RESUMEN

Este trabalho teve como o objetivo comparar dois Projetos Políticos Pedagógicos, descrever e analisar o desenvolvimento da visão humanística no curso de graduação em Odontologia da Universidade Federal Fluminense, a partir da ótica dos acadêmicos do referido curso. Realizou-se uma pesquisa descritivo-exploratória com enfoque quanti-qualitativo. A coleta de dados deu-se em 03 etapas, as duas primeiras por meio de categorização dos fatores selecionados pelos alunos e a terceira pelo método denominado grupo focal. As estratégias de análises utilizadas foram a categorização, operações estatísticas simples, análise temática e análise crítica com a literatura revisada. Entre os resultados da pesquisa têm-se: não existe diferença entre a visão humanística dos alunos no período inicial quando comparada com as dos alunos no final do período do ciclo profissional no Projeto Pedagógico Antigo, no Projeto Pedagógico Novo, em curso, os alunos demonstram em sua maioria estar voltados para uma visão mais humanística. Conclui-se que a humanização, do processo ensino-aprendizagem no contexto acadêmico pesquisado, apresenta ainda deficiências, constituindo-se, portanto, em um caminho a perseguir, onde o comprometimento de todos os envolvidos neste processo de transformação e formação tem um papel fundamental.

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The aim of this paper was to compare two Pedagogical Political Projects, to describe and analyze the development of humanistic vision in the undergraduate course in Dentistry of the Federal University of Fluminense, from the perspective of the academics of this course. A descriptive-exploratory research with quantitative-qualitative approach was carried out. The data collection took place in 03 stages; the first two by categorizing the factors selected by the students and the third by the method called the focal group. The analysis strategies used were categorization, simple statistical operations, thematic analysis and critical analysis with the reviewed literature. The results of the research are: there is no difference between the humanistic view of the students in the initial period when compared to the students at the end of the professional cycle in the Pedagogical Project. In the New Pedagogical Project, in progress, students demonstrate, in majority, aimed at a more humanistic view. It is concluded that the humanization of the teaching-learning process in the researched academic context still presents deficiencies, constituting, therefore, a path to be pursued, where the commitment of all those involved in this process of transformation and formation plays a fundamental role.

RESUMEN

O objetivo do presente estudo foi estabelecer um protocolo clínico de aplicação do produto DSP Desensitizer Gluhem em dentes com exposição radicular sem perda de estrutura dentária, e fazer uma análise dissertativa sobre o principal componente desse produto: glutaraldeído, no tratamento da hipersensibilidade dentinária. Para isso, a paciente apresentou-se à Clínica Odontológica da UFF| Niterói ­ RJ, queixando-se de sensibilidade intensa ao frio nos elementos 13 e 34. Primeiramente, foram coletadas informações durante a anamnese, e ao exame clínico foi observada recessão gengival e exposição radicular nesses elementos, porém não havia perda de estrutura dentária. Inicialmente foi feita a avaliação do nível de dor, com uso da Escala Analógica de Dor que pontua os níveis de dor de 0 a 10, sendo 0 "nenhuma dor' e 10 "pior dor possível". Após o questionamento, fez-se a secagem da região com jato de ar e aplicou-se o dessensibilizante Gluhem em solução por toda região cervical do elemento 13 até a margem gengival por 40 segundos com posterior secagem e lavagem com água. Também foi feita a aplicação da formulação em gel no elemento 34 seguindo o mesmo protocolo. A paciente não reagiu a dor após o protocolo. Conclui-se que o produto DSP Gluhem tanto na apresentação de solução como em gel atuaram efetivamente na sintomatologia dolorosa da HDC nas duas aplicações realizadas.

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The objective of the present study was to establish a clinical protocol for the application of the product GSP Desensitizer Gluhem in teeth with root exposure without loss of tooth structure, and to carry out a dissertation analysis on the main component of this product: glutaraldehyde, in the treatment of dentin hypersensitivity. For this, the patient went to the Dental Clinic of UFF| Niterói - RJ, complaining of intense sensitivity to cold in elements 13 and 34. First, information was collected during the anamnesis, and the clinical examination showed gingival recession and root exposure in these elements, but there was no loss of tooth structure. Initially, the pain level was evaluated using the Analog Pain Scale, which scores pain levels from 0 to 10, with 0 being "no pain" and 10 "worst possible pain". After questioning, the region was dried with an air jet and the desensitizing Gluhem solution was applied throughout the entire cervical region of element 13 up to the gingival margin for 40 seconds with subsequent drying and washing with water. The gel formulation was also applied to element 34 following the same protocol. The patient did not react to pain after the protocol. It is concluded that the product DSP Gluhem, both in solution and in gel presentation, effectively acted on the painful symptomatology of HDC in the two applications performed.

Asunto(s)

Humanos , Femenino , Adulto , Protocolos Clínicos , Glutaral/uso terapéutico , Sensibilidad de la Dentina , Desensibilizantes Dentinarios

RESUMEN

The aim of this study was to evaluate the influence of adding quaternary ammonium methacrylates (QAMs) to experimental adhesives by assessing the degree of conversion (DC), cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. Two QAMs were added to an experimental adhesive: dimethylaminododecyl methacrylate bromododecane (DMADDM) or dimethylaminododecyl methacrylate bromohexadecane (DMAHDM) at three concentrations each: 1, 2.5, and 5 wt.%. Experimental adhesive without QAMs (control group) and commercially available Transbond XT Primer (3M Unitek, Monrovia, California, USA) were used for comparisons. The adhesives were tested for DC, cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. DC, cytotoxicity against fibroblasts, and antibacterial activity were analyzed using one-way ANOVA and Tukey's multiple comparisons. Cytotoxicity against keratinocytes was evaluated using the Kruskal Wallis and Dunn's post-hoc (α = 5%) tests. Transbond showed lower DC as compared to 5% DMAHDM, 1% DMADDM, and 5% DMADDM (p < 0.05). However, all groups presented proper DC when compared to commercial adhesives in the literature. In the evaluation of cytotoxicity against keratinocytes, Transbond induced higher viability than 2.5 wt.% groups (p < 0.05). Against fibroblasts, Transbond induced higher viability as compared to 5 wt.% groups (p < 0.05). DMAHDM at 5 wt.% reduced biofilm formation when compared to all the other groups (p < 0.05). Despite their cytotoxic effect against keratinocytes, gingival fibroblasts showed higher viability. DMAHDM at 5 wt.% decreased Streptococcus mutans viability. The incorporation of DMAHDM at 5 wt.% may be a strategy for reducing the development of white spot lesions.

Asunto(s)

Antibacterianos , Bisfenol A Glicidil Metacrilato , Hidrocarburos Bromados , Metacrilatos , Metilaminas , Compuestos de Amonio Cuaternario , Metacrilatos/farmacología , Antibacterianos/farmacología

RESUMEN

BACKGROUND: Light-cured resins are widely used as gingival barriers to protect the gums from highly concentrated peroxides used in tooth bleaching. The impact of barrier brand on clinical outcomes is typically considered negligible. However, there is limited evidence on the effects of different brands on operator experience, barrier adaptation, and patient comfort. OBJECTIVE: This clinical trial assessed the impact of four commercial gingival barrier brands (Opaldam, Topdam, Lysadam, and Maxdam) on operator perception, adaptation quality, and patient comfort. METHODS: Twenty-one undergraduate students placed gingival barriers in a randomized sequence using blinded syringes. Photographs of the barriers were taken from frontal and incisal perspectives. After bleaching procedures, operators rated handling features and safety using Likert scale forms. Two experienced evaluators independently assessed barrier adaptation quality on a scale from 1 (perfect) to 5 (unacceptable). The absolute risk of barrier-induced discomfort was recorded. Data were analyzed using Friedman and Chi-square tests (α = 0.05). RESULTS: Opaldam and Topdam received the highest scores in most handling features, except for removal, which was similar among all brands. No significant difference was observed in barrier adaptation quality between the evaluated brands. Discomforts were mainly reported in the upper dental arch, with Maxdam having the highest absolute risk (35% for this arch and 24% overall). CONCLUSIONS: This study suggests that gingival barrier brands can influence operator perception and patient comfort. Opaldam and Topdam were preferred by operators, but all brands demonstrated comparable adaptation quality. CLINICAL TRIAL REGISTRATION: The study was nested in a randomized clinical trial registered in the Brazilian Clinical Trials Registry under identification number RBR-9gtr9sc.

Asunto(s)

Sensibilidad de la Dentina , Blanqueadores Dentales , Blanqueamiento de Dientes , Diente , Humanos , Sensibilidad de la Dentina/inducido químicamente , Sensibilidad de la Dentina/prevención & control , Sensibilidad de la Dentina/tratamiento farmacológico , Peróxido de Hidrógeno , Comodidad del Paciente , Percepción , Blanqueamiento de Dientes/efectos adversos , Blanqueadores Dentales/efectos adversos , Resultado del Tratamiento

RESUMEN

Abstract The aim of this study was to evaluate the influence of adding quaternary ammonium methacrylates (QAMs) to experimental adhesives by assessing the degree of conversion (DC), cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. Two QAMs were added to an experimental adhesive: dimethylaminododecyl methacrylate bromododecane (DMADDM) or dimethylaminododecyl methacrylate bromohexadecane (DMAHDM) at three concentrations each: 1, 2.5, and 5 wt.%. Experimental adhesive without QAMs (control group) and commercially available Transbond XT Primer (3M Unitek, Monrovia, California, USA) were used for comparisons. The adhesives were tested for DC, cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. DC, cytotoxicity against fibroblasts, and antibacterial activity were analyzed using one-way ANOVA and Tukey's multiple comparisons. Cytotoxicity against keratinocytes was evaluated using the Kruskal Wallis and Dunn's post-hoc (α = 5%) tests. Transbond showed lower DC as compared to 5% DMAHDM, 1% DMADDM, and 5% DMADDM (p < 0.05). However, all groups presented proper DC when compared to commercial adhesives in the literature. In the evaluation of cytotoxicity against keratinocytes, Transbond induced higher viability than 2.5 wt.% groups (p < 0.05). Against fibroblasts, Transbond induced higher viability as compared to 5 wt.% groups (p < 0.05). DMAHDM at 5 wt.% reduced biofilm formation when compared to all the other groups (p < 0.05). Despite their cytotoxic effect against keratinocytes, gingival fibroblasts showed higher viability. DMAHDM at 5 wt.% decreased Streptococcus mutans viability. The incorporation of DMAHDM at 5 wt.% may be a strategy for reducing the development of white spot lesions.

RESUMEN

BACKGROUND: Geographic Tongue (GT) is a benign inflammatory disorder of unknown etiology, which is characterized by the loss of epithelium due to the atrophy of filiform papillae. It usually occurs on the dorsum of the tongue and may extend to its lateral edges. It appears as an erythematous area surrounded by whitish and slightly elevated margins. In most cases, the condition is asymptomatic, although some individuals may report symptoms that include a burning sensation of the tongue. OBJECTIVE: Assess whether there was a change in the clinical aspect of Geographic Tongue (GT) during the COVID-19 pandemic. METHODS: Thirty-two participants were recruited from Dentistry School Universidade Federal Fluminense. Anamnesis and oral examination were performed to collect medical history. The participants were split into two groups: control group (no GT) n = 20 and test group (with GT) n = 12. In the second step, nine participants from a 12 (75%) of the test group were contacted by phone and answered a questionnaire about changes in the signs and symptoms of GT during the pandemic. The subjects were subdivided into two groups: GT with and without signs and symptoms exacerbation. RESULTS: In the first phase of the research, no statistical difference between control and test groups was observed regarding clinical criteria such as age (p + 0.72), gender (p = 0.24), and systemic diseases (p = 0.58). In the second phase, there was a statistical difference between GT groups with or without symptom exacerbation in terms of age and stress as a factor of the oral symptoms (p = 0.3 and 0.2), respectively. Younger patients showed a worsening of the oral lesions related to GT (p = 0.3) and reported stress during the pandemic (p = 0.02). CONCLUSION: Younger patients were more susceptible to stress and presented more exacerbation of the oral lesions related to GT.

Asunto(s)

COVID-19 , Glositis Migratoria Benigna , Humanos , COVID-19/epidemiología , Pandemias , Proyectos Piloto , Atrofia

RESUMEN

METHODOLOGY: Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes. RESULTS: The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05). CONCLUSION: Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.

Asunto(s)

Soportes Ortodóncicos , Antibacterianos , Biopelículas , Cementos Dentales , Ensayo de Materiales , Metacrilatos , Cementos de Resina , Streptococcus mutans

RESUMEN

BACKGROUND: Previous studies have shown that acidic bleaching gels could lead to worse collateral effects during an in-office bleaching procedure, while neutral or basic products leads towards a better experience. Considering this fact, the main purpose of this study was to evaluate the pH behavior of 6 in-office bleaching gels, compared to the information provided by their manufacturers. MATERIAL AND METHODS: Thirty enamel discs of bovine teeth were prepared, the initial colors of which were measured by a spectrophotometer and then divided into 6 groups. A pH meter was used to measure the pH every 30 seconds until the end of each procedure, when a new color evaluation was then made. The Tukey test was used for statistical analysis of the results. RESULTS: There was no difference in the color variation (ΔE) between the groups (p> 0.05). In two groups, the pH variation (ΔpH) showed neutral stability, with initial and final pH averages of 7.04 and 7.11 (p = 0.08) and 7.21 and 7.19 (p = 0.55), respectively; in another, there was alkaline stability, with an initial and final pH average of 8.54 and 8.37 (p = 0.14). In the other three brands, however, the results showed acidification, with initial and final pH averages of 6.14 and 5.22 (p = 0.001), 6.05 and 5.16 (p = 0.001) and 7.14 and 5.83 (p = 0.001), respectively. CONCLUSIONS: In 3 of the evaluated gels, a discrepancy existed between the manufacturer's information and the data obtained, which could lead, considering previous studies discussed throughout this article, to unexpected collateral effects on the patients, especially dental sensitivity. Thus, clinicians and researchers should be aware about pH stability studies of in-office bleaching gels for better predictability and safety on their clinical usage. Key words:Tooth bleaching, Bleaching agents, Hydrogen-ion concentration, Dentin sensitivity, Hydrogen peroxide.

RESUMEN

Abstract Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. Methodology: A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes. Results: The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05). Conclusion: Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.

Asunto(s)

Soportes Ortodóncicos , Streptococcus mutans , Ensayo de Materiales , Biopelículas , Cementos de Resina , Cementos Dentales , Metacrilatos , Antibacterianos

RESUMEN

Objetivo: identificar o perfil de formação e atendimento de cirurgiões dentistas (CDs) e procurar compreender qual a conduta prestada por esses profissionais em relação ao diagnóstico e ao tratamento das lesões cervicais não cariosas (LCNCs). Sujeitos e método: um questionário foi disponibilizado e enviado para CDs com o cadastro atualizado na base de dados do Conselho Regional de Odontologia do Rio de Janeiro. Os resultados foram analisados de forma descritiva e o teste de Qi-Quadrado com nível de significância de 5%. Resultados: a maioria dos CDs procura fazer distinção entre as diferentes formas de LCNCs (76,5%), porém não usa método auxiliar (83,2%) e não possui questionário específico (59,7%). Para 40,3% dos CDs, a etiologia das LCNCs é unifatorial ou não soube responder. A maioria faz uso de isolamento relativo (65,6%) e utiliza técnicas de retração/afastamento gengival (83,2%). O sistema adesivo convencional de dois passos (63%) e a resina composta do tipo híbrida/micro-híbrida (52,1%) são os materiais mais utilizados. Com relação à longevidade das restaurações, apenas 17,6% dos CDs acreditam na duração por um período acima de 5 anos. Com relação às associações, houve relação entre a forma de remuneração e o uso/método de isolamento (p = 0,004) e entre a forma de remuneração e o uso de técnicas de retração/afastamento gengival (p = 0,005). Conclusões: os CDs não possuem um protocolo preestabelecido para correto diagnóstico de LCNCs. A forma de remuneração influencia no uso do isolamento para o tratamento restaurador. O sistema adesivo convencional de dois passos é o mais utilizado pelos CDs.

RESUMEN

PURPOSE: to evaluate the shrinkage, polymerization stress, elastic and bulk modulus resulting from composites formulated by siloranes, 2(nd) generation ormocers, and dimethacrylates. MATERIALS AND METHODS: The bonded disc method was used to evaluate volumetric shrinkage. The polymerization stress was evaluated by mean of the Bioman. Cylindrical specimens (5 mm thickness and 6 mm diameter) were submitted to gradual loading. Young's and bulk modulus were obtained from the slope of the stress/strain curve. Data were analyzed using one-way analysis of variance and Tukey's test (5%). RESULTS: Grandio and ormocer showed significant higher elastic and bulk modulus. Silorane presented significant lowest bulk modulus and maximum shrinkage. Ormocer and silorane presented lower values for the maximum rate of shrinkage. Extra-low shrinkage (ELS) composite presented the greatest maximum shrinkage. The higher maximum rate of shrinkage was attained by Grandio and ELS, statistically similar from each other. The silorane showed lower values of maximum stress and maximum rate of stress. The higher values of maximum stress were presented by ELS and Grandio, statistical similar between them. Grandio showed the significantly greatest maximum rate of stress. CONCLUSION: Silorane showed to promote lower shrinkage/stress among the composites, with the lowest elastic modulus. Ormocer showed lower shrinkage/stress than methacrylates despite of its high modulus.

RESUMEN

Objetivo: Este trabalho tem como objetivo apresentar os achados da literatura com relação às indicações do reparo de restaurações, buscando conscientizar o profissional a não substituir algumas restaurações desnecessariamente, discutir os materiais a serem utilizados e técnica empregada, a fim de esclarecer e guiar o clínico na prática diária para desempenhar seu trabalho de maneira metódica e bem sucedida. Revisão de literatura: Mesmo que o dentista desenvolva um trabalho criterioso e tome os devidos cuidados ao realizar uma restauração, elas não duram a vida toda e, por vezes, fracassam num curto período de tempo, frustrando algumas expectativas dos pacientes. Infiltrações, recorrência de cáries, desgaste ou fratura da restauração e eventual fratura do elemento dental são alguns motivos que levam à falha da restauração. Diante dessas situações, alguns profissionais, seja por opção, seja por falta de informação, substituem toda a restauração, muitas vezes causando injúria e agressão desnecessária àquele elemento dental. Considerações finais: O avanço da odontologia adesiva oferece a possibilidade de um tratamento restaurador amplamente conservador, sem a necessidade da remoção total de algumas restaurações. Assim, o reparo pode ser empregado preservando a estrutura dental remanescente.

RESUMEN

O estudo verificou a influência da fonte de luz (FL) e do sistema fotoiniciador no grau de conversão (GC) e na densidade de ligações cruzadas (DLC) em compósitos com diferentes fotoiniciadores. Foram utilizadas as FLs XL2500® (3M/ESPE), Apollo95E® (DMD), UltraBlueIS® (DMC) e UltraLume5® (Ultradent), todas de acordo com as recomendações dos fabricantes e com 19J de energia aplicada, e os compósitos Pyramid-Bisco® (contendo fotoiniciador Lucirin TPO) e Filtek® Z250-3M/ESPE (fotoiniciador canforoquinona-CQ). O GC foi mensurado por espectroscopia de infra-vermelho transformada de Fourier. A DLC foi medida indiretamente por meio da leitura de dureza Knoop antes e após banho em etanol. Os dados foram submetidos à Anova e as médias, ao teste de Tukey (5%). Apollo 95E® produziu os maiores valores de GC para o compósito TPO (60,2%) quando a dose de energia foi mantida constante. A FL Ultra-BlueIS® não foi capaz de fotoativar o compósito TPO. Não existiram diferenças nos valores de GC para ocompósito CQ, a não ser quando Apollo 95E® foi usado pelo tempo recomendado pelo fabricante, levando a menor média (50,8%) de GC. Em geral, Ultra Lume5® produziu maior DLC, e Apollo 95E®, menor DLC para ocompósito TPO; para o compósito CQ não houve um padrão para os valores de DLC. Conclui-se que fontes de luz e fotoiniciadores influenciam as propriedades de compósitos dentais fotoativados.

Asunto(s)

Materiales Dentales , Restauración Dental Permanente , Odontología , Luz , Fototerapia

RESUMEN

AIM: The purpose of this study was to evaluate if Knoop hardness values (KHN) for top and bottom surfaces of resin composite materials can reach a plateau within a clinically acceptable photoactivation time. METHODS AND MATERIALS: Four light-curing units (LCUs) were evaluated in this study (n=5): QTH (Optilux501: 550 mW/cm2) and LEDs (FreeLight2: 1100 mW/cm2; UltraLume5: 900 mW/cm2; and Radii: 750 mW/cm2). Composite resin discs (4 mm x 2 mm) of Heliomolar (Ivoclar/Vivadent) and Herculite XRV (Kerr) were tested using five photoactivation times (20, 40, 60, 80, and 100 seconds). KHN were obtained for each test specimen and comparisons between LCUs, depths, and photoactivation times were analyzed using two-way analysis of variance (ANOVA) and polynomial regression analysis. RESULTS: Data for Heliomolar discs using linear regression found a relationship between the independent variables KHN and time with the Optilux501 at the top and bottom surfaces (r2=0.68/ r2=0.66). Radii presented a linear regression at the top surface (r2=0.75) and a quadratic regression at the bottom (r2=0.94). A quadratic regression was also detected for UltraLume5 and FreeLight2 at both top (r2=0.84/ r2=0.94) and bottom surfaces (r2=0.97/ r2=0.90), respectively, reaching a plateau at 80 seconds in all cases. For Herculite XRV, a quadratic regression was observed for all LCUs at the top and bottom surfaces and 80 seconds irradiation time was needed to reach a plateau in KHN. CONCLUSION: There is a specific, but not clinically acceptable, photoactivation time that KHN at both top and bottom surfaces can reach a plateau and is dependent on LCUs and the resin-composite tested. CLINICAL SIGNIFICANCE: The LCUs and the resin-composite formulation affected the exposure time required to stabilize hardness values. The overall performance of LED LCUs was better than the QTH LCU regardless of the material evaluated.

Asunto(s)

Resinas Compuestas/química , Materiales Dentales/química , Restauración Dental Permanente , Resinas Acrílicas/química , Resinas Acrílicas/efectos de la radiación , Resinas Compuestas/efectos de la radiación , Luces de Curación Dental/clasificación , Materiales Dentales/efectos de la radiación , Dureza , Humanos , Ensayo de Materiales , Poliuretanos/química , Poliuretanos/efectos de la radiación , Dosis de Radiación , Cementos de Resina/química , Cementos de Resina/efectos de la radiación , Propiedades de Superficie , Factores de Tiempo

RESUMEN

AIM: The aim of this study was to evaluate the influence of four photoactivation systems [quartz tungsten halogen (QTH), light-emitting diode (LED), argon ion laser (AL), and plasma arc curing PAC)] on cementum/dentin and enamel microleakage of Class II restorations using a microhybrid [Z250-3M ESPE] and two packable composites [(SureFil-Dentsply and Tetric Ceram HB-Ivoclair/Vivadent]. METHODS AND MATERIALS: Three hundred sixty "vertical-slot Class II cavities" were prepared at the mesial surface of bovine incisors using a 245 carbide bur in a highspeed handpiece. Specimens were divided into twelve groups (composite-photoactivation systems). Half of the specimens had the gingival margin placed in enamel (n=15) and the other half in cementum/dentin (n=15). Composites were inserted and cured in 2 mm increments according to manufacturers' recommended exposure times. After polishing, the samples were immersed in 2% methylene blue solution, sectioned, and evaluated at the gingival margins. Data were submitted to statistical analysis using the Kruskal-Wallis and Mann-Whitney tests. RESULTS: No significant differences were found among the photoactivation systems and among resin composites (p>0.05). Microleakage was not significantly affected by location (enamel vs. cementum/dentin, p>0.05). These findings suggested neither the photoactivation systems nor the resin composite types might have an effect on the microleakage at gingival margins Class II cavities.

Asunto(s)

Resinas Compuestas/efectos de la radiación , Equipo Dental , Filtración Dental/prevención & control , Restauración Dental Permanente/métodos , Luz , Animales , Bovinos , Preparación de la Cavidad Dental , Adaptación Marginal Dental , Halógenos , Rayos Láser , Transición de Fase , Distribución Aleatoria , Semiconductores , Estadísticas no Paramétricas , Xenón

RESUMEN

PURPOSE: This study was designed to analyze the influence of desensitizing procedures on dentin bond strength. MATERIALS AND METHODS: Forty bovine incisors were used, divided into four groups (n = 10): G1: control; G2: Gluma Desensitizer (Heraeus Kulzer); G3: Oxa-Gel (Art-Dent); G4: low-intensity laser (MMOptics). The buccal surface was wet ground flat with 180-, 400- and 600-grit silicon carbide abrasive paper to expose midcoronal dentin and create a uniform surface. After the application of the desensitizing agents to the exposed dentin, the specimens were etched with 35% phosphoric acid for 30 s, and an adhesive (Single Bond) was applied and light cured. A 4-mm high crown of composite resin (Filtek Z250) was then built up. Specimens were trimmed to an hourglass shape with cross sections of 1 mm2. Each specimen was individually fractured by a microtensile testing machine at a crosshead speed of 0.5 mm/min. The data, recorded in MPa, were analyzed with one-way ANOVA and the Duncan test (p = 0.05). RESULTS: Specimens treated with dentin desensitizers (except Gluma) yielded significantly lower mean bond strengths than nontreated control specimens. The mean values in MPa (+/- SD) were: G1: 13.4 (6.2); G2: 13.2 (4.8); G3: 7.15 (4.3); G4: 7.21 (4.6). CONCLUSIONS: Among the desensitizing agents studied, only Gluma Desensitizer did not detrimentally influence the bond strength values. It is a useful material for dentin desensitization.

Asunto(s)

Resinas Compuestas/química , Recubrimiento Dental Adhesivo , Sensibilidad de la Dentina/tratamiento farmacológico , Dentina/ultraestructura , Grabado Ácido Dental , Animales , Bisfenol A Glicidil Metacrilato/química , Bovinos , Celulosa/análogos & derivados , Celulosa/uso terapéutico , Dentina/efectos de los fármacos , Dentina/efectos de la radiación , Sensibilidad de la Dentina/radioterapia , Recubrimientos Dentinarios/química , Glutaral/uso terapéutico , Rayos Láser , Ensayo de Materiales , Metacrilatos/uso terapéutico , Microscopía Electrónica de Rastreo , Oxalatos/uso terapéutico , Ácidos Fosfóricos/química , Propiedades de Superficie , Resistencia a la Tracción

RESUMEN

PURPOSE: To investigate the behavior of two bonding systems: self-etching primer Clearfil Liner Bond 2V (CLB) and total-etch Single Bond (SB) when submitted to two bond strength tests: shear bond strength (SBS) and microtensile (MTBS). METHODS: Flat dentin surfaces were obtained at the facial surface of extracted bovine incisors. muTBS started with adhesive application and incremental resin composite insertion. Samples were then sliced into 1 mm slabs parallel to the long axis of the tooth. Half of the specimens from each group were trimmed in order to obtain dumbbell-shaped (D) specimens with a cross-sectional area of 1 mm2, and in the other half of the group, the slabs were cut into beams (B) with a cross section of 1 mm2 area. Specimens were individually fractured on a microtensile apparatus. For SBS, crown segments were embedded in polyester resin and a flat dentin surface was exposed for bonding. After adhesive and restorative procedures were accomplished, the specimens were kept in water for 24 hours prior to bond testing. The tests were performed in a universal testing machine. MPa values were analyzed by Tukey's test (P < 0.05), two-way ANOVA (muTBS) and Student's t-test (SBS). RESULTS: Mean values (SD) on muTBS were: SB/B: 42.6 (15.1), SB/D: 35.4 (6.8), CLB/B: 14.3 (10.3) and CLB/D: 27.0 (7.9). SBS values (SD) were: SB: 17.3 (5.6) and CLB 15.9 (7.2). Beam specimens bonded with CLB presented the lowest results. SBS did not show statistical differences between groups. The results showed that the shear bond test seemed to lack the sensitivity that is required to detect subtle differences between bonding agents or procedures.

Asunto(s)

Recubrimiento Dental Adhesivo , Materiales Dentales/química , Recubrimientos Dentinarios/química , Dentina/ultraestructura , Animales , Bisfenol A Glicidil Metacrilato/química , Compuestos Inorgánicos de Carbono/química , Bovinos , Resinas Compuestas/química , Pulido Dental , Análisis del Estrés Dental/instrumentación , Ensayo de Materiales/métodos , Metacrilatos/química , Distribución Aleatoria , Resistencia al Corte , Compuestos de Silicona/química , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción , Factores de Tiempo , Agua/química

RESUMEN

The aim of this study was to evaluate the microleakage of class II resin composite restorations polymerized with light-emitting diodes (LEDs) with different numbers of blue diodes. One hundred sixty-eight class II cavities were prepared in bovine teeth. A one-bottle adhesive system (Single Bond/3M ESPE) was applied. The microhybrid or packable resin composites were inserted in three horizontal increments and cured for 40 seconds each, according to the following groups (n=21): G1- Z250 + LED light curing unit with 19 LEDs (3M ESPE); G2- Surefil + LED light curing unit with 19 LEDs; G3- Z250 + LED light curing unit with 7 LEDs (DMC); G4- Surefil + LED light curing unit with 7 LEDs; G5- Z250 + LED light curing unit with 6 LEDs (MM Optics); G6- Surefil + LED light curing unit with 6 LEDs; G7- Z250 + conventional halogen light curing unit (Demetron-Kerr); G8- Surefil + conventional halogen light curing unit. After thermocycling, the specimens were immersed in 2% methylene blue solution and then evaluated for microleakage. The Kruskal-Wallis and non-parametric Multiple Comparison tests (p<0.05) showed statistically significant differences among groups median: G1: 1(d); G2: 4(a); G3: 1(cd); G4: 4(a); G5: 2(bc); G6: 4(a); G7: 1(cd); G8: 4(ab). The blue light-emitting diode units (LEDs) demonstrated similar results to the conventional halogen lamp unit and the microleakage of the packable resin composite was significantly more severe than that of the microhybrid resin composite

Asunto(s)

Bovinos , Resinas Compuestas , Filtración Dental , Técnicas In Vitro , Incrustaciones , Luz

RESUMEN

Para realização de qualquer procedimento estético, deve-se considerar o conceito subjetivo e variável, respeitando-se certos princípios básicos. O objetivo deste estudo é levar informações mais detalhadas sobre esses princípios gerais e específicos da estética aplicados à Odontologia, ressaltando a importância da forma, tamanho, proporção, cor e textura dos dentes e sua relação direta com a simetria para obtenção de faces e sorrisos mais harmônicos...

Asunto(s)

Estética Dental , Rehabilitación Bucal , Salud Bucal , Sonrisa

RESUMEN

The aim of the present study was to verify if there is any difference in the pulp chamber temperature rise during the photo-activation of two resin composites with different viscosities. Eighteen extracted bovine incisors were divided into two groups (n=9) that were restoredwith two different resin composites - Filtek Z250 and Filtek Flow (3M/ESPE Dental Products, St Paul, MN 55144, USA). During the photo-activation, with a conventional halogen light curing unit (XL 2500, 3M/ESPE), a type-K thermocouple registered the temperature rise peak in the pulp chamber. The temperature rise data were submitted to Student-t test at 5% significance. The resin compositeFiltek Flow shows statically higher mean temperature rise (<0.05). We conclude that the resin composites with different viscosities produce different temperature changes during the photo-activation

Asunto(s)

Resinas Compuestas , Cavidad Pulpar , Temperatura Corporal , Materiales Dentales