentan mayor respuesta inflamatoria, a diferencia en el tejido implantado con Theracal TM LC directamente.

TheraCalTM LC is a resin-modified calcium silicate (Ca) resin (SMCR) that has proven to be an ideal material for dentin-pulp treatment due to its high rate of calcium formation. Biomaterials due to their Ca content tend to have an increase in their bioavailability, stimulating the formation of the dental bridge through the cells involved in the formation of mineralized tissues, promoting the differentiation of fibroblasts in odontoblasts and increasing the activity of the pyrophosphate enzyme responsible in dentin mineralization. The present study aimed to evaluate the inflammatory response to TheracalTM LC subcutaneously in Wistar rats. Six Wistar strain rats were used in which four subcutaneous surgical pockets were made. Each of these pockets was determined as a different quadrant, containing the following implants: 1 TheracalTM LC in polyethylene tube, 2 polyethylene tubes, 3 TheracalTM LC direct and 4 as control. The histological samples were processed, and different cell types were evaluated by light microscopy at 100X using the H&E and AT pH 2.3 stains. The results showed that there are significant differences in all cell types observed during the different exposure times. The differences in the cell types observed could be due to the exposure time to TheracalTM LC, to the polyethylene tube and to both. The evaluated tissue of the polyethylene tube implant and the polyethylene tube with TheracalTM LC present a greater inflammatory response, unlike in the tissue implanted with TheracalTM LC directly.

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.

Influence of the incorporation of triclosan methacrylate on the physical properties and antibacterial activity of resin composite

Abstract The incorporation of antimicrobials in the composites as an attempt to reduce bacterial adhesion without jeopardizing mechanical properties is a challenge for Dentistry. Objective: To evaluate the bacterial adhesion and physical properties of a composite containing the methacrylate triclosan- derivative monomer (TM). Methodology: TM was synthesized and added to an experimental composite. Samples were divided into two groups: Control and TM (13.4 wt%). Antibacterial Activity: Three specimens of each material were prepared and placed on bacterial suspensions of Streptococcus mutans for 1, 5 and 10 days. After these periods the counting of the colonies (log10) was performed. Assays was performed in triplicate. Physical Properties: Three-body Abrasion (TBA): Ten specimens of each material were prepared and stored at 37°C/24 h. The surface roughness (Ra) and hardness (KHN) were analyzed. Next, the specimens were submitted to abrasive wear (30,000 cycles) and re-evaluated for Ra and KHN; Sorption/solubility (SS): cylindrical specimens (n=10) were prepared and weighted. The specimens were immersed in deionized water for 7 days at 37°C and then their weight was verified again. SS were calculated using accepted formulas; Diametral tensile strength (DTS): specimens (n=10) underwent test performed in an Instron universal testing machine at a crosshead speed of 1 mm/min. Data were submitted to appropriate statistical tests according to data distribution and assay (p<0.05). Results: Bacterial Adhesion: TM showed a significant reduction on biofilm accumulation in the evaluated periods: 1 day (1.537±0.146); 5 days (2.183±0.138) and 10 days (4.469±0.155) when compared with Control: 1 day (4.954±0.249); 5 days (5.498±0.257) and 10 days (6.306±0.287). Physical Properties: For TBA, SS and DTS no significant difference was found between groups Control and TM. The incorporation of methacrylate triclosan-based monomer in the experimental composite reduce bacterial adhesion of S. mutans and did not affect important polymer properties.

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

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

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials

Abstract The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

The effects of different restorative materials on periodontopathogens in combined restorative-periodontal treatment

Abstract Objective The aim of the study was to evaluate the association between subgingival restorations and the target periodontopathogenic bacteria (Pg, Td and Pi) in subgingival biofilm during one year after combined restorative-periodontal treatment. Material and Methods Seventeen systemically healthy subjects, who were positive for the presence of three cervical lesions associated with gingival recessions in three different adjacent teeth, were included in the study. A total of 51 combined defects were treated with connective tissue graft plus a nanofilled composite resin (NCR+CTG), a resin-modified glass ionemer cement (RMGI+CTG) and a fluoride-releasing resin material with pre-reacted glass (PRG), called giomer (Giomer+CTG). Periodontal clinical measurements and subgingival plaque samples were obtained from all combined defects at baseline and at 6 and 12 months after the surgery. The number of bacteria were evaluated by the real-time polymerase chain reaction (qPCR) method. Results No statistically significant difference in the amount of DNA copies of Pg, Td and Pi was observed in any of the groups at any time points (p>0.05). In addition, there was no statistically significant difference in the amount of DNA copies of the bacteria at baseline and at 6 and 12 months postoperatively, regardless of treatment group (p>0.05). Conclusion This study suggests that subgingivally placed NCR, RMGI and giomer restorations can show similar effects on periodontopathogenic bacteria in the treatment of gingival recessions that are associated with noncarious cervical lesions (NCCLs).

Model resin composites incorporating ZnO-NP: activity against S. mutans and physicochemical properties characterization

Abstract Although resin composites are widely used in the clinical practice, the development of recurrent caries at composite-tooth interface still remains as one of the principal shortcomings to be overcome in this field. Objectives To evaluate the activity against S. mutans biofilm of model resin composites incorporating different concentrations of ZnO-nanoparticles (ZnO-NP) and characterize their physicochemical properties. Materials and Methods Different concentrations of ZnO-NP (wt.%): E1=0, E2=0.5, E3=1, E4=2, E5=5 and E6=10 were incorporated into a model resin composite consisting of Bis-GMA-TEGDMA and barium borosilicate particles. The activity against S. mutans biofilm was evaluated by metabolic activity and lactic acid production. The following physicochemical properties were characterized: degree of conversion (DC%), flexural strength (FS), elastic modulus (EM), hardness (KHN), water sorption (Wsp), water solubility (Wsl) and translucency (TP). Results E3, E4, E5 and E6 decreased the biofilm metabolic activity and E5 and E6 decreased the lactic acid production (p<0.05). E6 presented the lowest DC% (p<0.05). No significant difference in FS and EM was found for all resin composites (p>0.05). E5 and E6 presented the lowest values of KHN (p<0.05). E6 presented a higher Wsp than E1 (p<0.05) and the highest Wsl (p<0.05). The translucency significantly decreased as the ZnO- NP concentration increased (p<0.05). Conclusions The incorporation of 2 - 5 wt.% of ZnO-NP could endow antibacterial activity to resin composites, without jeopardizing their physicochemical properties.

Effect of TiO2 nanoparticles incorporation on antibacterial properties and shear bond strength of dental composite used in Orthodontics

ABSTRACT Introduction: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Methods: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. Results: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Conclusions: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.

RESUMO Introdução: o acúmulo de placa e as descolagens de braquetes são algumas desvantagens presentes no tratamento ortodôntico, no qual se requer o uso de materiais compósitos para a colagem dos braquetes. Objetivo: tendo em vista que as propriedades antimicrobianas das nanopartículas (NPs) de TiO2 já foram confirmadas, o objetivo do presente estudo foi avaliar as propriedades antimicrobianas e mecânicas de resinas compostas modificadas pela adição de NPs de TiO2. Métodos: compósitos ortodônticos contendo 0%, 1%, 5% e 10% de NPs foram preparados. Cento e oitenta discos de compósito foram preparados para o teste de eluição, o ensaio de difusão em ágar por disco, e o ensaio de inibição da formação de biofilme, para se calcular as contagens de microrganismos ao longo de três dias, medir o diâmetro da inibição e, consequentemente, quantificar as contagens de colônias viáveis. Para o teste de resistência da colagem ao cisalhamento (SBS), 48 incisivos bovinos intactos foram divididos em quatro grupos, nos quais os compósitos contendo 0%, 1%, 5% e 10% de NPs foram utilizados para colagem dos braquetes. A SBS da interface braquete/dente foi medida em uma máquina universal de ensaios. Resultados: todas as concentrações de NPs de TiO2 apresentaram efeito significativo na formação e na extensão da zona de inibição. Para o S. mutans e o S. sanguinis, todas as concentrações de NPs de TiO2 causaram redução na contagem das colônias. O compósito contendo 10% de NPs de TiO2 apresentou uma diminuição significativa na contagem de colônias de S. mutans e S. sanguinis durante os três dias. A média mais alta da SBS foi observada no grupo controle, enquanto o valor mais baixo foi observado para o compósito com 10% de NPs. Conclusões: a incorporação de nanopartículas de TiO2 nas resinas compostas lhes conferiu propriedades antibacterianas, e o valor médio da SBS das resinas contendo 1% e 5% de NPs apresentou-se dentro de uma faixa aceitável.

Influence of addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride to an experimental adhesive

Abstract The aim of this study was to develop an experimental adhesive with addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) and to evaluate its mechanical and biological properties and its in vitro antibacterial activity. An experimental adhesive resin was formulated with Bis-GMA, TEGDMA, and HEMA. The antibacterial monomer was added at concentrations of 1%, 2.5%, and 5% (METAC groups). A group without METAC addition was used as control. The experimental adhesives were evaluated as to their antibacterial potential against Streptococcus mutans, degree of conversion, and softening in ethanol for 2 hours. The data were analyzed by one-way ANOVA, Tukey’s post-hoc test, and the paired Student’s t-test (significance level of 0.05). METAC showed antibacterial activity against S. mutans at all concentrations (p < 0.05). There was no statistical difference across METAC groups (p > 0.05). The 1%, 2.5%, and 5% groups yielded the highest mean values for degree of conversion (p < 0.05). The 1% group did not differ from the control group (p > 0.05). There was no statistical difference in baseline microhardness values (p > 0.05) and microhardness values after immersion in ethanol were lower than at baseline for all groups (p < 0.05). There was no statistical difference in the reduction of Knoop hardness number (KHN) after immersion in ethanol for any of the groups (p > 0.05). The results of the present study indicate that METAC is a promising antibacterial agent when added to an adhesive system.

Comportamento bimodular em osso cortical e novo método para calcular o módulo de elasticidade (E) em resinas compostas / Bimodular behavior in cortical bone and a novel method for measuring elastic modulus (E) of composite resins

O objetivo principal foi investigar se o osso cortical apresenta comportamento bimodular, ou seja, se os valores de módulo de elasticidade (E) dependem do tipo de carregamento que o método utiliza. Para alcançá-lo foi preciso: (1) "calibrar" os diferentes métodos em um material conhecidamente unimodular, para afastar a possibilidade de erros ligados à execução de um método. (2) Depurar os métodos já calibrados para torná-los exequíveis em osso cortical. O que foi feito em espécimes de resina composta, que é um material unimodular e com E parecido com o do osso cortical. Foi investigado se o método de medida interfere no valor do E obtido neste material (pois, pelas informações da literatura, existia uma dúvida consistente). Finalmente, (3) foi avaliado se o método de medida, a região anatômica e o indivíduo interferem nos valores de E em espécimes de osso cortical. Adicionalmente, (4) verificou-se a possibilidade de se encontrar e validar uma correlação entre E e dureza Knoop (KH), para medir o E de resinas compostas indiretamente. Espécimes de latão (n = 5) tiveram o seu E calculado por quatro métodos estáticos diferentes (flexão em três pontos; tração; compressão e método de Marshall), que foram calibrados até que todos medissem o valor esperado; os valores de cada método foram comparados por análise de variância de medidas repetidas (o método foi o fator vinculado e o nível de significância foi de 5%). Espécimes (n = 4) de cinco marcas diferentes de resina composta, também foram submetidos aos quatro métodos, fazendo as adaptações pertinentes (depuração), e tiveram o seu E calculado...

The main objective was to investigate whether the cortical bone has a bimodular behavior, that is, if the values of elastic modulus (E) depend on the load type used by the method. To achieve this, it was necessary: (1) "calibrate" the different methods in a material with well-known unimodular behavior, for excluding the possibility of systematic errors in the execution of the methods. (2) Depurate the calibrated methods to make them executable in cortical bone. This was made on specimens of composite resin, which is a unimodular material and has an E similar to that of cortical bone. It was also investigated if the method of measuring the E influences the obtained value in this material (because there was a consistent doubt in the literature). Finally (3), we assessed whether the E values in cortical bone are influenced by the measurement method, by the anatomical region and by the individual. Additionally, (4) it was verified if it would be possible suggesting and validating a correlation between E and Knoop hardness (KH), to indirectly measure the E of composite resins. Brass specimens (n = 5) had their E calculated by four different static methods (three point bending, tensile, compression and Marshall's method), which were calibrated until all the methods were capable of measuring the expected value; the E values of each method were compared by analysis of variance of repeated measures (the method was the linked factor and the significance level was 5%). Specimens (n = 4) of five different composite resins were also subjected to the four methods, making the relevant adjustments (depuration), and had their E calculated. These values were subjected to analysis of variance of repeated measures (the method was the linked factor and the significance level was 5%); Specimens (n = 48) obtained in different regions (periosteum, endosteum and "transverse") of bovine femurs from four different individual had their E calculated using the depurated methods...

Dureza da camada de adesivo e da camada híbrida e a sua relação com a resistência de união à dentina / Hardness of the adhesive layer and the hybrid layer and its relationship to bond strength to dentin

Este estudo avaliou in vitro a dureza da camada de adesivo e da camada híbrida de uma interface entre resina composta e dentina humana por meio de ensaios de nanodureza (DUH). Foi avaliada a resistência de união por meio de testes de microcisalhamento (MC) com o objetivo de observar a relação desta resistência com a propriedade da dureza. Os fatores de variação compreendem quatro sistemas adesivos (Adper Scotchbond Multiuso, Adper Single Bond 2, Clearfil SE Bond e Single Bond Universal) e duas profundidades dentinárias (dentina rasa e dentina profunda). As unidades experimentais foram compostas por 144 fragmentos dentais obtidos da face vestibular de molares humanos, os quais foram distribuídos em 16 grupos, 8 grupos com n=6 para os ensaios de DUH e 8 grupos com n=12 para os ensaios de MC de forma que os quatro sistemas adesivos foram aplicados sobre fragmentos de dentina rasa e de dentina profunda. Após a confecção das restaurações em resina composta e 24h de armazenamento em estufa a 37°C, os ensaios de DUH foram realizados no ultramicrodurômetro DUH-211S (Shimadzu) com carga de 1mN/mseg. Os testes de MC foram realizados na máquina de ensaios universais Instron 5942(Instron Co) com velocidade de 1mm/min seguido da análise do padrão de fratura em microscópio digital. A análise estatística foi realizada por ANOVA (p<0,01%), Tukey e correlação de Pearson (p<0,05%). O sistema SB Universal (M=31,82±4,72) evidenciou os maiores valores de resistência de união e o Clearfil SE (M=26,75±3,73) os menores.

O Single Bond 2 (M=28,83±4,07) e Scotchbond MP (M=28,53±4,61) não apresentaram diferenças entre si e obtiveram valores intermediários, não se diferenciando do maior e nem do menor valor. A resistência de união na dentina rasa (M=30,45±4,40) foi maior que em dentina profunda (M=27,52±4,01). Os sistemas SB Universal (M=22,57±2,42) e Scotchbond MP (M=22,13±2,89) não apresentaram diferença entre si e evidenciaram valores de dureza na camada de adesivo maiores que o Clearfil SE (M= 19,11±1,23). O sistema Single Bond 2 (M=20,11±1,49) apresentou valores intermediários de dureza e não foi diferente do maior e do menor valor. A camada híbrida em dentina rasa (M=38,23±3,08) apresentou maior dureza que a camada híbrida em dentina profunda (M=33,09±1,85). Pode-se concluir que tanto o sistema adesivo utilizado quanto a profundidade dentinária influenciaram nos resultados de resistência adesiva. A dureza da camada de adesivo varia conforme o sistema utilizado sendo que os adesivos SB Universal e o Scotchbond MP apresentaram os maiores valores de dureza. A dureza da camada híbrida foi influenciada pela profundidade dentinária do substrato. Foi observada uma correlação direta entre a dureza da camada de adesivo e a resistência adesiva.

This study evaluated in vitro the hardness of the adhesive layer and the hybrid layer interface between composite and human dentin using nanohardness test (DUH). Was evaluated the bond strength by microshear test (MC) in order to observe the relationship of this resistance with the hardness property. The variation factors consist of four adhesive systems (Adper Scotchbond Multi-Purpose, Adper Single Bond 2, Clearfil SE Bond and Single Bond Universal) and two dentin depths (superficial and deep dentin). The experimental units consisted of 144 dental fragments obtained from molars vestibular area, which were divided into 16 groups, 8 groups with n = 6 for DUH test and 8 groups with n = 12 for the MC test, so the four adhesive systems were applied on dentin fragments of superficial and deep dentin. After the construction of the composite resin restorations and 24h storage at 37 °C, DUH analysis were performed using a nanoindentation device DUH-211S (Shimadzu) with load of 1mN/mseg. The MC tests were performed in a universal testing machine Instron 5942 (Instron Co) with speed 1mm/min followed by analysis of the failure site in digital microscope. Statistical analysis was performed by ANOVA (p <0.01%), Tukey, and Pearson correlation (p <0.05%). The system SB Universal (M = 31.82 ± 4.72) showed higher values of bond strength and Clearfil SE (M = 26.75 ± 3.73) lower.

The Single Bond 2 (M = 28.83 ± 4.07) and Scotchbond MP (M = 28.53 ± 4.61) did not differ among themselves and had intermediate values, not differentiating the largest and the smallest value. The bond strength of superficial dentin (M = 30.45 ± 4.40) was higher than in deep dentin (M = 27.52 ± 4.01.) Universal Systems SB (M = 22.57 ± 2.42) and Scotchbond MP (M = 22.13 ± 2.89) did not differ among themselves and showed hardness values in the adhesive layer higher than Clearfil SE (M = 19.11 ± 1.23.) The system Single Bond 2 (M = 20.11 ± 1.49) showed intermediate values of hardness and was not different from the largest and smallest value. The hybrid layer in superficial dentin (M = 38.23 ± 3.08) was harder than the hybrid layer in depth dentin (M = 33.09 ± 1.85.) It can be concluded that both the adhesive system used as the dentin depth influenced the bond strength. The hardness of the adhesive layer varies depending on the system used and the SB Universal adhesive and Scotchbond MP showed higher hardness values. The hardness of the hybrid layer was influenced by the depth of the dentin substrate. We observed a direct correlation between the hardness of the adhesive layer and the bond strength.

Avaliação da influência da aplicação de um selante de superfície no comportamento clínico de restaurações de resina composta classe I / Evaluation of the influence of a surface sealant in the clinical behavior of composite resin class I restorations

A aplicação de selantes de superfície, através da penetração nas irregularidades superficiais e na interface dente/restauração, é realizada ao final do procedimento restaurador e pode minimizar algumas limitações, prolongando a longevidade clínica das restaurações de resina composta. Este estudo clinico randomizado se propôs a avaliar o efeito da aplicação de um selante de superfície no comportamento clínico de restaurações posteriores de resina composta do tipo classe I. Vinte e sete pares de dentes molares ou pré-molares, superiores ou inferiores, que apresentavam lesões de cárie (classe I) ou restaurações de amálgama ou resina composta (classe I) insatisfatórias, que necessitavam de substituição completa, foram aleatorizados e preparados e restaurados com a resina composta Esthet-X. Sobre a superfície da resina de apenas um dente de cada par foi aplicado o selante de superfície Lasting Touch utilizando o modelo experimental de boca dividida. A avaliação única foi realizada empregando-se o método direto USHPS modificado, nos tempos: baseline, 6 meses, 12 meses, por dois operadores. Radiografias interproximais e réplicas das faces oclusais foram obtidas por meio da moldagem com silicona de adição e vazadas com resina epóxica para avaliação qualitativa com Microscópio Eletrônico de Varredura. Os dados foram submetidos ao teste de Mc Nemar (p<0,05). Para a integridade marginal, após 6 meses de avaliação, apenas 1 (4%) restauração do grupo com selante de superfície recebeu o escore Bravo. Aos 12 meses, a integridade marginal apresentou 1 (4%) do grupo sem selante e 2 (7%) restaurações com selante com escore Bravo. Os resultado apresentados nos períodos de avaliação não apresentaram diferenças estatisticamente significantes (p=1,0, para todas as condições. Não houve diferença no desempenho clínico de restaurações de resina composta com e sem selante de superfície, sendo aceitáveis após 12 meses de avaliação. As observações em MEV demonstraram...

The finishing, polishing and surface sealant application, by superficial irregular penetration and between restoration interface, are applied at the end of the restoration and decrease these limitations, and extend the clinical longevity of composite resin restorations. This clinical randomized controled study however aimed to evaluate the effect of the surface sealant application in the clinical behavior of composite posterior resin class I restorations. Twenty seven pairs of upper or lower molars or premolars with carious lesions (class I), and unsatisfactory amalgam or composite resin restorations, which needed total replacement, were randomized and prepared and restored with Esthet X composite resin. The composite resin surface of one tooth from each pair was covered with Lasting Touch surface sealant (Split Mouth Design). The clinical evaluation was made by using the modified direct method USPHS, at the following times: baseline, 6 months and 12 months, by two different operators. Bitewing radiographs and replicas of the occlusal surfaces were obtained by using a silicone impression material poured with epoxy resin for the qualitative evaluation with Scanning Electron Microscopy. The data was analyzed with the McNemar test (p <0.05). Results showed that for the marginal integrity, after 6-month evaluation, only 1 (4%) sealed restoration had a Bravo rating. At the end of 12 months, the marginal integrity showed 1 (4%) sealed restoration and 2 (7%) non sealed Bravo restorations. Results at all evaluations periods did not show statistical significant differences (p=1.0) for all conditions. There was no difference in the clinical performance of the composite resin restorations (Esthet X) with or without the surface sealant (Lasting Touch), demonstrated good behavior after 12 months. Based on SEM examinations, the surface sealant application promoted a regular and smooth surface, for all the evaluation times. In a 12 months evaluations period, the surface...

Avaliação da influência da aplicação de um selante de superfície no comportamento clínico de restaurações de resina composta classe I / Evaluation of the influence of a surface sealant in the clinical behavior of composite resin class I restorations

A aplicação de selantes de superfície, através da penetração nas irregularidades superficiais e na interface dente/restauração, é realizada ao final do procedimento restaurador e pode minimizar algumas limitações, prolongando a longevidade clínica das restaurações de resina composta. Este estudo clinico randomizado se propôs a avaliar o efeito da aplicação de um selante de superfície no comportamento clínico de restaurações posteriores de resina composta do tipo classe I. Vinte e sete pares de dentes molares ou pré-molares, superiores ou inferiores, que apresentavam lesões de cárie (classe I) ou restaurações de amálgama ou resina composta (classe I) insatisfatórias, que necessitavam de substituição completa, foram aleatorizados e preparados e restaurados com a resina composta Esthet-X. Sobre a superfície da resina de apenas um dente de cada par foi aplicado o selante de superfície Lasting Touch utilizando o modelo experimental de boca dividida. A avaliação única foi realizada empregando-se o método direto USHPS modificado, nos tempos: baseline, 6 meses, 12 meses, por dois operadores. Radiografias interproximais e réplicas das faces oclusais foram obtidas por meio da moldagem com silicona de adição e vazadas com resina epóxica para avaliação qualitativa com Microscópio Eletrônico de Varredura. Os dados foram submetidos ao teste de Mc Nemar (p<0,05). Para a integridade marginal, após 6 meses de avaliação, apenas 1 (4%) restauração do grupo com selante de superfície recebeu o escore Bravo. Aos 12 meses, a integridade marginal apresentou 1 (4%) do grupo sem selante e 2 (7%) restaurações com selante com escore Bravo. Os resultado apresentados nos períodos de avaliação não apresentaram diferenças estatisticamente significantes (p=1,0, para todas as condições. Não houve diferença no desempenho clínico de restaurações de resina composta com e sem selante de superfície, sendo aceitáveis após 12 meses de avaliação. As observações em MEV demonstraram...

The finishing, polishing and surface sealant application, by superficial irregular penetration and between restoration interface, are applied at the end of the restoration and decrease these limitations, and extend the clinical longevity of composite resin restorations. This clinical randomized controled study however aimed to evaluate the effect of the surface sealant application in the clinical behavior of composite posterior resin class I restorations. Twenty seven pairs of upper or lower molars or premolars with carious lesions (class I), and unsatisfactory amalgam or composite resin restorations, which needed total replacement, were randomized and prepared and restored with Esthet X composite resin. The composite resin surface of one tooth from each pair was covered with Lasting Touch surface sealant (Split Mouth Design). The clinical evaluation was made by using the modified direct method USPHS, at the following times: baseline, 6 months and 12 months, by two different operators. Bitewing radiographs and replicas of the occlusal surfaces were obtained by using a silicone impression material poured with epoxy resin for the qualitative evaluation with Scanning Electron Microscopy. The data was analyzed with the McNemar test (p <0.05). Results showed that for the marginal integrity, after 6-month evaluation, only 1 (4%) sealed restoration had a Bravo rating. At the end of 12 months, the marginal integrity showed 1 (4%) sealed restoration and 2 (7%) non sealed Bravo restorations. Results at all evaluations periods did not show statistical significant differences (p=1.0) for all conditions. There was no difference in the clinical performance of the composite resin restorations (Esthet X) with or without the surface sealant (Lasting Touch), demonstrated good behavior after 12 months. Based on SEM examinations, the surface sealant application promoted a regular and smooth surface, for all the evaluation times. In a 12 months evaluations period, the surface...

Correcão estética dos dentes anteriores com resina composta nanoparticulada / Anterior teeth esthetic correction with nanofill resin composite

A realização de facetas estéticas diretas em resina composta permite a recuperação estética de forma conservadora de dentes com tratamento endodôntico que apresentam alteração cromática e não respondem às técnicas de clareamento dental. Este trabalho relata caso clínico de paciente que apresentava descontentamento com a cor escurecida do dente 21 e com o tamanho dos dentes adjacentes. O escurecimento ocorreu após trata- mento endodôntico e se manteve inalterado após realização de clareamento interno. Após anamnese, diagnóstico clínico e radiográfico, foi indicado à realização de faceta direta com resina composta nanoparticulada no dente 21. As resinas com nanopartículas apresentam à incorporação de partículas de carga com tamanho nanométrico entre 20 e 75 nanômetros, a matriz orgânica tendo como vantagens as propriedades estéticas das resinas de micro- partículas e propriedades de resistência similar às resinas híbridas, sendo um composto de indicação de uso universal. Após a realização da faceta, foi feito o recontorno cosmético nos dentes adjacentes com discos de lixa, usados em ordem decrescente de granulação. Obteve-se melhora na estética do sorriso recuperando a cor e alinhamento dentário.

The use of direct nanofill resin composite veneer allows an esthetic recovery of stained endodontically-treated teeth when dental bleaching techniques failure. This study shows a clinical case of an unsatisfied patient that complied about the tooth colored central incisor (21) and the shape of the others anterior teeth. The darkness appeared after the endo- dontic treatment and left unchanged after the use of walking-bleaching technique. After anamnesis, clinical and radiographic diagnosis, the use of direct nanofiller resin composite veneer was indicated for central incisor (21), and that cosmetic recountouring was made in the other teeth. A new class of dental composites, the nanofill resin composite has been developed with a nanometer-sized particles; averaging 20 and 75 nanometers in size the resin matrix, showed high translucency and polish retention similar to those of microfill, while maintaining physical properties and wear resistance equivalent to those of several hybrid composites, universal restorative is one. The patient got a better smile and recovered the color and alignment of anterior teeth.

Clinical evaluation of postoperative sensitivity using self-etching adhesives containing glutaraldehyde

The present clinical study aimed to assess the postoperative sensitivity (POS) after 48 hours and seven days in occlusal restorations bonded with three different adhesive systems, two of them containing glutaraldehyde. The restorative procedures were performed using the three-step etch-and-rinse Adper SBMP-Plus adhesive (SBMP), the two-step etch-and-rinse Gluma Comfort One Bond + Desensitizer adhesive (GC+D) and the all-in-one self-etching/priming I Bond (IB) adhesive, which also has glutaraldehyde in its formula. All cavities were restored with Filtek Supreme nanoparticle composite resin. After 48 hours and seven days the patients were recalled and the postoperative sensitivity evaluated. The data analyzed by non-parametric Friedman test showed no significant differences in POS among the three tested groups after 48 hours and seven days.

Antibacterial activity of root canal filling materials for primary teeth: zinc oxide and eugenol cement, Calen paste thickened with zinc oxide, Sealapex and EndoREZ

This study evaluated in vitro the antibacterial activity of 4 root canal filling materials for primary teeth - zinc oxide and eugenol cement (ZOE), Calen paste thickened with zinc oxide (Calen/ZO), Sealapex sealer and EndoREZ sealer - against 5 bacterial strains commonly found in endodontic infections (Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli and Staphylococcus aureus) using the agar diffusion test (agar-well technique). Calen paste, 1 percent chlorhexidine digluconate (CHX) and distilled water served as controls. Seven wells per dish were made at equidistant points and immediately filled with the test and control materials. After incubation of the plates at 37oC for 24 h, the diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a digital caliper under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (?=0.05). There were statistically significant differences (p<0.0001) among the zones of bacterial growth inhibition produced by the different materials against all target microorganisms. K. rhizophila was inhibited more effectively (p<0.05) by ZOE, while Calen/ZO had its highest antibacterial activity against E. faecalis (p<0.05). S. mutans was inhibited by Calen/ZO, Sealapex and ZOE in the same intensity (p>0.05). E. coli was inhibited more effectively (p<0.05) by ZOE, followed by Calen/ZO and Sealapex. Calen/ZO and ZOE were equally effective (p>0.05) against S. aureus, while Sealapex had the lowest antibacterial efficacy (p<0.05) against this microorganism. EndoREZ presented antibacterial activity only against K. rhizophila and S. aureus. The Calen paste and Calen/ZO produced larger zones of inhibition than 1 percent CHX when the marker microorganism was E faecalis. In conclusion, the in vitro antibacterial activity of the 4 root canal filling materials for primary teeth against bacterial strains...

Este estudo avaliou in vitro a atividade antibacteriana de 4 materiais obturadores de canais radiculares de dentes decíduos - cimento de óxido de zinco e eugenol (OZE), pasta Calen espessada com óxido de zinco (Calen/OZ), cimento Sealapex e cimento EndoREZ - sobre 5 cepas bacterianas comumente encontradas em infecções endodônticas: Kocuria rhizophila, Enterococcus faecalis, Streptococcus mutans, Escherichia coli e Staphylococcus aureus, usando o teste de difusão em ágar (técnica do poço). A pasta Calen, digluconato de clorexidina a 1 por cento (CHX) e água destilada foram usados como controle. Sete poços por placa foram preparados em pontos eqüidistantes e imediatamente preenchidos com os materiais experimentais e controle. Após incubação das placas a 37oC por 24 h, o diâmetro dos halos de inibição do crescimento bacteriano formados ao redor dos poços foi medido (em mm) com um paquímetro digital sob luz refletida. Os dados obtidos foram submetidos à análise de variância e ao pós-teste de Tukey (?=0,05). Com relação à atividade antibacteriana, evidenciaram-se diferenças estatisticamente significantes (p<0,0001) entre os halos de inibição formados pelos diferentes materiais, para todos os microrganismos avaliados. A K. rhizophila foi inibida mais eficazmente pelo OZE (p<0,05), enquanto que o E. faecalis foi inibido mais eficazmente pela Calen/OZ (p<0,05). O S. mutans foi inibido pela Calen/OZ, cimento Sealapex e OZE na mesma intensidade (p>0,05). A E. coli foi inibida mais eficazmente pelo OZE, seguido pela Calen/OZ e pelo cimento Sealapex (p<0,05). O S. aureus foi inibido pela Calen/OZ e OZE na mesma intensidade (p>0,05), e menos intensamente pelo cimento Sealapex (p<0,05). O cimento EndoREZ apresentou atividade antibacteriana apenas frente a K. rhizophila e ao S. aureus. A pasta Calen e a Calen/OZ ocasionaram halos de inibição maiores que a CHX quando o microrganismo indicador foi o E. faecalis. Pode-se concluir que a atividade antibacteriana...

Comparison of antibacterial properties of two fluoride-releasing and a nonfluoride-releasing pit and fissure sealants.

Occlusal pits and fissures are the most susceptible sites for the development of dental caries and prevention is difficult in the areas of occurrence. Although only 12.5% of all the tooth surfaces are occlusal, these surfaces develop more than two-thirds of total caries experienced by children. The fate of the bacteria is of significance when they are inadvertently sealed by a dental sealant. This study aimed in examining the antibacterial properties of three commercially available sealants, viz., Teethmate-F, Helioseal-F and Helioseal. Antibacterial testing was done by disc diffusion method. Selective agars were used to grow Streptococcus mutans and Lactobacillus acidophilus, which are implicated in the pathogenesis of dental caries. Statistical analysis was carried out using student's t test. The study proved that Helioseal-F and Helioseal did not possess antibacterial properties and Teethmate-F was the only sealant that showed antibacterial properties.

Atividade antimicrobiana de materiais restauradores e selantes / Inhibitory activity of restorative materials and sealants

Avaliou-se a atividade inibitória de diferentes materiais restauradores e selantes de fóssulas e fissuras sobre microrganismos cariogênicos através do método de difusão em ágar, empregado-se o ágar Mueller-Hinton acrescido de 5 por cento de sangue desfribrinado de carneiro. Verificou-se que a maioria dos materiais testados apresentou alguma atividade inibitória frente aos microrganismos isolados, particularmente os cimentos ionoméricos. As resinas compostas, à exceção do Dyract, não evidenciaram atividade antimicrobiana

Evaluation of microleakage in human, bovine and swine enamels

A adequação de dentes bovinos e suínos na substituição de dentes humanos extraídos tem sido avaliada em vários estudos. O objetivo deste estudo in vitro foi analisar o padrão de infiltração marginal em esmaltes humano, bovino e suíno. Cavidades cúbicas (2 x 2 x 2 mm3) foram realizadas em blocos de esmalte obtidos de dentes molares humanos, incisivos bovinos e molares suínos. As cavidades foram restauradas com compósito resinoso fotopolimerizável e cimento de ionômero de vidro. Os espécimes foram submetidos à termociclagem por 1.000 ciclos entre 5 ± 2ºC e 55 ± 2ºC e imersos em azul de metileno a 2%, por 12 horas. A concentração de corante infiltrado foi medida, quantitativamente, através de espectrofotometria. Os dados foram transformados em µg/ml e submetidos à análise estatística ANOVA, seguida pelo teste de Tukey. As médias de infiltração marginal (µg/ml ± DP) nos esmaltes bovino e suíno não foram significativamente diferentes (0,0668 ± 0,0246 vs. 0,0674 ± 0,0286), mas foram superiores e estatisticamente diferentes (p < 0,01) das encontradas no esmalte humano (0,0407 ± 0,0195, p < 0,01), e as médias de infiltração marginal foram superiores nas restaurações realizadas com o cimento de iônomero de vidro (0,0695 ± 0,01313 vs. 0,0471 ± 0,0163, p < 0,01). Os resultados permitiram concluir que os substratos bovino e suíno permitem uma maior infiltração marginal que o esmalte humano, indicando que a capacidade de selamento marginal pode ser afetada por diferenças entre esses substratos. Os resultados indicam que se deve ter prudência na substituição do esmalte humano em estudos laboratoriais de microinfiltração.

Sealing ability of MTA, Super EBA, Vitremer and amalgam as root-end filling materials

Este estudo avaliou a capacidade de selamento do agregado trióxido mineral (MTA Angelus), de um cimento de óxido de zinco e eugenol reforçado (Super EBA), de um cimento de ionômero de vidro reforçado por resina (Vitremer) e de um amálgama sem zinco (GS-80) (controle). Os canais radiculares de oitenta molares inferiores humanos foram acessados, limpos, modelados e obturados. Os ápices foram seccionados, e as cavidades, preparadas. Os dentes foram divididos em 4 grupos de 40 cavidades, retrobturados com os materiais e imersos em azul de metileno por 72 h a 37ºC. As raízes foram então seccionadas transversalmente a cada milímetro e avaliadas sob aumento, observando-se a penetração de corante a cada corte. Os dados foram avaliados usando-se o teste de Kruskal-Wallis (5%), que mostrou diferenças entre todos os materiais (p < 0,001). A ordem crescente de infiltração marginal foi MTA < Vitremer < Super EBA < amálgama. Níveis mais altos de infiltração foram observados nos cortes de primeiro milímetro de amálgama, Vitremer e MTA, quando comparados com o terceiro milímetro (p < 0,05).