Analysis of the atrophic mandible rehabilitated with fixed total prosthesis on mono or bicortical implants.

Rehabilitation of edentulous atrophic mandibles involves the placement of implants in the anterior segment of the mandible. The primary stability of these implants can be improved using the base of the mandible as complementary anchorage (bicorticalization). This study aimed to analyze the biomechanics of atrophic mandibles rehabilitated with monocortical or bicortical implants. Two three-dimensional virtual models of edentulous mandibles with severe atrophy were prepared. Four monocortical implants were placed in one model (McMM), and four bicortical implants were placed in the other (BcMM). An implant-supported total prosthesis was prepared for each model. Then, a total axial load of 600 N was applied to the posterior teeth, and its effects on the models were analyzed using finite element analysis. The highest compressive stresses were concentrated in the cervical region of the implants in the McMM (-32.562 Mpa); in the BcMM, compressive stresses were distributed in the upper and lower cortex of the mandible, with increased compressive stresses at the distal implants (-63.792 Mpa). Thus, we conclude that axial loading forces are more uniformly distributed in the peri-implant bone when using monocortical implants and concentrated in the apical and cervical regions of the peri-implant bone when using bicortical implants.

Intrusion of overerupted periodontally compromised posterior teeth using orthodontic mini implants: A mechanobiological finite element study.

INTRODUCTION: The intrusion of posterior teeth had been considered challenging up to the development of orthodontic mini implants. In periodontally compromised teeth, the challenge is even greater, because of the root resorption risk due to periodontal ligament over-compression. Still, the precise strategy to determine the force reduction level remains uncertain. OBJECTIVE: The objective of the study was to determine, by a finite element analysis (FEA), the force reduction needed to avoid root resorption and maintain the efficiency of orthodontic mechanics of periodontally compromised teeth similar to the sound one. METHODS: An anatomical model was constructed representing a premolar inserted into a maxillary bone. Based on the initial model (R0), three bone height loss conditions were simulated (R2 = 2 mm, R4 = 4 mm, and R6 = 6 mm). Two intrusive movements were simulated: pure intrusion (bilateral mini implant) and uncontrolled-tipping intrusion (buccal mini implant). The hydrostatic stress at the periodontal ligament was used to evaluate the risk of root resorption due to over-compression. RESULTS: For bilateral mini implant intrusion, the force had to be decreased by 16%, 32% and 48% for R2, R4 and R6, respectively. For buccal mini implant intrusion, the required reductions were higher (20%, 36% and 56%). A linear relationship between the intrusive force reduction and the alveolar bone height loss was observed in both intrusion mechanics. CONCLUSIONS: According to the FE results, 8% or 9.3% of force reduction for each millimetre of bone height loss is suggested for intrusion with bilateral or buccal mini implant, respectively. The buccal mini implant anchorage must be associated with a supplemental strategy to avoid buccal crown tipping.

Avaliação dos impactos financeiros gerados pela pandemia da Covid-19 aos técnicos de prótese dentária no Brasil / Assessing the financial impacts of the COVID-19 pandemic on denture technicians in Brazil

Resumo Introdução a pandemia da Covid-19 e medidas de controle da sua expansão impactaram diferentes segmentos da economia, dentre eles os profissionais da Odontologia. Objetivo este trabalho analisou o impacto financeiro gerado pela pandemia da Covid-19 aos técnicos de prótese dentária (TPDs) no Brasil. Material e método por meio de um estudo transversal descritivo, aplicou-se aos TPDs do Brasil um questionário relacionado ao perfil sociodemográfico e profissional, impacto financeiro e medidas adotadas para minimizar seus efeitos. O questionário foi aplicado de forma on-line em redes sociais entre 27 de janeiro e 15 de fevereiro de 2021. Resultado demonstrou-se que 59,8% dos participantes eram do sexo masculino; 47,5% até 30 anos de idade e 57,3% com menos de 10 anos de prática. As medidas para contenção da propagação do coronavírus impactaram financeiramente 89,6% dos participantes; 72,0% interromperam totalmente seus trabalhos; 97,7% tiveram redução no faturamento; 98,2% tiveram mudança na rotina de trabalho; 94,8% tiveram aumento das despesas do laboratório no período; houve queda do faturamento para 41,2% entre 0% e 25,0% e para 36,3% entre 25,0% e 50,0%; 66,6% continuaram trabalhando durante a pandemia devido à sua situação financeira. Não pensaram em fechar seu laboratório de forma definitiva 71,8% dos participantes; 92,2% seguiram rotineiramente os cuidados de higienização e 21,6% fizeram uso das reservas financeiras. Conclusão os TPDs tiveram impacto financeiro durante o período da pandemia da Covid-19 causado principalmente pela diminuição da carga horária de trabalho, redução do faturamento e aumento do custo operacional devido à mudança na rotina de biossegurança.

Abstract Introduction the COVID-19 pandemic and measures to control its expansion impacted different segments of the economy, including dentistry professionals. Objective this study analyzed the financial impact of the COVID-19 pandemic on dental technicians in Brazil. Material and method this is a descriptive cross-sectional study with the application of a questionnaire of sociodemographic and professional profile, financial impact, and effect containment measures to dental technicians in Brazil. The questionnaire was applied online on social networks between January 27 and February 15, 2021. Result 59.8% of the participants were male, with 47.5% aged up to 30 years, and 57.3% with less than 10 years of practice. The measures to contain the spread of the coronavirus had a financial impact on 89.6% of the participants: 72.0% had their work completely interrupted, 97.7% had their billing reduced, 98.2% changed their work routine, and 94.8% had higher laboratory expenses in the period. Revenue decreased between 0% and 25.0% for 41.2% and between 25.0% and 50.0% for 36.3%. In addition, 66.6% continued working during the pandemic due to their financial situation. 71.8% of the participants did not consider closing their laboratory permanently, whereas 92.2% followed hygiene protocols routinely and 21.6% made use of their financial reserves. Conclusion dental technicians were financially impacted by the COVID-19 pandemic, mainly caused by fewer working hours, revenue reduction, and higher operating costs due to the change in the biosafety routine.

Retrospective Analysis of the Prevalence of Teeth Endodontically Treated from Radiographs of Individuals from the Midwest Region of Brazil / Análise Retrospectiva da Prevalência de Dentes Tratados Endodônticamente a Partir de Radiografia de Indivíduos da Região do Centro Oeste no Brasil

Endodontic treatment is common in dentistry and for a correct diagnosis it is necessary to observe clinical and radiographic signs, taking into account pulp and periapical changes in the element to be treated. Studying this frequency can contribute to the literature, elucidating whether the greatest number of cases is occurring in young or elderly patients, women or men, anterior or posterior teeth. The objective of this study was to analyze the prevalence of endodontically treated teeth, through 900 panoramic radiographs. A cross-sectional study was carried out evaluating the prevalence of teeth treated endodontically from a sample of 900 panoramic radiographs, corresponding to exams performed in 2020, in a radiological clinic located in central west Brazil. The sample consisted of 540 (60%) female subjects and 360 (40%) male subjects, aged between 18 and 88 years old, being more prevalent for Individuals <31 years old with (34.9%) Sample. The prevalence of endodontically treated teeth was analyzed, the results showed 1,236 teeth in this condition, individually analyzing the upper right central incisor was the most frequent 9.22%, while for group analysis the upper teeth were 7.06%. Therefore, there was a higher prevalence of teeth treated endodontically in the maxilla, the tooth with the highest treatment index, the right upper central incisor. Women were more affected and it was observed that with increasing age, the number of teeth treated endodontically also increases. (AU)

O tratamento endodôntico é frequente na odontologia e para um correto diagnóstico é necessário observar sinais clínicos e radiográficos, levando em consideração as alterações pulpares e periapicais no elemento à ser tratado. Estudar essa frequência pode colaborar com a literatura, elucidando se o maior número de casos está ocorrendo em pacientes jovens ou idosos,mulheres ou homens, dentes anteriores ou posteriores O objetivo desse presente estudo foi analisar a prevalência de dentes tratados endodônticamente, por meio de 900 radiografias panorâmicas. Foi realizado um estudo transversal avaliando prevalência de dentes tratados endodônticamente a partir de uma amostra de 900 radiografias panorâmicas, correspondentes a exames realizados em 2020, em uma clínica radiológica situada no centro oeste do Brasil. A amostra foi constituída por 540 (60%) Indivíduos do gênero feminino e 360 (40%) do masculino, com idade entre 18 e 88 anos de idade, sendo mais prevalente para Indivíduos <31 anos de idade com (34,9%) da amostra. Foi analisada a prevalência de dentes tratados endodônticamente, os resultados mostraram 1.236 dentes nesta condição, analisando individualmente o incisivo central superiores direito foi o mais frequente 9,22%, enquanto para análise de dentes por grupos foram os dentes anteriores superiores 7,06%. Portanto, houve uma maior prevalência de dentes tratados endodônticamente em maxila, o dente com maior índice de tratamento o incisivo central superior direito. Mulheres foram mais acometidas e observou-se que com o aumento da idade, aumenta-se também o número de dentes tratados endodônticamente. (AU)

Can maxilla and mandible bone quality explain differences in orthodontic mini-implant failures?

Purpose: This study aimed to compare the risk of orthodontic mini-implant (OMI) failure between maxilla and mandible. A critical analysis of finite-element studies was used to explain the contradiction of the greatest clinical success for OMIs placed in the maxilla, despite the higher quality bone of mandible. Materials and Methods: Four tridimensional FE models were built, simulating an OMI inserted in a low-dense maxilla, control maxilla, control mandible, and high-dense mandible. A horizontal force was applied to simulate an anterior retraction of 2 N (clinical scenario) and 10 N (overloading condition). The intra-bone OMI displacement and the major principal bone strains were used to evaluate the risk of failure due to insufficient primary stability or peri-implant bone resorption. Results: The OMI displacement was far below the 50-100 µm threshold, suggesting that the primary stability would be sufficient in all models. However, the maxilla was more prone to lose its stability due to overload conditions, especially in the low-dense condition, in which major principal bone strains surpassed the pathologic bone resorption threshold of 3000 µstrain. Conclusions: The differences in orthodontic mini-implant failures cannot be explained by maxilla and mandible bone quality in finite-element analysis that does not incorporate the residual stress due to OMI insertion.

The Usefulness of a Facial Digital Biobank for Ameloblastoma Resection and Fracture Fixation - A Case Report.

Rationale: Ameloblastoma often requires complex facial treatments such as resection and reconstruction, which can be aided using three-dimensional resources towards improved surgical planning, reduction of surgical time, and customization. Patient Concerns: A 51-year-old patient, concerned about submandibular volumetric increase discovered performing imaging exams to install dental implants. Diagnosis and Treatment: Diagnosed with ameloblastoma, he underwent uneventful partial mandibular resection and placement of prebent mandibular reconstruction plate. Four months later, following a motorcycle accident, a deflection of the plate and mandibular fracture was observed. Using the initial prototyping, a new reconstruction plate was customized and surgically placed to reduce the mandibular fracture, with adequate titanium plate adaptation to the remaining bone and maintenance of aesthetic mandibular contour. Outcomes and Take-away Lessons: The current digital dentistry resources, such as computed tomography and intraoral scan, can be recovered and used as a backup of recorded anatomy anytime in future, providing a long-lasting facial digital biobank.

Correlation between magnetic resonance imaging and cone-beam computed tomography for maxillary sinus graft assessment.

PURPOSE: Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols. MATERIALS AND METHODS: A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Microcomputed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test. RESULTS: Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT. CONCLUSION: Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.

Three dimensionally printed surgical guides for removing fixation screws from onlay bone grafts in flapless implant surgeries.

The present technique report describes a digital workflow for flapless implant surgery after onlay block bone graft healing in the esthetic area. Virtual removal of block fixation screws and optimal single-tooth implant position and digital crown waxing were planned from cone beam computed tomography (CBCT) and intraoral scans. Two different surgical guides were digitally designed and 3D-printed to allow for flapless implant surgery. The first surgical guide was used to remove all 3 fixation screws from a healed onlay block graft, whereas the second guide was used to determine the implant position and direction. The present methodology may be considered a time-efficient flapless approach for placing implants in sites with block grafts.

Avaliação bidimensional e tridimensional do ângulo de curvatura de dentes permanentes: comparação entre radiografia periapical e TCFC / Bidimensional and tridimensional root canal curvature angle evaluation: comparison between periapical radiography and CBCT

A curvatura dos canais radiculares pode ser considerada um grande desafio para o sucesso do tratamento endodôntico, por tal motivo é necessária uma boa compreensão da anatomia interna dental. Diversas técnicas para avaliação qualitativa e quantitativa da curvatura foram propostas desde o século XVIII, porém ainda não foi aceita uma técnica que pudesse fornecer a pesquisadores e profissionais clínicos descrição detalhada sobre a curvatura do canal. O objetivo do presente estudo foi descrever uma técnica baseada em coordenadas delimitadas na luz do canal radicular (denominada método de pontos), utilizando fórmulas matemáticas e programas de desenho computacional, para que fosse possível determinar, tanto de maneira bidimensional quanto tridimensional, o desvio da trajetória do canal (considerado como ângulo de curvatura), o quão acentuado é esse desvio (grau de curvatura) e determinar a região em que as curvaturas se encontram no canal. Além desse objetivo, a metodologia foi aplicada em quatro grupos dentais (incisivo lateral superior, pré-molar inferior, molar superior e molar inferior) para estudar possíveis diferenças entre os grupos e entre os seus terços radiculares. Para realizar o estudo foram utilizadas imagens bidimensionais (radiografia periapical) e tridimensionais (tomografia computadorizada por feixe cônico). Na análise bidimensional, a aplicabilidade da metodologia proposta foi demonstrada comparando o método de pontos aos métodos de Schneider e de Pruett sobre radiografias periapicais de pré-molares inferiores. Os resultados mostraram que o método de pontos obteve valores angulares maiores quando comparados às outras técnicas e houve forte correlação entre o maior valor angulado encontrado pelo presente método quando comparado ao cálculo do raio de curvatura pelo método de Pruett. Para a análise tridimensional, foi comparada angulação de curvatura dos quatro grupos dentários e comparando os resultados obtidos pelo método de Schneider (por ser o mais comumente empregado), método de pontos bidimensional e método de pontos tridimensional. Os resultados desta avaliação demonstraram que em todos os grupos o valor angular obtido pelo método em três dimensões foi maior quando comparado aos outros métodos, indicando que a angulação tridimensional não é totalmente considerada ao ser realizada uma análise bidimensional da estrutura. Ao analisar a diferença entre os grupos dentários, os resultados mostraram que os dentes multirradiculares (molares superiores e inferiores) apresentaram curvatura mais acentuada da encontrada em dentes unirradiculares e na comparação entre os terços radiculares, o terço apical foi a região que concentrou os maiores valores de curvatura de canal.

Computer-Aided Design/Computer-Aided Manufacturing Milling of Allogeneic Blocks Following Three-Dimensional Maxillofacial Graft Planning.

Despite the advent of stereolithography in craniofacial surgery for creating surgical guides and custom synthetic scaffolds, little is known about the feasibility of computer-aided design/computer-aided manufacturing (CAD/CAM) milling of freeze-dried allogeneic bone blocks following previously designed volumetric graft plans. The aim of this technical report is to present a methodology for CAD/CAM milling to achieve the volume and shape of allogeneic bone blocks as estimated by using a virtual planning software. To perform the current methodology, an ex vivo simulation was performed. The milled allogeneic block presented satisfactory dimensional accuracy as compared with the respective three-dimensional virtual model.

Detection of furcation involvement using periapical radiography and 2 cone-beam computed tomography imaging protocols with and without a metallic post: An animal study.

PURPOSE: The purpose of this study was to assess the accuracy, sensitivity, and specificity of the diagnosis of incipient furcation involvement with periapical radiography (PR) and 2 cone-beam computed tomography (CBCT) imaging protocols, and to test metal artifact interference. MATERIALS AND METHODS: Mandibular second molars in 10 macerated pig mandibles were divided into those that showed no furcation involvement and those with lesions in the furcation area. Exams using PR and 2 different CBCT imaging protocols were performed with and without a metallic post. Each image was analyzed twice by 2 observers who rated the absence or presence of furcation involvement according to a 5-point scale. Receiver operating characteristic (ROC) curves were used to evaluate the accuracy, sensitivity, and specificity of the observations. RESULTS: The accuracy of the CBCT imaging protocols ranged from 67.5% to 82.5% in the images obtained with a metallic post and from 72.5% to 80% in those without a metallic post. The accuracy of PR ranged from 37.5% to 55% in the images with a metallic post and from 42.5% to 62.5% in those without a metallic post. The area under the ROC curve values for the CBCT imaging protocols ranged from 0.813 to 0.802, and for PR ranged from 0.503 to 0.448. CONCLUSION: Both CBCT imaging protocols showed higher accuracy, sensitivity, and specificity than PR in the detection of incipient furcation involvement. Based on these results, CBCT may be considered a reliable tool for detecting incipient furcation involvement following a clinical periodontal exam, even in the presence of a metallic post.

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs.

OBJECTIVE: To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. MATERIAL AND METHODS: Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. RESULTS: Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). CONCLUSION: Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

Abstract Objective To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

A three-dimensional finite element analysis of the sports mouthguard.

BACKGROUND/AIM: The aim of this study was to evaluate the compressive and tensile stresses on dentin and enamel in five different situations: no mouthguard and mouthguards from 1 mm thickness up to 4 mm thickness, using finite element analysis. MATERIALS AND METHODS: A three-dimensional geometry of an upper right central incisor was obtained from a computed tomography and transformed into a mesh separating enamel from dentin. A mouthguard was created covering the buccal surface of the enamel in different thicknesses, and a rubber ball with a velocity of 5 m s(-1) was made as the impact object. RESULTS: The maximum principal stress and the minimal principal stress were evaluated in all situations on dentin and enamel. Both maximum and minimal stress on enamel had the greatest value on the control situation (no mouthguard), and their value decreased as the mouthguard thickness increased. The reduction ranged from 66.62% to 85.5% for compressive stress and from 9.76% to 33.37% for tensile stress on enamel. The results for dentin were similar among the situations with or without mouthguards. CONCLUSION: The mouthguard had beneficial effect considering the stresses on enamel, and between the mouthguard thickness of 3 and 4 mm, there was minimum difference.

Estudo da eficácia de protetores bucais para esporte quanto à espessura por meio de análise em elementos finitos / Finite element analysis of the efficacy of sports mouthguards regarding thickness

Atletas de diversas modalidades esportivas estão sujeitos a sofrer lesões no complexo dento-maxilo-facial por diversos impactos mecânicos, como choques contra o solo, outros atletas, bolas, etc. As principais preocupações dos cirurgiões-dentistas em relação a esses choques são as lesões irreversíveis em elementos dentais e/ou bases ósseas. A melhor estratégia para controlar a ocorrência e gravidade dessas lesões é a utilização de protetores bucais invidualizados, que além da proteção, não diminuem o desempenho dos atletas. Para avaliar a eficiência dos protetores bucais a análise por elementos finitos foi empregada, e o objetivo do presente trabalho foi avaliar o comportamento mecânico do protetor em EVA de diversas espessuras diferentes. A análise por elementos finitos foi conduzida utilizando a geometria de um incisivo central obtida por meio de tomografia computadorizada. A simulação foi constituída pelo esmalte e dentina do elemento dental, protetor bucal em EVA e uma esfera de borracha que era o objeto impactante. As geometrias foram transformadas em elementos sólidos e apenas os nós do terço apical da dentina radicular foram fixados. O pré-processamento foi realizado no Hypermesh® e no LS-PrePost®,o processamento foi feito pelo software LS-DYNA®.O estudo foi observado em 3D.

Foram observadas a máxima e a tensão mínima principal no esmalte e na dentina em cinco variáveis: com protetor bucal de 1mm, 2mm, 3mm e 4mm, e como grupo controle foi utilizada uma geometria simples sem EVA. A tensão mínima principal no esmalte ocorreu no centro da face vestibular e seu valor foi maior sem o protetor bucal e diminuiu com o aumento da espessura do protetor, a tensão máxima no esmalte ocorreu na união entre esmalte e dentina na face vestibular. Na dentina a tensão máxima principal ocorreu na face vestibular da raiz e a tensão mínima ocorreu na face palatina. Os resultados mostraram que o protetor bucal foi benéfico, diminuindo as tensões compressivas e de tração no esmalte, porém não mostrou significante melhoria quando as tensões na dentina foram comparadas.

In different sports, the athletes are likely to experience injuries on teeth, soft tissue and bone, usually by mechanic trauma, such as falling on the ground, shocking against other player, balls, etc. The dentist main concerns are the permanent injuries on teeth and bone complex. The best strategy to fight these impairments still is the prevention, using individualized sports mouthguards. To evaluate the efficacy of the mouthguards, the finite element analysis was used, and the purpose of the present study was to evaluate the mechanical behavior to the EVA mouthguard on different thickness. The finite element analysis was made using geometry of a superior central incisor, which was acquired by computerized tomography. The simulation was made with enamel and dentin from the tooth, an EVA mouthguard and a rubber sphere that was the impacting object. All geometries was transformed into solid elements and the knots on the apical third of the root dentin were fixed. The pre-process was made using Hypermesh® and LS-PrePost® e and processing of data was made on LS-DYNA® software. The results were the maximum and minimum main stress on the enamel and dentin solids in five different situations: no mouthguard and mouthguard with thickness of 1mm, 2mm, 3mm and 4mm.

The minimum main stress on the enamel was measured at the center of the vestibular surface and the higher value was observed with no mouthguard and the values decreased as the thickness of the mouthguard increased, the maximum main stress on enamel occurred near the amelodentin junction on the vestibular surface, but no significant changes were observed among the situations. As for the dentin the maximum main stress occurred on the buccal surface of the root, and the minimum main stress on the lingual surface. The results show that the mouthguard was efficient decreasing the compressive and tensile stress on enamel, but did not make significant improvement as on both stresses on dentin.

Protetor bucal individualizado, para esporte, específico para Ortodontia / Individualized mouthguard specific to Orthodontics

O uso do protetor bucal para esporte entre atletas deve ser estimulado, Ele protege dentes, lábios e língua contra injúrias ocorridas durante treinos e competições, Em pacientes jovens o grande desafio está na estimulação do uso de protetores bucais para esporte, inclusive quando este jovem atleta está em tratamento ortodõntico com o uso de aparatologia fixa, Observa-se a grande incidência de injúrias contra, principalmente, lábios e língua quando este atleta em tratamento ortodõntico não faz uso de um protetor bucal para esporte individualizado e específico para ortodontia. O objetivo deste trabalho é apresentar uma técnica de confecção de protetor bucal individualizado e específico para atletas que estejam em tratamento ortodontico. Observando as regras internacionais e não interferindo em suas funções básicas como respiração, fala e deglutição

The use of mouthguard for sports among athletes should be encouraqed. It protects teeth, lips and tongue against injuries occurred during training and cornpetitions, In young patients, the challenge is stimulate the use of mouthguards for sports including when this young athlete is in orthodontic treatment using fixed orthodontic appliance. Observe the high incidence of injuries primarily against lips and tongue when this athlete undergoing orthodontic treatment does not make use of a sports mouthguard individualized and specific to orthodontics. The aim of this paper is to present a technique for creating an individualized and specific mouthguard for athletes who are undergoing orthodontic treatment Observing the international standards and not interfering with its basic functions such as breathing, speaking and swallowinq

University student's dental and maxillofacial fractures characteristics and epidemiology in sports / Características e epidemiologia das fraturas maxilo-faciais no esporte em estudantes universitários

Current study analyzes the characteristics and epidemiology of oral and nasal fractures and knowledge degree regarding the use of a mouthguard by an amateur university handball team in Brazil. A cross-sectional study comprised 138 students who practiced the sport. They were interviewed on dental and nasal fractures and on the need of mouthguards in games such as amateur handball. Data were processed by descriptive analysis. Results showed that 19.6% had suffered some type of dental injury during the practice of sports, namely 40 fractured teeth; 12% had fractured nasal bones; 57% underwent head and neck injuries; 32% were unaware of the need to use a mouthguard during sports; 68% had heard of mouthguards, but only 4.5% of the interviewees made use of this protection device. There was a high prevalence of nasal and dental fractures in the group under analysis. The upper central incisors were most susceptible to fracture. Even though most athletes knew a mouthguard was needed during sports activities, only 4.5% actually used one.

O presente estudo analisou as características epidemilógicas de fraturas orais e nasais, bem como o grau de conhecimento sobre o uso de um protetor bucal no esporte amador, cujo corpus é a equipe de handebol da Universidade no Brasil. Em um estudo transversal foram entrevistados 138 atletas sobre a ocorrência de fraturas dentais e nasais, além de seu conhecimento acerca da necessidade na prática de handebol amador universitário; os dados foram tabulados e apresentados por meio de análise descritiva. Um total de 19,6% sofreu algum tipo de lesão dental durante a prática do esporte, totalizando 40 dentes fraturados, 12% sofreram fraturas dos ossos nasais, 57% sofreram ferimentos na cabeça e pescoço, 32% não sabiam da necessidade de usar um protetor bucal para o esporte; 68% referiram já ter ouvido falar de protetores bucais, mas apenas 4,5% dos entrevistados fizeram uso deste dispositivo de proteção. Houve alta prevalência de fraturas nasais e dentais no grupo analisado. Os incisivos centrais superiores foram os dentes mais suscetíveis a fraturas. Mesmo que a maioria dos atletas saiba da necessidade de usar um protetor bucal, apenas 4,5% realmente fazem uso desse equipamento.

Mouthguard: a new technique for the partially edentulous patient.

Over the last decades, several articles have corroborated the need of using mouthguards in sports activities, manufactured with ethylene vinyl acetate (EVA) as their main material. There are different mouthguards techniques used by dentists worldwide to prevent injuries. A technique has been developed to help athletes, especially the partially edentulous patients, who were not getting the proper protection. The mouthguard technique consists in making EVA fillings to improve the adjustment and esthetics of mouthguard used by athletes. It is the authors' conviction that the technique may prevent injuries in sports activities without impairing the athletes' safety and esthetics.