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

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

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

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

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

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

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.

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

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

OBJECTIVES: The aim of the present study was to assess the effect of the exposure to food-simulating liquids prior to brushing simulation on the surface roughness of five composite materials (Quixfil, Filtek Supreme, Esthet-X, Filtek Z250, Tetric Ceram). Material and METHODS: Twenty cylinders (5 mm diameter and 4 mm height) of each composite were randomly allocated to 4 groups (n=5), according to the food-simulating liquid in which they were immersed for 7 days at 37°C: artificial saliva, heptane, citric acid, and ethanol. After this period, the top surface of composite cylinders was submitted to 7,500 brushing cycles (200 g load). Measurements of the surface roughness (Ra, ¼m) were carried out before and after the exposure to the chemicals/brushing simulation. Changes on the morphology of composite surfaces were observed through scanning electron microscopy (SEM). RESULTS: The statistical analysis (ANOVA with cofactor / Tukey's test, α=5%) detected a significant interaction between solutions and composite resins. Esthet-X, Filtek Z250 and Tetric Ceram were not affected by the food-simulating liquids/toothbrushing. Citric acid and ethanol increased the surface roughness of Quixfil and Filtek Supreme, respectively. SEM images corroborate the surface roughness findings, demonstrating the negative effect from chemical solutions and mechanical abrasion. CONCLUSIONS: The surface roughness of composite resin materials are differently affected by the food-simulating solutions, depending on the immersion media.

Statistical analysis interpretation is a critical field in scientifc research. When there is more than one main variable being studied in a research, the effect of the interaction between those variables is fundamental on experiments discussion. However, some doubts can occur when the p-value of the interaction is greater than the signifcance level. OBJECTIVE: To determine the most adequate interpretation for factorial experiments with p-values of the interaction nearly higher than the signifcance level. MATERIALS AND METHODS: The p-values of the interactions found in two restorative dentistry experiments (0.053 and 0.068) were interpreted in two distinct ways: considering the interaction as not signifcant and as signifcant. RESULTS: Different findings were observed between the two analyses, and studies results became more coherent when the signifcant interaction was used. CONCLUSION: The p-value of the interaction between main variables must be analyzed with caution because it can change the outcomes of research studies. Researchers are strongly advised to interpret carefully the results of their statistical analysis in order to discuss the findings of their experiments properly.

The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal&Protect (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm²/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action.

O objetivo deste trabalho foi avaliar, in vitro, o efeito cariostático de 6 materiais restauradores contendo ou não flúor (Fuji II LC, F-2000, Degufil Mineral, Sure Fil and Z-250) associados à aplicação de dentifrícios (fluoretado e não-fluoretado; Sensodyne Fórmula Original and Sensodyne Sodium Bicarbonate) em esmalte dental humano. Cavidades classe V foram preparadas no esmalte de 240 fragmentos dentais, aleatoriamente divididos em 12 grupos (6 materiais e 2 dentifrícios). Após serem restauradas as cavidades, os fragmentos foram submetidos a ciclos térmicos e de desmineralização e remineralização, simulando um alto desafio cariogênico. Sobre os fragmentos restaurados, ainda, foram aplicados dentifrícios contendo ou não flúor, 5 min por dia. As diferenças no desenvolvimento de lesões experimentais de cárie adjacente às restaurações foram avaliadas por 5 examinadores calibrados, através de inspeção visual, atribuindo-se escores de 0 a 3. Os resultados foram avaliados pelo teste de Kruskal-Wallis seguido pelo teste de comparações múltiplas (alfa=0,05). Quando associados ao dentifrício fluoretado, os materiais restauradores não diferiram entre si em relação ao potencial cariostático (p>0,05). Quando os materiais foram utilizados em associação com o dentifrício não-fluoretado o Ketac-Fil apresentou o maior potencial cariostático, seguido pelo Fuji II LC e pelos demais materiais. O Ketac-Fil foi o único material que não diferiu significativamente quando associado com o dentifrício com ou sem flúor. Sob as condições experimentais do estudo, a associação dos materiais restauradores ao dentifrício fluoretado resultou em uma maior ação cariostática, exceto para o cimento de ionômero de vidro convencional, que não diferiu com a aplicação dos dentifrícios.

This study evaluated in vitro the cariostatic effect of 6 restorative materials with and without fluoride release (Fuji II LC, F-2000, Degufil Mineral, Sure Fil and Z-250) associated with a fluoridated and a non-fluoridated dentifrice (Sensodyne Original Formula and Sensodyne Sodium Bicarbonate), on human enamel. Class V-like cavities were prepared on 240 enamel slabs, assigned to 12 groups (6 materials and 2 dentifrices). After cavity restoration, the slabs were submitted to a thermocycling regimen of 1000 thermal cycles and demineralization/remineralization cycles. During pH cycles, slurries of fluoridated and non-fluoridated dentifrices were applied for 5 min. Formation of artificial caries-like lesions was scored independently and blindly by 5 calibrated examiners according to an ordinal scale ranked 0 to 3 by visual examination. The results were analyzed statistically by the Kruskal-Wallis test and pair-wise comparisons (alpha=0.05). There were no significant differences (p>0.05) among the restorative materials associated with the fluoridated dentifrice. When used in association with the non-fluoridated dentifrice, Ketac-Fil showed the highest cariostatic effect followed by Fuji II LC and the other materials. Ketac-Fil was the only material that did not differ statistically when combined with either the fluoridated or the non-fluoridated dentifrice. In conclusion, under the tested experimental conditions, the association of restorative materials and fluoridated dentifrice yielded higher cariostatic effect, except for the conventional glass ionomer cement, whose cariostatic effect was not influenced by the type of dentifrice.