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AIM: This study evaluated the effect of ultrasonic vibration on the tensile strength required to remove intraradicular post cemented with different materials. MATERIALS AND METHODS: Bovine teeth were selected, and 7 mm of the cervical root canals were prepared to size 5 Largo drill, the posts were cemented with zinc phosphate, Enforce (resin) or Rely X (glass ionomer). The specimens were divided into six groups (n = 10), according to the following procedures: GI-cementation with zinc phosphate associated with traction force; GII-cementation with zinc phosphate associated with ultrasonic activation and traction force; G111-cementation with Enforce associated with traction force; GIV-cementation with Enforce associated with ultrasonic activation and traction force; GV-cementation with Rely X associated with traction force; and GVI-cementation with Rely X associated with ultrasonic activation and traction force. The tensile test was conducted using the electromechanical testing machine, the force was determined by a specialized computer program and ultrasonic activation using the Jet Sonic Four Plus (Gnatus) device in 10P. RESULTS: Concerning to average ranking, GI showed statistically significant difference in comparison with GII and GVI (p < 0.05); there was no statistical difference in GIII and GIV when compared to other groups (p > 0.05). CONCLUSION: The ultrasound favored the intraradicular post traction regardless of the employed cement in greater or lesser extent. CLINICAL SIGNIFICANCE: The post removal is a routine practice in the dental office, therefore, new solutions and better alternatives are need to the practitioner. We did not find in the literature many articles referring to this practice. Thus, the results from this study are relevant in the case planning and to promote more treatment options.
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Cementos Dentales/química , Análisis del Estrés Dental/métodos , Ultrasonido/métodos , Animales , Bovinos , Cementación/métodos , Recubrimiento Dental Adhesivo , Cementos Dentales/análisis , Cemento Dental , Retención de Prótesis Dentales , Análisis del Estrés Dental/instrumentación , Técnica de Perno Muñón , Materiales de Obturación del Conducto Radicular , Resistencia a la Tracción , Diente/químicaRESUMEN
UNLABELLED: Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations--namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. CLINICAL RELEVANCE: Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems.
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Esmalte Dental/ultraestructura , Dentina/ultraestructura , Terapia por Láser/métodos , Láseres de Estado Sólido/uso terapéutico , Absorción Fisicoquímica , Cristalografía , Preparación de la Cavidad Dental/métodos , Esmalte Dental/química , Esmalte Dental/cirugía , Dentina/química , Dentina/cirugía , Radiación Electromagnética , Humanos , Microscopía Electrónica de Rastreo , Gases em Plasma/química , Radiometría , Temperatura , Termodinámica , Volatilización , Agua/químicaRESUMEN
This study sought to assess the use of chlorhexidine with several excipients as a dentin surface treatment and its effect on marginal adaptation of class V restorations with current-generation dentin bonding agents. A total of 120 human third molars were selected and allocated into 12 groups, with standardized buccal class V restorations randomly divided into preconditioned dentin rinsed with: water; water + chlorhexidine; ethanol; or ethanol + chlorhexidine. After rinsing of dentin (previously conditioned with 35% phosphoric acid) with the test solutions, the Adper single bond 2, prime and bond 2.1, and Excite bonding systems were applied randomly. Restorations were performed with Filtek™ Z350 XT composite resin. The resulting specimens were subjected to thermal and mechanical load cycling. Quantitative analysis of marginal adaptation was performed on epoxy replicas by means of scanning electron microscopy. Results were assessed by means of the Kruskal-Wallis test (percentages of continuous margins) and Wilcoxon test (differences between percentages of continuous margins before and after thermal cycling and mechanical loading), at a significance level of p < 0.05. Outcomes in the chlorhexidine-treated groups were not superior to those obtained with other treatments.
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Recubrimiento Dental Adhesivo/métodos , Adaptación Marginal Dental , Restauración Dental Permanente/clasificación , Recubrimientos Dentinarios/química , Dentina/ultraestructura , Acetona/química , Grabado Ácido Dental/métodos , Clorhexidina/farmacología , Resinas Compuestas/química , Cementos Dentales/química , Esmalte Dental/ultraestructura , Pulido Dental/métodos , Dentina/efectos de los fármacos , Etanol/farmacología , Humanos , Metacrilatos/química , Microscopía Electrónica de Rastreo , Ácidos Fosfóricos/química , Ácidos Polimetacrílicos/química , Técnicas de Réplica , Capa de Barro Dentinario , Solventes/farmacología , Estrés Mecánico , Propiedades de Superficie , Temperatura , AguaRESUMEN
AIMS AND OBJECTIVES: The behavior of polymer-matrix composite is dependent on the degree of conversion. The aim of this study was to evaluate the degree of conversion of two resin cements following storage at 37°C immediately, 24 and 48 hours, and 7 days after light-curing by FTIR analysis. MATERIALS AND METHODS: The specimens were made in a metallic mold and cured with blue LED with power density of 500 mW/ cm(2) for 30 seconds. The specimens were pulverized, pressed with KBr and analyzed with FTIR following storage times. STATISTICAL ANALYSIS USED: ANOVA (two-way) and Tukey's post hoc. RESULTS: To the polymer-matrix composites between 24 and 48 hours does not show a significant increase (p > 0.05), however, the highest values were found after 7 days. CONCLUSION: The polymer-matrix composites used in this study showed similarity on the degree of conversion and increased of according to the time of storage.
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Resinas Compuestas/química , Cementos de Resina/química , Bisfenol A Glicidil Metacrilato/química , Carbono/química , Resinas Compuestas/efectos de la radiación , Luces de Curación Dental/clasificación , Humanos , Curación por Luz de Adhesivos Dentales , Ensayo de Materiales , Metacrilatos/química , Polietilenglicoles/química , Polimerizacion , Polímeros/química , Polímeros/efectos de la radiación , Ácidos Polimetacrílicos/química , Poliuretanos/química , Dosis de Radiación , Cementos de Resina/efectos de la radiación , Auto-Curación de Resinas Dentales , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo , Ácidos Tricarboxílicos/químicaRESUMEN
This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey's post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.
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Recubrimiento Dental Adhesivo , Técnica de Perno Muñón , Animales , Bovinos , Análisis de Varianza , Cementación , Dentina , Ensayo de Materiales , Cementos de Resina/química , Raíz del DienteRESUMEN
With the arrival of self-etch adhesives systems, there has been a rise in interest among clinicians, making it imperative for health professionals to have knowledge of the properties, characteristics, the association as well as the dental structures of these materials, in order to select them and use them correctly. The self-etch adhesive systems show good values of bond strength, microleakage and performance, and have therefore become an option in direct adhesive restorations. In the regard, this case study aims to describe the technique involving the use of selfetch adhesives system for direct restoration of anterior teeth.
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Grabado Ácido Dental/métodos , Restauración Dental Permanente/métodos , Recubrimientos Dentinarios/uso terapéutico , Cementos de Resina/uso terapéutico , Adolescente , Recubrimiento Dental Adhesivo , Caries Dental/terapia , Preparación de la Cavidad Dental/métodos , Humanos , Incisivo , Masculino , Ácidos FosfóricosRESUMEN
STATEMENT OF PROBLEM: Sealing ability and bond strengths of total-etch and self-etch dentin adhesives used for immediate dentin sealing have not been assessed and established. PURPOSE: The purpose of this study was to determine the effectiveness of immediate dentin sealing (IDS) using total-etch or self-etch dentin adhesives on microleakage and microtensile bond strength. MATERIAL AND METHODS: Twenty recently extracted molars were selected, and standard MOD inlay preparations were made with the gingival margins located below the cemento-enamel junction. The teeth were assigned to 4 experimental groups (n=5) according to the indirect composite restoration cementation technique used: (1) immediate dentin sealing with Adper Single Bond (TEBI); (2) conventional adhesive cementation technique using Adper Single Bond (TEAI); (3) immediate dentin sealing using Adper Prompt L-Pop (SEBI); or (4) conventional adhesive cementation technique using Adper Prompt L-Pop (SEAI). The restored teeth were thermal cycled 1,000 times between 5 degrees and 55 degrees C and then immersed in 50% ammoniacal silver nitrate. Three specimens per restoration were evaluated for microleakage, according to predefined scores, and submitted to Friedman's test (alpha=.05). The specimens were then sectioned to obtain 0.8 +/-0.2-mm-thick sticks (with n ranging from 32 to 57 specimens) and submitted to microtensile bond strength (muTBS) testing. The obtained data were submitted to 2-way ANOVA test (alpha=.05). RESULTS: None of the experimental groups demonstrated complete elimination of marginal microleakage. There were significant differences in microleakage of the tested adhesives (P>.001). IDS microleakage scores were similar to those obtained using the conventional cementation technique (CCT) for both adhesives. The highest mean bond strengths were obtained with TEBI (51.1 MPa), whereas SEAI showed the lowest mean bond strengths (1.7 MPa). IDS resulted in significantly higher bond strengths than CCT (P<.001). CONCLUSIONS: Total-etch and self-etch adhesives have a significant effect on IDS. IDS resulted in high bond strengths for both adhesives; however, the microleakage was similar to that obtained with CCT. (J Prosthet Dent 2009;102:1-9).
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Grabado Ácido Dental/métodos , Recubrimiento Dental Adhesivo , Adaptación Marginal Dental , Recubrimientos Dentinarios/química , Dentina/ultraestructura , Bisfenol A Glicidil Metacrilato/química , Cementación/métodos , Cerámica/química , Resinas Compuestas/química , Preparación de la Cavidad Dental/clasificación , Filtración Dental/clasificación , Restauración Dental Permanente/clasificación , Cementos de Ionómero Vítreo/química , Humanos , Ensayo de Materiales , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Cementos de Resina/química , Cemento de Silicato/química , Tinción con Nitrato de Plata , Estrés Mecánico , Propiedades de Superficie , Temperatura , Resistencia a la Tracción , Factores de Tiempo , Cuello del Diente/ultraestructuraRESUMEN
Abstract This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey's post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.
Resumo Avaliar o efeito do envelhecimento e sistemas de cimentação usando ionômero de vidro e cimentos resinosos na resistência de união à dentina após a cimentação do pino de fibra. Cento e vinte incisivos bovinos foram utilizados. Após o preparo do pós-espaço, os corpos de prova foram distribuídos aleatoriamente em 12 grupos (n = 10) de acordo com o período de envelhecimento (24 horas, 6 meses e 12 meses) e o sistema de cimentação utilizado: GC - cimento de ionômero de vidro (GC Gold Label Cimentação e Revestimento); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200. Cortes dos terços cervical, médio e apical foram obtidos e analisados por teste de resistência de união push-out e microscopia confocal de varredura a laser. ANOVA one-way e teste de Tukey foi usado a um nível de significância de 5%. Para o teste de resistência de união, não foram observadas diferenças entre GC, RU e MC nos terços cervical e médio, independentemente do período de armazenamento (P > 0,05). No terço apical, GC e RU apresentaram resistência de união semelhante, porém superior aos demais grupos (P > 0,05). Após 12 meses, o GC apresentou a maior resistência de união (P < 0,05). A resistência de união à dentina no espaço para pino diminuiu ao longo do tempo, independentemente do sistema de cimentação utilizado. A formação de tags foi semelhante entre todos os grupos. Após 12 meses, o GC apresentou os maiores valores de resistência de união.
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ABSTRACT: Orthognathic surgery is performed for the correction of craniofacial discrepancies. However, complications, such as tooth discoloration are possible. This case report presents two patients who underwent bilateral sagittal split ramus osteotomy associated with segmental Le Fort I osteotomy and genioplasty. During surgeries, the apical region of anterior teeth was accidentally injured in both cases. After three-week surgery follow-up, the injured teeth showed a change in color to dark pink. In both teeth, the root canal treatment was performed followed by the non vital tooth bleaching. Three sessions were necessary to achieve a significant color change of the teeth. The two-year follow-up showed that both teeth preserved an acceptable color. It was concluded that tooth discoloration after orthognathic surgery is a possible complication, which could be overcome following a conservative approach. Additionally, patients should be informed preoperatively.
RESUMEN: La cirugía ortognática es comúnmente realizada para corregir las discrepancias cráneo-faciales. Sin embargo, se pueden producir complicaciones tales como la pigmentación dentaria. Este reporte de casos presenta a dos pacientes que fueron sometidos osteotomía sagital bilateral de la rama mandibular asociada a osteotomía segmentaria Le Fort I y genioplastía. Durante la fase quirúrgica, la región apical de dientes anteriores fueron accidentalmente dañados en ambos casos. Después de tres semanas de seguimiento de la cirugía, los dientes afectados mostraron un cambio de color a rosado oscuro. Se realizó el tratamiento de conductos seguido de aclaramiento interno en ambas piezas dentarias. Fueron necesarias tres sesiones para lograr un cambio de color significativo. El seguimiento de dos años mostró que ambos dientess conservaron un color aceptable. En conclusión, la pigmentación dentaria después de la cirugía ortognática es una posible complicación, sin embargo, puede ser tratada por medio de un enfoque conservador. Además, los pacientes deben ser informados antes de la cirugía.
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Resumo Introdução Os adesivos autocondicionantes apresentam técnica adesiva simplificada e diminuição na sensibilidade pós-operatória. Quando aplicados sobre a dentina, atuam sobre a smear layer, cuja efetiva remoção ainda constitui um desafio. Uma substância utilizada como pré-tratamento dentinário na ajuda da remoção da smear layer é o etilenodiamino tetracético dissódico (EDTA). Objetivo Avaliar os efeitos do EDTA em associação com sistemas adesivos autocondicionantes na resistência de união ao microcisalhamento. Material e método Foram seccionadas as superfícies oclusais de 72 terceiros molares humanos extraídos, para expor superfície dentinária plana. Os dentes preparados foram divididos em: dentina sem pré-tratamento; dentina tratada com EDTA 0,1M; dentina tratada com EDTA 0,5M. Cada grupo recebeu tratamento de três sistemas adesivos autocondicionantes: Single Bond Universal (SBU), AdheSE (AdheSE) e Clearfil SE Bond (CSEB). Foi delimitada a área adesiva e assim posicionada uma matriz transparente, para inserção com resina composta Z250XT seguida de polimerização por 40 segundos. Após 24 horas de armazenamento, os dentes foram submetidos ao ensaio de microcisalhamento. Os dados obtidos foram analisados estatisticamente, utilizando-se os testes Two-Way ANOVA e Bonferroni, e sendo considerado nível de significância de 5%. Resultado Não houve diferença estatística significante na resistência de união entre os pré-tratamentos dentinários (p=0,8353), porém houve diferença significativa entre os adesivos (p<0,05) CSEB e AdheSE, mostrando semelhança entre CSEB e SBU, e entre SBU e AdheSE. Conclusão O pré-tratamento dentinário com solução de EDTA não afetou a resistência de união com nenhum dos sistemas adesivos autocondicionantes utilizados.
Abstract Introduction Self-etching adhesives have simplified adhesive technique and decreased the postoperative sensitivity. When applied on dentin, it acts on the smear layer, but it is still a challenge in the effectiveness of this removal. A substance used as a pre-treatment for the removal of the smear layer is disodium ethylenediaminetetraacetic acid (EDTA). Objective To evaluate the effects of EDTA in association with self-etching adhesive systems on micro-shear bond strength. Material and method The occlusal surfaces of 72 extracted human third molars were sectioned to expose a flat dentin surface. The prepared teeth were divided into: dentin without pre-treatment; dentin treated with 0.1M EDTA; dentin treated with 0.5M EDTA. Each group received treatment of 3 self-etching adhesive systems: Single Bond Universal (SBU), AdheSE (AdheSE), and Clearfil SE Bond (CSEB). The adhesive area was delimited and positioned a transparent matrix for insertion with Z250XT composite resin followed by polymerization for 40 seconds. After 24h of storage, the teeth were submitted to the micro-shear test. The data were analyzed statistically using the Two-Way ANOVA and Bonferroni tests, considering a level of significance of 5%. Result There was no statistically significant difference in bond strength between dentin pre-treatments (p = 0.8353), but showed a significant difference between CSEB and AdheSE adhesives (p <0.05), showing similarity between CSEB and SBU, and between SBU and AdheSE. Conclusion Dentin pretreatment with EDTA solution did not affect bond strength with any of the self-etching adhesive systems used.
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Adhesivos , Resultado del Tratamiento , Ácido Edético , Dentina , Hipoclorito de Sodio , Eficacia , Resistencia al Corte , Sensibilidad de la Dentina , PolimerizacionRESUMEN
OBJECTIVE: This study aimed at evaluating the degree of conversion (DC) of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs). MATERIAL AND METHODS: Filtek™ Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escence™ and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free Light™ 2) and one third-generation LED (Ultra-Lume LED 5) by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control). After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr). After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet) equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm(-1)) coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1). RESULTS: The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs) and the composite resins (p<0.001). The Tukeys test showed that the nanofilled resin (Filtek™ Z350) and Opallis when photo-activated by the halogen lamp (QTH) had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (Filtek™ Z350) was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free Light™ 2). CONCLUSIONS: The nanofilled resin showed the lowest DC, and the Vit-l-escence™ microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second-generation LED Radii-cal provided the lowest DC.
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Resinas Compuestas/química , Luces de Curación Dental , Nanocompuestos/química , Análisis de Varianza , Resinas Compuestas/efectos de la radiación , Luz , Ensayo de Materiales , Nanocompuestos/efectos de la radiación , Transición de Fase , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Factores de TiempoRESUMEN
To compare the number of colony forming units CFU and agar adherence of S. mutans on amalgam AM and resin composite RC occlusal restorations. Sixty-five healthy patients older than 18 years with high caries risk who had at least one occlusal AM and RC restorations n=130 were selected. METHODS: The restorations were evaluated according to the alpha Ryge criteria Cohen-Kappa 0.8. For each patient, a biofilm sample was taken using an impression tray technique with previously loaded with solid trypticase yeast extract cysteine sucrose with bacitracin agar placed over the AM restorations and RC restorations in the same patients. The tray was placed inside an oven at 37 °C for 48 h, and the S. mutans count was then performed. Data were analyzed with the test Wilcoxon with a 95% confidence level. RESULTS: RC restorations had statistically significant higher number of CFU of S. mutans than AM restorations p<0.05. CONCLUSIONS: In adult patients with high caries risk, RC occlusal surfaces showed greater agar adherence of S. mutans count than AM restorations...
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Humanos , Masculino , Femenino , Resinas Compuestas , Amalgama Dental , Caries Dental , Streptococcus mutansRESUMEN
Objective: This study assessed the Vickers hardness (VHN) provided by two LCUs when using (1) direct and indirect light-curing techniques, (2) 40 and 60 s and (3) top and bottom surfaces. Material & Methods: One halogen Curing Light 2500 (3M Espe) and one LED (MM Optics) were used by direct and indirect (0,1.0, 2.0 and 3.0 mm of dental structure) techniques during 40 and 60 s. The samples were made with FiltekTM Z250 in a metallic mould with a central orifice (4 mm in diameter, 2 mm in thickness). The samples were stored in dry mean by ± 24 h and the hardness measurements were performed in a testing machine (Buehler MMT-3 digital microhardness tester Lake Bluff, Illinois USA). A 50 gf load was used and the indenter with a dwell time of 30 s. The data were submitted to multiple ANOVA and Newman-Keulss test (p < 0.05). Results: Halogen LCU exhibited higher Vickers hardness values than LED mainly because of the power density used. Hardness values were influenced by LCUs, lightcuring techniques, irradiation times and surfaces. For both LCUs, hardness values were found to decrease with indirect light-curing technique, mainly for the bottom surface. Samples irradiated for 60 s exhibited higher hardness values when the halogen LCU was used. For 60 s, the VHN values were statistically significant greater than 40 s. Significant differences in top and bottom surfaces Vickers hardness number (VHN) values were observed among different LCUs used 40 and 60 s. Conclusion: The LCUs, lightcuring techniques, variations of irradiation times, and surfaces (top and bottom) influence the composite resin hardness.
Objetivo: Este estudo avaliou a dureza Vickers (VHN) em função de duas fontes de luz quando utilizadas diferentes (1) técnicas de fotoativação, direta e indireta, (2) 40 e 60 s, e (3) superfícies de topo e base. Material e Métodos: Uma fonte de luz halógena Curing Light 2500 (3M Espe) e um LED (MM Optics) foram utilizados nas técnicas de fotoativação direta e indireta (0 , 1,0, 2,0 e 3,0 milímetros de estrutura dental), durante 40 e 60 s. As amostras foram feitas utilizando-se FiltekTM Z250 em matriz metálica com orifício central (4 mm de diâmetro, com 2 mm de espessura). As amostras foram armazenadas em meio seco por ± 24 h e as medidas de dureza foram realizadas em microdurômetro (Buehler MMT-3 digital microhardness tester Lake Bluff, Illinois USA). Uma carga de 50 gf durante 30 s foi utilizada. Os dados foram submetidos à análise de variância múltipla e teste de Newman-Keuls (p < 0,05). Resultados: A fonte de luz halógena promoveu os maiores valores de dureza Vickers, principalmente, em função da densidade de potência utilizada. Os valores de dureza foram influenciados pelas fontes de luz, técnicas de fotoativação, tempos de irradiação e superfícies, topo e base. Para ambas as fontes de luz, os valores de dureza diminuíram com a técnica de fotoativação indireta, principalmente para a superfície de base. Amostras irradiadas por 60 s apresentaram valores de dureza maiores quando a fonte de luz halógena foi utilizada. Durante 60 s , os valores de VHN foram estatisticamente significativos maior do que 40 s. Diferenças significativas foram observadas nos valores dureza Vickers (VHN) para as superfícies de topo e base utilizando 40 e 60 s. Conclusão: As fontes de luz, técnicas de fotoativação direta e indireta, tempos de irradiação e superfícies (topo e base) influenciam na dureza da resina composta.
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Resinas Compuestas , Luces de Curación DentalRESUMEN
OBJECTIVES: To investigate the effects of adhesion technique using different contemporary adhesive systems on the cuspal movement in class II composite restorations in human premolar teeth. METHODS: Human premolar teeth were prepared with class II cavities and then restored with composite and etch-and-rinse (Adper Scotchbond Multi Purpose and Adper Single Bond) or self-etch (Clearfil SE Bond and Clearfil S3 Bond) adhesive systems under different bonding techniques (total bonding and selective bonding). The influence of an intermediate layer of flowable composite was also evaluated. The cuspal distance was measured before and after the restorative procedure, and the difference was recorded as cuspal movement. The data were submitted to ANOVA test and Tukey's post hoc comparison procedure test (alpha=0.05). RESULTS: For all adhesive systems, the teeth restored with selective bonding technique showed lower values of cuspal movement and the use of an intermediary layer of flowable composite did not show any influence on the cuspal movement. CONCLUSIONS: Both the adhesive techniques tested were not able to prevent the cuspal movement. However, selectively bonded class II composite restorations demonstrated lower values of cuspal movement comparing with total bonding technique, and the use of an intermediate layer of flowable composite did not diminish the values of cuspal movement.
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OBJECTIVE: Control of microleakage represents a challenge for posterior composite restorations. The technique for composite placement may reduce microleakage. The null hypothesis of this in vitro study was that centripetal incremental insertion of composite resin would result in less microleakage than that obtained with the oblique incremental technique or bulk technique. METHOD AND MATERIALS: Standardized Class 2 preparations were made in 60 caries-free extracted third molars and randomly assigned to 3 groups (n = 20): (1) oblique incremental insertion technique (control), (2) centripetal incremental insertion technique, and (3) bulk insertion. The teeth were restored with a total-etch adhesive and microhybrid composite resin. The specimens were isolated with nail varnish except for a 2-mm-wide area around the restoration and then thermocycled (1,000 thermal cycles, 5 degrees C/55 degrees C; 30-second dwell time). The specimens were immersed in an aqueous solution of 50% silver nitrate for 24 hours, followed by 8 hours of immersion in a photo-developing solution and subsequently evaluated for leakage. The microleakage scores (0 to 4) obtained from the occlusal and cervical walls were analyzed with median nonparametric tests (P < .05). RESULTS: The null hypothesis was rejected. All techniques attained statistically similar dentin microleakage scores (P = .15). The centripetal insertion technique displayed significantly less microleakage than the oblique technique at the enamel margins (P = .04). CONCLUSION: None of the techniques eliminated marginal microleakage in Class 2 preparations. However, in occlusal areas, the centripetal technique performed significantly better than the other techniques.
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Resinas Compuestas , Filtración Dental/prevención & control , Restauración Dental Permanente/métodos , Recubrimientos Dentinarios , Cementos de Resina , Dióxido de Silicio , Circonio , Preparación de la Cavidad Dental/clasificación , Adaptación Marginal Dental , Humanos , Bandas de Matriz , Diente MolarRESUMEN
Introduction: The finite element method (FEM) involves a series of computational procedures to calculate the stress in each element, which performs a model solution. Such a structural analysis allows the determination of stress resulting from external force, pressure, thermal change, and other factors. This method is extremely useful for indicating mechanical aspects of biomaterials and human tissues that can hardly be measured in vivo. The results obtained can then be studied using visualization software within the FEM environment to view a variety of parameters, and to fully identify implications of the analysis. Objective: An overview to show application of FEM in dentistry was undertaken. Literature review: This paper shows the basic concept, advances, advantages, limitations and applications of finite element method (FEM) in dentistry. Conclusion: It is extremely important to verify what the purpose of the study is in order to correctly apply FEM.
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The use of acid etchants to produce surface demineralization and collagen network exposure, allowing adhesive monomers interdiffusion and consequently the formation of a hybrid layer, has been considered the most efficient mechanism of dentin bonding. The aim of this study was to compare the tensile bond strength to dentin of three adhesive systems, two self-etching ones (Clearfil SE Bond--CSEB and One Up Bond F--OUBF) and one total-etching one (Single Bond--SB), under three dentinal substrate conditions (wet, dry and re-wet). Ninety human, freshly extracted third molars were sectioned at the occlusal surface to remove enamel and to form a flat dentin wall. The specimens were restored with composite resin (Filtek Z250) and submitted to tensile bond strength testing (TBS) in an MTS 810. The data were submitted to two-way ANOVA and Tukey's test (p = 0.05). Wet dentin presented the highest TBS values for SB and CSEB. Dry dentin and re-wet produced significantly lower TBS values when using SB. OUBF was not affected by the different conditions of the dentin substrate, producing similar TBS values regardless of the surface pretreatments.
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Grabado Ácido Dental , Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios/química , Dentina/química , Metacrilatos/química , Cementos de Resina/química , Adhesividad , Análisis de Varianza , Grabado Dental/métodos , Dentina/efectos de los fármacos , Permeabilidad de la Dentina , Recubrimientos Dentinarios/normas , Colágenos Fibrilares/química , Humanos , Ensayo de Materiales , Tercer Molar , Resistencia a la TracciónRESUMEN
OBJECTIVE:This study aimed at evaluating the degree of conversion (DC) of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs). MATERIAL AND METHODS: Filtek TM Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escenceTM and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free LightTM 2) and one third-generation LED (Ultra-Lume LED 5) by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control). After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr). After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet) equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm-1) coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1). RESULTS: The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs) and the composite resins (p<0.001). The Tukeys test showed that the nanofilled resin (FiltekTM Z350) and Opallis when photo-activated by the halogen lamp (QTH) had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (FiltekTM Z350) was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free LightTM 2). CONCLUSIONS: The nanofilled resin showed the lowest DC, and the Vit-l-escenceTM microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second-generation LED Radii-cal provided the lowest DC.
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Luces de Curación Dental , Resinas Compuestas/química , Nanocompuestos/química , Análisis de Varianza , Resinas Compuestas/efectos de la radiación , Luz , Ensayo de Materiales , Nanocompuestos/efectos de la radiación , Transición de Fase , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Factores de TiempoRESUMEN
Introdução: o clareamento dentários pode ser avaliado por meio de técnicas comparativas subjetivas (visual) ou objetivas (instrumental). Essa última tem se mostrado mais adequado para tal tipo de avaliação. Métodos: a avaliação do sistema foi realizado em laboratório, utilizando-se uma câmara digital, escala de cores Vita Classical e tres diferentes tipos de iluminação. No total, foram realizadas 480 imagens. Em seguida, o software foi avaliado quanto à sua eficiência clínica. Para tal, foi selecionado um caso de microabrasão complementado com clareamento dentário fotoacelerado. Resultados: os testes laboratoriais com diferentes iluminantes apresentaram resultados similares. Clinicamente, foram obsaervados diferentes níveis de clareamento em cada uma das sessões clínicas realizadas. Discussão: os vários métodos objetivos disponíveis atualmente apresentam diferentes graus de imitação na análise da cor de corpos semitranslúcidos (por exemplo, dentes e materiais dentários). Essas estão relacionadas ao posicionamento e ao sistema de cor utilizado (por exemplo, RGB, CYM) por cada equipamento. Portanto, o método proposto apresenta algumas vantagens em relação aos sistemas objetivos, como a ausência da necessidade de manutenção do posicionamento da amostra ou do paciente, algoritmo calibrador e a geração de gráficos e laudos. Conclusões: as comprovações geradas pelo sistema proposto geram maior conforto e segurança durante o tratamento
Introduction: The dental bleaching outcome can be evaluated using subjective (visual) and objective (instrumental) comparative techniques. The latter has demonstrated more suitable results to that kind of evaluation. Methods: The assessment of the proposed system was realized in th laboratory using Vita Classical color pallets, digital camera and three different illuminations. In total, 480 images were acquired. Next, the software was evaluated to check its clinical efficiency.For this, a case of micro-abrasion complemented with photoacelerated dental bleaching was chosen. Results: The laboratorial tests with different illuminants showed similar results. Clinically different levels of dental bleaching were observed in each one of the clinical appointments realized. Discussion: The several objective methods available nowadays present different limitation levels when analysing semitranslucid samples (e.g. teeth and dental materials). These limitations are related with the samples's position and with the color space used by each system (e.g. RGB, CYM). Therefore, the proposed method shows some advantages when compared with the traditional objective methods, such as the absence of position maintenance of the sample or of the patient, calibration algorithm and generation of graphs and reports. Conclusions: The outcomes generated by the proposed system can provide more security both to patient and professional during the treatment
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Materiales Dentales , Estética Dental , Procesamiento de Imagen Asistido por Computador , Programas Informáticos , Blanqueamiento de DientesRESUMEN
Objetivo: Avaliar a microdureza superficial de resinas compostas polimerizadas por diferentes fontes de luz. Métodos: Foram selecionadas três resinas compostas microhíbridas (Vit-l-escenceTM, Amelogen® Plus, Opallis) e uma nanoparticulada (FiltekTM Z350, 3M ESPE Dental Products, St. Paul, USA). Foram submetidas à polimerização utilizando-se um aparelho halógeno (Ultralux, Dabi Atlante, Ribeirão Preto, Brasil) com duas ponteiras, uma de vidro semi-orientada e outra de acrílico pintada e também um dispositivo à base de LED (UltraLume 2, Ultradent®, South Jordan, USA). Os corpos-de-prova obtidos a partir de uma matriz circular de alumínio, após receberem a resina composta, foram fotopolimerizados por 40 segundos e em seguida armazenados a seco por 24 horas. Decorrido esse período, procedeu-se ao ensaio de microdureza superficial Vickers, realizando-se quatro aferições na superfície de topo (dureza 1) e na superfície de base (dureza 2). Utilizou-se a análise de variância que foi complementada pelo teste de Newman-Keuls de comparações múltiplas de médias, ao nível de significância de 5%.Resultados: No topo, as menores médias de dureza foram obtidas com a resina Opallis submetida ao UltraLume 2 (Ultradent®, South Jordan, USA). As médias maiores referem-se ao compósito Vit-l-escenceTM (Ultradent®, South Jordan, USA) polimerizado com o Led UltraLume 2 (Ultradent®, South Jordan, USA) e luz halógena Ultralux PCP (Dabi Atlante, Ribeirão Preto, Brasil), seguidas da resina FiltekTM Z350 (3M ESPE Dental Products, St. Paul, USA) submetida ao UltraLume 2 (Ultradent®, South Jordan, USA). Quanto à base, a menor média de dureza também foi da resina composta Opallis (FGM, Santa Catarina, Brasil), sob ação do LED UltraLume 2 (Ultradent®, South Jordan, USA) e a maior da Vit-l-escenceTM (Ultradent®, South Jordan, USA), seguida pela Amelogen® Plus (Ultradent®, South Jordan, USA) quando polimerizada pelo Ultralux (Dabi Atlante, Ribeirão Preto, Brasil) com a ponta semi-orientada.Conclusão: O aparelho LED permitiu polimerização e consequentes valores de microdureza equivalentes ao dos aparelhos halógenos convencionais, para três dos quatro compósitos avaliados.
Objective: This study assessed the surface microhardness of compound resins cured by different light sources. Methods: Three micro hybrid (Vit-l-escenceTM, Amelogen® Plus, Opallis) and one nanoparticle (FiltekTM Z350, 3M ESPE Dental Products, St. Paul, USA) compound resins were selected. The resins were polymerized by a halogen light unit (Ultralux, Dabi Atlante, Ribeirão Preto, Brasil) with two tips, one semi-guided made of glass and another of painted acrylic and a LED-based source (UltraLume 2, Ultradent®, South Jordan, USA). Specimens constructed from a circular aluminum matrix were photopolymerized for 40 second after they received the compound resin and stored dry for 24 hours. After this period, a Vickers surface microhardness assay was performed, measuring the top (hardness 1) and base (hardness 2) surfaces four times each. Variance analyses were complemented by Newman-Keuls method, with significance set at 5%. Results: The Opallis (FGM, Santa Catarina, Brasil) resin subjected to UltraLume 2 (Ultradent®, South Jordan, USA) obtained the lowest mean hardness values for the top surface. The Vit-l-escenceTM (Ultradent®, South Jordan, USA) compound cured by Led UltraLume 2 (Ultradent®, South Jordan, USA) and by Ultralux PCP (Dabi Atlante, Ribeirão Preto, Brasil) halogen light obtained the highest mean hardness, followed by the FiltekTM Z350(3M ESPE Dental Products, St. Paul, USA) resin subjected to UltraLume 2 (Ultradent® South Jordan, USA). The Opallis (FGM, Santa Catarina, Brasil) resin cured by LED UltraLume 2 (Ultradent®, South Jordan, USA) also obtained the lowest mean hardness for the base surface and the Vit-l-escenceTM (Ultradent®, South Jordan, USA) resin obtained the highest value, followed by Amelogen® Plus, when cured by Ultralux (Dabi Atlante, Ribeirão Preto, Brasil) using the semi-guided tip. Conclusion: The polymerization and, consequently, the microhardness achieved by the LED unit was equivalent to those achieved by conventional halogen units for three of the four composites tested.