RESUMO
BACKGROUND: Obstructive sleep apnea (OSA) is a very common condition in patients with temporomandibular disorders (TMD). However, there is little evidence of a connection between them. OBJECTIVE: The aim of this systematic review and meta-analysis is to assess the association between OSA and TMD in adult population. METHODS: Case-control, cross-sectional and cohort studies on the association between TMD and OSA were searched in the EMBASE, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, Web of Science, Google Scholar, Open Grey and Pro Quest databases. TMD should be assessed using Research Diagnostic Criteria (RDC/TMD) or Diagnostic Criteria (DC/TMD) and OSA using polysomnography (PSG) and/or a validated questionnaire. The risk of bias was evaluated using the Joanna Briggs Institute Critical Assessment Checklists; and an association meta-analysis was performed. The effect measure included the odds ratio (OR) in dichotomous variables and a 95% confidence interval (CI). Certainty of evidence was determined by analysing groups using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: Out of the 1024 articles screened, 7 met the inclusion criteria for the qualitative synthesis, and 6 for quantitative analysis. All articles were classified at low risk of bias. A positive association with OSA was found in patients with TMD (OR = 2.61; 95% CI = 2.31, 2.95). A significant association was also found irrespective to the OSA diagnostic methods applied (for studies using PSG + validated questionnaires: OR = 2.74; 95% CI = 2.11, 3.57; for studies using validated questionnaires only: OR = 2.55; 95% CI = 2.22, 2.92). GRADE was moderate. CONCLUSION: Patients with TMD presented a significant association with OSA regardless of the OSA diagnostic method (PSG and/or validated questionnaires). OSA screening should be part of the TMD examination routine. Furthermore, due to the different OSA assessment methods used and the small number of studies included, there is a need to include a larger number of studies using PSG to better elucidate this association.
Assuntos
Polissonografia , Apneia Obstrutiva do Sono , Transtornos da Articulação Temporomandibular , Humanos , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Transtornos da Articulação Temporomandibular/complicações , Transtornos da Articulação Temporomandibular/fisiopatologiaRESUMO
The objective of this study is to examine the mechanical behavior of two-piece abutments (Morse taper with 16° internal angulation and Morse taper with 11.5° internal angulation) before and after cyclic fatigue testing, following ISO 14801:2016 guidelines. The specimens were divided into three groups: a modified Morse taper with a taper angle of 16° (GM group), a conventional Morse taper (taper angle of 11.5° deg) with a two-piece (CMt group), and one-piece abutments (CMo group). Each experimental group was formed by ten implants and ten abutments (n = 10) for a total of 30 specimens (n = 30). The abutments were tightened and loosened, and a fatigue test was applied with 15 Hz and 5 × 106 cycles. Subsequently, the abutments were loosened, and a pull-out test was performed on the CMt group. Finite element analysis (FEA) was conducted on stress concentration regions. The statistical analysis of the loosening test was performed using two-way ANOVA and Tukey's tests (p < 0.05) to compare screw loosening within each group and between the groups with and without mechanical fatigue. Significant differences were found among the three groups in the loosening test when analyzing the values with and without fatigue (p < 0.001) within each group. When the groups were compared with each other, there was also a significant difference between them (p < 0.001), except between groups GM and CMt without fatigue (p = 0.840). In the pull-out test of the CMt group, the sample exhibited frictional locking only after fatigue (mean = 94.2 N). The FEA demonstrated a varied stress distribution in all groups. The stress was found to be more concentrated in the upper third and middle third regions of the implant, as well as in the opposite region of the load application for all three groups. Although the CMo group showed lower rates of loosening, it displayed a poorer stress distribution in comparison to the GM and CMt groups. On the other hand, the CMt group exhibited a satisfactory frictional lock after undergoing the fatigue tests.
RESUMO
ABSTRACT The immediate rehabilitation of the posterior region of the mandible with dental implants, expands the set of possible actions for the dental surgeon, in the face of tooth loss. The purpose of this study is to describe two cases of single rehabilitation of mandibular molars with hybrid internal tapered implants indicated for immediate loading in post-extraction socket, associated with the maintenance of the prosthetic and peri-implant space. Implants with macrogeometry and surface treatment (Hydrophilic) were used to optimize primary stability, as well as the type of internal connection and prosthetic abutments that allows better accommodation and healing of adjacent tissues, and protection of the bone graft. Different methodologies of surgical guides did not influence the final result. The predictability of associating techniques and components can be observed in the 2-year follow-up. The initial planning combined with the new technologies enable to achieve stable and functional final restorations.
RESUMO A reabilitação imediata da região posterior da mandíbula com implantes dentários, amplia o conjunto de ações possíveis ao cirurgião dentista, frente as perdas dentárias. O intuito desse estudo é descrever dois casos de reabilitação unitária de molares inferiores com implantes cônicos internos híbridos indicados para carregamento imediato em alvéolos pós-extração, associado a manutenção do espaço protético e peri-implantar. Foram utilizados implantes com macrogeometria e tratamento de superfície que otimizassem a estabilidade primária (Hidrofílicos), bem como o tipo de conexão interna e abutments protéticos que permitisse melhor acomodação e cicatrização dos tecidos adjacentes, e proteção do enxerto ósseo. Diferentes metodologias de guias cirúrgicos não influenciaram o resultado final. A previsibilidade da associação de técnicas e componentes pode ser observada no follow-up de 2 anos. O planejamento inicial aliado às novas tecnologias permite restaurações finais estáveis e funcionais.
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ABSTRACT Studies have found the association between episodes of bruxism and the presence of signs and symptoms of temporomandibular disorder (TMD). The aim of the present study was to report the diagnosis and palliative therapy of bruxism associated with TMD. Patient, 23 years old, male gender, presented at dental clinic, complaining of pain in the temporomandibular joint on the left side and alteration of the form of the anterior teeth. During the anamnesis it was documented that this symptom was recurrent and reported the habit of grinding teeth. The clinical examination observed discrepancy between the centric relation and the maximum habitual intercuspation, unsatisfactory protrusive guide, presence of wear facets, clicking and mandibular deviation during mouth opening. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD) questionnaire was applied to diagnose TMD. By means of specific algorithms this disorder was classified as myofascial pain, disc displacement with reduction and osteoarthritis, all affecting the left side. Thus, it was proposed the assembly of the models in semi-adjustable articulator for occlusal mapping and waxing diagnosis, then the occlusal adjustment by selective wear and material addition was executed. After this procedure, the occlusal splint was installed as a palliative therapy for bruxism. This case report suggests that the dental approach by means of occlusal adjustment and occlusal splint, in a patient diagnosed with bruxism and temporomandibular disorder, reduces the signs and symptoms that affect the components of the Stomatognathic System.
RESUMO Estudos tem encontrado a associação entre os episódios de bruxismo e a presença dos sinais e sintomas de disfunção temporomandibular (DTM). O objetivo do presente trabalho foi relatar o diagnóstico e terapia paliativa do bruxismo associado à DTM. Paciente, 23 anos, gênero masculino, apresentou-se à clínica odontológica, queixando-se de dor na articulação temporomandibular do lado esquerdo e alteração da forma dos dentes anteriores. Durante a anamnese foi documentado que esse sintoma era recorrente e relatado o hábito de ranger os elementos dentais. No exame clínico observou-se discrepância entre relação cêntrica e máxima intercuspidação habitual, guia protrusiva insatisfatória, presença de facetas de desgaste, estalido e desvio mandibular durante o movimento de abertura bucal. O questionário Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) foi aplicado para diagnosticar a DTM. Por meio de algoritmos específicos essa desordem foi classificada como dor miofascial, deslocamento de disco com redução e osteoartrite, todos acometendo o lado esquerdo. Desta forma, foi proposto a montagem dos modelos em articulador semi-ajustável para mapeamento oclusal e enceramento diagnóstico. Em seguida o ajuste oclusal por desgaste seletivo e acréscimo de material foi executado. Finalizado esse procedimento, a placa estabilizadora da oclusão foi instalada como terapia paliativa para o bruxismo. Esse relato de caso sugere que a abordagem odontológica por meio do ajuste oclusal e placa oclusal, em paciente diagnosticado com bruxismo e disfunção temporomandibular, reduz os sinais e sintomas que afetam os componentes do Aparelho Estomatognático.
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OBJECTIVE: To evaluate the chemical and mechanical properties of enamel submitted to different in vitro radiation protocols. DESIGN: Third molars were divided into seven groups (n = 8): non-irradiated (NI); a single dose of 30 Gy (SD30), 50 Gy (SD50), or 70 Gy (SD70) of radiation; or fractional radiation doses of up to 30 Gy (FD30), 50 Gy (FD50), or 70 Gy (FD70). Hemisections were analysed by Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS) and Knoop microhardness (KHN) test. One-way ANOVA followed by Bonferroni's post-hoc test compared the test groups with the NI. Two-way ANOVA was performed for the fractionation and radiation dose, followed by Bonferroni's test (α = 0.05). RESULTS: FTIR revealed differences for the amide I band between the NI and FD50 and NI and FD70 groups (p < 0.001). For the organic matrix/mineral ratio, the FD70 group presented a lower ratio compared to NI (p = 0.009). Excluding the NI group, there were differences between the FD30 and FD50 (p = 0.045) and the FD30 and FD70 groups (p < 0.001). For EDS, there were differences for Ca (p = 0.011) and Ca/P (p < 0.001), with the FD70 group presenting lower values compared to NI (p = 0.015; p < 0.001). For KHN, the FD70 group presented lower values than the NI (p = 0.002). Two-way ANOVA showed difference for the dose (p < 0.001), with the 70 Gy group presenting a lower KHN value within the fractionated groups. CONCLUSION: Fractional doses 70 Gy irradiation caused chemical and mechanical changes to enamel. Radiation applied in single or fractional doses produced different effects to enamel.
Assuntos
Esmalte Dentário/efeitos da radiação , Doses de Radiação , Radiação Ionizante , Dureza , Humanos , Técnicas In Vitro , Espectrometria por Raios XRESUMO
With the onset of the new coronavirus disease (COVID-19) pandemic, the dental treatment of patients at risk of infection has become quite challenging. In view of this, patients with head and neck cancer may present with oral complications due to anticancer therapy, making dental assistance necessary. Thus, the objective of the study was to review the literature and critically discuss important concerns about the treatment of patients with head and neck cancer during the COVID-19 pandemic. Because dental professionals are in close contact with the main viral transmission routes, this study presents recommendations for management and protection during clinical dental care. The main characteristics and transmission routes of COVID-19 are also discussed. Dental professionals should control pain and the side effects of antineoplastic treatment and use preventive measures for infection control. During this pandemic, patients with head and neck cancer should not undergo elective procedures, even if they do not have symptoms or a history of COVID-19; therefore, in asymptomatic or painless cases, only preventive actions are recommended. In symptomatic or painful cases, precautions for safe interventional treatments must be implemented by following the hygiene measures recommended by health agencies and using personal protective equipment. During health crises, new protocols emerge for cancer treatment, and professionals must act with greater attention toward biosafety and updated knowledge. It is important to offer adequate individualized treatment based on the recommendations of preventative and interventional treatments so that patients can face this difficult period with optimized quality of life.
Assuntos
Betacoronavirus , Infecções por Coronavirus , Neoplasias de Cabeça e Pescoço , Doenças da Boca/terapia , Pandemias , Pneumonia Viral , COVID-19 , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Doenças da Boca/etiologia , Qualidade de Vida , SARS-CoV-2RESUMO
Abstract With the onset of the new coronavirus disease (COVID-19) pandemic, the dental treatment of patients at risk of infection has become quite challenging. In view of this, patients with head and neck cancer may present with oral complications due to anticancer therapy, making dental assistance necessary. Thus, the objective of the study was to review the literature and critically discuss important concerns about the treatment of patients with head and neck cancer during the COVID-19 pandemic. Because dental professionals are in close contact with the main viral transmission routes, this study presents recommendations for management and protection during clinical dental care. The main characteristics and transmission routes of COVID-19 are also discussed. Dental professionals should control pain and the side effects of antineoplastic treatment and use preventive measures for infection control. During this pandemic, patients with head and neck cancer should not undergo elective procedures, even if they do not have symptoms or a history of COVID-19; therefore, in asymptomatic or painless cases, only preventive actions are recommended. In symptomatic or painful cases, precautions for safe interventional treatments must be implemented by following the hygiene measures recommended by health agencies and using personal protective equipment. During health crises, new protocols emerge for cancer treatment, and professionals must act with greater attention toward biosafety and updated knowledge. It is important to offer adequate individualized treatment based on the recommendations of preventative and interventional treatments so that patients can face this difficult period with optimized quality of life.
Assuntos
Humanos , Pneumonia Viral , Infecções por Coronavirus , Pandemias , Betacoronavirus , Neoplasias de Cabeça e Pescoço/terapia , Doenças da Boca/terapia , Qualidade de Vida , SARS-CoV-2 , COVID-19 , Doenças da Boca/etiologiaRESUMO
Abstract Resin cements have led to great advances in dental ceramic restoration techniques because of their ability to bond to both dental structures and restorative materials. Objective The aim of this study was to assess the performance of resin cements when different curing modes are used, by evaluating the degree of conversion and bond strength to a ceramic substrate. Material and Methods Three resin cements were evaluated, two dual-cured (Variolink II and RelyX ARC) and one light-cured (Variolink Veneer). The dual-cured resin cements were tested by using the dual activation mode (base and catalyst) and light-activation mode (base paste only). For degree of conversion (DC) (n=5), a 1.0 mm thick feldspathic ceramic disc was placed over the resin cement specimens and the set was light activated with a QTH unit. After 24 h storage, the DC was measured with Fourier transform infrared spectroscopy (FTIR). For microshear bond strength testing, five feldspathic ceramic discs were submitted to surface treatment, and three cylindrical resin cement specimens were bonded to each ceramic surface according to the experimental groups. After 24 h, microshear bond testing was performed at 0.5 mm/min crosshead speed until the failure. Data were submitted to one-way ANOVA followed by Tukey test (p<0.05). Scanning electron microscopy (SEM) was used for classifying the failure modes. Results Higher DC and bond strength values were shown by the resin cements cured by using the dual activation mode. The Variolink II group presented higher DC and bond strength values when using light-activation only when compared with the Variolink Veneer group. Conclusion The base paste of dual-cured resin cements in light-activation mode can be used for bonding translucent ceramic restorations of up to or less than 1.0 mm thick.
Assuntos
Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Cerâmica/química , Bis-Fenol A-Glicidil Metacrilato/química , Compostos de Potássio/química , Cimentos de Resina/química , Cura Luminosa de Adesivos Dentários/métodos , Silicatos de Alumínio/química , Valores de Referência , Propriedades de Superfície , Fatores de Tempo , Teste de Materiais , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Análise de Variância , Resistência ao Cisalhamento , Lâmpadas de Polimerização Dentária , Processos Fotoquímicos , PolimerizaçãoRESUMO
A demanda de pacientes que buscam por tratamentos estéticos dos dentes anteriores está em constante crescimento. A busca incessante pelo desenvolvimento de novos materiais e técnicas odontológicas, visando procedimentos mais conservadores do elemento dental e resultado mais previsível, com excelentes propriedades estéticas e funcionais, tem levado as restaurações dos dentes anteriores a um novo patamar. As cerâmicas têm sido muito estudadas e, com isso, melhoras significativas nas suas propriedades mecânicas e estéticas foram obtidas. Associado a isso, o aperfeiçoamento de técnicas adesivas tornou possível a confecção de peças cerâmicas menos espessas, sem a necessidade de grandes desgastes da estrutura dentária. O aprimoramento do diagnóstico e o planejamento reverso possibilitaram resultados bastante previsíveis. Nesse contexto, o relato de caso apresentado neste artigo descreve a sequência clínica de reabilitação estética dos dentes 11, 12, 21 e 22 empregando facetas indiretas de cerâmica reforçadas por dissilicato de lítio associadas à aplicação de cerâmica feldspática, buscando a reprodução das características naturais dos dentes. O conhecimento da técnica operatória, dos materiais restauradores e a qualidade do trabalho protético são fundamentais para se obter um resultado estético e funcional de excelência (AU).
The number of patients seeking for aesthetic treatments of the anterior teeth is constantly growing. The incessant search for the development of new dental materials and techniques, aiming more conservative procedures of the dental element and more predictable results with excellent aesthetic and functional properties, has led the restoration of anterior teeth to a new level. Ceramics have been studied and thus significant improvements in their mechanical and aesthetic properties were obtained. Associated with this, the improvement of adhesive techniques has made possible the production of thinner ceramic parts without the need of large wear of the tooth structure. Improved diagnosis and reverse planning allowed fairly predictable results. In this context, the case report presented in this article describes the clinical sequence of aesthetic restoration of teeth 11, 12, 21 and 22 employing indirect pottery facets reinforced by lithium disilicate associated with application of feldspar ceramic seeking reproduction of the natural characteristics of teeth. The Knowledge of surgical techniques, restorative materials and the quality of prosthetic work are fundamental to get aesthetic and functional results of excellence (AU).
Assuntos
Humanos , Masculino , Adulto , Cerâmica , Satisfação do Paciente , Facetas Dentárias , Estética Dentária , Reabilitação Bucal/métodos , Sorriso , Brasil , Planejamento de Prótese Dentária/métodos , Compostos de Lítio/químicaRESUMO
Abstract The characteristics of non-obese patients with mild to moderate Obstructive Sleep Apnea Syndrome (OSAS) who will present with a good response to Mandibular Repositioning Appliance (MRA) treatment have not yet been well established in the literature. The aim of this study is to assess whether polysomnographic (PSG), demographic, anthropometric, cephalometric, and otorhinolaryngological parameters predict MRA success in the treatment of OSAS. Forty (40) males with mild and moderate OSAS were assessed pretreatment and 2-months post-treatment after wearing an MRA. Demographic, anthropometric, otorhinolaryngological (ENT), cephalometric, and polysomnographic parameters, including continuous positive airway pressure (CPAP) titrated pressure, dental models, Epworth Sleepiness Scale, quality of life (Short Form SF-36), and mood state (Profile of Mood States – POMS), were assessed. The responders exhibited fewer oropharyngeal alterations, increased upper pharyngeal space, reduced lower airway space, and increased mandibular intercanine width, and they had milder disease. Nevertheless, no predictive factors of MRA success could be found. MRA was more successful among men with a more pervious airway, a larger interdental width and milder OSAS. However, a combined [1] functional and structural assessment is needed to successfully predict the [2] effectiveness of MRA treatment of OSA.
Assuntos
Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Avanço Mandibular/instrumentação , Avanço Mandibular/métodos , Apneia Obstrutiva do Sono/terapia , Pontos de Referência Anatômicos , Índice de Massa Corporal , Cefalometria , Pressão Positiva Contínua nas Vias Aéreas/métodos , Modelos Lineares , Aparelhos Ortodônticos , Faringe , Polissonografia , Estudos Prospectivos , Qualidade de Vida , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Risco , Estatísticas não Paramétricas , Inquéritos e Questionários , Resultado do TratamentoRESUMO
A harmonia gengivo-dental define estética nas reabilitações do arco superior. Em situações, nas quais ocorre perda óssea alveolar no sentido vestíbulo-lingual e ápico-coronal, é necessária associação de técnicas reconstrutivas, visando recuperar volume tecidual. Paciente do gênero masculino, 32 anos, perdeu elemento 11 devido à reabsorção radicular após trauma na região anterior. Foi feita extração dentária, seguida por enxerto ósseo em bloco, instalação de implante e restauração adesiva com dente de estoque. Após o período de osseointegração foi realizado enxerto conjuntivo subepitelial tanto para ganho no sentido vestíbulo-lingual, como ápico-coronal. Imediatamente após o enxerto, iniciou-se o condicionamento gengival com a própria prótese adesiva com pôntico em formato convexo. Em seguida, foi feita a reabertura do implante, instalação de intermediário e confecção de provisório, preservando a arquitetura gengival conseguida. O procedimento provou ser eficiente, garantindo margem gengival e volume de tecido muito próximos do dente adjacente e satisfazendo a expectativa estética do paciente.
The aesthetics of maxillary restorations is defined by the harmony between gingiva and teeth. gingival-dental harmony defines the aesthetics in the upper arch rehabilitation. In cases of alveolar bone loss in buccolingual and apical-coronal direction an association of techniques is required to recover the tissues volume. Male patient, 32 years old, lost element 11 due to radicular resorption, after trauma in the anterior region. Tooth extraction, block bone graft, implant installation and adhesive restoration with a stock tooth were performed. After osseointegration period, a subepithelial connective tissue graft was made to have gain in both directions, buccolingual and apical-coronal. Immediately after the graft, gingival conditioning started with the same adhesive prosthesis with convex shape pint. Then implant was reopened, abutment was installed and the preparation of provisional was executed, preserving the achieved gingival architecture. The procedure proved to be efficient, ensuring gingival margin and tissue volume very close to the adjacent tooth and satisfying the aesthetic expectations of the patient.
Assuntos
Humanos , Masculino , Adulto , Estética Dentária , Gengiva/cirurgia , Implantes Dentários , Satisfação do Paciente , Brasil , Radiografia Dentária/instrumentaçãoRESUMO
The aim of this study was to evaluate the flexural strength and flexural modulus of different fiber-reinforcement composite (FRC) posts and determine the correlation between mechanical properties and structural characteristics. Eleven brands of fiber posts were analyzed (n=10): Exacto Cônico (Angelus), DT Light SL (VDW), RelyX Fiber Post (3M-Espe), Glassix Radiopaque (Nordim), Para Post Fiber White (Coltène), FRC Postec Plus (Ivoclar), Aestheti-Plus Post (Bisco), Superpost Cônico Estriado (Superdont), Superpost Ultrafine (Superdont), Reforpost (Angelus), and White Post DC (FGM). The posts were loaded in three-point bending test to calculate the flexural strength and flexural modulus using a mechanical testing machine (EMIC 2000 DL) at 0.5 mm/min. Data were submitted to one-way ANOVA and Scott-Knot test (p<0.05). The cross-sections of the posts were examined by scanning electron microscopy (SEM). Correlation between the mechanical properties and each of the structural variables was calculated by Pearson's correlation coefficients (p<0.05). The flexural strength values ranged from 493 to 835 MPa and were directly correlated with the fiber/matrix ratio (p=0.011). The flexural modulus ranged from 4500 to 8824 MPa and was inversely correlated with the number of fibers per mm2 of post (p<0.001). It was concluded that the structural characteristics significantly affected the properties of the FRC posts. The structural characteristic and mechanical properties of fiber glass posts are manufacture-dependent. A linear correlation between flexural strength and fiber/matrix ratio, as well as the flexural modulus and the amount of fiber was found.
Assuntos
Materiais Dentários , Técnica para Retentor Intrarradicular , Teste de Materiais , Microscopia Eletrônica de VarreduraRESUMO
Abstract The aim of this study was to evaluate the flexural strength and flexural modulus of different fiber-reinforcement composite (FRC) posts and determine the correlation between mechanical properties and structural characteristics. Eleven brands of fiber posts were analyzed (n=10): Exacto Cônico (Angelus), DT Light SL (VDW), RelyX Fiber Post (3M-Espe), Glassix Radiopaque (Nordim), Para Post Fiber White (Coltène), FRC Postec Plus (Ivoclar), Aestheti-Plus Post (Bisco), Superpost Cônico Estriado (Superdont), Superpost Ultrafine (Superdont), Reforpost (Angelus), and White Post DC (FGM). The posts were loaded in three-point bending test to calculate the flexural strength and flexural modulus using a mechanical testing machine (EMIC 2000 DL) at 0.5 mm/min. Data were submitted to one-way ANOVA and Scott-Knot test (p<0.05). The cross-sections of the posts were examined by scanning electron microscopy (SEM). Correlation between the mechanical properties and each of the structural variables was calculated by Pearson's correlation coefficients (p<0.05). The flexural strength values ranged from 493 to 835 MPa and were directly correlated with the fiber/matrix ratio (p=0.011). The flexural modulus ranged from 4500 to 8824 MPa and was inversely correlated with the number of fibers per mm2 of post (p<0.001). It was concluded that the structural characteristics significantly affected the properties of the FRC posts. The structural characteristic and mechanical properties of fiber glass posts are manufacture-dependent. A linear correlation between flexural strength and fiber/matrix ratio, as well as the flexural modulus and the amount of fiber was found.
Resumo O objetivo deste estudo foi avaliar a resistência à flexão e módulo de flexão de diferentes pinos reforçados com fibra (PRF) e determinar a correlação entre propriedades mecânicas e características estruturais. Foram analisadas onze marcas de pinos de fibra (n=10): Exacto Cónicos (Angelus), DT Luz SL (VDW), RelyX Fiber Post (3M ESPE), Glassix Radiopaque (Nordim), Pará Publicar Fiber White (Coltène), FRC Postec Plus (Ivoclar), Aestheti-Plus Post (Bisco), Superpost Cónicos Estriado (Superdont), Superpost Ultrafino (Superdont), Reforpost (Angelus), e White Post DC (FGM). Os pinos foram avaliados por meio de ensaio de flexão de três pontos para calcular a resistência à flexão e módulo de flexão utilizando uma máquina de ensaios mecânicos (EMIC 2000 DL) a 0,5 mm/min. Os dados foram submetidos a ANOVA one-way e teste de Scott-Knot (p<0,05). As secções transversais dos pinos foram examinadas usando microscopia eletrônica de varredura (MEV). A correlação entre as propriedades mecânicas e de cada uma das variáveis estruturais foi calculada por coeficientes de correlação de Pearson (p<0,05). Os valores da resistência à flexão variaram de 493-835 MPa e foram diretamente correlacionados com a proporção de fibra/matriz (p=0,011). O módulo de flexão variou de 4500 a 8824 MPa e foi inversamente correlacionado com o número de fibras por mm2 (p<0,001). Concluiu-se que as características estruturais afetam de forma significativa as propriedades dos pinos de fibra. As características estruturais e propriedades mecânicas dos pinos de fibra de vidro são dependentes do processo de fabricação. Existe uma correlação linear entre a resistência à flexão e proporção de fibra/matriz, bem como entre o módulo de flexão e a quantidade de fibras.
Assuntos
Materiais Dentários , Técnica para Retentor Intrarradicular , Teste de Materiais , Microscopia Eletrônica de VarreduraRESUMO
The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used a conventional halogen light-curing unit (Optilux 501 at 650 mW/cm2 for 120 s). Samples cured without the ceramic disc were used as control. The samples were stored at 37 °C for 24 h. ATR/FTIR spectrometry was used to evaluate the extent of polymerization in the samples (n=5). Micromechanical properties - VH and E - of the resin cements (n=5) were measured with a dynamic indentation test. Data were statistically analyzed with two-way ANOVA, Tukey's test and Pearson's correlation (α=0.05). DC was affected only by the type of resin cement (p=0.001). For VH, significant interaction was detected between resin cement and ceramic (p=0.045). The dual-cured resin cements showed no significant differences in mean values for E and significantly higher values than the chemically-cured resin cement. The degree of conversion and the mechanical properties of the evaluated resin cements depend on their activation mode and the type of ceramics used in 1.5 mm thickness. The dual-cured resin cements performed better than the chemically-cured resin cement in all studied properties.
Assuntos
Cerâmica , Lâmpadas de Polimerização Dentária , Cimentos de ResinaRESUMO
Abstract: The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used a conventional halogen light-curing unit (Optilux 501 at 650 mW/cm2 for 120 s). Samples cured without the ceramic disc were used as control. The samples were stored at 37 °C for 24 h. ATR/FTIR spectrometry was used to evaluate the extent of polymerization in the samples (n=5). Micromechanical properties - VH and E - of the resin cements (n=5) were measured with a dynamic indentation test. Data were statistically analyzed with two-way ANOVA, Tukey's test and Pearson's correlation (α=0.05). DC was affected only by the type of resin cement (p=0.001). For VH, significant interaction was detected between resin cement and ceramic (p=0.045). The dual-cured resin cements showed no significant differences in mean values for E and significantly higher values than the chemically-cured resin cement. The degree of conversion and the mechanical properties of the evaluated resin cements depend on their activation mode and the type of ceramics used in 1.5 mm thickness. The dual-cured resin cements performed better than the chemically-cured resin cement in all studied properties.
Resumo: O objetivo deste estudo foi mensurar grau de conversão (GC), microdureza Vickers (VH) e módulo de elasticidade (E) de cimentos resinosos polimerizados através de diferentes sistemas cerâmicos. Um disco de 1,5 mm de espessura de cada sistema cerâmico (cerâmica feldspática, dissilicato de lítio e zircônia coberto por cerâmica feldspática) foi utilizado. Três cimentos resinosos duais (Allcem, Variolink II e RelyX U200) e um cimento resinoso quimicamente ativado (Multilink) foram ativados através dos discos de cerâmica. Para os cimentos resinosos duais foi utilizado um aparelho de lâmpada halógena (Optilux 501 a 650 mW/cm2 por 120 s). Amostras polimerizadas sem a interposição do disco de cerâmica foram utilizadas como controle. As amostras foram armazenadas a 37 °C durante 24 h. ATR/FTIR foi utilizado para avaliar a extensão da polimerização nas amostras (n=5). Propriedades micromecânicas - VH e E - dos cimentos resinosos (n=5) foram medidas com um teste dinâmico de indentação. Os dados foram analisados através de análise de variância a dois fatores, teste de Tukey e correlação de Pearson (α=0,05). O GC foi afetado somente pelo tipo de cimento resinoso (p=0,001). Para VH, houve interação entre o tipo de cimento resinoso e o tipo de cerâmica (p=0,045). Os cimentos resinosos duais não apresentaram diferenças significativas nos valores médios de E e valores significativamente maiores que o cimento resinoso quimicamente ativado. O grau de conversão e as propriedades mecânicas dos cimentos resinosos avaliados dependem do seu modo de ativação e do tipo de cerâmica usada na espessura de 1,5 mm. Os cimentos resinosos duais desempenharam melhor que o cimento resinoso quimicamente ativado em todas as propriedades estudadas.
Assuntos
Cerâmica , Lâmpadas de Polimerização Dentária , Cimentos de ResinaRESUMO
Vários fatores podem levar à perda dentária, entre eles a reabsorção externa das raízes. Para este, entre outros casos, a reposição dos dentes perdidos com a instalação imediata de implantes e provisionalização imediata tem sido um procedimento com bom prognóstico. Fatores como extração minimamente traumática, manutenção das cristas ósseas proximais e das tábuas ósseas vestibular e lingual, estabilidade primária do implante e a confecção de provisório imediato livre de contatos oclusais são parâmetros importantes para a previsibilidade do caso. Esta técnica tem sido descrita por vários autores desde a década de 90 com alto índice de sucesso, otimizando a reabilitação dos pacientes com menor tempo de espera e a preservação da arquitetura dos tecidos gengival e ósseo. Este trabalho apresenta o relato de dois casos clínicos de exodontias de dentes com reabsorção externa, previamente submetidos ao tracionamento ortodôntico, seguidas de instalação imediata de implantes e provisionalização imediata, com acompanhamento clínico e radiográfico de 7 anos...
Several factors can lead to tooth loss, including external root resorption. In these cases, among others, the replacement of missing teeth with immediate implant placement and provisionalization has been a procedure with good prognosis. Factors including minimally traumatic extraction, maintenance of proximal bone crests and buccal and lingual bone plates, primary implant stability and immediate provisionalization free of occlusal contacts are strictly important for success and good long-term result. This technique has been described since the 90s with a high success rate. It can optimize the rehabilitation with a shorter waiting time maintaining of bone and gingival contours. This article describes a 7-year radiographic and clinical follow-up of two extraction cases of teeth with external root resorption followed by immediate implant placement and immediate provisionalization...
Assuntos
Humanos , Feminino , Adulto Jovem , Cirurgia Bucal/métodos , Carga Imediata em Implante Dentário , Reabsorção da Raiz , Dente Impactado/radioterapia , Radiografia Dentária/instrumentaçãoRESUMO
STATEMENT OF PROBLEM: The literature provides limited information regarding the performance of Ti-6Al-4V laser and plasma joints welded in prefabricated bars in dental applications. PURPOSE: The purpose of this study was to evaluate the mechanical strength of different diameters of Ti-6Al-4V alloy welded with laser and plasma techniques. MATERIAL AND METHODS: Forty-five dumbbell-shaped rods were created from Ti-6Al-4V and divided into 9 groups (n=5): a control group with 3-mm and intact bars; groups PL2.5, PL3, PL4, and PL5 (specimens with 2.5-, 3-, 4-, and 5-mm diameters welded with plasma); and groups L2.5, L3, L4, and L5 (specimens with 2.5-, 3-, 4-, and 5-mm diameters welded with laser). The specimens were tested for ultimate tensile strength (UTS), and elongation percentages (EP) were obtained. Fractured specimens were analyzed by stereomicroscopy, and welded area percentages (WAP) were calculated. Images were made with scanning electron microscopy. In the initial analysis, the data were analyzed with a 2-way ANOVA (2×4) and the Tukey Honestly Significant Difference (HSD) test. In the second analysis, the UTS and EP data were analyzed with 1-way ANOVA, and the Dunnett test was used to compare the 4 experimental groups with the control group (α=.05). The Pearson and Spearman correlation coefficient tests were applied to correlate the study factors. Finite element models were developed in a workbench environment with boundary conditions simulating those of a tensile test. RESULTS: The 2-way ANOVA showed that the factors welding type and diameter were significant for the UTS and WAP values. However, the interaction between them was not significant. The 1-way ANOVA showed statistically significant differences among the groups for UTS, WAP, and EP values. The Dunnett test showed that all the tested groups had lower UTS and EP values than the control group. The 2.5- and 3-mm diameter groups showed higher values for UTS and WAP than the other test groups. A positive correlation was found between welded area percentage and UTS and a negative correlation between these parameters and the diameters of the specimens. No statistically significant difference was found between the weld techniques. CONCLUSIONS: Under the experimental conditions described, diameters of 2.5 and 3 mm resulted in higher UTS and WAP for both laser and plasma welding and appear to be the best option for joining prefabricated rods in this kind of union.
Assuntos
Ligas Dentárias/química , Soldagem em Odontologia/métodos , Análise de Elementos Finitos , Lasers , Gases em Plasma , Titânio/química , Ligas , Desenho Assistido por Computador , Análise do Estresse Dentário/instrumentação , Módulo de Elasticidade , Elasticidade , Dureza , Humanos , Imageamento Tridimensional/métodos , Teste de Materiais , Microscopia , Microscopia Eletrônica de Varredura , Estresse Mecânico , Propriedades de Superfície , Resistência à TraçãoRESUMO
Aim: To investigate the prevalence of temporomandibular disorders (TMD) in undergraduate students and to correlate its prevalence with occlusal factors and parafunctional habits. Methods: 201 undergraduate students were evaluated. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was filled out at the beginning of the study, followed by occlusal analysis based on morphological and functional alterations. The identification of tooth grinding and clenching was carried out by self-reports. Statistical analysis was based on chi-square and multivariate logistic regression analyses. p-value for all statistical analysis was set at 5%. Results: According to RDC/TMD, 18.4% of subjects experienced myofascial pain (G-MPD), and 12.4% had joint disorder with disc displacement (G-DD). Tooth clenching was statistically associated with TMD (p=0.000). In the occlusal factors, overjet showed statistically significant correlation only with myofascial pain. No association between functional alteration and TMD was found. No statistically significant correlation was found between G-DD and occlusal alterations or parafunctional habits. Conclusions: Overjet and tooth clenching were correlated with G-MPD. Occlusal alterations or parafunctional habits did not show correlation with G-DD.
Assuntos
Humanos , Masculino , Feminino , Bruxismo , Transtornos da Articulação Temporomandibular/epidemiologia , Oclusão Dentária , Síndromes da Dor MiofascialRESUMO
The aim of this prospective clinical study was to evaluate patient rehabilitation with two immediately loaded implants and bar-retained mandibular overdentures after 48 months of follow-up. Twenty patients were treated with two implants each; of these, 17 patients were re-evaluated for comparison. Gender, age, plaque index, gingival inflammation, keratinized mucosa, probing depth, bleeding, and implant loss data were recorded, and periapical radiographs were obtained for measurement of marginal bone loss. The results were statistically analyzed with one-way analysis of variance (ANOVA) followed by Student's t-test and Pearson's correlation test. To compare the data at baseline and after 48 months, a Wilcoxon Signed Rank Test was performed (α = 0.05). One implant failed (2.9%) during the first year and was replaced. A total of 35 implants were evaluated. Bone loss values were 0.52-2.89 mm (mean, 1.46 mm). Probing depth was 1.75-3.75 mm (mean, 2.22 mm). Correlations were found between bone loss and plaque index and between bone loss and gender, but bone loss did not correlate with gingival inflammation, keratinized mucosa, probing depth, or age. The overall survival rate of the implants was 97.1%. Based on these results, the use of two immediately loaded splinted interforaminal implants to retain an overdenture with a bar attachment is a clinically viable option with a high survival rate.