Influence of the Prosthetic Index on Fracture Resistance of Morse Taper Dental Implants.

PURPOSE: Manufacturers have inserted a prosthetic index, an internal hexagon to guide prosthetic components inside Morse taper implants. However, it is still unclear if this mechanism could decrease the mechanical strength of Morse taper implants. The aim of this study was to evaluate the influence of the prosthetic index inside Morse taper implants on fracture resistance compared with nonindexed implants. MATERIALS AND METHODS: Fifty-seven Morse taper implants, with 11.5-degree angulation of the internal conical portion, were divided into three groups: implants without the prosthetic index and solid Morse taper universal post (group 1), implants with the prosthetic index and solid Morse taper universal post (group 2), and implants and abutments with the prosthetic index (group 3). All groups were modeled for finite element stress analysis (FEA), simulating force application of a perpendicular load to the abutments. Fracture resistance (n = 10) was determined under the same condition. Dynamic loading (n = 9) was also performed. The statistical analysis was performed using one-way analysis of variance (ANOVA), and the Tukey test was applied (α = .05). The metallographic analysis was used to identify the fracture distribution and the microstructure of the titanium alloy. RESULTS: There was no statistically significant difference between the values of all tested groups. According to the FEA, the prosthetic index region was out of stress. The mean fracture resistances and loading test were 353.7 N and 200 N for group 1, 397.3 N and 170 N for group 2, and 372.0 N and 160 N for group 3, respectively. Metallographic analysis showed a macroscopic failure pattern just as demonstrated by FEA. CONCLUSION: The presence of the prosthetic index on Morse taper implants did not decrease its resistance to fracture for the tested implants.

Influence of the Prosthetic Index Into Morse Taper Implants on Bacterial Microleakage.

PURPOSE: To evaluate the influence of Morse taper implant index on microleakage. MATERIALS AND METHODS: Thirty implants and abutments were divided into 3 groups (n = 10): CM1 (universal post and implant without index), CM2 (universal post and implant with index), and CM3 (abutment and implant with index). To evaluate the microleakage from the implant inner part, the implants were inoculated with Streptococcus sanguinis solution at a 0.5 McFarland and incubated for 7 days at 37°C in Eppendorf tubes with sterile broth. To evaluate the microleakage into the inner part of implant, these were inoculated with sterile Schaedler broth and immersed in a Fusobacterium nucleatum solution at a 0.5 McFarland. The samples were incubated for 30 days in an anaerobic chamber. RESULTS: Nine samples of each group of the first methodology showed no presented bacterial contamination. No samples of the second methodology demonstrated turbidity of the broth. CONCLUSION: The presence of the prosthetic internal index had no influence on bacterial microleakage of Morse taper implants under static conditions, for both methodologies.

Strain analysis of different diameter Morse taper implants under overloading compressive conditions.

The aim of this study was to evaluate the amount of deformation from compression caused by different diameters of Morse taper implants and the residual deformation after load removal. Thirty Morse taper implants lacking external threads were divided into 3 groups (n = 10) according to their diameter as follows: 3.5 mm, 4.0 mm and 5.0 mm. Two-piece abutments were fixed into the implants, and the samples were subjected to compressive axial loading up to 1500 N of force. During the test, one strain gauge remained fixed to the cervical portion of each implant to measure the strain variation. The strain values were recorded at two different time points: at the maximum load (1500 N) and 60 seconds after load removal. To calculate the strain at the implant/abutment interface, a mathematical formula was applied. Data were analyzed using a one-way Anova and Tukey's test (α = 0.05). The 5.0 mm diameter implant showed a significantly lower strain (650.5 µS ± 170.0) than the 4.0 mm group (1170.2 µS ± 374.7) and the 3.5 mm group (1388.1 µS ± 326.6) (p < 0.001), regardless of the load presence. The strain values decreased by approximately 50% after removal of the load, regardless of the implant diameter. The 5.0 mm implant showed a significantly lower strain at the implant/abutment interface (943.4 µS ± 504.5) than the 4.0 mm group (1057.4 µS ± 681.3) and the 3.5 mm group (1159.6 µS ± 425.9) (p < 0.001). According to the results of this study, the diameter influenced the strain around the internal and external walls of the cervical region of Morse taper implants; all diameters demonstrated clinically acceptable values of strain.

Strain analysis of different diameter Morse taper implants under overloading compressive conditions

The aim of this study was to evaluate the amount of deformation from compression caused by different diameters of Morse taper implants and the residual deformation after load removal. Thirty Morse taper implants lacking external threads were divided into 3 groups (n = 10) according to their diameter as follows: 3.5 mm, 4.0 mm and 5.0 mm. Two-piece abutments were fixed into the implants, and the samples were subjected to compressive axial loading up to 1500 N of force. During the test, one strain gauge remained fixed to the cervical portion of each implant to measure the strain variation. The strain values were recorded at two different time points: at the maximum load (1500 N) and 60 seconds after load removal. To calculate the strain at the implant/abutment interface, a mathematical formula was applied. Data were analyzed using a one-way Anova and Tukey’s test (α = 0.05). The 5.0 mm diameter implant showed a significantly lower strain (650.5 μS ± 170.0) than the 4.0 mm group (1170.2 μS ± 374.7) and the 3.5 mm group (1388.1 μS ± 326.6) (p < 0.001), regardless of the load presence. The strain values decreased by approximately 50% after removal of the load, regardless of the implant diameter. The 5.0 mm implant showed a significantly lower strain at the implant/abutment interface (943.4 μS ± 504.5) than the 4.0 mm group (1057.4 μS ± 681.3) and the 3.5 mm group (1159.6 μS ± 425.9) (p < 0.001). According to the results of this study, the diameter influenced the strain around the internal and external walls of the cervical region of Morse taper implants; all diameters demonstrated clinically acceptable values of strain.

Reabilitação de maxila edêntula com técnica cirúrgica guiada flapless em carga imediata / Rehabilitation of the edentulous maxillary arch using an immediate, surgically guided flapless technique – a case report

Este relato de caso demonstra o uso de um sistema de cirurgia guiada sem retalho para colocação de uma prótese em carga imediata. Uma paciente do gênero feminino, 38 anos de idade, compareceu à clínica com queixas estéticas e funcionais. Inicialmente, os dentes remanescentes na mandíbula foram extraídos e uma prótese implantossuportada foi instalada. Na maxila, após o enceramento diagnóstico, tomografias computadorizadas feixe cônico (TCFC) foram realizadas uma tomografia da paciente com o guia tomográfico em posição e um escaneamento apenas do guia. As imagens foram fundidas em um software específico, e o planejamento virtual foi realizado. Seis implantes de titânio com conexão cone-morse foram instalados (torque final 32 Ncm), conectados aos minipilares, e o processo de moldagem foi finalizado. A infraestrutura desenhada recebeu a prótese maxilar definitiva através de um processo de cimentação passiva (Panavia) dos cilindros de titânio, em carga imediata. Após três meses, foram realizados exames clínicos e uma nova radiografia panorâmica. A prótese foi removida e os implantes foram testados individualmente. Todos os implantes apresentaram-se osseointegrados, sem sinais e sintomas irreversíveis ou persistentes (dor, infecção, neuropatias, parestesia ou mobilidade) e sem evidência de radioluminescência peri-implantar. Dentro das limitações do caso e mediante indicação clínica adequada, a técnica de carga imediata com cirurgia sem retalho fornece excelentes resultados estéticos, reduzindo o tempo cirúrgico e os sintomas pós-operatórios, ao mesmo tempo em que preserva maior quantidade de tecido.

This case report demonstrates the use of flapless guided surgery for immediate implant placement and loading. A female, 38 years-old patient was referred with claims of poor esthetics and function. First, all remaining mandibular teeth were extracted and an implant-supported prosthesis delivered. For the maxillary arch, CBCTs were made based on the diagnostic wax-up, with and without the tomographic guide. Images were superimposed with the aid of an specifi c software, and the virtual planning was made. Six cone-morse dental titanium implants (32 Ncm torque) were installed and connected to mini-abutments for impression procedures. The designed framework received the definative prosthesis through passive cementation (Panavia) using titanium cylinders under immediate loading. Latter, the prosthesis was removed and all implants tested individually, showing osseointegration and no signs of irreversible or persistent symptoms (pain, infection, neuropathies, paresthesia, or mobility) or peri-implant radiolucency were seen. Within the limits of this case and following adequate clinical indication, the fl apless guided surgery with immediate implant loading provided excellent esthetic results, shortening the surgical time and postoperative discomfort, while also allowing for more tissue preservation

Surface treatment of glass fiber and carbon fiber posts: SEM characterization.

Morphology, etching patterns, surface modification, and characterization of 2 different fiber posts: Gfp, Glass fiber post; and Cfp, carbon fiber were investigated by SEM analysis, after different surface treatments. Thirty fiber posts, being 15 Gfp and 15 Cfp were divided into a 5 surface treatments (n = 3): C-alcohol 70% (control); HF 4%-immersion in 4% hydrofluoric acid for 1min; H(3) PO(4) 37%-immersion in 37% phosphoric acid for 30s; H(2) O(2) 10%-immersion in 10% hydrogen peroxide for 20 min; H(2) O(2) 24%-immersion in 24% hydrogen peroxide for 10 min. Morphology, etching patterns, surface modification and surface characterization were acessed by SEM analysis. SEM evaluation revealed that the post surface morphology was modified following all treatment when compared with a control group, for both type of reinforced posts. HF seems to penetrate around the fibers of Gfp and promoted surface alterations. The Cfp surface seems to be inert to treatment with HF 4%. Dissolution of epoxy resin and exposure of the superficial fiber was observed in both post groups, regardless the type of reinforcing fiber, H(2) O(2) in both concentrations. Relative smooth surface area was produced by H(3) PO(4) 37% treatment, but with similar features to untreated group. Surface treatment of fiber post is a determinant factor on micromechanical entanglement to resin composite core. Post treatment with hydrogen peroxide resulted strength of carbon and glass/epoxy resin fiber posts to resin composite core.

Tração reversa da maxila associada à disjunção palatina: relato de caso clínico / Maxillary protraction associated with rapid palatal expansion: case report

O objetivo do tratamento ortopédico precoce é corrigir o desenvolvimento esquelético, dentoalveolar e alterações funcionais. Com isso, pode-se ajudar a minimizar a possibilidade de um tratamento ortodôntico mais complexo envolvendo extração de dentes permanentes ou cirurgia ortognática. No caso clínico apresentado utilizou-se o protocolo de ativação de disjunção palatal que preconiza a ativação e desativação do disjuntor por semanas subsequentes. Em exame intraoral do paciente foi observada mordida cruzada anterior, má-oclusão Classe I de Angle, ausência do elemento 12 e elemento 22 conóide. Ao final de 10 meses de tratamento, após 6 meses de correção do trespasse horizontal, observou-se um aumento de 3° no SNA e 7° no NAP que após o tratamento significaram, respectivamente, um posicionamento maxilar em relação à base do crânio dentro dos padrões de normalidade (SNA=80°+ 2) e o perfil com característica convexa (NAP=7°). Diante dos dados clínicos e cefalométricos obtidos após o tratamento com protração maxilar associada à disjunção palatina com protocolo de ativação/desativação alternado pode-se concluir que obteve-se sucesso na correção do trespasse horizontal do caso clínico apresentado.

The aim of early orthopedic treatment is to correct the skeletal and dentoalveolar development and functional changes. Therewith, might be possible minimize the complexity of an orthodontic treatment, avoiding ex-traction of permanent teeth or orthognathic surgery. The case reported the protocol used for palatal disjunction which activation and deactivation calls for following weeks. During intraoral examination was observed anterior crossbite, Class I Angle malocclusion, absence of element 12 and element 22 conoid. At 10 months of treatment, 6 months after overjet correction, was observed an increase of 3° in SNA and 7° in NAP. This results means, respectively, a normal maxilla position in relation to the skull base (SNA = 80 ° + 2) and convex profile (NAP = 7°). Considering the clinical and cephalometric data obtained after treatment with maxillary protraction associated with rapid palatal expansion - protocol of activation/deactivation switched - could be conclude that the overjet of this clinical case was corrected successfully.

Parâmetros metodológicos da análise por elementos finitos em estudos ortodônticos: revisão da literatura / Methodological parameters of finite element analysis in orthodontic researches: literature review

Na busca de melhor entendimento biomecânico, diversos métodos têm sido utilizados na tentativa de predizer a resposta tecidual frente à aplicação de carga ortodôntica. Mesmo diante de algumas dificuldades oferecidas pela vasta complexidade dos tecidos orais, o método de análise por elementos finitos é o mais adequado para a simulação das propriedades desses componentes. Diante disso, o objetivo desse estudo foi discutir, a partir de releitura da literatura científica, parâmetros metodológicos da aplicação dessa metodologia em estudos ortodônticos. Após estabelecidos os parâmetros a serem discutidos (propriedades dos materiais, linearidade de análises e condições de contorno), a busca dos artigos foi feita pela base de dados online PubMed, relacionando as palavraschaves “orthodontics” e “finite element analysis”, e também por meio de busca manual de autores renomados nessa área. Foram selecionados artigos que apresentassem considerações críticas sobre os parâmetros metodológicos supracitados. Após discussão crítica dos aspectos propostos, pode-se concluir que diante do grande leque de opções metodológicas, as variáveis abordadas ao longo desse artigo devem ser cuidadosamente consideradas para avaliação do objetivo proposto pelo estudo, assim como para a correta interpretação dos resultados obtidos por meio da análise por elementos finitos.

In search of better biomechanical understanding, several methods have been used in an attempt to predict the tissue response to the application of orthodontic load. Even with some difficulties of the vast complexity of the oral tissues, the method of finite element analysis is most suitable for simulating the properties of these components. Therefore, the objective of this study was to discuss, through scientific literature reading, methodological parameters of the application of this technique in orthodontic studies. After set the parameters to be discussed (material properties, linear analysis and boundary conditions), the articles search was made by PubMed online database, with “orthodontics” and “finite element analysis” key words, and also through a manual search of authors in this area. Articles were selected about the mention of methodological parameters above. After critical discussion, it can be concluded that given the large number of methodological options, the variables discussed throughout this article should be carefully considered to assess the goal proposed by study, as well as the correct interpretation of the results obtained by finite elements analysis.

Avaliação da ocorrência de transtornos mentais comuns entre a população de rua de Belo Horizonte / Occurrence of common mental disorders among the homeless population in Belo Horizonte

Objetivo: avaliar a prevalência de transtornos mentais comuns entre a população de rua. Métodos: Estudo transversal com 245 moradores de rua em Belo Horizonte. Os transtornos mentais comuns e as categorias de sintomas foram avaliados pelo Self Reporting Questionnaire (SRQ-20). Resultados: 49,48 da população tem problemas mentais. Na distribuição dos sintomas há prevalência de depressão e ansiedade, seguida por sintomas somáticos, decréscimo de energia vital e pensamentos depressivos. Conclusão: A prevalência de transtornos mentais comuns encontradas em homens adultos que vivem nas ruas de Belo Horizonte pode ser o resultado da vulnerabilidade deste grupo social.

Objective: To assess the prevalence of common mental disorders among the homeless population. Methods: Cross sectional study with 245 homeless men in Belo Horizonte. Common mental disorders and the categories of symptoms were evaluated by the Self-Reporting Questionnaire (SRQ-20). Results: 49.48 of the population has mental disorders. In the distribution of symptoms there is prevalence of depressed mood and anxiety, followed by somatic symptoms, decrease of vital energy and depressive thoughts. Conclusion: The prevalence of common mental disorders found in adult males living on the streets of Belo Horizonte can be the result of the vulnerability of this social group.

Avaliação da ocorrência de transtornos mentais comuns entre a população de rua de Belo Horizonte / Occurrence of common mental disorders among the homeless population in Belo Horizonte

Objetivo: avaliar a prevalência de transtornos mentais comuns entre a população de rua. Métodos: Estudo transversal com 245 moradores de rua em Belo Horizonte. Os transtornos mentais comuns e as categorias de sintomas foram avaliados pelo Self Reporting Questionnaire (SRQ-20). Resultados: 49,48% da população tem problemas mentais. Na distribuição dos sintomas há prevalência de depressão e ansiedade, seguida por sintomas somáticos, decréscimo de energia vital e pensamentos depressivos. Conclusão: A prevalência de transtornos mentais comuns encontradas em homens adultos que vivem nas ruas de Belo Horizonte pode ser o resultado da vulnerabilidade deste grupo social.(AU)

Objective: To assess the prevalence of common mental disorders among the homeless population. Methods: Cross sectional study with 245 homeless men in Belo Horizonte. Common mental disorders and the categories of symptoms were evaluated by the Self-Reporting Questionnaire (SRQ-20). Results: 49.48% of the population has mental disorders. In the distribution of symptoms there is prevalence of depressed mood and anxiety, followed by somatic symptoms, decrease of vital energy and depressive thoughts. Conclusion: The prevalence of common mental disorders found in adult males living on the streets of Belo Horizonte can be the result of the vulnerability of this social group.(AU)

Padrão de uso de álcool entre homens adultos em situação de rua de Belo Horizonte / Alcohol use pattern among homeless adult men in Belo Horizonte / Patrón de consumo de alcohol entre hombres adultos en situación de calle de Belo Horizonte

Este estudo epidemiológico, de tipo descritivo, buscou conhecer a prevalência de consumo de álcool entre a população em situação de rua. Para coleta de dados, utilizou-se o AUDIT com 245 homens em situação de rua, de Belo Horizonte. Verificou-se maior frequência do uso nocivo e provável dependência nos adultos maduros e maior frequência do padrão de risco para aqueles que vivem em situação de rua, em período superior a 6 anos, e entre os que dormem em vias públicas. Este estudo realça a importância da construção de políticas de saúde voltadas para a população em situação de rua.

This descriptive, epidemiologic study aimed at identifying the prevalence of alcohol use among the homeless population. Data collection was performed using AUDIT with 245 men living on the streets of Belo Horizonte. It was found there is a high frequency of harmful alcohol use pattern with probable dependence in mature adults and a high rate of risk pattern for those living on the streets for over 6 years and among those sleeping in public areas. This study highlights the importance of building health policies that are aimed at the homeless population.

Este estudio epidemiológico de carácter descriptivo, buscó conocer la prevalencia de consumo de alcohol entre la población en situación de calle. Para la recolección de datos se utilizó el AUDIT con 245 hombres en situación de calle en Belo Horizonte. Se verifica mayor frecuencia del uso nocivo y probable dependencia en adultos maduros y mayor frecuencia del estándar de riesgo para los que viven en situación de calle por período superior a 6 años y entre los que duermen en la vía pública. Este estudio realza la importancia de construcción de políticas de salud orientadas a la población en situación de calle.

Padrão de uso de álcool entre homens adultos em situação de rua de Belo Horizonte / Alcohol use pattern among homeless adult men in Belo Horizonte / Patrón de consumo de alcohol entre hombres adultos en situación de calle de Belo Horizonte

Este estudo epidemiológico, de tipo descritivo, buscou conhecer a prevalência de consumo de álcool entre a população em situação de rua. Para coleta de dados, utilizou-se o AUDIT com 245 homens em situação de rua, de Belo Horizonte. Verificou-se maior frequência do uso nocivo e provável dependência nos adultos maduros e maior frequência do padrão de risco para aqueles que vivem em situação de rua, em período superior a 6 anos, e entre os que dormem em vias públicas. Este estudo realça a importância da construção de políticas de saúde voltadas para a população em situação de rua.(AU)

This descriptive, epidemiologic study aimed at identifying the prevalence of alcohol use among the homeless population. Data collection was performed using AUDIT with 245 men living on the streets of Belo Horizonte. It was found there is a high frequency of harmful alcohol use pattern with probable dependence in mature adults and a high rate of risk pattern for those living on the streets for over 6 years and among those sleeping in public areas. This study highlights the importance of building health policies that are aimed at the homeless population.(AU)

Este estudio epidemiológico de carácter descriptivo, buscó conocer la prevalencia de consumo de alcohol entre la población en situación de calle. Para la recolección de datos se utilizó el AUDIT con 245 hombres en situación de calle en Belo Horizonte. Se verifica mayor frecuencia del uso nocivo y probable dependencia en adultos maduros y mayor frecuencia del estándar de riesgo para los que viven en situación de calle por período superior a 6 años y entre los que duermen en la vía pública. Este estudio realza la importancia de construcción de políticas de salud orientadas a la población en situación de calle.(AU)

Effect of periodontal therapies on indirect restoration: a scanning electron microscopic analysis.

The aim of this study was to evaluate the influence of different periodontal therapies on the integrity of indirect restorations by scanning electron microscopy (SEM). Sixty single-rooted bovine teeth were selected and randomly assigned to 12 groups. Inlay cavities were prepared in the cervical region on the center of the cementoenamel junction, and were restored with laboratory processed resin and luted with a resin cement. Twelve periodontal therapies were used (n= 5): C: control (no treatment); MS: manual scaling with Gracey curettes; US: ultrasonic scaling; PP: prophylaxis with prophylactic paste; PS: prophylaxis with pumice-stone; SBJ: sodium bicarbonate jet; MS/PP; MS/PS; MS/SBJ; US/PP; US/PS; US/SBJ. The specimens were prepared and analyzed by SEM. SEM micrographs at x100 to x1000 magnification were obtained from the surface of the laboratory resin and the interface of the indirect restorations. The images were evaluated by 3 skillful, calibrated, blinded observers as to the presence of grooves, microcavities and fracture of margins. The results showed that PS produced groves on restoration surface. MS and US produced groves and marginal fractures on the restorations. SBJ resulted in resin cement degradation. These results suggest that except for PS, all procedures had deleterious effects on the marginal integrity of indirect restorations.

Mechanical and acid root treatment on periodontally affected human teeth: a scanning electronic microscopy

Aim: To evaluate the root topography of human teeth affected by periodontitis, after different root surface treatments. Methods: Forty-two periodontally affected single-rooted human teeth were selected and randomly divided into 7 groups (n=6): Cont- control group, which received no treatment; Sca- root surface scaling and root planning with curettes; ScaPh- Sca followed by 37%phosphoric acid gel etching for 15 s; ScaEdta- Sca followed by 24% EDTA gel pH 7 for 1 min; ScaCi- Sca followed by 30% citric acid pH 1.6 for 5 min; ScaTe- Sca followed by - mixture obtained by 500 mg tetracycline capsule dissolved in saline solution for 3 min; ScaTeg- Sca followed by 0.2 g/mL tetracycline gel pH 1.8 for 1 min. The specimens were analyzed by scanning electronic microscopy to verify the presence of calculus, demineralization level and residues of the product. Results: Calculus deposits were found in all control specimens. ScaEdta, ScaCi and ScaTeg removed completely calculus deposits and resulted in adequate demineralization without smear layer and smear plug on root surface. ScaTe produced great tetracycline residues with several demineralization areas on root dentin surface. Conclusions: ScaEdta, ScaCi and ScaTeg produced clean root surfaces associated with regular dentin demineralization.

Effect of periodontal therapies on indirect restoration: a scanning electron microscopic analysis

The aim of this study was to evaluate the influence of different periodontal therapies on the integrity of indirect restorations by scanning electron microscopy (SEM). Sixty single-rooted bovine teeth were selected and randomly assigned to 12 groups. Inlay cavities were prepared in the cervical region on the center of the cementoenamel junction, and were restored with laboratory processed resin and luted with a resin cement. Twelve periodontal therapies were used (n= 5): C: control (no treatment); MS: manual scaling with Gracey curettes; US: ultrasonic scaling; PP: prophylaxis with prophylactic paste; PS: prophylaxis with pumice-stone; SBJ: sodium bicarbonate jet; MS/PP; MS/PS; MS/SBJ; US/PP; US/PS; US/SBJ. The specimens were prepared and analyzed by SEM. SEM micrographs at ×100 to ×1000 magnification were obtained from the surface of the laboratory resin and the interface of the indirect restorations. The images were evaluated by 3 skillful, calibrated, blinded observers as to the presence of grooves, microcavities and fracture of margins. The results showed that PS produced groves on restoration surface. MS and US produced groves and marginal fractures on the restorations. SBJ resulted in resin cement degradation. These results suggest that except for PS, all procedures had deleterious effects on the marginal integrity of indirect restorations.

O objetivo desse estudo foi avaliar a influência de diferentes terapias periodontais na integridade de restaurações indiretas por meio de microscopia eletrônica de varredura (MEV). Sessenta raízes bovinas foram selecionadas e aleatoriamente divididas em 12 grupos. Preparos cavitários inlay foram realizados na região cervical central da junção cemento-esmalte e restaurados com resina laboratorial cimentado com cimento resinoso. Doze terapias periodontais foram usadas (n=5): C-sem tratamento (controle); MS-raspagem manual com cureta Gracey; US-raspagem com ultra-som; PP- profilaxia com pasta profilática; PS-profilaxia com pedra pomes; SBJ-jato de bicarbonato; MS/PP; MS/PS; MS/SBJ; US/PP; US/PS; US/SBJ. As amostras foram preparados e submetidas a MEV. Imagens, de ×100 a ×1000, da superfície da resina laboratorial e da interface das restaurações indiretas foram obtidas. As imagens foram avaliadas em procedimento cego por 3 observadores habilitados previamente calibrados seguindo os seguintes critérios: ranhuras, microcavidades e fratura de margem. Os resultados mostraram que a profilaxia com pedra pomes promoveu ranhuras na superfície das restaurações. Raspagem manual e ultrasônica promoveram ranhuras e fratura de margem das restaurações. Jato de bicarbonato resultou em degradação de cimento resinoso. Os resultados sugeriram que, exceto a profilaxia com pasta profilática, todos os procedimentos resultaram em efeitos deletérios na integridade da margem das restaurações indiretas.

Prevalência de depressão entre homens adultos em situação de rua em Belo Horizonte / Prevalence of depression among adult men in the streets in Belo Horizonte

Objetivo: Este estudo objetiva avaliar a prevalência de depressão entre a população de rua. Métodos: Realizado estudo transversal com homens adultos em situação de rua de Belo Horizonte. Para coleta de dados, foi utilizado o Inventário de Depressão de Beck e análise foi realizada por meio da estatística descritiva. Resultados: Evidenciam-se alta prevalência de depressão e o grau de severidade dos sintomas depressivos relacionados à faixa etária, tempo de moradia na rua, local onde dorme, relato de problema de saúde e uso de medicamento da população masculina adulta em situação de rua. Conclusão: O presente estudo ressalta a importância de construção de políticas de saúde voltadas para a população de rua.

Objective: This study aims to evaluate the prevalence of depression among the homeless population. Methods: A cross-sectional study was conducted with adult men in the streets of Belo Horizonte. To collect data we used the Beck Depression Inventory and analysis was performed using descriptive statistics. Results: Shows a high prevalence of depression and severity of depressive symptoms related to age, full-time dwelling on the street, where he sleeps, reported health problems and medication use in the adult male population in the streets. Conclusion: This study emphasizes the importance of building health policies for the homeless.

Two-dimensional FEA of dowels of different compositions and external surface configurations.

PURPOSE: The degree of stress generated in the endodontically treated and restored tooth can be influenced by the composition and configuration of the dowels used for the restoration. Using two-dimensional (2D) finite element analysis (FEA), this study tested the hypothesis that the characterization of the stress distribution can be influenced by which evaluation method is employed: protrusion loading and 4-point flexural strength test or varying the type of material (carbon and glass fiber) or the external configuration of the dowel (smooth and serrated). MATERIALS AND METHODS: For simulation of the protrusion load test, models were generated with Mechanical-AutoCAD V6 software from an image of an anatomical plate, one maxillary central incisor, and two dowels and exported to Ansys 9.0. The bone region model was fixed, and a tangential load of 1 N with a 135 degrees inclination to the tooth longitudinal axis was applied at the level of the palatal surface of the crown. In the simulation of a 4-point flexural strength test, a 1 N perpendicular load was applied in two points to the dowel. The dental materials and structures were considered elastic, isotropic, homogeneous, and linear, with the exception of the dowel, which was assumed to exhibit orthotropic behavior. Mechanical properties were defined based on a review of the literature, and the model was meshed with an eight node tetrahedral element. RESULTS: The stress results from both tests were analyzed according to von Mises criteria and principal stresses (Sx). Data from the 4-point flexural strength test simulation showed that, for the serrated dowels, a higher stress concentration was found; however, no difference in the occlusal load for material or dowel configuration was found. CONCLUSIONS: These results suggest that although the external configuration of the dowel influences direct loading, when the dowel is integrated to the tooth and setting material, the influence on biomechanical behavior disappears.

The influence of cavity design and glass fiber posts on biomechanical behavior of endodontically treated premolars.

The aim of this study was to evaluate the effect of cavity design and glass fiber posts on stress distributions and fracture resistance of endodontically treated premolars. Fifty extracted intact mandibular premolars were divided into 5 groups (n = 10): ST, sound teeth (control); MOD, mesio-occlusal-distal preparation + endodontic treatment (ET) + composite resin restoration (CR); MODP, mesio-occlusal-distal + ET + glass fiber post + CR; MOD2/3, mesio-occlusal-distal + two thirds occlusal-cervical cusp loss + ET + CR; and MODP2/3, mesio-occlusal-distal + two thirds cusp loss + ET + glass fiber post + CR. The specimens were loaded on a cusp slope until fracture. Fracture patterns were classified according to four failure types. Stress distributions were evaluated for each group in a two-dimensional finite element analysis. The fracture resistance of the MODP, MOD2/3, and MODP2/3 groups was significantly lower than the ST and MOD groups (p < 0.05). The loss of dental structure and the presence of fiber post restoration reduced fracture resistance and created higher stress concentrations in the tooth-restoration complex. However, when there was a large loss of dental structure (MODP2/3), the post reduced the incidence of catastrophic fracture types.

Effect of previous treatments on bond strength of two self-etching adhesive systems to dental substrate.

PURPOSE: The aim of this study was to evaluate the effectiveness of previous dental substrate treatments on the bond strength of two self-etching adhesives. MATERIALS AND METHODS: One hundred bovine incisors were sectioned at the cementoenamel junction. The labial tooth surface was ground to obtain flat superficial dentin. Teeth were randomly divided into two groups (n = 50): Clearfil Protect Bond and One Up Bond F. The specimens of each group were subdivided into five groups, according the dental substrate treatment, and then the adhesive system was applied as follows (n = 10): C: control, without previous treatment; TA: 37% phosphoric acid etching on enamel and dentin for 15 s; PA: 37% phosphoric acid etching only on enamel for 15 s; SB: Al2O3 sandblasting on dental surface; EDTA: enamel and dentin conditioning with 24% EDTA gel, pH 7.0. Resin composite blocks were fixed to the dental surfaces with dual-polymerized resin cement. Samples were sectioned in the mesiodistal direction and were trimmed to reduce the cross-sectional area to approximately 1.2 mm2. They were tested at a crosshead speed of 0.5 mm/min on a testing machine. Microtensile bond strength values from enamel, superficial dentin, and deep dentin were compared. Mean microtensile bond strength values were expressed in MPa and were analyzed by two-way ANOVA (2 x 3 x 5) and Tukey's tests. RESULTS: A significant difference was observed for interaction (p = 0.00001) among the factors. The highest mean bond strength to enamel was found with previous phosphoric acid etching, and to dentin when EDTA was previously applied. CONCLUSION: The most indicated previous treatment for increasing the bond strength to enamel and dentin simultaneously is EDTA for both self-etching adhesive systems used.

Effect of a bonding resin layer associated with a self-etching adhesive system on the bond strength of indirect restorations

The aim of this study was to evaluate the influence of a low-viscosity bonding resin applied over a self-etching adhesive system on the microtensile bond strength (µTBS) of indirect restorations. Comparisons were made using One Up Bond F (OB) self-etching adhesive system, Single Bond (SB) one-bottle adhesive system and Scotchbond Multi Purpose Plus (SMP) bonding component. Thirty bovine incisors were extracted and decoronated at the cementoenamel junction. The labial surfaces were ground so that superficial dentin and deep dentin were exposed. The specimens were randomized to three groups (n=10): G1- OB; G2- OB + SMP; G3- SB. In G2, a layer of the SMP bonding was applied over the OB adhesive system. Indirect composite restorations were bonded using dual-cure cement under 500 g load for 5 min. The specimens were serially sectioned with a bonding area of ± 1.0 mm² in 3 regions: enamel (E), superficial dentin (SD) and deep dentin (DD). The sticks were fixed with cyanoacrylate adhesive and submitted to µTBS test at a crosshead speed of 0.5 mm/min in a mechanical testing machine (EMIC DL 2000). The fractured specimens were examined under scanning electron microscopy to determine the failure mode. Data were analyzed by one-way ANOVA followed by Tukey's test (p<0.05). µTBS means (in MPa) were: G1/E: 15.5 ± 3.5b; G1/SD: 22.7 ± 7.6a; G1/DD: 19.4 ± 9.4a; G2/E: 15.9 ± 5.8b; G2/SD: 19.9 ± 6.9a; G2/DD: 15.3 ± 4.9a; G3/E: 23.2 ± 7.3a; G3/SD: 20.4 ± 8.2a; G3/DD: 19.1 ± 8.7a. The results showed that the use of a low viscosity bonding resin did not affect the µTBS means when associated with a self-etching adhesive system. The self-etching adhesive system was significantly more efficient in dentin than in enamel, while the one-bottle system was significantly more efficient in enamel when compared to the self-etching adhesive system.