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Objetivo: O presente estudo avaliou, por meio da extensometria, as microdeformações geradas ao redor de implantes, em duas conexões protéticas: hexágono externo(HE) e cone morse(CM), em duas diferentes níveis ósseos: sem perda e com perda de 5 milímetros, em coroas unitárias implantossuportada, confeccionadas em diferentes materiais restauradores: resina acrílica, totalmente metálica, metalocerâmica e cerâmica pura. Material e Métodos: Sete blocos retangulares de: 95 x 45 x 30 mm foram utilizados para simular o tecido ósseo, possuindo um degrau de 5 mm, que simulou uma perda óssea. Foram utilizados 28 implantes (3,75 x 13 mm) de mesmo desenho externo, mas diferentes plataformas protéticas, o pilar protético selecionado para o HE foi o UCLA e para o CM o CMN. O ensaio mecânico foi realizado por meio de um dispositivo de aplicação de carga (DAC) com carregamentos estáticos axiais sobre a superfície oclusal das coroas, com carga de 31,5 kgf por 10 segundos, sob três repetições. Os dados foram avaliados por teste ANOVA e Tukey com nível de significância 5% (P - 0,05). Resultados: Os resultados obtidos pela extensômetros demonstraram que: em relação ao nível ósseo e a conexão protética, houve diferença estatística entre os grupos de implantes à nível ósseo (HE - 308,6793 µÎµ e CM - 457,0536 µÎµ), contudo com a simulação de perda óssea de 5mm não registraram diferença estatística ( HE - 563,0707 µÎµ e CM - 522,8788 ). Em relação ao material da coroa, não houve diferença estatística independente da conexão protética e do nível ósseo ( Co-cr: 528,99µÎµ, metalocerâmica:420,57µÎµ, resina: 435,33µÎµ e cerâmica pura: 462,92µÎµ). Conclusão:O estudo concluiu que os implantes à nível ósseo com a conexão protética HE registrou valores de microdeformações estatisticamente menores que o CM, mas com 5 mm de perda o comportamento foi semelhante. Os diferentes materiais das coroas avaliados, não foram capazes de reduzir os valores de microdeformação, independente do nível ósseo do implante. (AU)

Objective: The present study evaluated, by means of extensometry, the microdeformations generated around implants, in different systems: External Hexagon (EH) and Cone Morse (CM), in two different bone heights: No bone loss and 5mm bone loss, in unitary crown implant, of different restorative materials (acrylic resin, metallic, metal-ceramic or all-ceramic). Material and Methods: Seven rectangular block with dimensions of 95 x 45 x 30 mm was used to simulate bone tissue, containing a 5 mm step, which simulated bone loss. 28 implants (3.75 x 13 mm) with the same geometry and different prosthetic platforms were used, the abutment of choice for the EH was the UCLA and for the CM the CMN. The mechanical test was performed using a load application device (DAC) with axial static loads on the occlusal surface of the crowns, the load used was 31.5 kgf for 10 seconds, with three repetitions. Data were evaluated by ANOVA and Tukey tests with significance level 5% (P - 0.05). Results: The results obtained by the strain gauges showed that: in relation to the bone level and the prosthetic connection, there was a statistical difference between the groups of implants at the bone level (EH - 308.6793 µÎµ and CM - 457.0536 µÎµ), however, with the simulation of 5mm bone loss, there was no statistical difference (EH - 563.0707 µÎµ and CM - 522.8788). Regarding crown material, there was no statistical difference regardless of the prosthetic connection and bone level. (Co-Cr 528.99µ).Conclusion: The study concluded that bone-level implants with the HE prosthetic connection registered statistically lower microdeformation values than the CM, but with 5 mm of loss the behavior was similar. The different crown materials evaluated were not able to reduce the microdeformation values, regardless of the bone level of the implant. (AU)

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The aim of this clinical study was to evaluate bacterial colonization, marginal bone loss, and optical alveolar density in implants with Morse taper (MT) and external hexagon (EH) connections. Thirty-five implants were installed in 7 patients (mean age: 65.8 ± 6.7 years). Implants were divided into 2 groups, according to platform design: G1 - MT, installed 2mm infra-osseous and G2 - EH, positioned according to Branemark protocol. Patients were evaluated at baseline (T0), 21 days (T1), 3 months (T2), 6 months (T3), and 12 months (T4) after installations. Bone loss and alveolar density were evaluated by standardized periapical radiographs and bacterial profile with checkerboard DNA-DNA hybridization. Statistical analyses were performed using SPSS 23.0. To present the results, boxplots and a line graph of mean were used. P-values ≤ .05 were statistically significant. After 3 months, alveolar bone loss was significantly higher in the G2 (T2-T0: P = .006; T3-T0: P = .003; and T4-T0: P = .005). No significant differences between G1 and G2 groups were observed for optical alveolar density. Microbiological analysis showed similar profiles between studied groups; however, there were significantly higher counts of Tannerella forsythia (P = .048), Campylobacter showae (P = .038), and Actinomyces naeslundii (P = .027) in G1 after 12 months. Based on the results of this study, it can be concluded that there was less peri-implant bone loss in MT compared to EH connections, but microbiological profile did not seem to influence bone changes.

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Introduction: The use of osseointegrated dental implants for the rehabilitation of patients has revolutionized dentistry. Objective: To retrospectively evaluate the survival rate and the frequency of complications with external hexagon platform supporting single crowns. Material and method: Dental forms of 110 patients who received 143 implants at the Ilapeo College (2004-2015) were used. The variables were: age, gender, systemic involvement at the time of surgery, region, implant design, type of surface, fixation system, pillar type and prosthesis material. The outcome variables were the incidence of complications in the implant or prosthesis and time in use. The mean follow-up period was 9 years. Result: 32.8% had some systemic disease. Ninety-six implants (67.1%) were installed in the maxilla and 47 (32.9%) in the mandible, 87 (60.8%) were in the posterior region and 56 (39.2%) in the anterior region, while 40 (28%) were placed in regions that had received bone reconstruction. The majority (97.2%) of the implants presented surface treatment, 42% had a cylindrical design and 58% were tapered. The majority of the prosthetic components (89.6%) used were UCLAs and most of the prostheses were fused-to-metal (79.7%). The rate of prosthetic complications was 19.58% and three implants had been lost (97.9% survival rate). There was no statistical difference between the variables analyzed for both the occurrence of prosthetic complications and for the loss of the implant. Conclusion: Implants with external hexagon connection were an effective and predictable option to support crowns and had high survival rates.

Introdução: O uso de implantes dentários osseointegrados para a reabilitação de pacientes revolucionou a Odontologia. Objetivo: Avaliar retrospectivamente o índice de sobrevivência e a frequência de complicações com plataformas de hexágono externo suportando coroas unitárias. Material e método: Foram utilizados prontuários de 110 pacientes que receberam 143 implantes na Faculdade Ilapeo (2004-2015). As variáveis foram: idade, sexo, envolvimento sistêmico no momento da cirurgia, região, desenho do implante, tipo de superfície, sistema de fixação, tipo de pilar e material da prótese. As variáveis de desfecho foram a incidência de complicações nos implantes e/ou próteses e o tempo em função. O tempo médio de acompanhamento foi de 9 anos. Resultado: 32,8% apresentavam alguma alteração sistêmica. Noventa e seis implantes (67,1%) foram instalados na maxila e 47 (32,9%) na mandíbula, 87 (60,8%) estavam em região posterior e 56 (39,2%) em região anterior, enquanto 40 (28%) necessitaram reconstrução óssea prévia. A maioria dos implantes (97,2%) apresentava tratamento de superfície, 42% eram cilíndricos e 58% cônicos. A maioria dos componentes protéticos (89,6%) eram UCLAs e a maioria das próteses fundidas em metal (79,7%). O índice de complicações protéticas foi de 19,58% e 3 implantes foram perdidos (97,9% de índice de sobrevivência). Não houve diferença estatística em relação às variáveis estudadas e a ocorrência de complicações protéticas e perda de implantes. Conclusão: Implantes com plataforma de hexágono externo são uma opção efetiva e previsível de reabilitação unitária e apresenta elevado índice de sobrevivência.

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Objetivo: avaliar pela análise microbiológica in vitro a capacidade de selamento bacteriano de dois modelos de implante conexão cone-morse e hexágono externo. Material e métodos: foram utilizados 28 implantes osseointegráveis (Colosso Emfils ­ Itu/SP, Brasil) divididos em dois grupos (14 implantes cada), nos quais os componentes protéticos foram parafusados com um torque de 20 Ncm, em um ambiente controlado e após contaminação propositada da parte interna dos implantes por Escherichia coli. As colônias bacterianas foram transportadas por meio de hastes confeccionadas por fios ortodônticos, previamente esterilizadas, e então fixados seus respectivos pilares protéticos. Em seguida, um microbrush umedecido em solução salina a 0,9% estéril foi levemente friccionado na interface da superfície externa implante/conector protético. Cada conjunto implante/componente protético foi imerso em um tubo de ensaio contendo 5 ml de caldo BHI, permanecendo imerso no meio de cultura. As amostras foram monitoradas em relação ao crescimento bacteriano. Resultados: após 14 dias, verificou-se que não houve contaminação em nenhum dos tipos de conexões. Conclusão: a utilização desses implantes já evitaria a contaminação bacteriana nos primeiros dias após a carga imediata, determinando assim o aumento do índice de sucesso desse procedimento.

Objective: to evaluate by in vitro microbiological analysis the bacterial sealing ability of two implant models (Morse cone and external hexagon connections). Material and methods: Twentyeight dental implants (Colosso Emfi ls ­ Itu/SP, Brazil) were divided into two groups (14 implants each) and the prosthetic components screwed with a 20 Ncm torque in a controlled environment and after deliberate contamination of the internal part of the implants by Escherichia coli. The bacterium strain was transported by orthodontic wire loops previously sterilized and then the prosthetic abutments were fastened. After, a microbrush moistened with a 0.9% saline sterile solution was lightly rubbed into the external implant/ prosthetic abutment surface. Each implant/prosthetic assembly was immersed in a test tube containing 5 ml of BHI broth remaining immersed in the culture medium. Samples were monitored for bacterial growth. Results: after 14 days, no contamination was observed in any of the implant connections. Conclusion: the use of these implants would already prevent bacterial contamination in the first days after immediate loading, thus increasing the success rate of this procedure.

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The aim of this study is to evaluate hexagon deformation of dental implant regarding to the insertion force, verifying the external hexagon platforms before and after each torque performed. Thereunto, 25 implants were selected and divided into 5 groups with 5 implants each one; every group received different torque 10N, 20N, 30N, 40N and 100N. A Surgical torque wrench was used, with the implant installation key, what established the insertion force for each group. The platform measurements were carried out before and after apply the torque by analyses of images acquired through implant platforms. We conclude, by this study methodology, 100N forces were able to cause changes on hexagon dimensions; however, it did not damage the prosthesis platform adaptation.

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Objetivo: avaliar a remodelação óssea radiográfica ao redor de implantes hexágono externo (EH) que possuem roscas no módulo da crista. Material e métodos: doze pacientes desdentados totais receberam quatro implantes (Ø 3,8 mm x 13 mm) customizados na região interforaminal. Doze desses implantes foram hexágono externo com roscas no módulo da crista. Todos os pacientes receberam uma prótese implantossuportada imediata. A distância entre o topo do implante e o primeiro contato osso/implante (IT-FBIC) foi avaliada em radiografias periapicais digitais padronizadas adquiridas em um, três, seis e 12 meses de acompanhamento. A comparação entre vários períodos de observação foi realizada utilizando análise de variância (Anova) para medidas repetidas, seguida pelo teste post-hoc de Tukey. Resultados: a variação radiográfica da perda óssea peri-implantar foi significativamente diferente entre os períodos de acompanhamento (p < 0,001). A média de IT-FBIC foi de 1,17 ± 0,44 mm, depois de 12 meses de carregamento funcional. Conclusão: a remodelação óssea peri-implantar ocorrerá para implantes com hexágono externo, independentemente da presença de elementos de retenção no módulo da crista do implante

Objective: to evaluate the radiographic bone remodeling around implants using external hexagon (EH) with a threaded implant crestal module. Material and methods: twelve patients with totally edentulous mandibles received four custom-made (Ø 3.8 x 13 mm) implants in the interforaminal region. Twelve of the implants were external hexagon with a threaded implant crestal module. All patients received an immediate implant-supported prosthesis. The distance between the top of the implant and the first bone-to-implant contact (IT-FBIC) was evaluated on standardized digital periapical radiographs acquired at one, three, six, and 12 months of follow-up. Comparison among multiple observation periods was performed using repeated-measures analysis of variance (Anova), followed by a Tukey post-hoc test. Results: the radiographic periimplant bone loss was significantly different among the follow-up periods (p < 0.001). Mean IT-FBIC was 1.17 mm ± 0.44 mm, at 12 months follow-up period. Conclusions: radiographic periimplant bone remodeling will occur for implants using external hexagon, regardless of the presence of retention elements at the implant crestal module.

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Objetivos: avaliar o comportamento biomecânico de três tipos de conexão protética em implantes de diâmetro reduzido. Material e Métodos: implantes com diâmetro 3,25 mm (plataforma 3,4 mm) foram inseridos em polioximetileno (poliacetal) com torque máximo de 45 Ncm e receberam componentes protéticos calcináveis divididos em três grupos: G1: cone-morse (CM), hexágono interno (HI), e Hexágono externo (HE). Todo os pilares foram sobrefundidos em liga de CoCr e aparafusados com torque de 20 Ncm conforme recomendações do fabricante. A avaliação biomecânica ocorreu conforme a norma ISO 14801-2007: carregamento compressivo 30º e fadiga cíclica (f=15Hz, 5 milhões de ciclos) em ambiente seco. A análise estatística foi conduzida usando-se os testes Anova e Tukey (nível de significância 5%). Resultados: os valores compressivos médios foram: G1 (317,43 N), G2 (559,44 N), e G3 (290,83 N). Diferenças signifi cativas foram vistas entre G1 e G2 (p < 0,001) e entre G2 e G3 (p < 0,0001). Não houve diferença entre grupos no teste de fadiga. Os valores correspondentes foram: G1 (190,80 N), G2 (163,25 N), e G3 (141,77 N). Conclusões: todos os grupos demonstraram desempenho biomecânico aceitável

Objectives: to evaluate the biomechanical behavior of three types of prosthetic abutment connections in reduced implant diameters. Material and Methods: 3.25 mm-diameter dental implants (3.4 mm implant platform) were inserted in polyoxymethylene (polyacetal) resin with maximum torque of 45Ncm and received burnout prosthetic abutments divided into three groups: G1: cone-morse (CM), Internal Hex (IH), and External Hex (EH). All abutments were overcast in a CoCr alloy and fastened to 20 Ncm following manufacturer’s instructions. Biomechanical evaluation was performed according to ISO 14801-2007 standards: 30º compressive and fatigue loading (f = 15 Hz, 5 million cycles) in dry environment. Statistical analysis was conducted with Anova and post-hoc Tukey tests (5% signifi cance level). Results: mean compressive values were: G1 (317.43 N), G2 (559.44 N), and G3 (290.83 N). Signifi cant differences were seen between G1 and G2 (p < 0.001) and between G2 and G3 (p < 0.0001). No differences among groups were seen for fatigue loading. The correspondent endurance limits were: G1 (190.80 N), G2 (163.25 N), and G3 (141.77 N). Conclusions: all groups demonstrated acceptable biomechanical performance.

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AIM: To evaluate the loss of applied torque (detorque) values in cast and pre-machined abutments for external hex abutment/implant interface of single implant-supported prostheses subjected to mechanical cycling. METHODS: Ten metal crowns were fabricated using two types of UCLA abutments: cast and pre-machined with metal base in NiCrTi alloy and tightened to regular external hex implants with a titanium alloy screw, with an insertion torque of 32 N.cm, measured with a digital torque gauge. Samples were embedded with autopolymerizing acrylic resin in a stainless steel cylindrical matrix, and positioned in an electromechanical machine. Dynamic oblique loading of 120 N was applied during 5 x 10(5) cycles. Then, each sample was removed from the resin and detorque values were measured using the same digital torque gauge. The difference of the initial (torque) and final (detorque) measurement was registered and the results were expressed as percentage of initial torque. The results of torque loss were expressed as percentage of the initial torque and subjected to statistical analysis by the Student's t-test (p<0.05) for comparisons between the test groups. RESULTS: Statistical analysis demonstrated that mechanical cycling reduced the torque of abutments without significant difference between cast or pre-machined UCLA abutments (p=0.908). CONCLUSIONS: Within the limitations of this in vitro study, it may be concluded that the mechanical cycling, corresponding to one-year use, reduced the torque of the samples regardless if cast or pre-machined UCLA abutments were used.

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PURPOSE: The purpose of this study was to evaluate the rotational freedom between implant and abutment counterpart of two abutments types over external hexagon implants submitted to mechanical cycling. MATERIALS AND METHODS: Ten implants with external hexagon (3.75 mm × 13 mm), five cast abutments, and five premachined abutments both with 4.1 mm plataform size were used in this study. Ten metallic crowns were fabricated using the two types of abutments and were fixed to each implant using titanium screws (Ti6Al4V). Rotational freedom measurements were made before and after the cast procedure and after the mechanical cycling. Groups were classified according to the rotational misfit register using University of California, Los Angeles abutment and implants as new (group 1 = G1); using crowns and implants after crown casting (group 2 = G2); and using crowns and implants after mechanical cycling (group 3 = G3). Oblique loading of 120N at 1.8 Hz and 5 × 10(5) cycles was applied on specimen. RESULTS: Statistical analysis (p < .05) showed that no significant difference was observed when cast abutment was compared with premachined abutment after casting (p = .390) and mechanical cycling (p = .439); however, significant difference was noted before the casting (p = .005) with higher values for the cast abutments. CONCLUSIONS: Within the limitations of this in vitro study, it could be concluded that the abutment type used do not influenced the rotational freedom after casting and the amount of applied cycles (500,000 cycles) was not sufficient to significantly alter the values of rotational freedom at the implant/abutment joint.

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