To evaluate the association between temporomandibular disorder (TMD) and anxiety, quality of sleep, and quality of life in nursing professionals at theHospital de Clínicas de Uberlândiaof theUniversidade Federal de Uberlândia – HCU-UFU (Medical University Hospital of the Federal University of Uberlândia), four questionnaires were given to nursing professionals. The questionnaires were completed by 160 of these professionals. The Fonseca’s questionnaire was used to evaluate the presence and severity of TMD, the IDATE was used to evaluate anxiety, the SAQ was used to evaluate quality of sleep, and the SF-36 was used to evaluate quality of life. Forty-one nurses (25.6%) reported having no TMD (Fonseca’s questionnaire score ≤ 15), 66 (41.3%) had mild TMD (Fonseca’s questionnaire score 20–40), 39 (24.4%) had moderate TMD (Fonseca’s questionnaire score 45–65), and 14 (8.8%) had severe TMD (Fonseca’s questionnaire score ≥ 70). According to Fonseca’s questionnaire, the presence of TMD was associated with trait anxiety, but the TMD severity was associated with state anxiety classification (mild, moderate, severe). The SAQ score differed significantly from Fonseca classification. The Fonseca’s questionnaire score correlated negatively with the score of each dimension of the SF-36 (r = –0.419 to –0.183). We conclude that TMD is common among nursing professionals; its presence was associated with trait anxiety, and its severity was associated with state anxiety. Hence, the presence of TMD may reduce quality of sleep and quality of life.

O objetivo deste estudo foi avaliar a capacidade de identificação de prematuridades oclusais por meio de imagens obtidas de cortes paraxiais de tomografias computadorizadas de feixe cônico. Para este fim, realizou-se um estudo piloto em que 16 pacientes jovens assintomáticos foram submetidos ao exame clínico, incluindo análise oclusal criteriosa, e em seguida foram confeccionados dispositivos desprogramadores individuais (“JIG de Lucia”). Mediante manipulação mandibular e marcação interoclusal com papel carbono (Accufilm) identificou-se clinicamente o contato prematuro em relação cêntrica (RC) de cada paciente. Posteriormente estes dispositivos foram ajustados na posição de contato cêntrico e utilizados durante os exames tomográficos para que se pudessem obter imagens tomográficas na posição de relação cêntrica. Após o processamento das imagens, estas foram analisadas com o intuito de identificar prematuridades oclusais nas imagens visualizadas por 30 profissionais divididos de acordo com as áreas de atuação (Oclusão, Clínica Geral e Radiologia, n=10 para cada área) e tempo de exercício profissional (<5; entre 5 e 10; e >10 anos). Mediante comparação entre os contatos prematuros identificados na análise clínica oclusal e as imagens tomográficas apontadas pelos profissionais como áreas de contatos prematuros, foram calculados os índices de concordância entre essas duas variáveis. Os dados obtidos foram analisados estatisticamente pela Análise de Variância ANOVA e teste de Scott-Knott (α=0,05). Os resultados deste estudo demonstraram que a identificação de prematuridades oclusais por meio de cortes paraxiais de tomografias computadorizadas de feixe cônico mostrou-se como um método de confiabilidade média.

The aim of this study was to evaluate the ability to identify occlusal prematurity by images from paraxial slices of cone-beam computed tomography (CBCT). For such purpose, a pilot study was performed in which 16 asymptomatic young patients were subjected to a clinical examination, including a careful occlusal analysis and then individual deprogrammer devices (“Lucia's JIG”) were fabricated. Premature contacts were clinically identified in centric relation (CR) for each patient by jaw manipulation and interocclusal marking with articulating paper (Accufilm). Subsequently, these devices were adjusted in CR and used during the tomographic exams in such a way that CBCT in CR could be obtained. After routine processing, the images were analyzed in order to identify occlusal prematurity on the displayed images by 30 professionals divided according to areas of activity (occlusion specialist, general practitioner and radiologist; n=10 per area) and time of professional experience (less than 5, between 5 and 10, and over 10 years). By comparing the premature contacts identified in the clinical analysis and CBCT images, an agreement index between these two variables was calculated. Data were analyzed statistically by ANOVA and Scott-Knott test (α=0.05). The results showed that the identification of occlusal prematurity by paraxial CBCT slices was proven to be a method of average reliability.

O leite de soja (LS) é largamente consumido em todo o mundo como substituto para o leite bovino. Este é uma fonte de vitaminas, carboidratos e açúcares, mas a sua capacidade para preservar a viabilidade celular não foi avaliada. A finalidade do estudo foi investigar a eficácia do LS em manter a viabilidade de fibroblastos humanos em períodos curtos em comparação com diferentes leites bovinos. Fibroblastos de boca humanos foram cultivados e armazenados nos seguintes meios à temperatura ambiente: 10% de meio Dulbecco's Modified Eagle (DMEM) (grupo controle positivo); leite bovino integral longa vida (LI); leite bovino desnatado longa vida - LD; leite em pó - LP; leite de soja - LS. Depois de 5, 15, 30 e 45 min, a viabilidade celular foi analisada usando o método de MTT. Os dados foram analisados estatisticamente pelo teste de Kruskal-Wallis e posteriormente usando o método de Dunn (α=0,05). O grupo LD apresentou a menor capacidade para manter a viabilidade celular em todos os tempos analisados (p<0,05). Aos 30 e aos 45 min, os níveis de absorbância no grupo controle (DMEM) e LS foram significativamente maiores que no grupo LD (p<0,05). A viabilidade celular diminuiu ao longo do tempo (5-45 min). Os resultados indicaram que LS pode ser usado como meio de armazenamento mais adequado para dentes avulsionados. LD não foi eficaz na preservação da viabilidade das células como o meio de cultura de células e o LS.

Soy milk (SM) is widely consumed worldwide as a substitute for cow milk. It is a source of vitamins, carbohydrates and sugars, but its capacity to preserve cell viability has not been evaluated. The purpose of the present study was to investigate the efficacy of SM to maintain the viability of human fibroblasts at short periods compared with different cow milks. Human mouth fibroblasts were cultured and stored in the following media at room temperature: 10% Dulbecco's Modified Eagle Medium (DMEM) (positive control group); long shelf-life ultra-high temperature whole cow milk (WM); long shelf-life ultra-high temperature skim cow milk (SKM); powdered cow milk (PM); and soy milk (SM). After 5, 15, 30 and 45 min, cell viability was analyzed using the MTT assay. Data were analyzed statistically by the Kruskal-Wallis test with post-analysis using the Dunn's method (α=0.05). SKM showed the lowest capacity to maintain cell viability in all analyzed times (p<0.05). At 30 and 45 min, the absorbance levels in control group (DMEM) and SM were significantly higher than in SKM (p<0.05). Cell viability decreased along the time (5-45 min). The results indicate that SM can be used as a more adequate storage medium for avulsed teeth. SKM was not as effective in preserving cell viability as the cell culture medium and SM.

The magnitude of occasional discrepancies between the centric relation and maximal intercuspation positions remains a controversial subject. This study quantitatively evaluated the possible discrepancies in the condyle/mandibular fossa relationship between these positions using cone-beam computed tomography. Twenty young and asymptomatic volunteers were distributed equally into normal occlusion and Angle Class I, II and III malocclusion groups. They were submitted to one tomographic scan in maximal intercuspation and one in centric relation. Measurements were performed on lateral and frontal cuts of the patients' temporomandibular joints, and the data collected were compared using Student's t test at a significance level of 5%. The results showed that there were no statistically significant differences between the centric relation and maximal intercuspation positions in young and asymptomatic patients with practically intact dentitions using cone-beam computed tomography.

O objetivo deste estudo foi avaliar o efeito de diferentes parâmetros de solda a plasma verificando a resistência flexural de barras de liga de titânio (Ti-6Al-4V). Quarenta espécimes de Ti-6AL-4V e dez espécimes de liga de NiCr foram preparados (40 mm de altura e 3,18 mm de diâmetro) e divididos em 5 grupos (n=10). As barras de liga titânio do grupo controle não foram seccionadas e nem submetidas a processo de soldagem. Os grupos PL10, PL12 e PL14, continham barras de titânio seccionadas e soldadas com uma corrente de 3 A por períodos de 10,12 e 14 ms, respectivamente. O grupo NCB consistiu de barras de liga de NiCr soldadas pelo método de brasagem convencional. Em seguida as barras foram submetidas ao teste de flexão de três pontos e os valores obtidos foram transformados em resistência flexural (MPa). Análise estatística foi realizada usando ANOVA de fator único e o teste Tukey com o nível de significância de 0,05. Diferença estatística foi verificada entre os grupos avaliados (p<0,001), com os maiores valores pra o grupo controle. Não foram encontradas diferenças entre os grupos de solda plasma (p>0,05). O grupo NCB apresentou os menores valores de resistência flexural embora tenha sido estatisticamente semelhante ao grupo PL14. Não houve diferença significante na profundidade de penetração entre os grupos de solda plasma (p=0,05). Três espécimes representativos foram aleatoriamente selecionados para serem avaliados por meio de microscopia eletrônica de varredura. A composição das regiões soldadas foi verificada por meio de espectroscopia por energia dispersiva. Este estudo fornece informações iniciais de parâmetros para permitir a utilização de soldagem plasma durante a fabricação de estruturas em liga de titânio.

The aim of this study was to assess the effect of different plasma arc welding parameters on the flexural strength of titanium alloy beams (Ti-6Al-4V). Forty Ti-6Al-4V and 10 NiCr alloy beam specimens (40 mm long and 3.18 mm diameter) were prepared and divided into 5 groups (n=10). The titanium alloy beams for the control group were not sectioned or subjected to welding. Groups PL10, PL12, and PL14 contained titanium beams sectioned and welded at current 3 A for 10, 12 or 14 ms, respectively. Group NCB consisted of NiCr alloy beams welded using conventional torch brazing. After, the beams were subjected to a three-point bending test and the values obtained were analyzed to assess the flexural strength (MPa). Statistical analysis was carried out by one-way ANOVA and Tukey's HSD test at 0.05 confidence level. Significant difference was verified among the evaluated groups (p<0.001), with higher flexural strength for the control group (p<0.05). No significant differences was observed among the plasma welded groups (p>0.05). The NCB group showed the lowest flexural strength, although it was statistically similar to the PL 14 group (p>0.05). The weld depth penetration was not significantly different among the plasma welded groups (p=0.05). Three representative specimens were randomly selected to be evaluated under scanning electron microcopy. The composition of the welded regions was analyzed by energy dispersive X-ray spectroscopy. This study provides an initial set of parameters supporting the use of plasma welding during fabrication of titanium alloy dental frameworks.

A adição de diferentes polímeros como o politetrafluoretileno (PTFE) às resinas para base de próteses removíveis pode ser uma opção para modificar as propriedades mecânicas das resinas acrílicas. Este estudo avaliou a dureza de superfície, a resistência ao impacto e à flexão, o módulo flexural e a carga de ruptura de duas resinas acrílicas, uma submetida ao ciclo longo e a outra ao ciclo curto de polimerização, as quais foram preparadas com ou sem a adição de PTFE a 2%. Quatro grupos foram formados de acordo com os ciclos de polimerização e a adição ou não de PTFE. Quarenta espécimes foram preparados para cada teste (10 espécimes por grupo) com as seguintes dimensões: dureza de superfície (30 mm diametro x 5 mm espessura), resistência ao impacto (50 x 6 x 4 mm), resistência à flexão (64 x 10 x 3,3 mm). O módulo flexural e a carga de ruptura foram calculados a partir dos valores obtidos no teste de resistência à flexão. Todos os testes foram realizados em conformidade com a Norma ISO 1567:1999. Os dados foram submetidos à análise de variância e teste de Tukey com nível de significância de 5%. Não foram encontradas diferenças estatisticamente significantes (p>0,05) para dureza de superfície. Os valores de resistência à flexão, resistência ao impacto e carga de ruptura foram maiores para as resinas sem a adição de PTFE (p<0,05). O valor do módulo flexural da resina acrílica com adição de PTFE a 2%, polimerizada por ciclo longo, foi maior do que as outras resinas (p<0,05). Dentro das limitações deste estudo, pode-se concluir que a adição de politetrafluoretileno não melhorou as propriedades mecânicas das resinas acrílicas avaliadas.

The addition of different polymers, such as polytetrafluorethylene (PTFE), to denture base resins could be an option to modify acrylic resin mechanical properties. This study evaluated the surface hardness, impact and flexural strength, flexural modulus and peak load of 2 acrylic resins, one subjected to a long and another subjected to a short polymerization cycle, which were prepared with or without the addition of 2% PTFE. Four groups were formed according to the polymerization cycle and addition or not of PTFE. Forty specimens were prepared for each test (10 per group) with the following dimensions: hardness (30 mm diameter x 5 mm thick), impact strength (50 x 6 x 4 mm) and flexural strength (64 x 10 x 3.3 mm) test. The results of the flexural strength test allowed calculating flexural modulus and peak of load values. All tests were performed in accordance with the ISO 1567:1999 standard. Data were analyzed statistically by ANOVA and Tukey's test with the level of significance set at 5%. No statistically significant differences (p>0.05) were found for surface hardness. Flexural strength, impact strength and peak load were significantly higher (p<0.05) for resins without added PTFE. The flexural modulus of the acrylic resin with incorporated 2% PTFE polymerized by long cycle was significantly higher (p<0.05) than that of the other resins. Within the limits of this study, it may be concluded that the addition of PTFE did not improve the mechanical properties of the evaluated acrylic resins.

O objetivo desse estudo foi avaliar a influência de diferentes terapias periodontais na integridade de restaurações indiretas por meio de microscopia eletrônica de varredura (MEV). Sessenta raízes bovinas foram selecionadas e aleatoriamente divididas em 12 grupos. Preparos cavitários inlay foram realizados na região cervical central da junção cemento-esmalte e restaurados com resina laboratorial cimentado com cimento resinoso. Doze terapias periodontais foram usadas (n=5): C-sem tratamento (controle); MS-raspagem manual com cureta Gracey; US-raspagem com ultra-som; PP- profilaxia com pasta profilática; PS-profilaxia com pedra pomes; SBJ-jato de bicarbonato; MS/PP; MS/PS; MS/SBJ; US/PP; US/PS; US/SBJ. As amostras foram preparados e submetidas a MEV. Imagens, de ×100 a ×1000, da superfície da resina laboratorial e da interface das restaurações indiretas foram obtidas. As imagens foram avaliadas em procedimento cego por 3 observadores habilitados previamente calibrados seguindo os seguintes critérios: ranhuras, microcavidades e fratura de margem. Os resultados mostraram que a profilaxia com pedra pomes promoveu ranhuras na superfície das restaurações. Raspagem manual e ultrasônica promoveram ranhuras e fratura de margem das restaurações. Jato de bicarbonato resultou em degradação de cimento resinoso. Os resultados sugeriram que, exceto a profilaxia com pasta profilática, todos os procedimentos resultaram em efeitos deletérios na integridade da margem das restaurações indiretas.

The aim of this study was to evaluate the influence of different periodontal therapies on the integrity of indirect restorations by scanning electron microscopy (SEM). Sixty single-rooted bovine teeth were selected and randomly assigned to 12 groups. Inlay cavities were prepared in the cervical region on the center of the cementoenamel junction, and were restored with laboratory processed resin and luted with a resin cement. Twelve periodontal therapies were used (n= 5): C: control (no treatment); MS: manual scaling with Gracey curettes; US: ultrasonic scaling; PP: prophylaxis with prophylactic paste; PS: prophylaxis with pumice-stone; SBJ: sodium bicarbonate jet; MS/PP; MS/PS; MS/SBJ; US/PP; US/PS; US/SBJ. The specimens were prepared and analyzed by SEM. SEM micrographs at ×100 to ×1000 magnification were obtained from the surface of the laboratory resin and the interface of the indirect restorations. The images were evaluated by 3 skillful, calibrated, blinded observers as to the presence of grooves, microcavities and fracture of margins. The results showed that PS produced groves on restoration surface. MS and US produced groves and marginal fractures on the restorations. SBJ resulted in resin cement degradation. These results suggest that except for PS, all procedures had deleterious effects on the marginal integrity of indirect restorations.

OBJECTIVES: Alterations in the temporomandibular complex can reflect in adaptations of the individual's entire muscular system, intervening with the head position and scapular waist, developing postural alterations and modifying all corporal biomechanics. The aim of this study was to evaluate the head position (HP) and head postural alterations before and after installation of occlusal splints. MATERIAL AND METHODS: Twenty patients with temporomandibular disorders (TMD) underwent clinical and postural examination, before the installation of an occlusal splint, and after 1 week and 1 month of use. RESULTS: There were statistically differences for HP, between the initial values and after 1 week of use of the occlusal device (p= 0.048) and also between 1 week and 1 month of evaluation (p= 0.001). Decrease of the painful symptomatology and maintenance of the rectification were also observed. CONCLUSIONS: The individual's postural position can suffer biomechanical alterations due to stomatognathic alterations, causing clinically visible changes in dysfunctional individuals and affecting the performance of the involved structures.

This research consisted of a quantitative assessment, and aimed to measure the possible discrepancies between the maxillomandibular positions for centric relation (CR) and maximum intercuspation (MI), using computed tomography volumetric cone beam (cone beam method). The sample of the study consisted of 10 asymptomatic young adult patients divided into two types of standard occlusion: normal occlusion and Angle Class I occlusion. In order to obtain the centric relation, a JIG device and mandible manipulation were used to deprogram the habitual conditions of the jaw. The evaluations were conducted in both frontal and lateral tomographic images, showing the condyle/articular fossa relation. The images were processed in the software included in the NewTom 3G device (QR NNT software version 2.00), and 8 tomographic images were obtained per patient, four laterally and four frontally exhibiting the TMA's (in CR and MI, on both sides, right and left). By means of tools included in another software, linear and angular measurements were performed and statistically analyzed by student t test. According to the methodology and the analysis performed in asymptomatic patients, it was not possible to detect statistically significant differences between the positions of centric relation and maximum intercuspation. However, the resources of cone beam tomography are of extreme relevance to the completion of further studies that use heterogeneous groups of samples in order to compare the results.

This study evaluated the influence of the method and period of storage on the adhesive bond strength of indirect composite resin to bovine dentin. Ninety bovine incisors were stored in three different solutions: 0.2% thymol, 10% formalin, and 0.2% sodium azide, during 3 periods of storage: 7 days, 30 days and 6 months, resulting in 9 groups (n = 10). The roots were cut off and the buccal surface was ground with #600-grit silicon carbide paper. The surface was conditioned with 37% phosphoric acid for 15 s and a composite resin restoration (TPH Spectrum) was fixed using a one-bottle adhesive system (Adper Single Bond) and a dual-cured resinous cement (Rely X ARC) under a load of 500 g for 5 minutes. The samples were serially cut perpendicular to the bonded interface to obtain slices of 1.2 mm in thickness. Each slab was trimmed with a cylindrical diamond bur resulting in an hourglass shape with a cross-sectional area of approximately 1 mm². The microtensile bond strength (μTBS) testing was performed in a testing machine (EMIC 2000 DL) at a 0.5 mm/minute crosshead-speed until failure. After fracture, the specimens were examined under SEM to analyze the mode of fracture. μTBS Means were expressed in MPa and the data were analyzed by two-way ANOVA (3X3) and the Tukey test (α = 0.05). The storage times of 7 and 30 days produced no significant difference irrespective of the solution type. The formalin and thymol solutions, however, did have a negative influence on bond strength when the teeth were stored for 6 months.

Este trabalho teve como objetivo correlacionar o nível de desajuste vertical pilar/implante a perda do torque aplicado (destorque). Um modelo de trabalho foi obtido a partir de uma matriz metálica com cinco implantes tipo hexágono externo (Titamax, Neodent, Curitiba, Brasil) com plataforma regular (4,1 mm). Sobre esta matriz, quatro infra-estruturas foram enceradas utilizando pilares tipo UCLA e fundidas em monobloco com titânio comercialmente puro (Tritan grau I, Dentaurum, Alemanha). Os desajustes foram analisados com um microscópio óptico comparador (Mytutoyo, Japão) após torque de 20 Ncm. O maior valor de desajuste observado por pilar foi utilizado. O valor do torque de desaperto, avaliado com um torquímetro digital (TQ-680, Instrutherm, Brasil), foi calculado em porcentagem do valor do torque inicial (100%) dado aos parafusos protéticos. O teste de correlação de Pearson (p<0,05), entre os valores de desajuste (29,08 ± 8,78 µm) e as porcentagens da perda de torque (50,71 ± 11,37%), não mostrou correlação estatisticamente significante (p=0,295) entre tais fatores. Dentro das limitações do estudo, pode ser concluído que não necessariamente grandes valores de desajustes verticais implicarão em grades perdas de torque.

This study investigated whether there is a direct correlation between the level of vertical misfit at the abutment/implant interface and torque losses (detorque) in abutment screws. A work model was obtained from a metal matrix with five 3.75 x 9 mm external hex implants with standard platform (4.1 mm). Four frameworks were waxed using UCLA type abutments and one-piece cast in commercially pure titanium. The misfit was analyzed with a comparator microscope after 20 Ncm torque. The highest value of misfit observed per abutment was used. The torque required to loose the screw was evaluated using a digital torque meter. The torque loss values, measured by the torque meter, were assumed as percentage of initial torque (100%) given to abutment screws. Pearson's correlation (α=0.05) between the misfit values (29.08 ± 8.78 µm) and the percentage of detorque (50.71 ± 11.37%) showed no statistically significant correlation (p=0.295). Within the limitations of this study, it may be concluded that great vertical misfits dot not necessarily implies in higher detorque values.

Bruxism is a pathological activity of the stomatognathic system that involves tooth grinding and clenching during parafunctional jaw movements. Clinical signs of bruxism are mostly related to dental wear and muscular and joint discomforts, but a large number of etiological factors can be listed, as local, systemic, psychological and hereditary factors. The association between bruxism, feeding and smoking habits and digestive disorders may lead to serious consequences to dental and related structures, involving dental alterations (wear, fractures and cracks), periodontal signs (gingival recession and tooth mobility) and muscle-joint sensivity, demanding a multidisciplinary treatment plan. This paper presents a case report in which bruxism associated with acid feeding, smoking habit and episodes of gastric reflow caused severe tooth wear and great muscular discomfort with daily headache episodes. From the diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow up with counseling on diet and smoking habits and management of the gastric disorders. This was followed by the installation of an interocclusal acrylic device in centric relation of occlusion (CRO) for reestablishment of the occlusal stability, vertical dimension of occlusion, anterior guides and return to normal muscle activity (90-day use approximately). After remission of initial symptoms, oral rehabilitation was implemented in CRO by means of full resin composite restorations and new interocclusal device for protection of restorations. Satisfactory esthetics, improved function and occlusal stability were obtained after oral rehabilitation. The patient has attended annual follow-ups for the past 2 years. The multidisciplinary treatment seems to be the key for a successful rehabilitation of severe cases of dental wear involving the association of different health disorders.

Um ajuste inadequado na interface pilar/implante pode gerar problemas mecânicos e biológicos. Etapas laboratoriais podem induzir a um desajuste em tal interface quando pilares do tipo UCLA calcináveis são utilizados. Este estudo propôs-se a avaliar comparativamente o desempenho de três laboratórios de prótese dentária (Labs A, B e C) pela análise do ajuste vertical de pilares UCLA calcináveis durante o processo de fundição e solda de uma mesma prótese. Quatro próteses fixas foram confeccionadas por cada laboratório utilizando pilares do tipo UCLA calcinável. A avaliação foi feita em microscopia eletrônica de varredura sob aumento de 500 x nas faces mesial e distal de cada elemento da prótese, totalizando 24 medidas por laboratório. Os resultados foram analisados estatisticamente pelo teste de Kruskal-Wallis (p<0,05). Na fundição, os valores apresentados pelos laboratórios diferiram estatisticamente (p=0,004). Após a análise da solda, os valores não apresentaram diferença significante entre os laboratórios (p=0,948). Pode-se concluir que os valores de ajuste obtidos no estágio de fundição de pilares UCLA, podem ser influenciados quando processados por diferentes laboratórios e que o processo de solda convencional, por si só, aumenta o grau de desajuste da infra-estrutura, independente do laboratório que a realizou.

An inadequate fit at the abutment/implant interface can generate mechanical and biological problems. The laboratorial stages could induce misfit in such interface when the castable UCLA abutment type is used. The purpose of this study was to comparatively evaluate the performance of three prosthetic laboratories (Labs A, B and C) by vertical fit analysis of castable UCLA abutments on the casting and soldering stages of the same prosthesis. Four fixed prostheses were built by each laboratory using castable UCLA abutments. The evaluation was made by scanning electron microscopy under 500x magnification in the mesial and distal regions of each element of the prosthesis, totalizing 24 measurements per laboratory. The results were analyzed statistically by Kruskal-Wallis test (p<0.05). In the casting process, the values presented by the laboratories differed significantly to each other (p=0.004). After soldering, the values presented by the laboratories showed no significant difference (p=0.948). It may be concluded that the fit values obtained in the casting stage of UCLA abutments can be influenced when processed by different laboratories, and that conventional soldering itself increased the degree of framework misfit, regardless of which laboratory made it.

A resistência da união metal/porcelana tem um importante papel na subistituição das ligas de ouro por ligas à base de níquel-cromo na Odontologia. Este estudo avaliou a resistência da união metal/porcelana de três sistemas cerâmicos (Vita VMK 88, Williams e Duceram) em combinação com três ligas metálicas à base de níquel-cromo (Durabond, Lite Cast B e Resistal P) e uma liga experimental à base de cobalto-cromo-titânio. Trinta corpos-de-prova cilíndricos (15 mm de altura; 6 mm de diâmetro) foram obtidos para cada liga, sendo 10 corpos-de-prova de cada liga testados com cada uma das porcelanas. A resistência de união foi calculada utilizando uma máquina EMIC aplicando uma força de cisalhamento paralela ao corpo-de-prova até a fratura. Os testes de Kruskal-Wallis e U de Mann-Whitney foram usados para a análise estatistica das interações metal/porcelana (p<0,05). A combinação Duceram/Resistal P apresentou resistência de união significantemente maior (44,38±9,12 MPa) (p<0,05) que as outras combinações, exceto a associaçãoVita VMK 88/liga experimental Co-Cr-Ti (38,41±12,64 MPa). A combinção da liga de Co-Cr-Ti com o sistema cerâmico Williams teve resistência ao cisalhamento significantemente maior que a combinação das outras ligas com a mesma porcelana (28,20±3,86 MPa) (p<0,05). Com base nestes resultados e dentro das limitações de um estudo in vitro, pode-se concluir que a resistência da união metal/porcelana dos três sistemas cerâmicos testados às ligas de Ni-Cr e Co-Cr-Ti variaram significativamente, mostrando que a compatibilidade metal/porcelana foi muito importante para esta união.

Ceramometal bond strength has played an important role for the replacement of gold alloys by nickel-chromium alloys in dentistry. This study evaluated the metal/porcelain bond strength of three ceramic systems (Vita VMK 88, Williams and Duceram) associated with three nickel-chromium alloys (Durabond, Lite Cast B and Resistal P) and one experimental cobalt-chromium-titanium alloy. Thirty cast cylinder specimens (15 mm in height; 6 mm in diameter) were obtained for each alloy, in away that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis of the alloy/ceramic combinations (p<0.05). Resistal P/Duceram had significantly higher bond strength (44.38±9.12 MPa) (p<0.05) than the other combinations, except for Co-Cr-Ti alloy/Vita VMK 88 (38.41±12.64 MPa). The association of the experimental Co-Cr-Ti alloy with Williams porcelain had significantly higher bond strength (28.20±3.86 MPa) than the combination of other alloys with the same porcelain (p<0.05). Based of these results and within the limitations of an in vitro study, it may be concluded that the bond strength of the three ceramic systems to the Ni-Cr and Co-Cr-Ti alloys varied significantly, indicating that metal/ceramic compatibility was very important to the bond strength.