Effectiveness of Elastic Therapeutic Tape in Reducing Edema, Pain and Trismus following Surgery for Facial Fractures: A Systematic Review and Meta-Analysis.

Facial fractures cause postoperative morbidity, including edema, pain, and trismus. Elastic therapeutic tapes are used for optimizing recovery. Background: The aim of the present systematic review and meta-analysis was to evaluate the effectiveness of elastic tape Kinesio taping (KT) in reducing postoperative morbidity in facial fractures surgeries. Methods: A systematic review was conducted in accordance with the PRISMA guidelines. Searches were conducted in the Cochrane, Medline, Scopus, Embase and Web of Science databases using a pre-established search strategy. Results: A total of 811 studies were retrieved after the duplicates were removed, and only randomized clinical trials were included. Eight trials, involving 319 participants, were deemed eligible. One study solely investigated the effect on edema, while the others analyzed at least two of the variables of interest. Results from two RCTs, where qualitative analysis was applicable, suggest a potential reduction in edema in the KT group compared to the control group on the second (RR -0.55, 95% CI -0.89 to -0.22; p = 0.01; I2 = 0%) and third postoperative days (RR -0.71, 95% CI -1.01 to -0.40; p < 0.00001; I2 = 0%). Conclusions: KT is effective in controlling postoperative edema following surgery for facial fractures. However, the effects on pain and trismus should be explored further in studies with standardized methods.

Factors Associated with Nonadaptation to New Mandibular Complete Dentures: A Scoping Review.

PURPOSE: To identify and map the scientific evidence regarding factors associated with the nonadaptation of completely edentulous patients to mandibular complete dentures. MATERIALS AND METHODS: This scoping review followed the PRISMA-ScR statement for Scoping Reviews and was based on guidelines proposed by Arksey and O'Malley and the Joanna Briggs Institute Manual for Evidence Synthesis. The methodology was registered on the Open Science Framework. An electronic search strategy was conducted in PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, Virtual Health Library, ClinicalTrials.gov, Google Scholar, and ProQuest databases was conducted. Studies that evaluated factors associated with adaptation to and acceptance of mandibular complete dentures were included, such as sociodemographic, psychologic, patient-related, and denture-related items. RESULTS: The search conducted in March 2022 yielded 9,978 studies. In total, 24 studies were included for data extraction. Sociodemographic factors did not interfere with adaptation to a mandibular complete denture. Psychologic factors and patient-related aspects showed greater association with nonadaptation to mandibular complete dentures than denture-reported factors. CONCLUSION: Although it is suggestive that psychologic and patient-related factors have higher association with the acceptance of new dentures, data must be interpreted with caution due to the variability of methodologies of the studies included in this review.

Rehabilitation with dental prostheses and its influence on brain activity: A systematic review.

STATEMENT OF PROBLEM: The consequences of edentulism depend on its complexity and are far-reaching, but limited evidence regarding its association with neurologic health is available. PURPOSE: The purpose of this systematic review was to establish the relationship between oral prosthetic rehabilitation and the regional increase in brain activity. MATERIAL AND METHODS: This systematic review was registered in the International Prospective Register of Systematic Reviews (CRD42021262247), and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was followed. Randomized clinical trials, prospective studies comparing the brain activity of patients rehabilitated with and without the use of dental prostheses, and studies that analyzed the human brain by using noninvasive techniques were used as inclusion criteria. The risk of bias in each study was assessed by using the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I). RESULTS: The search was carried out in the PubMed/MEDLINE, Embase, Cochrane Library, and https://clinicaltrials.gov databases up to June 2021. After a search conducted by 2 reviewers, 8 articles were included in the review. A regional increase in blood flow and regional cerebral activity during dental prosthesis use was identified in the studies. CONCLUSIONS: A positive association was found between the different types of prosthetic rehabilitation and brain function. Prostheses may preserve and restore neurological health.

Do Computerized Delivery Systems Promote Less Pain and Anxiety Compared to Traditional Local Anesthesia in Dental Procedures? A Systematic Review of the Literature.

PURPOSE: The aim of this study is to assess whether the use of computerized devices to deliver local anesthesia results in less pain and anxiety compared to traditional anesthesia in adult dental procedures. METHODS: This review was registered at PROSPERO (CRD 42021265046), based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was structured according to the PICO strategy. The studies were selected based on eligibility criteria, and data were collected by 1 author and reviewed by another. RESULTS: Nine of the 10 studies included were randomized controlled trials. Differences related to pain and anxiety were observed, which favored computerized techniques; however, caution should be exercised when interpreting these results due to differences in assessment methods. The studies used different local anesthetics, including 2% lidocaine, 4% articaine, or 3% mepivacaine with epinephrine diluted 1:80,000 to 1:200,000. A total of 560 patients were evaluated. CONCLUSIONS: Computerized anesthesia devices yielded better results than conventionally delivered anesthesia after qualitative evaluation. Nevertheless, conventional anesthesia is widely used, safe, and effective. Due to the heterogeneity among the included studies, it is strongly recommended that new randomized clinical trials using well-defined methodologies be performed to improve the quality of evidence regarding this topic.

Do ball-type attachment systems for overdenture result in better patient-satisfaction? A systematic review of randomized crossover clinical trial.

OBJECTIVE: This review is to compare patient-satisfaction with ball-type overdenture attachment systems with others attachment systems. MATERIAL AND METHODS: This study was registered in PROSPERO (CRD42018097234) and adheres the PRISMA guidelines. Electronic searches on PubMed/MEDLINE, Scopus, Cochrane, and Web of Science databases for published articles were performed before October 2020. The PICO question was: "Do patients with a ball-type overdenture retention system have greater satisfaction, when compared to other attachment systems?" The evaluation of risk of bias was performed using the Cochrane risk of bias tool. RESULTS: After searching the databases, seven articles were selected out of a total of 2583. A total of 312 implants were placed in 139 patients, with a mean age of 65.9 years. The risk of bias in the included studies varied according to the different domains in a risk of uncertain bias or low bias risk. No difference was found between the ball attachment systems and the others systems, with respect to patient-satisfaction. The meta-analysis revealed no statistically significant difference between the ball systems and another systems (P = 0.11; MD: 10.90; 95% CI: -2.55 to 24.35). CONCLUSIONS: Regarding patient general satisfaction, it was not possible to determine differences between the ball system and another types of attachment system for overdenture. The ball-type system was statistically superior only to the magnet system.

Existe relação entre doenças respiratórias e próteses dentárias removíveis contaminadas? Uma revisão sistematizada da literatura / Relationship between respiratory diseases and contaminated removable dental prostheses

Objetivo: O objetivo dessa revisão sistematizada da literatura foi analisar a associação entre o uso de próteses dentárias removíveis e doenças respiratórias prevalentes. Materiais e métodos: Este estudo foi conduzido seguindo os critérios do PRISMA check-list (Preferred Reporting Items for Systematic Review and Meta-Analysis). A base de dados eletrônica selecionada foi a PubMed/MEDLINE, sem restrições do ano de publicação. Estudos prospectivos e retrospectivos (ensaios clínicos randomizados, ensaios clínicos controlados, estudos de coorte, estudos caso-controle e estudos transversais), estudos in vitro e publicados em inglês foram escolhidos como critérios de elegibilidade. Resultados: A busca inicial na base de dados obteve 553 artigos e 8 deles foram selecionados baseados nos critérios de elegibilidade e subdivididos em dois tópicos: doença pulmonar obstrutiva crônica e pneumonia por aspiração. Conclusão: Com base nos estudos avaliados existe associação entre as próteses dentárias removíveis contaminadas e doenças respiratórias... (AU)

Objective: The purpose of this review was to analyze the association between the use of removable dental prostheses and the prevalence of respiratory diseases. Methodology: This study was conducted following the criteria of PRISMA check-list (Preferred Reporting Items for Systematic Review and Meta-Analysis). The database selected was PubMed/MEDLINE, with no restrictions on the year of publication. Prospective and retrospective studies (randomized clinical trials, controlled clinical trials, cohort studies, case-control studies and cross-sectional studies), in vitro studies and published in English were selected in tehe eligibility criteria. Results: The search in the database obtained 553 articles and 8 of them were selected based on the eligibility criteria and subdivided into two topics: chronic obstructive pulmonary disease and aspiration pneumonia. Conclusion: Based on the studies evaluated, there is an association between contaminated removable dental prostheses and respiratory diseases... (AU)

Use of chlorhexidine chip after scaling and root planning on periodontal disease: A systematic review and meta-analysis.

OBJECTIVE: This systematic review aims to assess the efficacy chlorhexidine chip as an adjunctive therapy of scaling and root planning on periodontal disease treatment. MATERIAL AND METHODS: This study follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) and was registered in the PROSPERO database (CRD42019148221). The search was performed in PubMed/MEDLINE, Scopus, and Cochrane databases until April 2020. The PICO question was: "Is the chlorhexidine chip (CHX) effective as an adjunctive therapy of scaling and root planning on periodontal disease treatment?". Inclusion criteria involved: randomized controlled clinical trials, with a minimum of 15 patients included on the sample and each patient has two sites of probing depth of ≥5 mm; The minimum follow up was at least 1 months of follow-up and the outcomes present in the studies probing depth (PD), plaque index (PI) and clinical attachment level (CAL) after scaling and root planning (SRP). RESULTS: After searching the databases, 13 articles were selected for qualitative and 8 for quantitative analysis. Were included 427 patients, with a mean age of 45.6 years. The results shown that the association of chlorhexidine chips to scaling and root planning reduce periodontal pocket depths (P < 0.00001; MD -0.77 [CI -1.0 to -0.55]; I2 = 23%, P = 0.24), gain on the clinical attachment level (P < 0.0001; MD -0.57 [CI -0.86 to -0.27]; I2 = 33%, P = 0.18P < 0.0001) and reduction on plaque index (P = 0.04; MD -0.23 [CI -0.45 to -0.01]; I2 = 91%, P < 0.00001). CONCLUSIONS: Thus, we can conclude that chlorhexidine chip when used associated to scaling and root planning promoted a significant improvement the reduction of periodontal diseases.

Relationship between bariatric surgery and dental erosion: a systematic review.

BACKGROUND: Bariatric surgery can have several oral repercussions, including tooth erosion due to decreased salivary flow associated with the action of acidic pH and behavioral modifications in the diet that lead to the dissolution of mineralized dental tissues. OBJECTIVES: This systematic review aimed to evaluate whether bariatric surgery presented a greater risk of dental erosion. SETTING: Dentistry School, Pernambuco University, Camaragibe, Pernambuco, Brazil. METHODS: This review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) and registered at the International Prospective Registry of Systematic Reviews (CRD42019124960). A search was performed in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases using the following descriptors: "dental erosion OR tooth wear OR oral health OR dental wear OR tooth erosion OR salivary flow AND bariatric surgery OR gastrectomy OR obesity surgery". RESULTS: The review included 553 articles (after exclusion of duplicates) submitted for title and abstract reading, of which 24 were selected for full text analysis. Five articles fulfilling the eligibility criteria were included in the qualitative and quantitative analysis review. Because of high heterogeneity of the studies, meta-analysis could not be performed. CONCLUSIONS: Based on the review, we concluded that patients undergoing bariatric surgery had a higher incidence of dental erosion. All studies presented a high degree of dental erosion in patients submitted to bariatric surgery (P < .05).

Influence of addition of zirconia on PMMA: A systematic review.

The objective of this systematic review is to evaluate the effect of the incorporation of zirconia (ZrO2) particles on the mechanical properties of PMMA (polymethyl methacrylate), and to establish which characteristics of this material yield the best results aiming their biomedical applicability. This study was carried out in accordance with the Items of Preferred Reports for Systematic Reviews and Meta-Analyzes (PRISMA) and is registered in PROSPERO under registration number: CRD42018095801. The searches were carried out in the PubMed, MEDLINE, Scopus and Cochrane Library databases for articles published up until April 2018. After the different stages of the article selection process, eight articles were selected for qualitative and quantitative analysis. All were in vitro studies, totaling 536 evaluated samples. The concentrations of zirconia ranged from 0.5% to 20% and the particle sizes were between 15 nm and 10 µm. The incorporation of zirconia particles did not increase the flexural strength of PMMA in only one study. While the concentration of zirconia influences PMMA, the type of acrylic resin, size, and silanization of zirconia particles did not influence the results. Thus, the addition of zirconia particles showed a positive effect on PMMA enhancing their use in the medical and dental field, especially when certain anatomical areas requires higher strength of the materials, providing longevity for the rehabilitation.

Systematic review and meta-analysis of welding procedures in one-piece cast implant-supported frameworks.

The objective of this systematic review and meta-analysis was to evaluate the effect of welding techniques on implant-supported prostheses and determine whether they contribute to a better adaptation compared with a one-piece cast. A search was conducted using the PubMed/MEDLINE, Embase, and Cochrane Library databases, and articles published until November 2017 were obtained from these databases. This review followed the PRISMA criteria and is registered on the PROSPERO platform (CRD42017081865). The PICO question was "Do welding procedures in one-piece cast implant-supported frameworks influence implant/abutment-framework marginal misfits?" Eleven studies were selected for a qualitative analysis, and seven studies were selected for a quantitative analysis. A total of 189 specimens were fabricated using different materials (cp-Ti, Ni-Cr, Cr-Co, and noble alloys), and welding techniques such as laser welding, conventional welding, tungsten inert gas, and brazing were applied. A vertical marginal misfit was measured using an optical microscope, a stereomicroscope, and/or a scanning electron microscopy. The qualitative analysis in the studies demonstrated a positive effect of the welding techniques on the adaptation of the infrastructures. The meta-analysis confirmed the results (p < 0.00001; MD: -36.14; 95%CI: -48.69 to -23.59). Within the limitations of this study and regarding the heterogeneity of the samples, we conclude that the soldering point technique is effective for obtaining relatively low values of marginal misfit, with laser welding as the most effective technique. However, additional studies were recommended due to the heterogeneity of different variables (alloys, connection, and misfit evaluation) in the included studies.

Clinical periodontal conditions in individuals after bariatric surgery: a systematic review and meta-analysis.

The aim of the present study was to perform a systematic review and meta-analysis to assess the influence of bariatric surgery on the clinical periodontal conditions in patients with obesity. This review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and registered at the International Prospective Registry of Systematic Reviews (CRD42018099313). A search was conducted by 2 investigators in the PubMed/MEDLINE, Web of Science, and Cochrane Library databases for relevant articles published up to May 2018. The inclusion criteria were randomized controlled trials, prospective and retrospective studies, observational studies, longitudinal studies, and cohort studies with at least 3 months of follow-up. No language restrictions were imposed. The exclusion criteria were studies that did not evaluate or report the periodontal measurements, cross-sectional studies (without follow-up after surgery), studies that performed periodontal treatment, and those with insufficient periodontal data. The meta-analysis was based on the Mantel-Haenszel method and inverse variance. The quantitative analysis revealed no statistically significant differences with regard to bleeding on probing (P = .9; mean deviation: -.70; confidence interval = -11.43 to 10.04) or probing pocket depth (P = .41; mean deviation: -.46; confidence interval = -1.55 to .63) before and after intervention. Clinical attachment loss showed a statistically significant difference (P = .0002; mean deviation: .18; confidence interval = .07-.30). It can be concluded that bariatric surgery does not influence bleeding on probing or probing pocket depth, but leads to a worsening of clinical attachment loss.

Three-Dimensional Finite Element Analysis of Varying Diameter and Connection Type in Implants with High Crown-Implant Ratio

Abstract The aim of this study was to evaluate the effect of varying the diameter, connection type and loading on stress distribution in the cortical bone for implants with a high crown-implant ratio. Six 3D models were simulated with the InVesalius, Rhinoceros 3D 4.0 and SolidWorks 2011 software programs. Models were composed of bone from the posterior mandibular region; they included an implant of 8.5 mm length, diameter Ø 3.75 mm or Ø 5.00 mm and connection types such as external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Models were processed using the Femap 11.2 and NeiNastran 11.0 programs and by using an axial force of 200 N and oblique force of 100 N. Results were recorded in terms of the maximum principal stress. Oblique loading showed high stress in the cortical bone compared to that shown by axial loading. The results showed that implants with a wide diameter showed more favorable stress distribution in the cortical bone region than regular diameter, regardless of the connection type. Morse taper implants showed better stress distribution compared to other connection types, especially in the oblique loading. Thus, oblique loading showed higher stress concentration in cortical bone tissue when compared with axial loading. Wide diameter implant was favorable for improved stress distribution in the cortical bone region, while Morse taper implants showed lower stress concentration than other connections.

Resumo O objetivo deste estudo foi avaliar o efeito da variação do diâmetro e dos tipos de conexão na distribuição do estresse no osso cortical para implantes com a proporção coroa-implante. Seis modelos 3D foram simulados com os programas InVesalius, Rhinoceros 3D 4.0 e SolidWorks 2011. Os modelos foram compostos de osso da região mandibular posterior. Foram incluídos implantes de 8,5 mm de comprimento, diâmetro Ø 3,75 mm ou Ø 5,00 mm, e tipos de conexão como hexágono externo (EH), hexágono interno (IH) e cone Morse (MT). Os modelos foram processados usando os programas Femap 11.2 e NeiNastran 11.0 e usando uma força axial de 200 N e força oblíqua de 100 N. Os resultados foram registrados em termos da tensão principal máxima. O carregamento oblíquo mostrou alta tensão no osso cortical em comparação com a carga axial. Os resultados mostraram que os implantes com maior diâmetro apresentaram distribuição de tensões mais favorável, independentemente do tipo de conexão, enquanto que os implantes cone Morse apresentaram melhores distribuição de tensões comparado aos outros tipos de conexão, especialmente no carregamento oblíquo. Assim, os implantes de maior diâmetro foram mais favoráveis para distribuição das tensões na região de tecido ósseo cortical, enquanto que os implantes cone Morse apresentam menores concentrações de tensões do que as outras conexões.

Three-Dimensional Finite Element Analysis of Varying Diameter and Connection Type in Implants with High Crown-Implant Ratio.

The aim of this study was to evaluate the effect of varying the diameter, connection type and loading on stress distribution in the cortical bone for implants with a high crown-implant ratio. Six 3D models were simulated with the InVesalius, Rhinoceros 3D 4.0 and SolidWorks 2011 software programs. Models were composed of bone from the posterior mandibular region; they included an implant of 8.5 mm length, diameter Ø 3.75 mm or Ø 5.00 mm and connection types such as external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Models were processed using the Femap 11.2 and NeiNastran 11.0 programs and by using an axial force of 200 N and oblique force of 100 N. Results were recorded in terms of the maximum principal stress. Oblique loading showed high stress in the cortical bone compared to that shown by axial loading. The results showed that implants with a wide diameter showed more favorable stress distribution in the cortical bone region than regular diameter, regardless of the connection type. Morse taper implants showed better stress distribution compared to other connection types, especially in the oblique loading. Thus, oblique loading showed higher stress concentration in cortical bone tissue when compared with axial loading. Wide diameter implant was favorable for improved stress distribution in the cortical bone region, while Morse taper implants showed lower stress concentration than other connections.

Conhecimento sobre uso, conservação e higienização de próteses totais em população desfavorecida socioeconomicamente assistida por um projeto de extensão universitária / Knowledge of use, maintenance and cleaning of dentures in socioeconomically disadvantaged population assisted by a university extension project

Introdução: a prótese dentária total é um órgão artificial que deve promover a saúde e a qualidade de vida. O modo de uso, conservação e higienização é parte fundamental para o sucesso e longevidade da mesma. Uma ferramenta que parece ser eficaz na detecção e disseminação desse tipo de informação é a extensão universitária. Objetivo: analisar o nível de conhecimento sobre o uso, conservação e higienização de próteses totais em uma população de baixa renda, através de estudo epidemiológico transversal. Métodos: a amostra de conveniência foi composta por 37 usuários de próteses totais atendidos em uma ação do programa de extensão universitária Resgatando Sorrisos da Universidade de Pernambuco, que promove ações terapêuticas e informativas sobre as áreas de prótese dentária, dentística, patologia e pacientes com necessidades especiais. Após assinatura do termo de consentimento livre e esclarecido (TCLE), foram coletadas informações sociodemográficas e sobre hábitos de uso e higiene das próteses, através de um questionário aplicado por pesquisadores em ambiente reservado. Os dados foram interpretados por meio de análise descritiva e analítica entre as variáveis com nível de significância considerado, p < 0,05. Resultados e Discussão: dos pacientes, 70,27% dormem com as próteses; sobre frequência de higienização, 43,2% relatam fazer pelo menos 3 vezes ao dia, sendo o uso da escova e creme dental o método mais utilizado (83,78% - 31 entrevistados); características como bases e dentes desgastados, presença de biofilme/tártaro foram encontradas em mais 50% das próteses totais. Não foi observada nenhuma correlação estatisticamente significativa entre as variáveis (p>0,05). Conclusão: o nível de conhecimento sobre o uso, conservação e higienização de próteses totais da população estudada precisa ser melhorado, uma vez parte da população ainda apresenta hábitos de uso e higiene de próteses totais inadequados.(AU)

Introduction: the dental total prosthesis is an artificial organ that should promote health and quality of life. The way of use, conservation and hygiene is fundamental for the success and longevity of it. One tool that seems to be effective in detecting and disseminating this type of information is activities of University extension. Objectives: to analyze the level of knowledge about the use of complete sets of dentures and their conservation in a low-income population through a cross-sectional epidemiological study. Methods: This research had a convenience sample of 37 users of complete sets of dentures. Datawas collected using a questionnaire applied by two trained examiners. The data were interpreted via descriptive and statistical analysis (tests of Kruskal-wallis e Kolmogorov ­ Smirnov/ p =0,05). Results: The average income of the sample was R$ 668.00. The average time of denture use was 7.3 years; 70.27% of the patients sleep with their dentures, and 83.78% of them sanitize the dentures with a toothbrush and toothpaste. Conclusion: Regarding the variables association, we noticed tendencies yet to be explored in the habits of the complete denture wearer. Moreover, we conclude that the population's level of knowledge on the subject needs to be improved. Thereby, once these conditions are detected and transmitted to government officials, the extension project through the research tool will be able to assist government's course of action regarding oral health.(AU)

Impacto de uma experiência extensionista na formação universitária / Impact of an extension experience in university education

Este estudo teve como objetivo analisar o impacto do projeto de extensão universitária, Resgatando Sorrisos, na formação de estudantes do curso de Odontologia da FOP - UPE, nos anos de 2013 e 2014. Foram utilizados 02 questionários em momentos distintos, tendo como amostra 71 alunos. Foi utilizado o teste de hipótese estatística Wilcoxon para comparar as respostas de antes e depois da ação. Diante da elevada frequência de respostas, como "muitíssimo" e "bastante", observamos um alto grau de aceitação e entendimento da importância do projeto na formação do aluno, assim como no que se refere à capacidade de mudança que o projeto pode causar na vida dos pacientes e sua possível aplicabilidade no sistema público de saúde, dentre outras questões. Contudo, observa-se no ano de 2014 em quesito referente ao grau de expectativa inicial e satisfação final do projeto, uma diferença estatística entre a ida e a volta, p=o,o1. Conclui-se que os alunos apresentam um entendimento positivo em relação à ação extensionista, considerando-a importante para sua formação profissional e pessoal... (AU)

The aim of this study was to analyze the impact of the University Extension Project, ResgatandoSorrisos, in the graduation process of students of Dentistry course FOP - UPE in the years of 2013 and 2014. There were 02 questionnaires used, at different times, with a sample size 71 students. Wilcoxon statistical hypothesis test was used to compare responses before and after the action. Such high frequency responses of "vital" and "enough", a high degree of acceptance and understanding of the importance of the project in the formation of the student was observed, as well as the capacity of a change that the project may cause in the lives of patients and its possible applicability in the public health system, among other issues. However, in 2014, there was a statistical difference between the outward and return (p = o, o1) in a question referring to initial degree of expectation and ultimate satisfaction of the project. It was concluded that students have a positive understanding about the extension action, and they consider it important for their professional and personal training... (AU)

A 3-D Finite Element Study of the Influence of Crown-Implant Ratio on Stress Distribution

The purpose of this study was to assess the influence of the crown height of external hexagon implants on the displacement and distribution of stress to the implant/bone system, using the three-dimensional finite element method. The InVesalius and Rhinoceros 4.0 softwares were used to generate the bone model by computed tomography. Each model was composed of a bone block with one implant (3.75x10.0 mm) with external hexagon connections and crowns with 10 mm, 12.5 mm and 15 mm in height. A 200 N axial and a 100 N oblique (45°) load were applied. The models were solved by the NeiNastran 9.0 and Femap 10.0 softwares to obtain the results that were visualized by maps of displacement, von Mises stress (crown/implant) and maximum principal stress (bone). The crown height under axial load did not influence the stress displacement and concentration, while the oblique loading increased these factors. The highest stress was observed in the neck of the implant screw on the side opposite to the loading. This stress was also transferred to the crown/platform/bone interface. The results of this study suggest that the increase in crown height enhanced stress concentration at the implant/bone tissue and increased displacement in the bone tissue, mainly under oblique loading.

A proposta deste estudo foi avaliar a influência da altura da coroa de implantes de hexágono externo sobre o deslocamento e distribuição de tensões para o sistema implante/osso utilizando o método de elementos finitos. Os softwares InVesalius e Rhinoceros 4.0 foram usados para gerar o modelo de osso por meio de uma tomografia computadorizada. Cada modelo foi composto de um bloco ósseo com um implante (3.75 x 10.0 mm) com conexão de hexágono externo e coroas de 10 mm, 12.5mm e 15 mm em altura. Uma carga axial de 200 N e oblíqua (45°) de 100 N foram aplicadas. Os modelos foram resolvidos pelo software NeiNastram 9.0 e Femap 10.0 para obtenção dos resultados que foram visualizados por meio de mapas de deslocamento, de von Mises (coroa/implante) e tensão máxima principal (osso). A altura da coroa sob carga axial não influenciou o deslocamento e concentração de tensões, enquanto que a carga oblíqua aumentou a ação destes fatores. A maior concentração de tensões foi observada no pescoço do parafuso do implante no lado oposto à aplicação de carga. Esta tensão foi transferida para a interface coroa/plataforma/interface óssea. Os resultados deste estudo sugerem que o aumento da coroa amplia a concentração de tensões no tecido ósseo/implante, aumentando o deslocamento no tecido ósseo, principalmente sob carga oblíqua.