Abstract Objectives This study aimed to assess the prevalence of oral lesions in patients living with HIV infection and their association with CD4 count, viral load, and antiretroviral therapy in patients with HIV. Methods A cross-sectional study was conducted on a sample of 161 patients attending the… All the patients were examined for their oral lesions, current CD4 counts, type, and duration of the therapy. Data analyses were carried out using Chi-Square, Student T/Mann-Whitney, and logistic regression tests. Results Oral lesions were observed in 58.39% of patients with HIV. Periodontal disease with 78 (48.45%) or without mobility 79 (49.07%) was observed more frequently, followed by hyperpigmentation of oral mucosa 23 (14.29%), Linear Gingival Erythema (LGE) 15 (9.32%), candidiasis pseudomembranous 14 (8.70%). Oral Hairy Leukoplakia (OHL) was observed only in 3 (1.86%). A relationship between periodontal disease with dental mobility and smoking was found (p = 0.04), as well duration of treatment (p = 1.53e-3) and age (p = 0.02). Hyperpigmentation was related to race (p = 0.01) and smoking (p = 1.30e-6). CD4 count, CD4:CD8 ratio, viral load, or type of treatment were not associated with oral lesions. Logistic regression showed that the duration of treatment has a protective effect on the periodontal disease with dental mobility (OR = 0.28 [−2.27 to −0.25]; p-value = 0.03), independent of age or smoking. To hyperpigmentation, the best model included smoking (OR = 8.47 [1.18-3.10], p = 1.31e-5), without race or type and duration of treatment. Conclusion Among HIV patients undergoing antiretroviral treatment, oral lesions can be observed, predominantly periodontal disease. Pseudomembranous candidiasis and oral hairy leukoplakia were also observed. No relationship was found between associated oral manifestations in HIV patients and the start of the treatment, TCD4+ and TCD8+ cell count, TCD4:TCD8 ratio, or viral load. The data indicate that there is a protective effect of duration of treatment with relation to periodontal disease with mobility and that hyperpigmentation seems to be more related to smoking than type and duration of treatment. Level of evidence Level 3 (OCEBM Levels of Evidence Working Group*. "The Oxford 2011 Levels of Evidence"). CD count load crosssectional cross sectional 16 counts ChiSquare, ChiSquare Chi Square, Square Chi-Square T/MannWhitney, TMannWhitney T/Mann Whitney, T Mann Whitney T/Mann-Whitney tests 5839 58 39 58.39 7 48.45% 4845 48 45 (48.45% 49.07% 4907 49 07 (49.07% frequently 2 14.29%, 1429 14.29% , 29 (14.29%) LGE (LGE 1 9.32%, 932 9.32% 9 32 (9.32%) 8.70%. 870 8.70% . 8 70 (8.70%) OHL (OHL 1.86%. 186 1.86% 86 (1.86%) 0.04, 004 0.04 0 04 0.04) 1.53e3 153e3 e 1.53e 53e 1.53e-3 0.02. 002 0.02 02 0.02) 0.01 001 01 1.30e6. 130e6 1.30e 6 30e 1.30e-6) CD4CD8 CDCD CD8 CD4:CD ratio OR 028 28 0.2 −2.27 227 27 [−2.2 −0.25 025 25 −0.25] pvalue value 0.03, 003 0.03 03 0.03) 847 47 8.4 1.183.10, 118310 1.18 3.10 18 10 [1.18-3.10] 1.31e5, 131e5 1.31e 5 31e 1.31e-5) TCD4 TCD TCD8 TCD4TCD8 TCDTCD TCD4:TCD OCEBM Group Group* 201 Evidence. Evidence") MannWhitney T/MannWhitney TMann 583 58.3 48.45 484 4 (48.45 49.07 490 (49.07 142 14.29 (14.29% 93 9.32 (9.32% 87 8.70 (8.70% 1.86 (1.86% 00 0.0 53e3 153e 1.53e- 30e6 1.30e6 130e 1.30e-6 CD4CD 0. −2.2 22 [−2. −0.2 84 8. 183 1.183.10 11831 118 1.1 310 3.1 [1.18-3.10 31e5 1.31e5 131e 1.31e-5 TCD4TCD 20 Evidence" 58. 48.4 (48.4 49.0 (49.0 14.2 (14.29 9.3 (9.32 8.7 (8.70 1.8 (1.86 1.30e- −2. [−2 −0. 1.183.1 1183 11 1. 31 3. [1.18-3.1 1.31e- 48. (48. 49. (49. 14. (14.2 9. (9.3 (8.7 (1.8 −2 [− −0 1.183. [1.18-3. (48 (49 (14. (9. (8. (1. − [ 1.183 [1.18-3 (4 (14 (9 (8 (1 [1.18- ( [1.18 [1.1 [1. [1

Resumo Introdução O conhecimento da biomecânica de implantes de diâmetro reduzido indica dimensões seguras para uso clínico. Objetivo O objetivo do presente estudo foi comparar biomecanicamente implantes de diâmetro regular e reduzido para suporte de próteses implantossuportadas unitárias na região anterior da maxila por meio de análise de elementos finitos 3D (3D-FEA). Material e método Quatro modelos 3D-FEA foram desenvolvidos a partir de recomposição de tomografia computadorizada e dados da literatura: um bloco ósseo na região incisiva lateral superior direita com implante e coroa. M1: 3,75 x 13 mm, M2: 3,75 x 8,5 mm, M3: 2,9 x 13 mm e M4: 2,9 x 8,5 mm. Foi aplicada carga de 178 N nos ângulos 0, 30 e 60 graus em relação ao longo eixo do implante. Foram avaliados mapas de tensão de Von Mises, tensão principal máxima e microdeformação. Resultado: M3 e M4 apresentaram maiores valores de tensão e microdeformação que M1 e M2, principalmente quando foram aplicadas forças inclinadas. Porém, M3 apresentou comportamento biomecânico melhor do que M4. Conclusão Pode-se concluir que reduzir o diâmetro dos implantes pode prejudicar a biomecânica durante a aplicação de forças, mas a distribuição e intensidade das tensões, bem como os valores de microdeformação podem ser melhorados se o comprimento do implante for aumentado. clínico D 3DFEA. 3DFEA DFEA FEA . (3D-FEA) literatura coroa M 375 3 75 3,7 1 M2 85 8 5 8, 29 2 9 2, 17 0 6 Mises Resultado inclinadas Porém Podese Pode tensões aumentado (3D-FEA 37 7 3,

Abstract Introduction Narrow diameter implants biomechanics knowledge indicates safe dimensions for clinical use. Objective Purpose of the present study was biomechanically to compare regular and narrow diameter implants to support single implant-supported prosthesis in the anterior region of the maxilla by 3D finite element analysis (3D-FEA). Material and method Four 3D-FEA models were developed form CT scan recompositing and literature data: a bone block in the right upper lateral incisive region with implant and crown. M1: 3.75 x 13 mm, M2: 3.75 x 8.5 mm, M3: 2.9 x 13 mm and M4: 2.9 x 8.5 mm. It was applied load was of 178 N at 0, 30 and 60 degrees in relation to implant long axis. Von Mises stress, maximum principal stress and microdeformation maps were evaluated. Result M3 and M4 did show higher tension and higher microdeformation values than M1 and M2, especially when inclined forces were applied. However, M3 presented enhanced biomechanical behavior than M4. Conclusion It can be concluded that reduce the diameter of the implants can disadvantage to the biomechanics during the application of forces, but the distribution and intensity of the stresses, as well as the micro deformation values can be improved if the length of the implant is increased. use implantsupported supported D 3DFEA. 3DFEA DFEA FEA . (3D-FEA) data crown M 375 3 75 3.7 1 M2 85 8 5 8. 29 2 9 2. 17 0 6 axis evaluated However stresses increased (3D-FEA 37 7 3.

Abstract Temporomandibular disorders (TMD) is a term used to describe a set of clinical conditions that may compromise the temporomandibular joint (TMJ) and masticatory muscles and/or associated structures, considered the most frequent cause of orofacial pain of non-dental origin. In recent years, many forms of physical therapy have been used in the treatment of TMD to reduce pain and improve the range of mandibular movement present in this impairment. Among these resources are kinesiotherapy (exercise), electrothermal and manual therapy, acupuncture, training posture, mobilizations, and biofeedback. Objectives To determine if exercises with or without occlusal splints are effective in reducing pain in patients with temporomandibular disorders (TMD) of myogenic origin. Methodology This systematic review was registered in the International Prospective Register of Systematic Reviews (CRD 42019134244). Controlled trials published in PubMed, Scopus, and Cochrane Library following PRISMA guidelines up to April 2022 were randomized and included. The population above 18 years, which evaluated the effectiveness of exercise with or without occlusal splints in reducing pain in patients with TMD of myogenic origin, diagnosed through the Research Diagnostic Criteria for Temporomandibular Disorders, was also included. There was no restriction on the period of publication. Cochrane risk of bias analysis was performed. Results Of the five included articles, all showed a reduction of pain, but without significant differences between the interventions performed. Additionally, studies that evaluated the quality of life and mandibular movements showed a reduction in pain, but no significant differences between therapies. Conclusion The analyzed studies showed no difference in the improvement of pain, quality of life, and mandibular movements between the groups that performed only exercises or the associated treatments. (TMD TMJ (TMJ andor structures nondental non dental origin years impairment exercise, , (exercise) acupuncture posture mobilizations biofeedback CRD 42019134244. 42019134244 . 42019134244) PubMed Scopus 202 1 Disorders publication articles Additionally therapies treatments (exercise 4201913424 20 420191342 2 42019134 4201913 420191 42019 4201 420 42 4

Abstract This study aimed to investigate if SNP rs6313, SNP rs2770304, SNP rs4941573, and SNP rs1923884 of the 5-HT2A receptor gene and SNP rs6295 of the 5-HT1A receptor gene are associated with bruxism etiology. Methodology This systematic review was registered in PROSPERO (CRD42018094561). A search was conducted for articles published in or before May 2021. To qualify for eligibility in this review, the studies had to be case-controls, cohort or cross-sectional. The inclusion criteria were the articles with a group of patients with bruxism and a control group in which the presence of these SNPs was evaluated. The exclusion criteria were the investigations of other polymorphisms, the studies that did not consider a control group for comparison, case reports, and reviews. The NOS and JBI were used to evaluate the methodological quality of studies. Results We conducted this study with databases, such as Web of Science, Scopus, Embase, PubMed/MEDLINE, and ProQuest. We considered four studies eligible. A total of 672 participants were included,187 with sleep bruxism, 105 with awake bruxism, 89 with sleep and awake bruxism, and 291 controls. One study found a strong association between the SNPs rs6313, rs2770304 and rs4941573 of the 5-HT2A receptor gene and sleep bruxism. In one study, we considered the C allele of the SNP rs2770304 a risk factor for sleep bruxism. We found no significant results of other SNPs in sleep bruxers compared to controls. We found no positive association concerning the SNPs and groups of awake bruxism and sleep and awake bruxism. Conclusion The different results regarding the SNPs in sleep bruxers could be explained by the genetic distinction between Chilean, Mexican, Japanese, and Polish population. More clinical trials and prospective studies must be conducted with larger sample size and in different ethnicities to confirm the results of this review.

Abstract 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.

Resumo O objetivo deste estudo foi avaliar a adaptação marginal vertical e horizontal de infraestruturas de prótese fixas de três elementos confeccionadas por diferentes técnicas e diferentes sistemas CAD/CAM. Um total de 40 infraestruturas foram confeccionadas e divididas em quatro grupos: fundição por cera perdida (G1); fundição por cera perdida com ponto de solda (G2); escaneamento óptico extraoral para escaneamento do modelo (3S/DWOS); escaneamento óptico intraoral (Cerec Bluecam/Sirona) (G4). Uma matriz metálica foi utilizada para simular uma prótese fixa de três elementos (com pôntico central). As infraestruturas do G1 e G2 foram fundidas em liga metálica de níquel-cromo (NiCr), enquanto que as infraestruturas de G3 e G4 foram fresadas em zircônia. Todos os grupos foram analisados quanto à adaptação marginal vertical e horizontal (sobrecontorno e subcontorno) em microscópio óptico tridimensional (Quick Scope, Mitutoyo). Os resultados apresentaram maiores valores de desadaptação marginal vertical no G1 comparados aos outros grupos (p<0,001). Em relação a desadaptação marginal horizontal, maiores valores de sobrecontorno foram observado no G3 em comparação com os demais grupos (p<0,001). Não foi observado valores de subcontorno para o G3, enquanto que os demais grupos não apresentaram diferença significante para o subcontorno (p> 0,05). Dentro das limitações do presente estudo, pode-se concluir que a técnica convencional após ponto de solda é uma alternativa viável para confecção de infraestruturas de próteses fixas de três elementos comparado ao uso de sistemas CAD/CAM, uma vez que as técnicas apresentaram valores de adaptação marginal vertical similares. Os sistemas CAD/CAM extraoral apresentou o maior desajuste horizontal (sobrecontorno) em comparação com outros grupos.

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

Resumo O objetivo deste estudo foi avaliar diferentes sistemas de retenção (cimentada x parafusada) e configuração da coroas (unitárias x esplintadas) de próteses fixas implantossuportadas em relação a distribuição de tensões nos implantes/componentes e tecido ósseo pela análise de elementos finitos 3D. Quatro modelos 3D foram simulados com auxílio dos programas Invesalius, e Rhinoceros 3D, e SolidWorks. Os modelos foram confeccionados simulando bloco ósseo de região posterior da maxila (tipo ósseo III), com 3 implantes cone Morse com 4,0 mm de diâmetro e diferentes comprimentos, suportando prótese metalocerâmica de 3 elementos. Os modelos foram processados pelos programas FEMAP e NEiNastran sob força axial de 400 N e oblíqua de 200N. Os resultados foram plotados através de mapas de tensão de von Mises (vM) (implantes e componentes) e tensão máxima principal (TMP) (tecido ósseo). Sobre o carregamento axial, não foi observada diferenças entre os diferentes sistemas de retenção e tipo de prótese na distribuição das tensões nos implantes/componentes, porém, sobre o carregamento oblíquo as próteses cimentadas apresentaram melhor distribuição de tensões em comparação com as próteses parafusadas, enquanto que as próteses esplintadas apresentou uma tendência de redução das tensões no implante do primeiro molar. No tecido ósseo as próteses cimentadas apresentaram melhor distribuição das tensões em comparação com as próteses parafusadas, independente do carregamento. A esplintagem foi favorável somente para as próteses parafusadas, não havendo influência sobre as próteses cimentadas. As próteses cimentadas sobre implantes cone Morse apresentam melhor comportamento biomecânico nos implantes/componentes e tecido ósseo. A esplintagem foi efetiva somente nas próteses parafusadas sob carregamento oblíquo.

Abstract The purpose of this study was to evaluate different retention systems (cement- or screw-retained) and crown designs (non-splinted or splinted) of fixed implant-supported restorations, in terms of stress distributions in implants/components and bone tissue, by 3-dimensional (3D) finite element analysis. Four 3D models were simulated with the InVesalius, Rhinoceros 3D, and SolidWorks programs. Models were made of type III bone from the posterior maxillary area. Models included three 4.0-mm-diameter Morse taper (MT) implants with different lengths, which supported metal-ceramic crowns. Models were processed by the Femap and NeiNastran programs, using an axial force of 400 N and oblique force of 200 N. Results were visualized as the von Mises stress and maximum principal stress (σmax). Under axial loading, there was no difference in the distribution of stress in implants/components between retention systems and splinted crowns; however, in oblique loading, cemented prostheses showed better stress distribution than screwed prostheses, whereas splinted crowns tended to reduce stress in the implant of the first molar. In the bone tissue cemented prostheses showed better stress distribution in bone tissue than screwed prostheses under axial and oblique loading. The splinted design only had an effect in the screwed prosthesis, with no influence in the cemented prosthesis. Cemented prostheses on MT implants showed more favorable stress distributions in implants/components and bone tissue. Splinting was favorable for stress distribution only for screwed prostheses under oblique loading.

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.

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.

Abstract Polymethyl methacrylate (PMMA) has been considered a suitable material for cranioplasty. However, no consensus has been reached concerning the best material for cranioplasty with regard to minimizing complications. Thus, this systematic review and meta-analysis aimed to compare the complication rates of PMMA with those of autologous bone and titanium mesh. This review was registered with PROSPERO (CRD42016042725). Systematic searches were conducted on PubMed/MEDLINE, Scopus, and Web of Science. The focus question was, “Do PMMA prostheses used in cranioplasty have complications rates similar to those of autologous bone and titanium mesh?” A meta-analysis of complication rates was performed on the basis of dichotomous outcomes assessed by risk ratio (RR) with corresponding 95% confidence intervals (CI). From 1014 data sources, 11 articles were selected according to eligibility criteria. These articles involved 1,256 individuals and 1,278 cranioplasties using autologous bone (n = 408), PMMA (n = 379), or titanium (n = 151). The follow-up period ranged from 63 days to 54.3 months. No difference was observed between the complication rates of PMMA and autologous bone (p = 0.94; RR, 0.98; 95%CI, 0.54–1.75) or between PMMA and titanium (p = 0.38; RR, 1.59; 95%CI, 0.57–4.48). Sub-analysis of the reasons for craniotomy (trauma/non-trauma) was conducted, which revealed no significant difference (p = 0.91; RR, 0.95; 95%CI, 0.37–2.42). The meta-analysis indicated that the use of PMMA yields complication rates that are near those of autologous bone and titanium mesh.

Abstract This study compared the survival rate of dental implants, amount of marginal bone loss, and rates of complications (biological and prosthetic) between short implants and long implants placed after maxillary sinus augmentation. This systematic review has been registered at PROSPERO under the number (CRD42017073929). Two reviewers searched the PubMed/MEDLINE, Embase, LILACS, and Cochrane Library databases. Eligibility criteria included randomized controlled trials, comparisons between short implants and long implants placed after maxillary sinus augmentation in the same study, and follow-up for >6 months. The Cochrane Collaboration’s tool for assessing the risk of bias in randomized trials was used to assess the quality and risk of bias of the included studies. The search identified 1366 references. After applying the inclusion criteria, 11 trials including 420 patients who received 911 dental implants were considered eligible. No significant difference was observed in the survival rate [p = 0.86; risk ratio (RR): 1.08; 95% confidence interval (CI): 0.46–2.52] or in the amount of marginal bone loss (p = 0.08; RR: −0.05; 95%CI: −0.10 to 0.01). However, higher rates of biological complications for long implants associated with maxillary sinus augmentation were observed (p < 0.00001; RR: 0.21; 95%CI: 0.10–0.41), whereas a higher prosthetic complication rate for short implants was noted (p = 0.010; RR: 3.15; 95%CI: 1.32–7.51). Short implant placement is an effective alternative because of fewer biological complications and similar survival and marginal bone loss than long implant placement with maxillary sinus augmentation. However, the risk of mechanical complications associated with the prostheses fitted on short implants should be considered.

Resumo Introdução O comportamento biomecânico de dentes tratados endodonticamente é variável conforme o material restaurador selecionado e situação do dente a ser restaurado. Objetivo Analisar por meio do método dos elementos finitos bidimensional o comportamento biomecânico de diferentes retentores intrarradiculares e diâmetros em dentes com 2mm de remanescente coronário. Material e método Foram confeccionados seis modelos com três tipo de retentores: pino de fibra de vidro, pino de fibra de carbono e núcleo metálico fundido, ambos com diâmetro #1 (1,1mm de diâmetro) e #2 (1,3mm de diâmetro). A modelagem foi realizada através do programa Rhinoceros 4.0, e em seguida nos programas FEMAP 10.2 e NeiNastran 9.2 para desenvolvimento d os modelos de elementos finitos. Nos carregamentos foram utilizadas forças de 100N axial e oblíquo. Os resultados foram visualizados pelo mapa de tensão von Mises, e pela análise de variância (ANOVA) e pós-teste Tukey, com nível de significância à 5%. Resultado O carregamento oblíquo apresentou maiores valores de tensões (p<0,001). O pino de fibra de vidro apresentou menores concentrações de tensões em ambos os carregamentos (p<0,001). O pino de fibra de carbono apresentou diferença significativa em relação ao núcleo metálico somente no carregamento oblíquo (p=0,007). O diâmetro não influenciou para o aumento de tensões dos retentores avaliados (p=0,302). Conclusão Os pinos de fibras são mais favoráveis para restaurações de dentes tratados endodonticamente; O aumento do diâmetro não influenciou no aumento de tensões; A carga oblíqua é mais prejudicial à tanto para o retentor quanto para a estrutura dentária.

Abstract Introduction The biomechanical behavior of endodontically treated teeth depending on the selected restorative material and tooth situation to be restored. Objective To analyze by the two-dimensional finite element method the biomechanical behavior of different diameters in intraradicular posts and teeth with coronal remaining of 2mm. Material and method Six models were made with three types of posts, as follows: Glass fiber post, carbon fiber post, and cast metal post, both with diameter # 1 (1.1 mm in diameter) and # 2 (1.3 mm of diameter). The modeling was performed using the Rhinoceros 4.0 program. The FEMAP 10.2 and NEiNastran 9.2 programs were used to develop finite element models. The loading used was 100N for axial and oblique forces. The results were visualized using the von Mises stress map. The statistical analysis was made using analysis of variance (ANOVA) and Tukey post-test, with a significance level of 5%. Result The oblique loading stress values were higher than the axial loading (p<0.001) for both situations. The glass fiber post showed the lowest concentrations of stress on both loads (p<0.001). The carbon fiber post presented significant difference compared to the cast metal post, only in the oblique load (p=0.007). The diameter did not increase the stress of the evaluated posts (p=0.302). Conclusion The fiber posts were more favorable for restoration of endodontically treated teeth; the increase of diameter did not influence the increase of tension; the oblique load was more harmful for both posts and tooth structure.

ResumoIntroduçãoOs materiais restauradores provisórios são amplamente utilizados, porém pouco se sabe a respeito de sua estabilidade de cor.ObjetivoAvaliar a estabilidade de cor de materiais restauradores provisórios: resina acrílica e resinas bisacrílicas, após a imersão em soluções pigmentantes, durante diferentes períodos de armazenamento.Material e métodoQuatro materiais foram testados (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) sendo confeccionadas 30 amostras (15 mm de diâmetro e 2 mm de espessura) por material. Estes foram divididos de acordo com o meio de imersão (saliva artificial, saliva + refrigerante tipo cola e saliva + café) e período de armazenamento (2, 5, 7 e 15 dias). As mensurações de cor foram realizadas antes e após as imersões, com auxílio de um espectrofotômetro, através do sistema CIE L*a*b*. Os dados foram analisados com análise de variância (ANOVA) e Tukey, com nível de significância à 5%.ResultadoA resina acrílica apresentou maior estabilidade de cor quando comparada às resinas bisacrílicas (p<0,001). Comparando as resinas bisacrílicas, não foi observado diferença significativa entre as resinas Structur e Luxatemp (p=0,767). Em relação as soluções testadas, o café apresentou os maiores valores de alteração de cor (p<0,001), sendo que quanto maior o período de armazenamento, maior foi a alteração de cor de todos os materiais provisórios analisados (p<0,001).ConclusãoA resina acrílica apresentou maior estabilidade de cor, quando comparada às bisacrílicas. O café causou a maior alteração de cor, e o tempo de imersão foi determinante na estabilidade de cor dos materiais provisórios analisados.

AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001).ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.