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The present study analyzed the microhardness and degree of conversion of three Bulk Fill resins (M1 - Filtek Bulk Fill; M2 - Tetric N-Ceram Bulk Fill and M3 - Opus Bulk Fill) polymerized by single peak and polywave Light-emitting Diode Curing Lights. A total 90 test specimens (n=10) were obtained using a Teflon matrix for the purpose of testing microhardness; and for degree of conversion: 135 specimens (n=5) by using a 2 x 6 cm matrix. The specimens were light polymerized using 3 light sources (L1 - Optilight Max, L2 - Bluephase, L3 - VALO). They were kept in artificial saliva om an oven at 37±1°C during the experiment. The degree of conversion was measured by FTIR 24 h after obtaining each test specimen. The microhardness readouts were performed with a microdurometer at the time intervals of 48 hours (T0), 7 days (T1), 14 days (T2) and 21 days (T3). M1L3 was found to show the highest microhardness values in T2, and M1 showed the lowest degree of conversion in the deep third with L1. It was concluded that Filtek Bulk Fill resin showed the best results in comparison with the other resins.
El presente estudio analizó la microdureza y el grado de conversión de tres resinas Bulk Fill (M1 - Filtek Bulk Fill; M2 - Tetric N-Ceram Bulk Fill y M3 - Opus Bulk Fill) polimerizadas por lámparas de curado de diodo emisor de luz de pico único y polionda. Se obtuvieron un total de 90 especímenes de prueba (n=10) utilizando una matriz de teflón con el propósito de probar la microdureza; y para grado de conversión: 135 especímenes (n=5) utilizando una matriz de 2 x 6 cm. Las muestras se fotopolimerizaron utilizando 3 fuen- tes de luz (L1 - Optilight Max, L2 - Bluephase, L3 - VALO). Se mantuvieron en saliva artificial en estufa a 37 ±1°C durante el experimento. El grado de conversión se midió por FTIR 24 h después de obtener cada muestra de prueba. Las lecturas de microdureza se realizaron con un microdurómetro en los intervalos de tiempo de 48 horas (T0), 7 días (T1), 14 días (T2) y 21 días (T3). Se encontró que M1L3 mostraba los valores más altos de microdureza en T2, y M1 mostraba el grado más bajo de conversión en el tercio profundo con L1. Se concluyó que la resina Filtek Bulk Fill mostró los mejores resultados en comparación con las demás resinas.
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ABSTRACT: The present study analyzed the color change (DE) and surface roughness (Ra) of glass ionomer cements (GICs) subjected to typical herbaceous South American beverage action - Ilex paraguariensis. 90 specimens (n = 10) were made: M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). After light curing/ polymerization of GICs, specimens were divided for being submitted to solutions for one hour a day for 21 days: S1 - Yerba Mate Pajarito Traditional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Water (control). Four DE and Ra readings were taken: T0 - initial; T1 - 7 days; T2 - 14 days and T3 - 21 days, with a spectrophotometer and a roughness meter respectively. The obtained data were submitted to ANOVA statistical analysis and Bonferroni. S1 and S2 at T1 and T2 there was no statistical difference between the materials, and at T3 Materials M1=M2, M1=M3, and M2>M3. For S3 at T1, T2 and T3 there was no difference between the materials. Analyzing surface roughness, there was no statistical significance. Concluded that all materials changed color with greater influence of time, but without changing surface roughness.
RESUMEN: En el presente estudio se analizó el cambio de color (DE) y la rugosidad superficial (Ra) de los cementos ionómero de vidrio (CIV) sometidos a la acción típica de las bebidas herbáceas sudamericanas - Ilex paraguariensis. Se realizaron 90 especímenes (n = 10): M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). Después de la fotopolimerización/ polimerización de los CIV, los especímenes se dividieron y fueron sometidos a soluciones durante una hora al día durante 21 días: S1 - Yerba Mate Pajarito Tradicional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Agua (control). Se tomaron cuatro lecturas de DE y Ra: T0 - inicial; T1 - 7 días; T2 - 14 días y T3 - 21 días, con espectrofotómetro y rugosímetro respectivamente. Los datos obtenidos fueron sometidos a análisis estadístico ANOVA y Bonferroni. S1 y S2 en T1 y T2 no hubo diferencia estadística entre los materiales y en T3 Materiales M1=M2, M1=M3 y M2>M3. Para S3 en T1, T2 y T3 no hubo diferencia entre los materiales. Al analizar la rugosidad de la superficie, no hubo significación estadística. En conclusion, todos los materiales cambiaron de color con mayor influencia del tiempo, pero sin cambiar la rugosidad de la superficie.
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Life is becoming more convenient as advancement in materials has been taking place since the beginning of human history. The increased demand of aesthetics in day to day life and on the other hand disadvantages of the existing materials, clinicians are shifting their paradigms towards metal free restorations. Various researches are going on to identify the ideal restorative material with all the improved mechanical and physical qualities. Advances in the field of dental materials are providing promising results but each material is falling short of being an ideal one. One such material is biomaterials. Biomaterials are mainly used in medical sciences to replace or augment a natural function. Biomaterials are widely used in dentistry, they are divided into four categories metal, composites, polymer and resins. Biomaterials are considered as materials which replace the defects by either replacements or repair. Presently Poly-Ether Ether Ketone (PEEK) is a semi crystalline, synthetic, aromatic, thermoplastic material. Previously, it was used for industrial purposes but due to its excellent properties and biocompatibility, it has been used in medicine and dentistry. There are various applications of PEEK in dentistry such as orthodontic wires and brackets which are made from it to achieve aesthetics and strength. In endodontics PEEK posts and PEEK endocrowns are used when extensive tooth structure loss occurs, even due to its aesthetic property, it is used for anterior restorations. PEEK is a synthetic polymer and is greyish in colour which has a monomer unit of ether ether ketone. In prosthodontics, aesthetics plays an important role. Therefore, PEEK is considered as an alternative option to conventional dental materials because of its aesthetics and it being a scientifically approved material. In prosthodontics, it can be used in removable partial dentures, fixed partial dentures, dental implants and abutments, implant crowns as well as for restoring the maxillofacial defects. This review article describes the various applications of PEEK in prosthodontics in detail.
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@# Colour stability of the material is an essential factor that contributes to the selection of a flexible denture material. Staining effects on the denture may result in unattractive appearance, the dissatisfaction of the wearer, and limited usage period of the denture. This study aims to identify the colour stability of the Valplast flexible denture material using three types of beverages. Methods: A total of 32 disc-shaped flexible resin materials (20 +/- 0.1 mm in diameter and thickness 3 +/- 0.1 mm) were prepared based on the manufacturer instructions. The samples were randomly divided into 4 groups of immersion: distilled water (control), coffee solution, tea solution and red wine. The samples were left in the specified immersion solution for up to 60 days. Colour changes were measured after 1, 3, 7, 14, 21, 30, 45 and 60 days of immersion. Results: The samples immersed in coffee solution changed from S1 to S2, whereas samples in tea solution changed from S1 to S3. Additionally, samples in red wine changed from S1 to S4, as observed using the Valplast colour tone guide. The highest reflection measured using spectroscopy was 65.146 at 385.19 nm of the control samples, whereas the lowest reflection was 1.974 at the wavelength of 385.97 nm on the samples immersed in the red wine. Conclusion: The most significant difference can be observed in the red wine group, followed by samples in tea and coffee solutions. Moreover, increasing the immersion period causes increasing staining effect of the denture.
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A aparência dos dentes e do tecido gengival ao redor dos mesmos tem um papel muito importante na estética da região anterior da maxila tendo em vista que, anormalidades na simetria e no contorno podem afetar significativamente a harmonia de uma dentição natural. O aumento de coroa clínica estético seguido de reanatomização dos dentes vem se tornando uma opção viável para pacientes com discrepâncias gengivais e dentárias. O objetivo do presente trabalho é apresentar o planejamento integrado periodontal e restaurador proposto em um caso clínico. O paciente foi diagnosticado com alterações na linha gengival do sorriso e presença de discrepâncias dentárias. Ele foi submetido à instrução de higiene bucal e rigoroso controle de placa bacteriana. Após o estudo do caso com auxílio de modelos de gesso, optou-se pela realização do aumento de coroa clínica estética e reanatomização dos dentes antero-superiores com resina composta. Este trabalho evidenciou a necessidade de um conhecimento multidisciplinar do cirurgião-dentista para realização de um plano de tratamento adequado, visando maior harmonia e estética do sorriso, buscando a satisfação do paciente para o sucesso final do tratamento.
The appearance of the teeth and the soft tissue around them have an important role in aesthetics of the maxillary anterior region since abnormalities in symmetry and contour can significantly affect the harmony of a natural dentition. The surgical crown lengthening and reconstruction of anterior teeth are becoming a viable option for patients with dento-gingival discrepancies. The aim of the present study is to show the integrated Periodontal and Restorative treatment planning porposed for the patient. The one showed excessive gingival display and tooth discrepancies. First of all the patient got oral hygiene instruction and underwent a rigorous plaque control. After analysing the case with the aid of study models, aesthetics crown lengthening was perfomed and reconstruction of anterior teeth with composite resin restorations were done. This paper has highlighted the need for a multidisciplinary knowledge of the dentist to suggest an appropriate treatment plan, seeking greater harmony and aesthetics of the smile and patients satisfaction for the success of treatment.
Subject(s)
Humans , Female , Adult , Esthetics, Dental , Dental Materials , Oral Surgical ProceduresABSTRACT
A resistência à tração diametral (TD) é um requisito essencial para o sucesso clínico das restaurações. Dessa forma, este estudo objetivou avaliar a resistência à TD de três tipos cimentos ionômero de vidro (CIV) em comparação com uma resina composta, todos utilizados em seis postos de saúde pública do município de Duque de Caxias/RJ. O TD foi realizado em uma máquina universal com uma célula de carga de 200 Kgf. Os valores médios de resistência à TD, em MPa, foram: 11,46 (CIV A), 10 (CIV B), 31 (CIV C) e 38,13 (Resina). Os resultados foram analisados pelos testes Anova e Turkey (p < 0,05). Concluiu-se que os CIVs apresentaram resistência à TD semelhante entre eles, porém inferior à resina, mas ainda sendo uma ótima opção para restauração preconizada pelo Serviço Público de Saúde (SUS).
The diametric tensile strength (DT) is a prerequisite for clinical success of restoration. Thus, this study aimed to evaluate the resistance of DT of three types of glass ionomer cements (IO) for restorative, and compare with a composite resin. Eight samples of each material were using by bipartite matrices. All of the materials were used according to manufacturers. The DT test was performed using a universal testing machine with a load of 200 kgf. The results were analyzed using Anova and Turkey (p <0.05). Mean values for resistance to DT in MPa were: 11.46 (IO A), 10 (IO B), 31 (IO C) and 38.13 (Resin composite). We concluded that IO showed similar DT among themselves.
Subject(s)
Tensile Strength , Composite Resins , Dental Materials , Glass Ionomer CementsABSTRACT
A resistência à tração diametral (TD) é um requisito essencial para o sucesso clínico das restaurações. Dessa forma, este estudo objetivou avaliar a resistência à TD de três tipos cimentos ionômero de vidro (CIV) em comparação com uma resina composta, todos utilizados em seis postos de saúde pública do município de Duque de Caxias/RJ. O TD foi realizado em uma máquina universal com uma célula de carga de 200 Kgf. Os valores médios de resistência à TD, em MPa, foram: 11,46 (CIV A), 10 (CIV B), 31 (CIV C) e 38,13 (Resina). Os resultados foram analisados pelos testes Anova e Turkey (p < 0,05). Concluiu-se que os CIVs apresentaram resistência à TD semelhante entre eles, porém inferior à resina, mas ainda sendo uma ótima opção para restauração preconizada pelo Serviço Público de Saúde (SUS).
The diametric tensile strength (DT) is a prerequisite for clinical success of restoration. Thus, this study aimed to evaluate the resistance of DT of three types of glass ionomer cements (IO) for restorative, and compare with a composite resin. Eight samples of each material were using by bipartite matrices. All of the materials were used according to manufacturers. The DT test was performed using a universal testing machine with a load of 200 kgf. The results were analyzed using Anova and Turkey (p <0.05). Mean values for resistance to DT in MPa were: 11.46 (IO A), 10 (IO B), 31 (IO C) and 38.13 (Resin composite). We concluded that IO showed similar DT among themselves.
Subject(s)
Tensile Strength , In Vitro Techniques , Composite Resins , Dental Materials , Glass Ionomer CementsABSTRACT
Objective]To measure and compare the MRI artifacts caused by common metal ic dental materials and common ceramic dental materials on different field-strength magnets.[Methods] A total of 3 common metal ic dental materials and 2 common ceramic dental materials were tested with 0.35T, 1.5T and 3.0T MR imagers. The artifact areas on these 3 different field-strength magnets were measured and statistical y compared. [Results]Zirconia in three field magnetic resonance(NMR) in T1 and T2 as no artifacts, casting porcelain, metal al oy, nickel chromium al oy and CoCr-al oy in three fields magnetic resonance(NMR) in T1 and T2 as al can produce different degree of artifacts, and artifacts area increased in turn. Cobalt chromium al oy and nickel chromium al oy measurements on the high side, the cobalt chromium al oy than other four kinds of materials on the high side( P<0.05),high nickel-chromium al oy was precious metal al oy, casting porcelain( P<0.05). [Conclusions]Commonly used metal ic dental materials could cause MR artifacts and image degradation. Compared with that on 0.35T, the artifact was increased on 1.5T magnet. Compared with that on 1.5T, the artifact was increased on 3.0T magnet.
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Objective: To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Material and Methods: Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Results: Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). Conclusions: All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.
Subject(s)
Animals , Male , Rats , Aluminum Compounds/chemistry , Biocompatible Materials/chemistry , Calcium Compounds/chemistry , Calcium Sulfate/chemistry , Dental Cements/chemistry , Oxides/chemistry , Subcutaneous Tissue , Silicates/chemistry , Drug Combinations , Materials Testing , Rats, Wistar , Surface Properties , Time FactorsABSTRACT
Este estudo avaliou a atividade antimicrobiana de um reembasador resiliente Coe Soft® (RRCS) combinado ao polímero antimicrobiano poli (2 tert-butilaminoetil) metacrilato (PTBAEMA) sobre formação de biofilme de Staphyloccocus aureus, Streptococcus mutans e Candida albicans. Espécimes circulares (15mm x 3mm) do RRCS foram confeccionados (n=27), esterilizados, divididos em três grupos de acordo com as concentrações de PTBAEMA a 0% (controle), 10% e 25% e individualmente inoculados em tubos de falcon contendo 5mL de caldo RPMI para os fungos, TSB para S. aureus e BHI para S. mutans e mantidos em overnight a 37ºC em incubadora com agitação orbital a 75rpm, sendo o S. mutans em microaerofilia. Após a inoculação dos espécimes seguiu-se a formação e maturação do biofilme a 37ºC sob agitação orbital a 75rpm. Em seguida cada espécime foi transferido para tubos contendo PBS e diluições seriadas foram realizadas. Alíquotas dessas diluições foram semeadas em placas de Petri e incubadas a 37ºC por 48h. Os dados obtidos foram transformados em log (UFC+1)/mL, considerando-se α=0,05. Os resultados demonstraram que o grupo contendo 25% de PTBAEMA inibiu completamente a formação de biofilme de S. aureus e S. mutans. Uma redução significativa na contagem de S. aureus e S. mutans (Kruskal- Wallis e Dunn; p=0,001) para o grupo contendo 10% de PTBAEMA foi observada quando comparada aos valores encontrados nos respectivos grupos controle. Para C. albicans não foi encontrada diferença significante entre grupos contendo PTBAEMA e o grupo controle (ANOVA; p>0,05). Conclui-se que os RRCS contendo 10% e 25% de PTBAEMA inibiram a formação de biofilme de S. aureus e S. mutans. Entretanto não teve efeito significante na formação de biofilme de C. albicans
This study evaluated the antimicrobial activity of the resilient reliner Coe Soft ® (RRCS) combined with antimicrobial polymer poly (2-tert butylaminoethyl) methacrylate (PTBAEMA) on Staphylococcus aureus, Streptococcus mutans and Candida albicans biofilm formation. RRCS circular specimens were prepared (n=27), sterilized, divided into three groups according to PTBAEMA concentrations of 0% (control), 10% and 25% and inoculated into individual falcon tubes containing 5 mL of RPMI broth for fungi, TSB for S. aureus and BHI for S. mutans and kept overnight at 37°C with orbital shaking incubator at 75rpm, and S. mutans in microaerophilic. The specimens' inoculations were followed by biofilm formation and its maturation at 37°C under orbital shaking at 75rpm. After that, each sample was transferred to tubes containing PBS and serial dilutions were performed. Aliquots of these dilutions were plated in Petri dishes and incubated at 37°C for 48h. The data were transformed into log (CFU +1)/mL, considering α = 0.05. The results showed that the group containing 25% of PTBAEMA inhibited completely biofilm formation of S. aureus and S. mutans. A significant reduction in counts of S. aureus and S. mutans (Kruskal- Wallis and Dunn; p = 0.001) were found in group containing 10% of PTBAEMA when compared to the values in the corresponding control groups. C. albicans had no significant differences between groups containing PTBAEMA and the control group (ANOVA; p> 0.05). It is concluded that the RRCS containing 10% and 25% PTBAEMA inhibited the biofilm formation of S. aureus and S. mutans. However, no significant effect was found on C. albicans biofilm formation
Subject(s)
Polymers , Staphylococcus aureus , Streptococcus mutans , Candida albicans , Biofilms , Dental Materials , Denture Liners , Analysis of Variance , Statistics, NonparametricABSTRACT
OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.
OBJETIVO: avaliar as propriedades mecânicas de três cimentos de ionômero de vidro (CIVs) utilizados para cimentação de anéis ortodônticos. MÉTODOS: foram utilizados dois CIVs convencionais (Ketac Cem Easy mix/3M-ESPE e Meron/Voco) e um CIV modificado por resina (Multi-Cure Glass ionomer/3M-Unitek). Para os testes de resistência à compressão e tração diametral, foram confeccionados 12 corpos de prova de cada material. Para os testes de microdureza, foram confeccionados 15 corpos de prova de cada material; para os testes de resistência de união ao cisalhamento, foram utilizados 45 dentes bovinos incluídos em resina acrílica, sobre os quais foi cimentada uma lâmina de anel ortodôntico com braquete soldado a ela para a realização dos ensaios. Para os testes de compressão, tração diametral e cisalhamento, foi utilizada uma máquina universal de ensaios a uma velocidade de 1mm/min; para os testes de microdureza Vickers, foi utilizado um microdurômetro com 200g de carga durante 15 segundos. Os resultados foram submetidos à análise estatística ANOVA, complementada pelo teste de Tukey ao nível de significância de 5%. RESULTADOS: os resultados demonstraram que o Multi-Cure Glass Ionomer apresentou resistência à tração diametral significativamente maior (p < 0,01) e maior resistência à compressão (p = 0,08) em relação aos CIVs convencionais. Além disso, o Ketac Cem apresentou microdureza significativamente maior que os demais materiais (p < 0,01). CONCLUSÃO: o CIV modificado por resina apresentou propriedades mecânicas superiores às dos CIVs convencionais, que, por sua vez, apresentaram poucas diferenças entre si.
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Introducción: el objetivo fue describir los cambios físico-químicos que ocurren en los tejidos y materiales dentales empleados en un tratamiento endodóncico convencional, al ser sometidos a altas temperaturas, a través de microscopía electrónica de barrido (MEB). Métodos: in vitro, se sometieron dos dientes premolares humanos a 200 y 400 ºC respectivamente, con el fin de estandarizar una técnica para la observación de los cambios físicos y químicos en los tejidos dentales (esmalte y dentina) y de los materiales de uso odontológico empleados comúnmente en endodoncia (gutapercha y cemento endodóncico a base de resina epóxica). Resultados: tanto los tejidos como los materiales dentales observados en este estudio piloto, presentaron gran resistencia a las altas temperaturas sin variar considerablemente su macroestructura, de tal manera que los cambios físicos (estabilidad dimensional, fisuras, grietas, fracturas, textura, carbonización) y químicos (elementos químicos constituyentes) pueden llegar a ser identificables y asociarse a cada rango de temperatura específico através del análisis MEB y espectrofotométrico. Conclusiones: los tejidos y los materiales dentales presentan gran resistencia a la acciónde altas temperaturas sin alterar su macroestructura de forma significativa. Del mismo modo, presentan cambios físicos y químicos que pueden contribuir con el proceso de identificación de un cadáver o restos humanos quemados, incinerados o carbonizados.
Introduction: the objective of this study was to describe the physicochemical changes occurring in dental tissues andmaterials used in a conventional endodontic treatment when subjected to high temperatures, by means of scanning electron microscopy(SEM) Methods: in vitro, two human premolar teeth were subjected to temperatures of 200°C and 400°C respectively, with the purpose ofstandardizing a technique for the observation of physical and chemical changes in dental tissues (enamel and dentin) and dental materialscommonly used in endodontic treatment (root canal gutta-percha and epoxy resin-based endodontic cement). Results: both the tissues and the dental materials analyzed in this pilot study presented great resistance to high temperatures without significantly changing their macrostructure; therefore, the physical changes (dimensional stability, cracks, crevices, fractures, texture, carbonization) and the chemical ones (constituent chemical elements) may turn out to be identifiable and associated with each specific temperature range by means of SEM and spectrophotometric analysis. Conclusions: dental tissues and materials display great resistance to the action of high temperatures, without significantly altering their macrostructure. Similarly, they experience physical and chemical changes that may contribute to theprocess of identification of a corpse or human remains that have been burned, incinerated or charred.
Subject(s)
Humans , Endodontics , Microscopy, Electron, ScanningABSTRACT
In this paper,to evaluate the existence and extent of MRI artifacts caused by frequently used metallic dental materials and to compare the influence of different MRI sequences on artifacts. The artifact of Au-Pt-Pd alloy crown were the smallest and Au-Ag-Pd alloy crown, pure Titanium crown were smaller. But the artifact of Ni-Gr alloy crown were the largest.With the same scan sequences, the different metal materials can make different effects on MRI images with the different scan sequences, the MRI artifact is not obvious caused by the same metal materials. Artifacts produced by oral metallic materials related closely to the type of the materials.The high quality MRI can be gained by choosing proper metallic materials.
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This study evaluated the surface microhardness and fluoride release of 5 restorative materials - Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom and Fluorofil - in two storage media: distilled/deionized water and a pH-cycling (pH 4.6). Twelve specimens of each material, were fabricated and the initial surface microhardness (ISM) was determined in a Shimadzu HMV-2000 microhardness tester (static load Knoop). The specimens were submitted to 6- or 18-h cycles in the tested media. The solutions were refreshed at the end of each cycle. All solutions were stored for further analysis. After 15-day storage, the final surface microhardness (FSM) and fluoride release were measured. Fluoride dose was measured with a fluoride-specific electrode (Orion 9609-BN) and digital ion analyzer (Orion 720 A). The variables ISM, FSM and fluoride release were analyzed statistically by analysis of variance and Tukey's test (p<0.05). There was significant difference in FSM between the storage media for Vitremer (pH 4.6 = 40.2 ± 1.5; water = 42.6 ± 1.4), Ketac-Fil Plus (pH 4.6 = 73.4 ± 2.7; water = 58.2 ± 1.3) and Fluorofil (pH 4.6 = 44.3 ± 1.8; water = 38.4 ± 1.0). Ketac-Fil Plus (9.9 ± 18.0) and Fluorofil (4.4 ± 1.3) presented higher fluoride release in water, whereas Vitremer (7.4 ± 7.1), Fuji II LC (5.7 ± 4.7) and Freedom (2.1 ± 1.7) had higher fluoride release at pH 4.6. Microhardness and fluoride release of the tested restorative materials varied according to the storage medium.
Este estudo avaliou as propriedades de microdureza de superfície e liberação de flúor de 5 materiais restauradores (Ketac-Fil Plus, Vitremer, Fuji II LC, Freedom e Fluorofil) em dois meios de imersão: água destilada/deionizada e modelo de ciclagem de pH (4,6). Doze corpos-de-prova de cada material foram confeccionados e tiveram a microdureza de superfície inicial (MSI) determinada utilizando o microdurômetro Shimadzu HMV-2000 Micro Hardness Tester (carga estática Knoop). Os corpos-de-prova foram submetidos a ciclos de 6 e 18 h para os dois meios de imersão. A cada final de ciclo as soluções foram substituídas e armazenadas. Após 15 dias de imersão, a microdureza de superfície final (MSF) e a liberação de flúor foram determinadas. A dosagem de flúor foi feita com um eletrodo específico combinado para íon flúor (9609 BN - Orion) e analisador de íons digital (Orion 720 A). As variáveis MSI, MSF e liberação de flúor foram submetidas à análise de variância e teste de Tukey (p<0,05). Houve diferença estatisticamente significante na MSF entre os meios de imersão para o Vitremer (pH 4,6 = 40,2 ± 1,5; água = 42,6 ± 1,4), Ketac-Fil Plus (pH 4,6 = 73,4 ± 2,7; água = 58,2 ± 1,3) e Fluorofil (pH 4,6 = 44,3 ± 1,8; água = 38,4 ± 1,0). O Ketac-Fil Plus (9,9 ± 18,0) e o Fluorofil (4,4 ± 1,3) liberaram mais flúor na água; o Vitremer (7,4 ± 7,1), Fuji II LC (5,7 ± 4,7) e o Freedom (2,1 ± 1,7) no pH 4,6. A microdureza e liberação de flúor dos materiais restauradores estudados variaram de acordo com o meio de imersão.
Subject(s)
Humans , Cariostatic Agents/chemistry , Dental Materials/chemistry , Fluorides/chemistry , Acetates/chemistry , Buffers , Calcium/chemistry , Compomers/chemistry , Composite Resins/chemistry , Diffusion , Glass Ionomer Cements/chemistry , Hardness , Hydrogen-Ion Concentration , Ion-Selective Electrodes , Materials Testing , Maleates/chemistry , Phosphorus/chemistry , Resins, Synthetic/chemistry , Surface Properties , Tromethamine/chemistry , Water/chemistryABSTRACT
objective: To investigate the effects of cerium oxide content on the color of alumina glass composite. Methods: Infiltration glass powder with different content of cerium oxide (1%～4%) were fabricated. Alumina glass composite was prepared by infiltrating molten glass into presintered alumina block at 1 250 ℃ for 2 h, and the color of the alumina glass composite were measured with Minolta chromatic instrument(CR 321) . For comparison, the color of VITA In Ceram alumina technical shade guide was recorded too. Results: After infiltration, the b * range of the alumina glass composite was in accord with that of the shade guide. With the increasing content of the cerium oxide, a *, b * and chroma increased, L * decreased, the hue of the alumina glass composite shifted from yellow green to yellow red. Conclusion: Cerium oxide may effectively enhance b * of the alumina glass composite, but its ability of reducing L * and enhancing a * is weak.
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Objective To evaluate short-term fowllow-up results of castable ceramic-IPS Empress Ⅱ onlays in restoring severe tooth defects with low occlusogingival dimension from clinical aspects.Methods 41 units of the onlay were fabricated and applied in 37 patients,who were divided into experimental group and control group.The experimental group were restored with IPS EmpressⅡcastable ceramic onlay which was bonded by a dual-cure adhesive system.The control group were restored with mental onlay which was bonded by glass-ionomer cements.All these cases were followed at 6 and 12 months after cementation of the restorations.Metewands were established to evaluate its clinical effects.Results Onlay made from IPS Empress Ⅱ castable ceramic demonstrated natural and esthetical appearance.In addition,proximal contact,retention and marginal fit of the restorations were good.No gingivitis was found.Conclusion The reliability of onlay made from IPS Empress Ⅱ castable ceramic is greatly improved due to the strengthening effects of the lithium disilicate structures.In addition,the better esthetics compared to resin filling technique makes it a comparatively ideal all-ceramic system for onlays.
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0.05). Conclusion:Ti-29Nb-13Ta-4.6Zr alloy is histocompatible.
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Objective To evaluate the biological compatibility of dental nano-silicon dioxide/high-strength-glass fiber/EAM resin composites(FRC). Methods Experiments of general acute toxicity, cytotoxicity, hemolysis and mucous membrane irritation were performed on the newly developed FRC. Results The newly developed FRC induced no cytotoxicity, hemolysis, acute toxicity or mucous membrane irritation. Conclusion The newly developed FRC has good biocompatibility in vitro and vivo.