Efficacy of prostheses bonding using silane incorporated to universal adhesives or applied separately: A systematic review.

Currently, the long-term success of esthetic rehabilitation with ceramics is required. Hence, professional knowledge about the most indicated dental material for each clinical situation as well as its usage protocol is essential. The aim of this systematic review of clinical and laboratorial studies was to compare the bond strength of prostheses using silane incorporated to universal adhesives or applied separately. The literature search in databases "Cochrane Library," "MEDLINE," "Web of Science," "Scopus," "LILACS," "Scielo," and "Google Scholar" was based on the keywords "Silane;" "Silanes;" "Silane coupling agent;" "Universal adhesive;" and "Universal adhesives." A total of five articles were included in this review. In general, the studies showed better results for ceramic etching with hydrofluoric acid and application of silane separately to the universal adhesive. As a conclusion, the treatment with pure silane or as an additional pretreatment with universal adhesives improved the bond strength of glass ceramics. Hence, higher shear bond strength can be achieved, resulting in treatment longevity.

Influence of crown ferrule heights and dowel material selection on the mechanical behavior of root-filled teeth: a finite element analysis.

PURPOSE: This study used the 3D finite element (FE) method to evaluate the mechanical behavior of a maxillary central incisor with three types of dowels with variable heights of the remaining crown structure, namely 0, 1, and 2 mm. MATERIALS AND METHODS: Based on computed microtomography, nine models of a maxillary central incisor restored with complete ceramic crowns were obtained, with three ferrule heights (0, 1, and 2 mm) and three types of dowels (glass fiber = GFD; nickel-chromium = NiCr; gold alloy = Au), as follows: GFD0--restored with GFD with absence (0 mm) of ferrule; GFD1--similar, with 1 mm ferrule; GFD2--glass fiber with 2 mm ferrule; NiCr0--restored with NiCr alloy dowel with absence (0 mm) of ferrule; NiCr1--similar, with 1 mm ferrule; NiCr2--similar, with 2 mm ferrule; Au0--restored with Au alloy dowel with absence (0 mm) of ferrule; Au1--similar, with 1 mm ferrule; Au2--similar, with 2 mm ferrule. A 180 N distributed load was applied to the lingual aspect of the tooth, at 45° to the tooth long axis. The surface of the periodontal ligament was fixed in the three axes (x = y = z = 0). The maximum principal stress (σ(max)), minimum principal stress (σ(min)), equivalent von Mises (σ(vM)) stress, and shear stress (σ(shear)) were calculated for the remaining crown dentin, root dentin, and dowels using the FE software. RESULTS: The σ(max) (MPa) in the crown dentin were: GFD0 = 117; NiCr0 = 30; Au0 = 64; GFD1 = 113; NiCr1 = 102; Au1 = 84; GFD2 = 102; NiCr2 = 260; Au2 = 266. The σ(max) (MPa) in the root dentin were: GFD0 = 159; NiCr0 = 151; Au0 = 158; GFD1 = 92; NiCr1 = 60; Au1 = 67; GFD2 = 97; NiCr2 = 87; Au2 = 109. CONCLUSION: The maximum stress was found for the NiCr dowel, followed by the Au dowel and GFD; teeth without ferrule are more susceptible to the occurrence of fractures in the apical root third.

Otoneurological assessment and quality of life of individuals with complaints of dizziness and temporomandibular disorders: a case-control study.

OBJECTIVES: To evaluate the impact of temporomandibular disorders on the quality of life of patients with dizziness. METHODS: An observational, case-control study evaluated 60 individuals with dizziness (20 cases and 40 controls), who were matched for gender and age. The individuals underwent to anamnesis, overall physical and otoneurological examination, tonal and vocal audiometry and impedanciometry, video head impulse test and the dizziness handicap inventory questionnaire. RESULTS: The otoscopy was normal for all patients. There was an association between the presence of temporomandibular disorders and aural fullness (p < 0.01) and otalgia (p < 0.01). Audiometry was normal in 90% of the patients in the case group, with a significant association between temporomandibular disorders and normal audiometry (p < 0.01). The video head impulse test findings were normal in 66% of the patients in the case group and 45% of the control group, and there was no association between having temporomandibular disorders and vestibular alterations at the video head impulse test (p = 0.12). There were significant differences in total dizziness handicap inventory and in the functional and emotional domains (p < 0.01), with higher scores in the control group. CONCLUSION: Aural fullness and otalgia symptoms are associated with temporomandibular disorders in patients with dizziness, and there is an association between normal complementary audiological tests and temporomandibular disorders. Vestibular alterations are not associated with temporomandibular disorders. However, patients with dizziness and without temporomandibular disorders showed greater quality of life impairment. LEVEL OF EVIDENCE: 3: Original case-control study.

Association of sleep quality and psychological aspects with reports of bruxism and TMD in Brazilian dentists during the COVID-19 pandemic.

BACKGROUND: Dentists are exposed to contamination by SARS-CoV-2 due to dental interventions, leading to a state of alert and potential risk of negative impact in mental health and sleep quality, associated with Temporomandibular Disorder (TMD) and bruxism. OBJECTIVE: to evaluate the psychosocial status, sleep quality, symptoms of TMD, and bruxism in Brazilian dentists (DSs) during the COVID-19 pandemic. METHODOLOGY: The sample (n=641 DSs) was divided into three groups (quarantined DSs; DSs in outpatient care; and frontline professionals), which answered an electronic form containing the TMD Pain Screening Questionnaire (Diagnostic Criteria for Temporomandibular Disorders - DC/TMD), the Pittsburgh Sleep Quality Index (PSQI), the Depression, Anxiety and Stress Scale (DASS-21), and the sleep and awake bruxism questionnaire. ANOVA test and Mann Whitney post-test were used, with Bonferroni adjustment (p<0.016) and a 95% confidence level. RESULTS: Probable TMD was found in 24.3% (n=156) of the participants, while possible sleep and awake bruxism were diagnosed in 58% (n=372) and 53.8% (n=345) of them, respectively. Among all variables evaluated, only symptoms of depression were significantly greater in the quarantined DSs group when compared to those who were working at the clinical care (p=0.002). Working DSs were significantly less likely (OR=0.630, p=0.001) to have depressive symptoms. Those who were not worried or less worried about the pandemic were less likely to experience stress (OR=0.360), anxiety (OR=0.255), and poor sleep quality (OR=0.256). Sleep had a strong positive and moderate correlation with psychological factors on frontline workers and DSs in outpatient care, respectively. CONCLUSION: The results suggest confinement may have a more negative impact on the life of DSs than the act of being actively working. The concern about Covid-19 and poor sleep quality was significantly prevalent and may negatively affect the quality of life of DSs. Thus, further research on the topic is needed.

Relationship between anxiety, quality of life, and sociodemographic characteristics and temporomandibular disorder.

OBJECTIVES: The aim of this study was to evaluate the relationship between anxiety, quality of life (QL), and sociodemographic aspects and temporomandibular disorders (TMDs) and to assess the predisposition to TMDs in patients with low QL and anxiety. STUDY DESIGN: In total, 120 patients (60 TMD/60 non-TMD) were screened to assess QL (World Health Organization Quality of Life Brief Version [WHOQOL]); anxiety (Beck Anxiety Inventory [BAI]; the State-Trait Anxiety Inventory[STAI-S and -T]; the Hospital Anxiety and Depression Scale [HADS]); and TMD (Research Diagnostic Criteria for Temporomandibular Disorders-RDC/TMD). Pearson's χ2 test, the Student t test, odds ratio (OR) analysis, and nonconditional logistic regression analysis were performed. RESULTS: Among patients with TMD, 60% were women (P = .002), 65.1% were single (P = .009), and 71.4% were employed (P = .008). Most of the anxious individuals had TMD, according to HADS, 75% (P < .001); STAI-S, 55.6% (P = .035); STAI-T, 54.9% (P = .011); and BAI, 63.9% (P = .002). WHOQOL showed higher QL for non-TMD participants (P < .001). Sociodemographic data showed an association with TMD: gender (OR = 3.5), professional status (OR = 3.3), and marital status (OR = 2.8). WHOQOL presented higher association strength (OR = 9.2), followed by HADS (OR = 5.0). CONCLUSIONS: A relationship exists between sociodemographic aspects, anxiety, and QL and TMD. Patients with TMD have higher anxiety levels and lower QL, and this can interfere with treatment, reinforcing the need for therapies that consider the various factors of the disorder.

Otoneurological assessment and quality of life of individuals with complaints of dizziness and temporomandibular disorders: a case-control study

Abstract Objectives: To evaluate the impact of temporomandibular disorders on the quality of life of patients with dizziness. Methods: An observational, case-control study evaluated 60 individuals with dizziness (20 cases and 40 controls), who were matched for gender and age. The individuals underwent to anamnesis, overall physical and otoneurological examination, tonal and vocal audiometry and impedanciometry, video head impulse test and the dizziness handicap inventory questionnaire. Results: The otoscopy was normal for all patients. There was an association between the presence of temporomandibular disorders and aural fullness (p<0.01) and otalgia (p<0.01). Audiometry was normal in 90% of the patients in the case group, with a significant association between temporomandibular disorders and normal audiometry (p<0.01). The video head impulse test findings were normal in 66% of the patients in the case group and 45% of the control group, and there was no association between having temporomandibular disorders and vestibular alterations at the video head impulse test (p = 0.12). There were significant differences in total dizziness handicap inventory and in the functional and emotional domains (p<0.01), with higher scores in the control group. Conclusion: Aural fullness and otalgia symptoms are associated with temporomandibular disorders in patients with dizziness, and there is an association between normal complementary audiological tests and temporomandibular disorders. Vestibular alterations are not associated with temporomandibular disorders. However, patients with dizziness and without temporomandibular disorders showed greater quality of life impairment. Level of evidence: 3. Original case-control study.

Avaliação da amplitude de abertura bucal em pacientes com disfunção temporomandibular após tratamento com terapia manual / Evaluation of mouthopening amplitude in patients with temporomandibular disorder after treatment with manual therapy / Evaluación de la amplitud de aperturade la bocaen pacientes con transtorno temporomandibulardespués del tratamiento con terapia manual

Introdução:A disfunção temporomandibular,distúrbio que acomete as estruturas ósseas, musculares e articulares da região orofacial tem sido cada vez mais recorrente. Esse distúrbio causa dores, limitação de movimento e alteração na qualidade de vida dos pacientes acometidos com a doença. Se fazemnecessáriasmedidas de controle e tratamento dessadoença de prevalência crescente. Objetivo:Avaliar a amplitude de abertura bucal em pacientes portadores de disfunção temporomandibular, submetidos ao tratamento com fisioterapia após 1 e 3 meses de tratamento.Metodologia:Avaliou-se a amplitude de abertura bucal de 25 pacientes submetidos ao tratamento com fisioterapia. Todos os pacientes foram diagnosticados com disfunçãode acordo com o eixo 1 do "Research Diagnostic Criteria for Temporomandibular Disorders". Os dados colhidos foram avaliados através do programa SPSS e foi realizado o teste Wilcoxon, com nível de confiança de 95%. Resultados:Para pacientes que apresentavam comprometimento da amplitude de abertura máxima sem auxílio, a fisioterapia possibilitou melhora significativa do ganho de amplitude no tempo inicial e após um mês de terapia (p= 0,002), mantendo a amplitude até o terceiro mês, sem apresentar ganho significativo. Conclusões:Para a variável amplitude de abertura bucal, a fisioterapia se mostra como uma boa alternativa de tratamento, alcançando resultados satisfatórios para o ganho de amplitude e melhoria do quadro sintomático do paciente (AU).

Introduction:Temporomandibulardisorder, a disorder that affects bone, muscle and joint structures in the orofacial region has been increasingly recurrent. This disorder causes pain, movement limitation and changes in the quality of life of patients affected by the disease. Control measures and treatment of the disease of increasing prevalence are necessary. Objective:To evaluate the range of mouth opening in patients undergoing treatment with physiotherapy after 1 and 3 months of treatment. Methodology:It was the amplitude of mouth opening in 25 patients submitted to treatment with physiotherapy. All patients were diagnosed with disorder according to axis 1 of the Research Diagnostic Criteria for Temporomandibular Disorders. The collected data were evaluatedusing the SPSS program and the Wilcoxon test was performed, with a 95% confidence level. Results:For patients who presented impairment of the maximum opening amplitude without assistance, physiotherapy enabled a significant improvement in amplitude gainin the initial time and after one month of therapy (p= 0.002), maintaining the amplitude until the third month, without showing any significant gain. Conclusions:For the variable mouth opening amplitude, physiotherapy is shown to be a good treatment alternative, achieving satisfactory results for gaining amplitude and improving the patient's symptomatic condition (AU).

Introducción: El trastorno temporomandibular, un trastorno que afecta las estructuras óseas, musculares y articulares en la región orofacial, ha sido cada vez más recurrente. Este trastorno causa dolor, limitación de movimiento y cambios en la calidad de vida de los pacientes afectados por la enfermedad. Son necesarias medidas de control y tratamiento de la enfermedad de prevalencia creciente.Objetivo: Evaluar la amplitud de la apertura de la boca en pacientes con disfunción temporomandibular, sometidos a tratamiento con fisioterapia después de 1 y 3 meses de tratamiento.Metodología: Se evaluó la amplitud de la apertura de la boca en 25 pacientes sometidos a tratamiento de fisioterapia. Todos los pacientes fueron diagnosticados con trastorno de acuerdo con el eje 1 del Criterios de diagnóstico de investigación para trastornos temporomandibulares. Los datos recopilados se evaluaron utilizando el programa SPSS y se realizó la prueba de Wilcoxon, con un nivel de confianza del 95%. Resultados: Para los pacientes que presentaron deterioro de la amplitud máxima de apertura sin asistencia, la fisioterapia permitió una mejora significativa en la ganancia de amplitud en el tiempo inicial ydespués de un mes de terapia (p=0,002), manteniendo la amplitud hasta el tercer mes, sin mostrar ninguna ganancia significativa.Conclusiones: Para la amplitud variable de apertura de la boca, se muestra que la fisioterapia es una buena alternativa de tratamiento, logrando resultados satisfactorios para aumentar la amplitud y mejorar la condición sintomática del paciente (AU).

Association of sleep quality and psychological aspects with reports of bruxism and TMD in Brazilian dentists during the COVID-19 pandemic

Abstract Dentists are exposed to contamination by SARS-CoV-2 due to dental interventions, leading to a state of alert and potential risk of negative impact in mental health and sleep quality, associated with Temporomandibular Disorder (TMD) and bruxism. Objective: to evaluate the psychosocial status, sleep quality, symptoms of TMD, and bruxism in Brazilian dentists (DSs) during the COVID-19 pandemic. Methodology: The sample (n=641 DSs) was divided into three groups (quarantined DSs; DSs in outpatient care; and frontline professionals), which answered an electronic form containing the TMD Pain Screening Questionnaire (Diagnostic Criteria for Temporomandibular Disorders - DC/TMD), the Pittsburgh Sleep Quality Index (PSQI), the Depression, Anxiety and Stress Scale (DASS-21), and the sleep and awake bruxism questionnaire. ANOVA test and Mann Whitney post-test were used, with Bonferroni adjustment (p<0.016) and a 95% confidence level. Results: Probable TMD was found in 24.3% (n=156) of the participants, while possible sleep and awake bruxism were diagnosed in 58% (n=372) and 53.8% (n=345) of them, respectively. Among all variables evaluated, only symptoms of depression were significantly greater in the quarantined DSs group when compared to those who were working at the clinical care (p=0.002). Working DSs were significantly less likely (OR=0.630, p=0.001) to have depressive symptoms. Those who were not worried or less worried about the pandemic were less likely to experience stress (OR=0.360), anxiety (OR=0.255), and poor sleep quality (OR=0.256). Sleep had a strong positive and moderate correlation with psychological factors on frontline workers and DSs in outpatient care, respectively. Conclusion: The results suggest confinement may have a more negative impact on the life of DSs than the act of being actively working. The concern about Covid-19 and poor sleep quality was significantly prevalent and may negatively affect the quality of life of DSs. Thus, further research on the topic is needed.

Protocolo clínico e laboratorial na reabilitação oral com prótese obturadora e satisfação do paciente: caso clínico / Clinical and laboratory protocol in oral rehabilitation with shutterprosthesisand patient satisfaction: clinical case / Protocolo clínico y de laboratorio en rehabilitación oral con prótesis de obturación y satisfacción del paciente: caso clínico

Introdução:Aenorme dificuldade de deglutição e fala apresentada em pacientes que sofreram maxilectomiatotal ou parcial por consequência de patologias bucais, afeta grande parte da população que realizou tal procedimento. A alternativa de minimizar o impacto causado pela sequela deixada após cirurgia em maxila está na confecção de um obturador palatino, que tem como objetivo obstruir a comunicação oronasal.Objetivo:Este trabalho objetivou descrever um relato de caso evidenciando o passo a passo clínico e laboratorial de uma prótese total obturadorae a satisfação do paciente com a mesma.Método:Paciente do gênero masculino, maxilectomizado há seisanos devido a presença de um CarcinomaAdenóideCístico foi reabilitado com prótese total obturadora superior e prótese total convencional inferior. A reabilitação superior seguiu os mesmos passos de uma prótesetotal convencional, com exceção da moldagem funcional, na qual foi feita a moldagem da comunicação bucosinusal com silicona de condensação antes da moldagem do selado periférico e moldagem funcional propriamente dita. Na etapa laboratorial, foi necessáriaa realização de três prensagens a fim de deixar a prótese oca na porção obturadora.Resultados:O tratamento restabeleceu a dimensão vertical perdida, proporcionou uma oclusão adequada, se mostrou melhor esteticamentee o paciente mostrou-se extremamente satisfeito com a reabilitação.Conclusões:Como conclusão, obteve-se uma prótese total obturadora superior com qualidades funcionais e estéticas satisfatórias. Ademais, ao comparar com a antiga, a novamostrou-se satisfatória de acordo com a percepção do usuário epossui um menor peso, favorecendo uma melhor retenção (AU).

Introduction:The enormous difficulty in swallowing and speaking presented in patients who underwent total or partial maxillectomy as a result of oral pathologies affects a large part of the population that performed this procedure. The alternative of minimizing the impact caused by the sequelae left after maxillary surgery is by making a palatal obturator, which aims to obstruct oronasal communication.Objective:This study aimed to describe a case report highlighting the clinical and laboratory step by step of a complete obturator prosthesis and patient satisfaction with it. Methods:A male patient who had been maxillectomized for 6 years due to the presence of a cystic adenoid carcinoma was rehabilitated with superior obturator total denture and inferior conventional total denture. The superior rehabilitation followed the same steps of a conventional total prosthesis, except for the functional molding, in which the bucosinusal communication with condensation silicon was molded before the peripheral sealing molding and the functional molding itself. In the laboratory stage, it was necessary to perform three presses in order to leave the hollow prosthesis in the obturator portion.Results:The treatment restored the lost vertical dimension, provided an adequate occlusion,was better aesthetically and the patient was extremely satisfied with the rehabilitation.Conclusions:In conclusion, a superior total obturator prosthesis with satisfactory functional and aesthetic qualities was obtained. Moreover, when compared to the old one, the new one was satisfactory according to the user's perception and has a lower weight, favoring a better retention (AU).

Introduccion: La enorme dificultad para tragar y hablarpresentada en pacientes que han sufrido una maxillectomía total o parcial como resultado de patologías orales afecta a gran parte de la población que realizó este procedimiento. La alternativa de minimizar el impacto causado por las secuelas que quedan después de la cirugía maxilar es hacer un obturador palatino, que tiene como objetivo obstruir la comunicación oronasal. Objetivo: Este estudio tuvo como objetivo describir un informe de caso que muestra la clínica y el laboratorio paso a paso de una prótesis obturadora completa y la satisfacción del paciente con ella. Método:Un paciente masculino que había sido maxillectomizado durante seis años debido a la presencia de un carcinoma adenoide quístico fue rehabilitado con una prótesis obturadora total superior y una prótesis total inferior convencional. La rehabilitación superior siguió los mismos pasos de una prótesis total convencional, excepto el moldeado funcional, en el cual la comunicación bucosinusal con silicio de condensación se moldeó antes del moldeado de sellado periférico y el moldeado funcional en sí. En la etapa de laboratorio, fue necesario realizar tres prensas para dejar la prótesis hueca en la porción del obturador. Resultados:El tratamiento restableció la dimensión vertical perdida, proporcionó una oclusión adecuada, fue mejor estéticamente y el paciente quedó extremadamente satisfecho con la rehabilitación. Conclusiones:Como conclusión, se obtuvo una prótesis obturadora superior con cualidades funcionales y estéticas satisfactorias. Además, en comparación con el anterior, el nuevo fue satisfactorio de acuerdo con la percepción del usuario y tiene un peso menor, lo que favorece una mejor retención (AU).

Impacto da alteração de dimensão vertical na disfunção temporomandibular: revisão integrativa / Impact of vertical dimension change on temporomandibular dyfunction: integrative review

Introdução:A Disfunção Temporomandibular (DTM) é uma condição bastante frequente na população mundial e a identificação de fatores causais, junto ao seu tratamento é de suma relevância para a qualidade de vida dos indivíduos.Objetivo:Objetivou-se por meio de uma revisão integrativada literatura de todos os tipos de estudos, avaliar se a alteraçãode dimensão vertical impacta no aparecimento das disfunções temporomandibulares.Método:As estratégias de busca foram realizadas nas bases de dados "Cochrane Library", "MEDLINE", "Web of Science", "Scopus", "LILACS", "Scielo" e "Google Acadêmico", utilizando os seguintes descritores e/ou palavras: "Temporomandibular Joint Disorders"; "Craniomandibular Disorders"; "Occlusion Vertical Dimension"; "Occlusion Vertical Dimensions"; "Vertical Dimension of Occlusion"; "Vertical Dimension".Resultados:Um total de 4 artigos foram incluídos nesta revisão.A maioria dos estudos demostram que na presença de uma DVO diminuída, o sistema estomatognático é capaz de adaptar-se, não provocando o aparecimento de DTM.Conclusões:Como conclusão, os resultados indicam que não há evidência científica suficiente que permita afirmar que a perda de dimensão vertical predispõe ao aparecimento de sinais e sintomas relacionados à disfunção temporomandibular (AU).

Introduction:TemporomandibularDysfunction (TMD) is a very frequent condition in the world population and the identification of causal factors, along with its treatment, is extremely relevant to the quality of life of the individuals.Objective:The aim of this study was to integrativereview the literature of all types of studies to assess whether loss of vertical dimension has an impact on the appearance of temporomandibular disorders.Methods:The search strategies were performed in the Cochrane Library, Medline, Web of Science, Scopus, Lilacs, Scielo and Google Scholar databases using the following descriptors and / or words : "Temporomandibular Joint Disorders"; "Craniomandibular Disorders"; "Occlusion Vertical Dimension"; "Occlusion Vertical Dimensions"; "Vertical Dimension of Occlusion"; "Vertical Dimension". Results:A total of 4 articles were included in this review. Most of the studies show that in the presence of a reduced OVD, the stomatognathic system is able to adapt, not provoking the appearance of TMD. Conclusions:In conclusion, the results indicate that there is insufficient scientific evidence to show that the loss of vertical dimension predisposes to the appearance of signs and symptoms related to temporomandibular dysfunction (AU).

Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data.

OBJECTIVE: The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. MATERIAL AND METHODS: Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σ(max)) values were evaluated for the root dentin, cement layer, and glass fiber post. RESULTS: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). CONCLUSION: The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root.

Influence of voids in the hybrid layer based on self-etching adhesive systems: a 3-D FE analysis.

UNLABELLED: The presence of porosities at the dentin/adhesive interface has been observed with the use of new generation dentin bonding systems. These porosities tend to contradict the concept that etching and hybridization processes occur equally and simultaneously. Therefore, the aim of this study was to evaluate the micromechanical behavior of the hybrid layer (HL) with voids based on a self-etching adhesive system using 3-D finite element (FE) analysis. MATERIAL AND METHODS: Three FE models (Mr) were built: Mr, dentin specimen (41x41x82 µm) with a regular and perfect (i.e. pore-free) HL based on a self-etching adhesive system, restored with composite resin; Mp, similar to M, but containing 25% (v/v) voids in the HL; Mpp, similar to Mr, but containing 50% (v/v) voids in the HL. A tensile load (0.03N) was applied on top of the composite resin. The stress field was obtained by using Ansys Workbench 10.0. The nodes of the base of the specimen were constrained in the x, y and z axes. The maximum principal stress (σmax) was obtained for all structures at the dentin/adhesive interface. RESULTS: The Mpp showed the highest peak of σmax in the HL (32.2 MPa), followed by Mp (30 MPa) and Mr (28.4 MPa). The stress concentration in the peritubular dentin was high in all models (120 MPa). All other structures positioned far from voids showed similar increase of stress. CONCLUSION: Voids incorporated into the HL raised the σmax in this region by 13.5%. This behavior might be responsible for lower bond strengths of self-etching and single-bottle adhesives, as reported in the literature.

Bone stress evaluation in implants with Regular and Switching platforms / Avaliação da tensão óssea em implantes com plataforma Regular e Switching

Objective: Considering that the bone stress caused by the internal hexagon implant is lower in comparison with that caused by external hexagon implant, the aim of this study was to evaluate stress distribution of the peri-implant bone, by simulating the influence of the switching platform in external hexagon implants in comparison with regular platform in the internal hexagon implant. Methods: Two mathematical models of an implant-supported central incisor were created: Regular (R), 4.5 x 11.5 mm internal hexagon implant and 4.5 mm abutment and Switching (S), 5.0 x 11.5 mm external hexagon implant and 4.1 mm abutment. The models were created using the SolidWorks 2010 (3Dtech, São Paulo, Brazil) program. Oblique forces (100 N) were applied to the palatine surface of the central incisor. The bone/implant interface was considered perfectly integrated. Maximum and minimum principal stress values were evaluated in the cortical and medullary bones. The numerical analysis was performed using the ANSYS Workbench 10.0 (Swanson Analysis System, Houston, Pa). Results: For the cortical bone, the highest stress values were observed in the R (48.8 MPa), followed by the S (48.5 MPa). For the medullary bone, the highest stress values were observed in the S (3.66 MPa), followed by the regular (1.51 MPa). Conclusion: External hexagon implant with switching platform showed a biomechanical performance similar to that of the internal hexagon implant with regular platform in the cortical bone analysis. Whereas, for the medullary bone, the switching platform model transmitted more stress than the regular model.

Objetivo: Avaliar a distribuição de tensão no osso peri-implantar de implante hexágono interno com plataforma regular e implante hexágono externo com plataforma switching. Métodos: Foram confeccionados dois modelos matemáticos representativos de uma maxila parcial da região do elemento 11, sendo um modelo Regular, com implante hexágono interno (4,5 x 11,5 mm) e pilar 4,5 mm e outro modelo Switching, com implante hexágono externo (5,0 x 11,5 mm) e pilar 4,1 mm. Ambos os modelos continham uma coroa cimentada sobre o pilar do implante. Os modelos foram desenvolvidos pelo programa SolidWorks 2010 (3Dtech, São Paulo, Brasil). Forças oblíquas (100 N) foram aplicadas na face palatal das coroas. A interface osso-implante foi considerada perfeitamente integrada. Máxima e mínima tensão principal foram avaliadas no osso cortical e medular. A análise numérica foi realizada através do programa ANSYS Workbenck 10,0 (Swanson Analysis System, Houston, Pa). Resultados: No osso cortical, os maiores valores de tensão foram observados para R (48,8 MPa), seguido de S (48,5 MPa). Para o osso medular, os maiores valores de tensão foram observados no modelo S (3,66 MPa), seguido por R (1,51 MPa). Conclusão: O modelo switching apresentou comportamento biomecânico semelhante ao modelo de plataforma regular na análise do osso cortical. Enquanto que no osso medular, o modelo switching transmitiu mais tensão óssea do que o modelo Regular.

Stress distribution on dentin-cement-post interface varying root canal and glass fiber post diameters. A three-dimensional finite element analysis based on micro-CT data

Objective: The aim of the present study was to analyze the influence of root canal and glass fiber post diameters on the biomechanical behavior of the dentin/cement/post interface of a root-filled tooth using 3D finite element analysis. Material and Methods: Six models were built using micro-CT imaging data and SolidWorks 2007 software, varying the root canal (C) and the glass fiber post (P) diameters: C1P1-C=1 mm and P=1 mm; C2P1-C=2 mm and P=1 mm; C2P2-C=2 mm and P=2 mm; C3P1-C=3 mm and P=1 mm; C3P2-C=3 mm and P=2 mm; and C3P3-C=3 mm and P=3 mm. The numerical analysis was conducted with ANSYS Workbench 10.0. An oblique force (180 N at 45º) was applied to the palatal surface of the central incisor. The periodontal ligament surface was constrained on the three axes (x=y=z=0). Maximum principal stress (σmax) values were evaluated for the root dentin, cement layer, and glass fiber post. Results: The most evident stress was observed in the glass fiber post at C3P1 (323 MPa), and the maximum stress in the cement layer occurred at C1P1 (43.2 MPa). The stress on the root dentin was almost constant in all models with a peak in tension at C2P1 (64.5 MPa). CONCLUSION: The greatest discrepancy between root canal and post diameters is favorable for stress concentration at the post surface. The dentin remaining after the various root canal preparations did not increase the stress levels on the root. .

Barra de titânio pré-fabricada para prótese implantossuportada do tipo protocolo carga imediata: relato de caso clínico / Titanium prefabricated bar for immediate loading implant supported prosthesis: clinical report

A estabilidade primária dos implantes é um fator importante para o sucesso da osseointegração e fundamenta a aplicação das barras pré-fabricadas em mandíbulas edêntulas quando do uso de carga imediata. No entanto em algumas situações esta alternativa de tratamento não está indicada, devendo o profissional conhecer as características anatômicas do arco do paciente para ter segurança em utilizar a barra pré-fabricada. O presente artigo tem o objetivo de descrever um caso clínico utilizando uma barra pré-fabricada em mandíbula edêntula preparada para receber uma prótese implantossuportada do tipo protocolo carga imediata com acompanhamento clínico de 2 anos. Foi utilizado o sistema Neopronto (Neodent Implante Osseointegrável, Neodent, Curitiba, PR, Brasil) para direcionar paralelamente 4 implantes inter-foraminais e facilitar a instalação imediata da prótese protocolo. Pode-se constatar que a utilização da técnica da barra pré-fabricada é uma alternativa viável de tratamento para mandíbulas edêntulas, pois permite um nível da adaptação e passividade previsíveis, reduzindo o tempo clínico. Entretanto, sua indicação é precisa para casos em que o formato do arco do paciente se adapte perfeitamente a técnica.

The primary stability of implants is an important factor for osseointegration successful and justifies the application of prefabricated bars in edentulous mandible when the use of immediate loading. However in some situations this alternative treatment is not indicated, and the professional know the anatomic characteristics of the arch of the patient to have safety in using prefabricated bar. The purpose of this article was to describe a clinical report using a prefabricated bar in edentulous mandible prepared to receive an immediate loading implant-supported prosthesis type protocol with clinical follow-up of 2 years. The Neopronto system (Neodent Implante Osseointegrável, Neodent, Curitiba, PR, Brazil) was used to drive four parallel inter-foraminal implants and facilitate the installation of the immediate loading prosthesis. It can be conclude that the use of this prefabricated bar technique is a viable alternative treatment for edentulous mandible, because it allows a level of adaptability and passivity predictable, reducing clinical time. However, his indication is accurate for cases in which the shape of the arch of the patient perfectly suits technique.

Influence of high insertion torque on implant placement: an anisotropic bone stress analysis

The aim of this study was to evaluate the influence of the high values of insertion torques on the stress and strain distribution in cortical and cancellous bones. Based on tomography imaging, a representative mathematical model of a partial maxilla was built using Mimics 11.11 and Solid Works 2010 softwares. Six models were built and each of them received an implant with one of the following insertion torques: 30, 40, 50, 60, 70 or 80 Ncm on the external hexagon. The cortical and cancellous bones were considered anisotropic. The bone/implant interface was considered perfectly bonded. The numerical analysis was carried out using Ansys Workbench 10.0. The convergence of analysis (6 percent) drove the mesh refinement. Maximum principal stress (σmax) and maximum principal strain (εmax) were obtained for cortical and cancellous bones around to implant. Pearson's correlation test was used to determine the correlation between insertion torque and stress concentration in the periimplant bone tissue, considering the significance level at 5 percent. The increase in the insertion torque generated an increase in the σmax and εmax values for cortical and cancellous bone. The σmax was smaller for the cancellous bone, with greater stress variation among the insertion torques. The εmax was higher in the cancellous bone in comparison to the cortical bone. According to the methodology used and the limits of this study, it can be concluded that higher insertion torques increased tensile and compressive stress concentrations in the periimplant bone tissue.

O objetivo deste estudo foi avaliar a influência dos altos valores de torque de inserção na distribuição de tensões e deformações no osso cortical e medular. Com base em imagens de tomografia computadorizada, um modelo matemático representativo de um segmento da maxila foi construído utilizando os programas Mimics 11.11 e Solid Works 2010. Seis modelos foram construídos e cada um recebeu um implante com os seguintes torques de inserção no hexágono externo: 30, 40, 50, 60, 70 ou 80 Ncm. O osso cortical e medular foi considerado anisotrópico. A interface osso/implante foi considerada perfeitamente unida. A análise numérica foi realizada através do Ansys Workbench 10.0. A convergência de análise (6 por cento) determinou o refinamento da malha. A tensão máxima principal (σmax) e a deformação máxima principal (εmax) foram obtidos para o osso cortical e medular ao redor do implante. O teste de correlação de Pearson foi utilizado para determinar a correlação entre torque de inserção e de concentração de tensões e deformações no tecido ósseo peri-implantar, considerando o nível de significância de 5 por cento. O aumento no torque de inserção gerou um aumento nos valores σmax e εmax para o osso cortical e medular. O σmax foi menor para o osso medular, com maior variação de tensão entre os torques de inserção. O εmax foi maior no osso medular em relação ao osso cortical. De acordo com a metodologia utilizada e com os limites do estudo, pode-se concluir que torques alto de inserção aumentou as concentrações de tensões de tração e compressão no tecido ósseo peri-implantar.

Pesquisa estatística sobre os tipos de conexões implante/componentes protéticos mais utilizados no Brasil / Statistical survey of types of connections implant/prosthetic component most used in the Brazil

Atualmente encontra-se disponível no mercado de Implantodontia uma grande variedade de desenhos de implante e de componentes protéticos, propiciando os mais diversos tipos de designs de restauração sobre implante. O objetivo deste trabalho foi avaliar o design da restauração (plataforma regular ou reduzida) e o tipo de conexão do implante (hexágono externo, hexágono interno e cone morse) preferencialmente usados no Brasil e os motivos que justificaram essa escolha pelos profissionais. Para isso, foram entrevistados 216 profissionais durante o 31º Congresso Internacional de Odontologia de São Paulo (CIOSP), realizado no ano de 2013. A maioria dos entrevistados foi do gênero masculino (67,7%), especialistas (59,2%) e com até cinco anos de graduado (25,0%). Observou-se que a maioria dos profissionais entrevistados utiliza hexágono externo (52,8%), seguido por hexágono interno (22,2%), cone morse (24,0%) e replace select (0,9%). Em relação aodesignda interface pilar implante, observou-se que a maioria prefere plataforma regular (58,4%) em relação à plataforma reduzida (41,6%). Concluiu-se que a maioria dos profissionais que atua na área de Implantodontia no Brasil opta pela utilização de restaurações sobre implante com hexágono externo e plataforma regular principalmente devido à conveniência de uso...

It is currently available in the Implantology market a wide variety of implant designs and abutments, providing many types of designs for implant-supported restorations. The aim of this study was to evaluate the restoration design (regular or reduced platform) and the type of implant connection (external hexagon, internal hexagon, and morse-tape connection) preferably used in Brazil and the reasons for that choice. For this, 216 professionals were interviewed during the 31st International Dental Congress of São Paulo (CIOSP), in 2013. The respondents were mostly men (67.7%), specialists in Implantology (59.2%), and up to five years of graduation (25%). Among the types of the implant connections selected, most of respondents used external hexagon (52.8%), followed by internal hexagon (22.2%), morse-tape connection (24.0%), replace select system (0.9%). Regarding the design of implant-abutment interface, it was observed that most of the respondents used regular platform (58.4%), followed by reduced platform (41.6%). It was concluded that most of the professionals working with dental implants in Brazil prefer external hexagon and regular platform due convenience of use...

Influence of voids in the hybrid layer based on self-etching adhesive systems: a 3-D FE analysis

The presence of porosities at the dentin/adhesive interface has been observed with the use of new generation dentin bonding systems. These porosities tend to contradict the concept that etching and hybridization processes occur equally and simultaneously. Therefore, the aim of this study was to evaluate the micromechanical behavior of the hybrid layer (HL) with voids based on a self-etching adhesive system using 3-D finite element (FE) analysis. MATERIAL AND METHODS: Three FE models (Mr) were built: Mr, dentin specimen (41x41x82 μm) with a regular and perfect (i.e. pore-free) HL based on a self-etching adhesive system, restored with composite resin; Mp, similar to M, but containing 25 percent (v/v) voids in the HL; Mpp, similar to Mr, but containing 50 percent (v/v) voids in the HL. A tensile load (0.03N) was applied on top of the composite resin. The stress field was obtained by using Ansys Workbench 10.0. The nodes of the base of the specimen were constrained in the x, y and z axes. The maximum principal stress (σmax) was obtained for all structures at the dentin/adhesive interface. RESULTS: The Mpp showed the highest peak of σmax in the HL (32.2 MPa), followed by Mp (30 MPa) and Mr (28.4 MPa). The stress concentration in the peritubular dentin was high in all models (120 MPa). All other structures positioned far from voids showed similar increase of stress. CONCLUSION: Voids incorporated into the HL raised the σmax in this region by 13.5 percent. This behavior might be responsible for lower bond strengths of self-etching and single-bottle adhesives, as reported in the literature.

Biomecânica em prótese sobre implante relacionada às inclinações das cúspides e às angulações dos implantes osseointegrados: revisão de literatura / Biomechanics in prosthesis over implant related to cusp inclinationsand angulations of osseointegrated implants: a literature review

Os aspectos biomecânicos em prótese sobre implante influenciam significantemente o sucesso dos implantes osseointegrados. O fator chave para a obtenção deste sucesso é a maneira como o estresse é transferido à interface osso-implante. Nesse sentido, evidências mecânicas mostram que os fatores que influenciam a distribuição de tensão no osso são a inclinação da cúspide da coroa, o momento de torque e a inclinação do implante. Por este motivo, realizou-se uma revisãoda literatura sobre a influência de fatores biomecânicos, como a inclinação da cúspide e a angulação do implante osseointegrado, na distribuição de tensão ao osso, a fim de facilitar a compreensão dosprincípios oclusais e conferir maior segurança aos cirurgiões-dentistas na confecção das próteses sobre implantes. Para tanto, utilizaram-se os indexadores OldMedline, Medline database e BBO no período de 1989 a 2007, cruzando os termos cusp inclination e implant inclination e selecionaram-se os artigos que possuíam uma maior correlação com o objetivo do presente trabalho. De acordo com os autores analisados, pode-se concluir que: a oclusão em prótese sobre implante é um fatorfundamental para melhorar a distribuição de forças ao longo eixo do implante, devendo-se diminuir a inclinação das cúspides, reduzindo o braço de alavanca e a ocorrência de contatos excêntricos; asinclinações acentuadas dos implantes devem ser evitadas, sempre que possível, a fim de favorecer a distribuição de forças ao longo eixo do implante.

The biomechanic aspects in prosthesis over implant have significant influence on the success of osseointegrated implants. The key-factor to obtaining this success is the way how stress is tranfered to interface-bone-implant. In this sense, mechanic evidences show that the factor thatinfluence stress distribution on the bone are crown cusp inclination, the torque moment and implant inclination. For this reason, a literature review was elaborated on the influence of biomechanic factors, such as cusp inclination and the angulation of osseointegrated implants on bone stressdistribution, in order to make it easier to understand the occlusal principles and provide dentistsurgeons with better safety in preparing prostheses over implants. Hence, OldMedline, Medline Database and BBO indexers were used during the period from 1989 to 2007, crossing the termscusp inclination and implant inclination and the articles which had more co-relation to the purpose of the present paper were selected. According to the evaluated authors, it can be concluded that: occlusion in prosthesis over implant is a fundamental factor to improve the distribution of forcesto the long axis of the implant, so that cusp inclination must be diminished by reducing the lever arm and the occurrence of eccentric contacts; accentuated implant inclinations must be avoided whenever it is possible in order to favor the distribution of forces to the long axis of the implant.

Avaliação da Qualidade do Sono em Grupos com Diferentes Níveisde Desordem Temporomandibular / Evaluation of the Sleep Quality in Groups with Different Levels of Temporomandibular Disorders

Objetivo: Avaliar a prevalência entre as DTMs e a qualidade dosono.Método: Foram distribuídos 101 questionários para uma populaçãode universitários, com idade variando entre 17 a 28 anos, compostade 36 homens e 65 mulheres. Cada indivíduo respondeu a doisquestionários, um para avaliar a presença de DTM e outro a qualidadedo sono. O paciente foi qualificado como portador de DTMs emquatro graus distintos: severo, moderado, leve e sem DTM, e comnível de qualidade de sono variando de 0 (ótima qualidade de sono)até 21 (qualidade de sono péssima).Resultados: A maior parte da população estudada apresentougrau de DTM leve e uma pequena parcela, DTM severa. Osresultados mostraram que a distribuição das DTMs na populaçãogeral foi de 51 por cento para DTM leve, 23 por cento para DTM moderada e 7 por centopara DTM severa. E ainda, cerca de 50 por cento possui um PSQId”5, comsono de baixa qualidade.Conclusão: O aumento do grau de desordem leva a uma piora daqualidade do sono ou vice-versa, com 50 por cento da população sem DTMapresentando PSQI<5 para 70 por cento da população com DTM severaapresentando PSQI<5. Por ser estudo de prevalência (sem testesde correlação ou associação), sugerimos que os resultados sejamutilizados para identificar uma tendência a ser confirmada emestudos futuros.