A utilização dos implantes cone morse muito favorece a estética peri-implantar e seu uso em conjunto com próteses cimentadas favorece ainda mais a estabilidade do sistema, simplificando também os procedimentos protéticos. O presente estudo histológico e histomorfométrico utilizou os implantes cone morse com o intuito de avaliar o comportamento tecidual com relação à posição da margem da cimentação protética em relação ao tecido ósseo quando se faz o uso próteses cimentadas. Foram utilizados quatro cães, os quais tiveram todos os pré-molares inferiores extraídos numa primeira fase cirúrgica. Após três meses, realizou-se a segunda fase cirúrgica, na qual foi realizada a técnica da carga imediata, com a instalação dos implantes juntamente com os pilares protéticos. Foram instalados vinte e quatro implantes numa profundidade de 3 mm infra óssea e eles foram igualmente divididos entre os grupos Controle e Experimental. Os pilares protéticos utilizados foram do tipo munhão universal e apresentavam diferentes alturas transmucosas iguais a 1.5 mm, 3.5 mm, e 5.5 mm. Isto fez com que a margem da cimentação se posicionasse a 1.5 mm infra óssea, a 0.5 mm supra óssea e a 2.5 mm supra óssea. No grupo Controle, foi realizada a instalação dos implantes e dos pilares protéticos somente. No grupo Experimental, foi realizada a instalação dos implantes, dos pilares protéticos e, sobre estes, foram cimentados cilindros de alumina. Os animais permaneceram sobre controle de placa durante 10 semanas subsequentes a instalação dos implantes, sendo este o tempo final do experimento através da realização da eutanásia. As amostras foram preparadas para análise histológica e avaliação dos tecidos peri-implantares. A região de interesse foi medida através da distância entre a margem do pilar protético e a porção mais coronal da crista óssea peri-implantar. Foram utilizados os testes estatísticos ANOVA a três critérios com medidas repetidas e teste de Tukey com o nível de significância de p < 0.05. Os resultados mostraram que não houve diferenças estatisticamente significantes entre os grupos Controle e Experimental (p = 0.2764) e que os pilares de 1.5 mm mostram menos perda óssea comparada aos outros pilares, considerando que a distância média da remodelação óssea foi menor neste grupo (0.6859 mm) comparada com os pilares de 3.5 mm (1.2917 mm) e 5.5 mm (1.0823 mm). Conclui-se que não há influência da profundidade da margem da cimentação protética no comportamento da crista óssea e que a utilização de diferentes alturas dos pilares protéticos não parece alterar o tecido ósseo marginal ao redor dos implantes Cone Morse. / The use of Morse taper implants has increased because of some positive features. Cemented crowns can be extensively used, taking advantage of the system connection stability, also simplifying the prosthetic procedures. The present histological and histomorphometric study used Morse taper implants with the purpose of evaluating bone behavior with respect to the cementation margin position of the prosthetic crown. Four dogs had all premolars extracted at a first surgical procedure. After three months, there was a second surgical procedure with simultaneous installation of implants and abutments, submitted to immediate load. Twenty four implants were installed 3 mm below the bone level and they were equally divided between Control and Experimental groups. The universal post abutments used had three different transmucosal heights, 1.5 mm, 3.5 mm and 5.5 mm. Thus there were implants with the level of the cementation margin positioned 1.5 mm below the bone level, as well as 0.5 mm and 2.5 mm above the bone level. In the Control group, installation of implants and abutments only was performed. In the Experimental group immediately after the placement of implants and abutments alumina cylinders were cemented. The animals were kept on plaque control for 10 weeks after implant placement and then euthanized. Samples were prepared for histological analysis and evaluation of peri-implant tissues. The region of interest was measured by the distance between the prosthetic margin of the abutment to the most coronal peri-implant bone crest. ANOVA test at three criteria with repeated measures and Tukey test with a significance level of p < 0.05 were applied. The results showed no statistically significant differences between Control and Experimental groups (p = 0.2764). The 1.5 mm abutments presented less bone loss compared to all other abutments tested, because the distance average of bone remodelation was shorter in this group (0.6859 mm) compared to the 3.5 mm abutment (1.2917 mm) and the 5.5 mm one (1.0823 mm). Conclusion: There is no influence of the depth of prosthetic marginal cementation on the behavior of bone crest and the use of different transmucosal heights of abutments does not seem to change the marginal bone surrounding morse taper implants.

As pesquisas relacionadas ao vírus da imunodeficiência adquirida (HIV) e a síndrome da imunodeficiência adquirida (AIDS) visam encontrar formas de proporcionar melhor qualidade de vida e, se possível, o controle e remissão do vírus. Com a expectativa de vida aumentada, em decorrência do uso dos anti-retrovirais (ARV), aumenta também a necessidade de investir em tratamentos reabilitadores eficazes. Os implantes osseointegrados constituem uma alternativa na execução da reabilitação oral de pacientes que perderam dentes. 17 pacientes soropositivos para o HIV e 10 pacientes normorreativos participaram do projeto e foram reabilitados com 36 implantes osseointegrados e foram acompanhados por 12 meses. Os pacientes soropositivos para o HIV apresentaram resposta clínica ao tratamento semelhante aos pacientes normorreativos. Nenhum implante foi perdido durante o período de proservação. / Studies related to human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) propose to find better ways to improve the quality of life and, if possible, control and remission of the disease. As the life expectancy of HIV-positive individuals increase, esthetic and more functional treatments become more significant, and implants-supported prostheses should be considered. Seventeen HIV-positive patients and ten HIV-negative patients participated in this project and received 36 endosseous oral implants. These implants were followed for 12 months and all HIV-positive and HIV-negative patients showed the same clinical response. All the implants are fully integrated without any single loss.

A grande variedade de modelos de implantes disponíveis no mercado, assim como a variabilidade óssea nos pacientes, torna cada vez mais difícil a seleção do implante que permita obter uma maior estabilidade primária, fator essencial para osseointegração. O objetivo desse trabalho foi avaliar a influência do formato e tratamento de superfície de implantes, assim como do substrato utilizado, na estabilidade primária; aferida por meio de ensaios de desempenho e freqüência de ressonância. Foram utilizados 32 implantes Conexão®: 8 implantes cilíndricos hexágono externo sem tratamento de superfície (MS), 8 cilíndricos hexágono externo com tratamento Porous duplo (MP), 8 cilíndricos hexágono interno com tratamento Porous (CA), 8 cônicos sem tratamento (CC); todos com 11,5 mm de comprimento, e 3,75 mm de diâmetro para cilíndricos e 3,5 mm para os cônicos. Foram inseridos em diferentes substratos: osso de costela suína; osso artificial de poliuretana Synbone©; poliuretana Nacional® em três densidades - 15, 20 e 40 PCF; e madeira pinus. Para o ensaio de desempenho foi quantificado o torque de inserção com o torquímetro digital Mackena®, e a força de arrancamento por meio de força axial de tração com célula de carga de 200 kg, realizada na Máquina Universal de Ensaios Emic® DL-10000, e Software Tesc 3.13. A análise da freqüência de ressonância foi realizada com o aparelho Osstell Mentor®. Para obtenção dos resultados estes receberam tratamento estatístico ANOVA e Teste de Tukey com nível de significância a 5%. Ao analisar o torque de inserção, implantes com tratamento de superfície não foram diferentes estatisticamente do usinados, assim como os implantes cilíndricos não tiveram diferença estatística com os cônicos em todos os substratos (P>0,05), com exceção da poliuretana Synbone©, onde os cônicos apresentaram a menor média (4.45 ± 0.82) e tiveram diferença estatistica com os cilíndricos, hexágono externo (MP= 11.39 ± 0.76; MS= 10.34 ± 1.68), e interno (12.18 ± 3.78). No osso suíno, na poliuretana Nacional® de 15 PCF e na madeira, os implantes cônicos mostraram um melhor desempenho que nos outros substratos. Da mesma forma que no torque de inserção, em relação à força máxima de arrancamento, implantes tratados e usinados, assim como cônicos e cilíndricos, não tiveram diferença estatística (P>0,05), em todos os substratos; implantes cônicos só não apresentaram menores médias de força de arrancamento em matérias menos densos - osso suíno (138.19 ± 57.41 N), poliueretana Nacional® de 15 (209.57 ± 9.60 N) e 20 PCF(206.57 ± 31.51 N); e implantes cilindricos hexágono interno mostraram a maior média numérica em todos os materiais de inserção. Os valores de freqüência de ressonância mostraram que, apesar dos implantes com tratamento de superfície apresentarem maior média de ISQ que os implantes usinados em todos os substratos, estes não apresentaram diferença estatística entre si (P>0,05), com exceção da inserção na poliuretana Nacional de 20 PCF. Pôde-se concluir que, tanto o formato, como o tratamento de superfície dos implantes não influenciaram nas análises realizadas, entretanto, o substrato utilizado e sua densidade tiveram uma maior influência nos resultados obtidos. / The great variety of implant models available in the market, as well as the variability of patients bones, makes the selection of the implant that allows greatest primary stability, an essential factor for osseointegration, increasingly difficult. The aim of this study was to evaluate the influence of the format and surface treatment of implants, as well as the substrate used in primary stability; verified through resonance frequency and performance tests. 32 Conexão® implants were used: 8 cylindrical external hexagon implants without surface treatment (MS), 8 cylindrical external hexagon implants with double Porous treatment (MP), 8 cylindrical internal hexagon implants with Porous treatment (CA), and 8 tapered implants without treatment (CC). All had a length of 11.5 mm, while the cylindrical ones had a of diameter 3.75 mm compared with 3.5 mm for the tapered ones. They were inserted in different substrates: pig rib bone; artificial bone made from polyurethane Synbone©; Nacional® polyurethane in three densities - 15, 20 and 40 PCF; and pinus wood. For the performance test the insertion torque (N.cm) was quantified using the digital Mackena® torque meter, and the pull-out force (N) by means of axial traction force with a 200 kg load cell, carried out in the Emic® DL-10000 Universal Test Machine and the Tesc 3.13 software. The analysis of the resonance frequency (ISQ) was carried out with the Osstell Mentor® device. To obtain the results the ANOVA and Tukey statistical tests were used with a level of significance 5%. When analyzing the insertion torque, implants with surface treatment were not statistically different from the machined ones, nor did the cylindrical implants have any statistical difference from the tapered ones in all the substrates (P> 0.05), with exception of polyurethane Synbone©, where the tapered ones had a lower average (4.45 ± 0.82) and a statistical difference from the external hexagon (MP= 11.39 ± 0.76; 10.34 MS= ± 1.68), and internal hexagon (12.18 ± 3.78) cylindrical ones. In the pig bone, the 15 PCF Nacional® polyurethane and the wood tapered implants had a better performance that in the other substrate. Similar to the insertion torque, treated and machined implants, and tapered and cylindrical, did not have any statistical difference (P>0.05) in all the substrates; tapered implants only did not have a lower average of pull-out except in less dense substrates pig bone (138.19 ± 57.41 N), 15 Nacional® polyurethane (209.57 ± 9.60 N) and 20 PCF (206.57 ± 31.51 N). Internal cylindrical hexagon implants had the highest numerical average of all the inserted materials. The resonance frequency values showed that although the implants with surface treatment had a greater average ISQ that the machined implants in all the substrates, there was no statistical difference between them (P> 0.05), with the exception of the insertion of 20 PCF Nacional® polyurethane. It can be concluded that both the format and surface treatment of implants did not influence the analyses, however, the substrate used and their densities had a bigger influence on the results obtained.

O objetivo deste estudo foi comparar, in vitro, os sistemas de implante cone Morse, frente ao vedamento contra a penetração bacteriana entre o implante e o componente protético, em função de alterações estruturais e uso de selantes industriais. Foram utilizados 126 implantes Titamax CM EX distribuídos em três tipos de componentes protéticos: Munhão Universal CM, Munhão Universal CM com Parafuso Passante e Munhão Universal CM Exact, todos da empresa Neodent (Curitiba, Paraná, Brasil). Estes implantes foram divididos em 3 grupos de 42 implantes componentes protéticos, sendo os grupos devidamente denominados: Grupo 1 (G1) - Controle, Grupo 2 (G2) - Jateamento e Grupo 3 (G3) - Adesivo. Estes implantes, devidamente distribuídos entre os componentes protéticos e seus grupos, foram avaliados quanto à contaminação bacteriana em um período de 28 dias após o término da experimentação inicial em que foi realizado o efeito de ciclagem sobre as amostras (sem e com carga). Os implantes foram perfurados em sua porção apical com uma fresa de 1mm de diâmetro, até o encontro de sua câmara interna. Foram instalados os componentes protéticos de titânio em cada grupo com torque recomendado pelo fabricante (32 e 15 N.cm). Antes os componentes dos grupos G2 e G3 passaram por alterações estruturais (jateamento e adesivo Dermabond® respectivamente). As peças foram anexadas a tampas de tubo de ensaio, com a porção do componente voltada para o interior do tubo. Os tubos de ensaio foram preenchidos com meio de cultura líquido LB, utilizando-se seringa estéril. Todos os conjuntos receberam esterilização por radiação Gama (Embrarad, Campinas, Brasil). Após a confirmação da efetividade da esterilização por meio de amostras controle, os orifícios apicais foram cuidadosamente desobstruídos e inoculados com cultura de E. coli. O controle de turvamento das amostras foi realizado diariamente, os resultados apontaram que três das amostras do G1, sete do G2 e duas do G3, que não foram submetidas a ciclagem, sofreram contaminação num período de até 28 dias, e que três amostras do G1, dez do G2 e nenhuma do G3, quando submetidas ao efeito da ciclagem, foram contaminaram. Todos os grupos apresentaram infiltração bacteriana, independentemente do componente protético e da ciclagem. Ficou evidenciado que o grupo jateamento apresentou os piores resultados e que o adesivo apenas reduziu, mas não impediu a infiltração bacteriana para o interior dos implantes cone Morse. / The aim of this study was to compare, in vitro, Morse taper implant systems sealing against bacterial penetration between implant and prosthetic component after modifying the abutment structure or using industrial strength sealants. 126 Titamax CM EX implants and three different types of prosthetic components were used: Universal Post CM, CM Universal Post with passing screw and Universal Post CM Exact (Neodent implants, Curitiba, Parana, Brazil). These samples were divided into three groups: Group 1 Control group (G1); Group 2 Sandblasting (G2); and Group 3 Adhesive (G3). The implant / prosthetic component bacterial leakage from each group was evaluated after 28 days with or without cyclic loading. A hole at the apical portion of the implant was done with a 1 mm bur to access the implant internal threads. The abutments were inserted and torqued according to the manufacturer recommendation (15 or 32 N.cm). G2 abutments were sandblasted before insertion. G3 abutments were sealed with Dermabond® adhesive. The samples were sterilized by Gamma irradiation (Embrarad, Campinas, Brazil) and attached to the test tube lid and placed in the test tube filled with bacterial growth media (LB). Control samples from each group were used to assess bacterial contamination before starting the experiment. The access holes at the apical part of the implants were accessed and an E. coli culture was inoculated inside the implant internal threads and then sealed again. Changes in the media color (turbidity), indicative of bacterial leakage from inside the implant to the media were evaluated daily. Three samples from G1, seven from G2 and two from G3 without cyclic loading showed bacterial leakage after 28 days. Three samples from G1, ten from G2 and none of the samples from G3 showed bacterial leakage in the cyclic loading condition. All groups demonstrated bacterial leakage disregard of the type of abutment and loading conditions. It was demonstrated that G2 (sandblasted surface) had the worst results. Use of industrial sealant reduced but did not completely prevented bacterial leakage in Morse taper implants.

Objetivo: As alterações na altura óssea da região posterior ao último implante mandibular em indivíduos reabilitados com próteses fixas implanto suportadas foram correlacionadas com força de mordida (FM) e com a atividade massetérica em função. Métodos: radiografias panorâmicas antes e 1 ano depois da reabilitação de 10 pacientes do Hospital de Reabilitação de Anomalias Craniofaciais (HRAC – USP), foram avaliadas quanto à presença de alteração dimensional óssea. A FM foi registrada por meio de um gnatodinamômetro. Eletromiografia dos masseteres foi realizada e traduzida pelos parâmetros: contração voluntária isométrica máxima (CVIM) durante 5 segundos, mastigação habitual de cenoura (MHC) e mastigação unilateral direita (MUD) e esquerda (MUE) com látex. Resultados: houve um aumento médio da altura óssea mandibular de 0,23 ±0,4 mm; a FM média foi 42 ±5,9 Kgf e a CVIM foi de 66,7 ±23,7 µV. Os valores médios para MHC foram: ato 0,52 ±0,02 s; ciclo 1,3± 0,67s e amplitude (potência) 85,98 ±19,53µV; para MUD com látex foram: ato 0,59s, ciclo 0,89 ±0,22s amplitude 86,93 ±26,67µV, e os da MUE com látex foram: ato 0,56s, ciclo 1,35 ±0,69s e amplitude 90,89 ±32,96µV. Somente houve significância estatística do lado direito entre alteração dimensional óssea e o ato da MHC (p= 0,036); do lado esquerdo com o ato da MUD com látex - lado de balanceio (p= 0,026). Conclusão: o aumento médio da altura óssea na região posterior da mandíbula não se correlacionou significantemente com a maioria dos parâmetros analisados, sugerindo que a duração, mais que a potência da atividade muscular pode ter influência nas alturas observadas. / Objectives: Changes on mandibular high posterior to the most distally positioned implant on patients provided with implant-supported fixed prosthesis were related to bite force (FM) and functional maseteric activity. Methods: orthopantograms taken before and one year after rehabilitation of 10 patients from the Hospital for Rehabilitation of Craniofacial Anomalies (HRAC-USP) were evaluated. The FM was registered by a gnatodynamometer. Electromyography of masseteric muscle was performed and interpreted as follows: maximum voluntary isometric clench (CVIM) during 5 seconds, habitual chewing of carrot (MHC) and unilateral right (MUD) and left (MUE) chewing with latex. Results: there was a mean increases in mandibular bone high of 0,23 ± 0,4mm; the mean FM was 42 ±5,9Kgf and CVIM was 66,7 ± 23,7 µV. The mean values for MHC were: act 0,52± 0,02s; cycle 1,3± 0,67s and the voltage amplitudes 85,98± 19,53µV; for MUD with latex the values were: act 0,59s, cycle 1,35 ± 0,69s and voltage amplitudes 90,89± 32,96µV. There was only statistically significant difference between dimensional bone changes and act of MHI (p= 0,036) for the right side; and for the left side between MUD act with latex and balance side (p=0,026). Conclusions: the mean increase on bone high observed at the posterior region of the mandible was not significantly related to the majority of the analyzed parameters. This suggests that the lasting more than the amplitude of the muscular activity may have influenced the measurements observed.

Objective: The objective of this study was to measure and assess the implant education received by graduates from the University of Iowa College of Dentistry and Dental Clinics. This study measured the self-reported competency levels of dental practitioners with regards to providing and maintaining dental implants as treatment modalities to their patients. The study assessed dental graduates’ willingness to practice and perform dental implant procedures, including both surgical and prosthetic treatments. Additionally, the study identifies challenges that face practicing dentists treating patients with dental implants and identifies the preferred way practitioners seek future training after completing dental school. Methods: A 36-item electronic survey was created and distributed to 737 dentists who graduated from the University of Iowa College of Dentistry and Dental Clinics. Dentists’ demographics, practice characteristics, and detailed self-reported competency in implant dentistry were collected. Statistical analysis of the responses consisted of descriptive statistics and bivariate analysis, and nonparametric Wilcoxon rank-sum test and Spearman’s rank correlation test along with a chi-square test were used for detecting the differences, correlations and associations under different conditions. Results: 154 dentists completed the survey (21% response rate), while only 143 subjects who fulfilled the inclusion criteria were included for the statistical analysis. The survey consisted mostly of males (56.6%). The mean age of respondents was 34.2 years old with a mean practice time of 6.2 years. Of the responding dentists, 21.7% completed a postgraduate training program and 51% of the respondents were in group practice. 66% of the respondents practice in the Midwest region of the US and 71.3% of the respondents took continuing educational courses in implant dentistry and the mean cumulative hours of CE courses in implant dentistry was 33.8 hours. The mean average of implant restorations provided per year was 11.7 and the mean average of implant placements per year was 19.6. There was a significant correlation between cumulative hours of Continuing Education courses and number of implant units on average placed or restored. 64.3% of the dentists are not satisfied with the implant education given at the dental student level. 95.8% of the dentists reported that dental school training is not adequate to surgically place dental implants in their practice. Only 32.4% reported that dental school training was not adequate to restore dental implants in their practice. The preferred way to receive additional training about dental implants is short-term CE courses and workshop courses conducted by implant companies. 23.6% of the dentists reported they are competent at surgically placing dental implants in their practice. 79.1% reported they are competent at restoring dental implants in the dental office. Only 28.4% reported that they feel dental implants are more difficult than other dental treatments. Conclusions: Graduate dentists from the University of Iowa are not expected to be competent in all components of implant dentistry without further postgraduate training. Respondents stated that their dental school training in surgical placement of implants was inadequate. To build upon their dental school training, the two main preferred education pathways as reported by respondents were short-term continuing education courses and workshops courses conducted by implant companies. Within the parameters of this study, we can conclude the following: 1.Age, GPA, number of CE hours in dental implant therapy, specialty status, and time since graduation did not influence undergraduate education satisfaction in dental implant therapy. 2.There is a positive correlation between the number of CE course hours and the number of implant units restored or placed by general dentists. 3.Male dentists, those who practice in group practice settings, and those who have graduated six or more years ago reported a greater number of CE course hours in dental implant therapy. 4.Those who graduated with GPAs less than or equal to 3.4, general dentists, and those who enrolled in a high number of CE courses were more confident in restoring dental implants. 5.Those who graduated with a GPA greater than or equal to 3.5, specialist dentists, and those who enrolled in a high number of CE courses were more confident in surgically placing dental implants. 6.Males, general dentists, those who practice in a group practice setting, and those who graduated six years or more ago restored more implants on average per year. 7.Males, specialist dentists, those who practice outside the Midwest US, and those who graduated six years or more ago surgically place more implants on average per year.

Orientador: Lafayette Nogueira Junior / Banca: Tarcísio José de Arruda Paes Junior / Banca: Fernanda de Cassia Papaiz Gonçalves / Banca: Rodrigo Máximo de Araújo / Banca: Jean Soares Miranda / Resumo: A sobrecarga do hexágono durante a inserção dos implantes dentários de hexágono externo pode gerar danos irreversíveis ao mesmo ocasionando problemas futuros na reabilitação. Sendo assim, esse trabalho teve por objetivo avaliar a deformação e resistência ao contra-torque dos hexágonos com o uso de um montador modificado proposto pelo autor para inserção dos implantes tipo hexágono externo (HE) tendo como hipótese de que o montador modificado apresente resultados diferentes do montador padrão. Para isso, 44 implantes foram divididos em dois grupos, controle (montador normal MN; n=12) e o teste (montador modificado MM; n=12), e foram submetidos ao teste de torção seguindo os parâmetros da norma ISO 13498:2013. Em seguida, a deformação dos hexágonos e possíveis deformações causadas às roscas internas dos implantes foram analisadas, respectivamente, de forma qualitativa por meio de microscopia eletrônica de varredura. Já para o teste de fadiga, controle (MN; n=10) e teste (MM; n=10), os parâmetros utilizados foram da norma ISO 14801:2007. Ao final de 1,2 x 106 (4Hz) ciclos, o valor de destorque dos pilares foi registrado. A desadaptação da junta pilar/implante foi avaliada qualitativamente por meio da microscopia MEV. Como resultados pudemos observar maior manutenção da estrutura da conexão pelo grupo MM comparado ao grupo MN, sugerindo-se que o grupo MM apresentaram comportamento mais seguro e previsível quando comparado ao grupo MN / Abstract: Hexagon overload during the insertion of external hexagon dental implants can lead to irreversible damage, leading to future problems in rehabilitation. Thus, this study aimed to evaluate the deformation and reverse torque resistance of hexagons with the use of a modified mount proposed by the author for insertion of external hexagon (HE) implants with the hypothesis that the modified mount presents different results compared to the default assembler. For this, 44 implants were divided into two groups, control (normal mount MN; n = 12) and the test (modified mount MM; n = 12), and were submitted to torsion testing following the parameters of ISO 13498: 2013. Then, the deformation of the hexagons and possible deformations caused to the internal threads of the implants were analyzed qualitatively, respectively by scanning electron microscopy. For the fatigue test, control (MN; n = 10) and test (MM; n = 10), the parameters used were from ISO 14801: 2007. At the end of 1.2 x 106 (4Hz) cycles, the abutment value of the abutments was recorded. Abutment of the abutment / implant joint was qualitatively evaluated by SEM microscopy. As a result we could observe a better maintenance of the connection structure by the MM group compared to the MN group, suggesting that the MM group presented a safer and more predictable behavior when compared to the MN group / Doutor

Orientador: Fellippo Ramos Verri / Resumo: O objetivo deste estudo foi avaliar a distribuição de tensão e deslocamento em implantes de diâmetro reduzido em reabilitações unitárias em região maxilar anterior, variando o posicionamento do implante (ao nível ósseo e 1,5 mm infra-ósseo), através do método de elementos finitos tridimensionais (MEF-3D). Quatro modelos 3D representando uma hemisecção do lado direito da região anterior da maxila foram simulados com a presença de coroa cimentada sobre implante (cone morse) de 10mm de comprimento, variando-se o diâmetro do implante (2,9 mm e 3,5 mm) e a instalação dos implantes no tecido ósseo em rebordo alveolar de 4,5 mm de espessura. O modelo ósseo tridimensional foi construído por recomposição tomográfica com uso dos softwares Invesalius e Rhinoceros 3D. O implante e os componentes foram modelados a partir de modificações do formato original no programa SolidWorks e finalizados no Rhinoceros, bem como o desenho da coroa simulada. A discretização dos modelos foi feita no software ANSYS 19.2, incluindo caracterização dos materiais, contatos, elaboração das malhas, condições de carregamento (178N em direção de 0, 30 e 60 graus em relação ao longo eixo do implante) e de contorno (com restrição em direção x, y, z nas secções laterais dos modelos). Os resultados mostraram comportamento biomecânico similar, com diminuição dos níveis de deslocamento e estresse para implantes de 3,5 mm e implantes infra-ósseos, muito embora os valores obtidos estiveram dentro de valores fisiológicos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Abstract: The Aim of this study was to evaluate the distribution of stress on implants of narrow diameter, in single unit cemented crowns in the anterior maxillary region, varying the position of the implant (at the bone level and 1.5 mm infra-osseous), through the 3D finite element analysis (3D-FEA). Four 3D models representing a right hemisection of the anterior maxillary region were simulated with the presence of a cemented crown over a 10mm long implant (morse cone), with the implant diameter varying among 2.9 mm and 3.5 mm in an simulated alveolar ridge of 4,5mm thickness. The bone of 3D models was simulated by tomographic recomposition using the software Invesalius and Rhinoceros 3D. The implant and components were modeled from modifications of the original design in the SolidWorks software and modeled in the Rhinoceros, as well as the design of the simulated crown. The discretization of the models was done in the ANSYS 19,2 software, including characterization of materials, contacts, meshes, loading conditions (178N towards 0, 30 and 60 degrees in relation to the implant long axis) and boundary conditions in the x, y, z direction in the lateral sections of the models). The results of dislodgment and von Mises showed similar maps distribution, decreasing dislodgment and stress in implants of 3,5mm diameter and in infra-osseous position, besides these results were inside physiologic values. It was possible to conclude that 2.9mm implants were no more biomechanically favo... (Complete abstract click electronic access below) / Mestre

Objective: The aim of the study was to evaluate the clinical outcomes of oral implant treatment provided at the School of Dentistry, University of Otago from 1989 to 2005. Methods: Oral implant patients (n=320) with 586 implants were identified and invited to attend for a clinical examination. Implant demographics of all the patients were extracted from the files. Implant demographics of the examined and unexamined patients were compared to assess if the examined patients were representative of the total group. One hundred and three patients with 214 implants agreed to attend for an examination. In the clinical examination full mouth plaque scores, probing depths, bleeding on probing and suppuration were measured. In addition, around implants recession and width of keratinized gingiva were also recorded. For the radiographic examination, baseline radiographs and radiographs taken at the time of examination were digitized and compared to measure the amount of bone lost or gained around implants using NIH Image J software. Results: There were equal numbers of males and females with a mean age of 46.3 � 15 years at the time of implant placement. The smoking history at the time of examination was recorded, 56% of the patients were non-smokers, 37% former smokers, and 7% were current smokers. More than half of the implants (56%) were placed in the anterior region. Based on the type of implant system, 79% were Branemark implants, 10% Straumann, 6% Southern implants and 4% were unknown. Most of the patients (64%) had implant-supported crowns, 19% had fixed denture prostheses, and 17% had implant-supported overdentures. The overall implant survival rate was 97.7% with five implants lost (2.3%) and 8 implants treated for peri-implantitis (3.8%). The mean PD around implants was 2.3mm (SD 0.6mm), mean recession was 0.5mm (SD 0.8mm) and mean attachment level of 2.8mm (SD 0.9mm). Probing depths [greater than or equal to] 4mm with BOP were recorded around implants in 8.9% of patients. The mean full mouth plaque score was 30% while mean plaque score around implants was 15.9%. The average bone loss around implants was 0.3mm (SD 0.8). Maximum bone loss observed was 2.9 mm. Conclusion: The prevalence of peri-implant inflammation and implant survival rates in this group of patients appeared comparable to that reported in the literature. The prevalence of peri-implant lesions was low in the group of patients examined.

Objectives: To compare the osseointegration of conventionally and immediately restored tapered implants in a split-mouth animal model, and to compare different methods of analysis for measuring osseointegration. Materials & Methods: Twenty tapered implants were placed in the posterior mandibles of ten sheep, three months after premolar extractions. Ten control implants were placed and were restored after three months submerged healing. Ten test implants were placed on the contralateral side at this time and immediately restored. Animals were sacrificed after a further three months healing. Resonance frequency analysis (Implant Stability Quotient, ISQ), and standardized radiographs were taken at all stages. Alveolar bone height relative to the implant shoulder was measured on digitized radiographs. Histomorphometric and micro-Computed Tomograph ([mu]CT) morphometric analysis for Bone-to-Implant Contact (BIC) and Bone Density (BD) were performed. Radiographic, stability and morphometric measurements were compared statistically. Results: Only three (30%) of conventionally restored and two (20%) immediately restored implants survived (p = 0.74). Mean crestal bone level after three months loading differed significantly (control 5.3 � 0.9 mm versus test 0.9 � 1.3 mm; p = 0.02). Control implants lost more crestal bone over three months than test implants but this was not statistically significant (3.5 � 1.0 mm versus 0.7 � 1.0 mm; p = 0.06). The test group showed a higher mean ISQ value (85.4 � 6.9) compared to the control group (72 � 14.4; p = 0.349). Both groups showed a slightly reduced stability during the loaded period. This was more marked for the test group but not statistically significant (-0.5 � 3.8 ISQ versus -4.35 � 6.6 ISQ; p = 0.8). A statistically significant negative correlation was found between the loss of crestal bone and ISQ with loading (Pearson�s coefficient of correlation r = -0.473 p = 0.026). Both groups showed a statistically significant difference in BIC for both histomorphometric analaysis (HMA); p = 0.039 and [mu]CT morphometric analysis; p = 0.013. When the two forms of morphometric analysis were compared, HMA and [mu]CT morphometric analysis differed significantly for both BIC (p = 0.05) and BD (p = 0.048). However, a statistically significant correlation was found between the two measuring techniques, for both BIC (r = 0.335 p = 0.013) and BD (r = 0.439 p = 0.01). Conclusions: The placement of wide-bodied 3i Osseotite NT[TM] tapered implants into sheep mandible resulted in high failure rate regardless of the loading protocol. The sheep mandibular model may be inappropriate as a model for evaluation of immediate loading, and to test implants which are designed for soft bone. Further investigations are needed to look into the variations in bone microstructure along with their impact on the mechanics of implant-bone union. Although a statistically significant difference was found between the two measurement techniques, a positive correlation was found between HMA and [mu]CT morphometric analysis suggesting non-invasive methods may have a potential in assessing osseointegration. Further research is required to optimize the variables in [mu]CT analysis, such as, voltage, filters, and thresholding to minimize artifacts and to maximize bone contrast when titanium implants are present.