Os implantes imediatos que recebem restaurações imediatas vêm sendo apresentados na literatura como uma opção de tratamento confiável para a reposição de dentes condenados. No entanto, recentemente, dúvidas com relação à estabilidade dos tecidos periimplantares utilizando esta técnica têm sido levantadas. Neste estudo prospectivo, doze pacientes tiveram seus incisivos centrais superiores condenados substituídos por implantes imediatos e restaurações imediatas. Durante 18 meses, foram acompanhados o comprimento das coroas implanto-suportadas e a distância entre a ponta das papilas e a borda incisal dos dentes vizinhos. Não foi observada diferença estatisticamente significativa entre as medidas obtidas. Os resultados obtidos podem ser atribuídos ao rigoroso critério de seleção dos casos e a técnica cirúrgica aplicada. Pode-se afirmar que os tecidos moles periimplantares de implantes imediatos com restaurações imediatas, mantiveram-se estáveis ao longo dos 18 meses de observação seguindo-se os critérios de seleção e execução desse estudo. / The immediate implants that receive immediate restorations have been presented in literature as a reliable alternative to the replacement of condemned teeth. Recently, however, doubts regarding the perimplantar tissue stability have been raised. In this prospective study, twelve patients had their central maxillary incisor replaced by immediate implant and immediate restoration. After 18 months the papillae height and the Zenith of implant supported crown were compared to the dimensions before dental extraction. No statistically significant difference was observed between the obtained measurements. The authors justify the obtained results to the rigorous selection criteria of the cases that had been part of this sample and the surgical technique applied. In the selections criteria and executions followed in this work to the immediate implant placement and immediate restorations, we can state that the soft perimplantar tissues have been remained stable for the 18 months? observation.

Orientador: Jose Ricardo de Albergaria Barbosa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-11T23:04:29Z (GMT). No. of bitstreams: 1 Perez_MiguelAngelJaimes_M.pdf: 6909101 bytes, checksum: 41413f644c388e8bd46795ab371670ee (MD5) Previous issue date: 2008 / Resumo: Este estudo teve como objetivo analisar a influência do desenho dos implantes endósseos na distribuição de tensões geradas nos modelos fotoelásticos após aplicação de cargas verticais e oblíquas a 7,5N, em quatro marcas comerciais de implantes endósseos. Foram selecionados doze implantes, divididos em quatro grupos: I.) Máster Conect Cônico1 4,3 x 13 mm; II.)Titamax Ti Medular2 3,75 x 13 mm; III.) Colosso3 RC 4,0 x 13mm; IV.) Bicon Uncoated Implant4 3,5 x 11mm, cada grupo contendo 3 implantes da mesma marca comercial. Através da Microscopia Eletrônica de Varredura foi analisado o desenho estrutural dos implantes. Para a análise da distribuição de tensão foram confeccionados oito modelos em resina fotoelástica com dimensões de 40 mm x 10 mm de base e 30 mm de comprimento. Dois implantes para cada grupo foram posicionados e fixados no interior dos modelos fotoelásticos. Uma vez verificada a ausência de tensões nos oito modelos foram iniciados os ensaios. Quatro modelos dos diferentes grupos receberam cargas verticais e quatro receberam cargas oblíquas de 7,5N. Por meio do polariscópio circular pertencente ao laboratório de Materiais Dentários e Prótese da USP-Riberão Preto, foi possível visualizar as franjas de tensões geradas nos modelos. Cada seqüência foi fotografada, sendo mantida a mesma distância focal em todos os ensaios. Os resultados obtidos foram analisados por grupos. O Grupo I, implante de hexágono interno longo com porção cervical polida, topo das roscas arredondadas, passos das roscas contínuas, espirais angulados e configuração cônica, apresentou concentração das tensões na região apical, quando submetida à carga vertical e oblíqua. O Grupo II, implante de hexágono externo, porção cervical polida, topo das roscas em forma de "v", passos das roscas contínuos, espirais anguladas e configuração cilíndrica, apresentou distribuição das tensões na região apical, médio e cervical do implante quando submetida à carga vertical e oblíqua. O Grupo III, implante com hexágono interno, porção cervical polida, topo das roscas em forma cônica, passos das roscas contínuos, espirais anguladas e configuração cilíndrica, apresentou distribuição das tensões nas regiões apical, médio e cervical do implante após aplicação de carga vertical e oblíqua. O Grupo IV, implante com sistema cone morse, ombro cervical inclinado, platô ou barbatanas, topo do platô quadradas, passos do platô descontinuais, e configuração cilíndrica, distribuiu as tensões nas regiões apical, médio e cervical do implante após aplicação de carga vertical e oblíqua. Baseado nos resultados obtidos e dentro da metodologia deste estudo conclui-se que: O grupo I, de configuração cônica concentrou a distribuição das tensões em região apical. Os grupo II, III e IV, de configuração cilíndrica, distribuíram as tensões com intensidade e localização similares nos terços apical médio e cervical. O presente estudo evidenciou haver diferenças na distribuição das cargas de um tipo de implante para outro, levando acreditar que essas diferenças possam ter relação com o desenho das roscas e platô. / Abstract: The meaning of this study was analyze on 4 dental implants brands the influence of its thread design on tensions distribution generated thru photoelastic models, after applying a 7.5N load on vertical and oblique directions. Twelve implants, organized in four groups had been selected: I.) Máster Conect Cônico1 4.3 x 13 mm; II.) Titamax Ti Medular2 3.75 x 13 mm; III.) 4,0 Colosso3 RC x 13mm; IV.) Bicon Uncoated Implant4 3.5 x 11mm, being in each group, three dental implants of the same commercial brand. The structural designs of the implants were analyzed with Electronic Microscopy Sweepings. For the tension distribution analysis, eight models had been confectioned in photoelastic resin with 40mm x 10mm base dimensions and 30 mm of length. Two implants of each group had been located and fixed in the interior of photoelastic models. Once verified the absence of tensions in the eight models the analysis were started. Four models of the different groups had received 7.5N load on vertical and four received this same load on oblique direction. By means of the circular polariscope developed in the Dental Materials and Prostheses laboratory the Ribeirão Preto Dental School (USP/RP), it was possible to visualize the tensions fringes generated in the models. Each sequence was photographed, being kept the same focal distance in all the assays. The gotten results had been analyzed by groups. Group I., implants with long internal hexagon and polishing cervical portion, top of rounded off threads, angled steps of continuous threads, spirals and conical configuration, presented tensions concentration on the apical region, when submitted to the vertical and oblique load. Group II, implants with external hexagon, polishing cervical portion, top of threads in form of v, angled steps of continuous threads, spirals and cylindrical configuration, presented tensions distribution on the apical, medial and cervical regions of the dental implants, when submitted to the vertical and oblique load. Group III., implants with internal hexagon, polishing cervical portion, top of threads in conical form, steps of threads continuous, spirals angled and cylindrical configuration, presented tensions distribution on the apical, medial and cervical regions . Group IV, implants with cone morse system, inclined cervical shoulder, square shaped threads, fin or plateau, angled plateau steps discontinuous, and cylindrical configuration, distributed the tensions on the apical, medial and cervical regions after the application of vertical and oblique loads. Based in the results gotten and respecting the limitations of this study it can be concluding that: Group I. with conical configuration, the tension distributions is concentrated on the apical region. Groups II, III and IV, with cylindrical configuration, had distributed the tensions with similar intensity and localization on the apical, medial and cervical regions. In the present study it is evidenced to have differences in the distribution of loads on the dental implants analyzed, being not evident that these differences have relation with the threads design. / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica

Please read the abstract in the section 00front of this document / Thesis (PhD (Dentistry))--University of Pretoria, 2005. / Community Dentistry / unrestricted

Orientador: Altair Antoninha Del Bel Cury / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-07T21:11:17Z (GMT). No. of bitstreams: 1 Panza_LeonardoHenriqueVadenal_M.pdf: 663328 bytes, checksum: 9c68a1e736e333278ff91bfba5ca2da4 (MD5) Previous issue date: 2006 / Resumo: O sucesso da terapia reabilitadora com implantes requer um equilíbrio entre fatores biológicos e mecânicos. Os fatores biológicos são multifatoriais, já os mecânicos associam-se à instabilidade da conexão implante-parafuso-intermediário. Entre os fatores responsáveis pela manutenção da estabilidade desta conexão, a manutenção da pré-carga do parafuso é o mais importante. Com base nestas informações, este estudo buscou avaliar a manutenção da pré-carga de parafusos de ouro, após a aplicação de carga simulada, por meio da realização de ciclagem mecânica do conjunto protético, e também observar a ocorrência de rotação da coroa ou do intermediário protético em relação aos implantes. Para tanto, foram utilizados 40 implantes, 20 com hexágono interno e 20 externo, conectados a intermediários protéticos do tipo Esteticone com angulação de 17° e sem angulação, todos retidos por parafusos de titânio rosqueados a 20N/cm, sobre os quais foram parafusadas coroas confeccionadas em resina acrílica simulando pré-molares superiores humanos com parafusos de ouro apertados a 10N/cm. Cada conjunto foi então submetido ao ensaio de fadiga com aplicação de forças médias de 115 N no sentido do longo eixo do implante por 0.2 s, com uma freqüência de 1 Hz, totalizando um total de 250.000 de ciclos (correspondendo aproximadamente a 3 meses de uso). A manutenção da pré-carga dos parafusos, foi avaliada pelo destorque dos parafusos, após a realização do ensaio de fadiga, com a utilização de um torquímetro digital. Os resultados foram então submetidos à análise de variância a 2 critérios e ao teste de Tuckey, através dos quais foi possível observar que, para o parafuso protético, ocorreu diferença estatisticamente significante entre os tipos de implante, mas sem interação com o tipo de intermediário. No entanto para o parafuso do intermediário ocorreu diferença significativa tanto para o tipo de implante como entre os intermediários, com interação entre os fatores. A análise estatística apontou um desempenho melhor para a manutenção da pré-carga inicial dos parafusos, nos intermediários angulados tanto nos implantes de hexágono interno, quanto nos de hexágono externo. Nenhum dos corpos de prova apresentou rotação de coroa ou intermediário protético quando analisados ao microscópio / Abstract: After osseointegration failures, screw loosening is the most common problem in implant dentistry. However, controversies still exist regarding to the influence of type connection implant to abutment in screw loosing or fracture. This study evaluated pre-tightening maintenance in abutment and prosthetic screws of external and internal implant hexagon with standard and 17° angulated abutments after fatigue testing. Also, the rotational dislodgement was checked using digital measurement microscope. Four subsets (n=10) of implants and abutments were assessed: (G1) internally hexed implant and standard abutment (G2) internally hexed implant and 17° angulated abutment (G3) externally hexed implant and standard abutments (G4) externally hexed implant and 17° angulated abutment. Abutments were retained by titanium screws tightened to 20 N/cm. Acrylic resin crowns were manufactured and were retained over the abutments with gold screws tightened at 10 N/cm, using an electronic torque controller. A vertical line was ascribed across the implant-abutment and crown-abutment interface to identify any rotational displacement. The fatigue tests were performed in a servo-hydraulic machine which delivered forces between 100 and 120 N for 250,000 cycles, through a piston to the crown. The implant-abutment interface were evaluated using a light microscope. Then, screw was removed and detorque value was recorded. Data were statistically analyzed using ANOVA and Tukey test (a=.05) No horizontal displacement of acrylic resin crown and abutments were observed. ANOVA showed significant difference for prosthetic screw between implant types, but without interaction with abutment. However, for abutment screw, there was a significant difference between implant type and abutment. Also, it was observed interaction between implant and abutments types. Internally hexed implants (G1 and G2) and externally hexed implants (G3 and G4) showed significant difference with a better performance for angulated abutment in comparison to standard abutment. Within the limitations of this study it was concluded that pre-tightening maintenance of screw was affected by the type of abutment and the type connection implant used. There was no dislodgement for crown or abutment when standard or pre-angulated abutments were used after 250.000 cycles of simulated loading. Indeed, internal and external hexed connections were effective to avoid rotation of crowns / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Orientador: Mauro Antonio de Arruda Nóbilo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T22:26:53Z (GMT). No. of bitstreams: 1 Castro_GabrielaCassarode_D.pdf: 33391431 bytes, checksum: 639a953ad32049093199c81dd2ea3cb7 (MD5) Previous issue date: 2015 / Resumo: Muito se discute sobre importância da passividade, seus efeitos mecânicos e biológicos e a dificuldade em sua obtenção. Devido aos procedimentos inerentes ao processo de confecção da infraestrutura metálica, desde a moldagem à fundição, distorções são incorporadas. Estas tornam-se preocupação biomecânica por gerar tensão no conjunto prótese-implante-osso. Propõe-se avaliar as tensões ao redor dos implantes em infraestruturas de Titânio para prótese total fixa sobre 4 implantes, com diferentes desajustes marginais por meio da fotoelasticidade. Quatro implantes hexágono externo 4,1 x 11,5 mm, foram posicionados sobre uma matriz simulando uma mandíbula edêntula e nomeados da esquerda para direita em A, B, C e D. Aos implantes, foram aparafusados mini-pilares cônicos e entre os pilares e a infraestrutura foram posicionados anéis espaçadores com dimensões conhecidas: para o grupo HE300 (n=5) foi simulado desajuste, respectivamente de A-D: 0 µm, 100 µm, 200 µm e 300 µm, para o grupo HE100 (n=5) apenas desajuste de 100 µm no implante D. A matriz foi duplicada em resina fotoelástica utilizando as infraestruturas como transferente de moldagem. Foram realizadas medições em 6 pontos em cada implante através do teste do parafuso único, em microscópio óptico, para aferir a desadaptação real obtida. Para obter as imagens fotoelásticas padronizadas a infraestrutura foi aparafusada aos pilares e levadas ao polariscópio circular. A tensão cisalhante máxima (Kgf) foi aferida em 7 pontos ao redor de cada implante e comparados quanto as tensões conjuntas em todos os implantes, ao redor de cada implante e na região cervical e apical. Os dados foram tabulados e submetidos à análise estatística pelo teste t de Student, para avaliar a diferença entre as médias de desadaptação e tensão e o teste de correlação de Spearman para verificar a relação entre tensão e desadaptação. A desadaptação média observada foi de 56,96 (±13,23) ?m para o grupo HE100 e de 194,53 (±162,98) ?m para HE300, apresentando diferença entre os grupos. Com relação à tensão, os grupos HE300 e HE100 mostraram-se iguais estatisticamente (p = 0,291). Mas verificou-se correlação positiva entre desadaptação e tensão em HE100 e HE300. Os implantes B, C e D apresentaram maior tensão no grupo HE100 (p < 0,0001) e no grupo HE300, não foi constatado diferença entre os implantes. As tensões foram maiores na cervical do que na região apical em ambos grupos, para HE 100: 36,92 (±9,33) Kgf na região cervical e 17,78 (±4,09) Kgf na região apical; para HE300: 50,37 (±13,20) Kgf na região cervical e para a região apical 21,20 (±3,95) Kgf. O grupo HE300 exibiu significantemente maior valor de tensão na região cervical (p = 0,012). Conclui-se que o desajuste obtido em HE300 foi maior que do grupo HE100 e gerou maior tensão na região cervical. Ao analisar os implantes em conjunto as tensões foram semelhantes estatisticamente. Foi observado correlação entre desajuste e tensão em ambos grupos. Nas duas situações simuladas, a tensão na região cervical foi maior que na apical / Abstract: There is concern over the importance of passivity, its mechanical and biological effects and the difficulty to obtain it. Misalignments are incorporated due to the procedures inherent in the manufacture of the metal frameworks process, from impression to casting. This becomes a biomechanical concern for generating tension in the prosthesis-implant-bone set. It proposes to analyze the stresses around the implants after being bolted with Titanium frameworks for fixed dentures on 4 implants with different marginal misfits through photoelasticity. Four external hex implants, 4.1 x 11.5 mm, were positioned on a matrix simulating an edentulous jaw and named from left to right, A, B, C and D, respectively. Tapered mini-pillars were screwed to the implants and between the pillars and frameworks were positioned spacer rings with known dimensions: For the HE300 (n=5) group there was a simulated misfit, with AD: 0 microns, 100 microns, 200 microns and 300 microns, respectively. For the just misfit HE100 (n=5) group of 100 microns in implant D, the matrix was duplicated in photoelastic resin using the framework as transfer abutment. Measurements were performed in 6 points in each implant, with the single screw test and an optical microscope to measure the real mismatch obtained. For the standardized photoelastic images, infrastructure was bolted to the columns and analyzed at circular polariscope. The maximum shear stress (kgf) was measured at 7 points around each implant and compared as joint stresses in all implants around each implant, cervical and apical region. Data were tabulated and submitted to statistical analysis by Student's t-test, to evaluate the difference between the means of misfit and tension, and the Spearman correlation test to verify the relationship between stress and maladjustment. The average misfit observed was 56.96 (±13.23) microns for the HE100 group, and 194.53 (±162.98) microns for HE300, with differences between groups. Regarding the strain, the HE300 and HE100 groups were statistically equal (p = 0291). Yet there was a positive correlation between misfit and strain into HE100 and HE300. The B, C and D implants presented a higher tension in the HE100 group (p <0.0001) and HE300 group difference was not observed between the implants. Tensions were higher in the cervical than in the apical region in both groups, for HE100: 36.92 (±9.33) and 17.78 (±4.09) kgf in the cervical region, and in the apical region; for HE300: 50.37 (±13.20) kgf in the cervical region, and the apical region 21.20 (±3.95) Kgf. The HE300 group exhibited significantly more tension the cervical region (p = 0.012). It is concluded that the misfit obtained in HE300 was higher than the misfit group HE100 and generated increased tension in the cervical region. However, the analysis of the photoelastic model found tensions to be equal. A direct relationship between misfit and tension was observed in both groups. In both cases simulated, the tension in the cervical region was larger than in the apical / Doutorado / Protese Dental / Doutora em Clínica Odontológica

Wear particles and ions from cobalt-chromium-molybdenum (CoCrMo)-based implants have been shown to cause adverse immune responses, including periprosthetic osteolysis leading to aseptic loosening, the main cause of implant failure. Previous studies have shown that these wear and corrosion products can lead to the release of inflammatory cytokines, including interleukin-1β (IL-1β), suggesting the involvement of the NLRP3 inflammasome. However, the mechanisms leading to IL-1β release have not been fully elucidated. The primary objectives of this thesis were to determine if, in murine macrophages, IL-1β release induced by micrometre-size CoCrMo particles and nanometre-size chromium oxide (Cr2O3) particles is: 1. Caspase-1-dependent; 2. Reduction-oxidation (redox)-dependent; and 3. NLRP3 inflammasome-dependent. Additionally, the effects of metal ions (Co2+, Cr3+, and Ni2+) on NLRP3 inflammasome activation and the effects of matrix metalloproteinase (MMP) inhibition on IL-1β release induced by CoCrMo particles were analyzed. Results showed that IL-1β release induced by CoCrMo particles was partly caspase-1-, redox-, and MMP-dependent, but NLRP3 inflammasome-independent. On the other hand, IL-1β release induced by Cr2O3 particles appeared to be NLRP3 inflammasome-dependent. Finally, IL-1β release induced by Cr3+, but not Co2+, appeared to be NLRP3 inflammasome-dependent, while Ni2+-induced IL-1β release appeared to be only partially NLRP3 inflammasome-dependent, suggesting that other pathways may also be involved. These findings, which provide additional insights into the mechanisms leading to IL-1β release induced by wear particles and ions from CoCrMo-based implants, may help the future development of therapeutic treatments to modulate wear product-induced inflammation and increase implant longevity.

The aim of this study was to establish a classification system for use in immediate implant placement by examining fresh extraction sockets in maxillary premolars and evaluation of the varying morphologies using CBCT imaging. Selection criteria included dentulous patients ages 15-85 that had CBCT imaging taken for varying treatment. A total of 400 maxillary premolars were classified by their root morphology as Type I (two-rooted premolar with interradicular bone), II (fused roots with mesiodistal alveolar constriction) or III (single blunted root with no interradicular bone). The internal root angle was measured for all Type 1 maxillary first premolars (n=40), as well as the interradicular septal bone height. A Type 1 premolar socket is present in 32% of the sampled maxillary first and second premolars. Type 2 socket was present in 22% of premolars, and type 3 socket was present in 46% of premolars. The average internal angle formed between the long axis of the crown versus the long axis of the palatal root was 11.46 ± 4.35° (range 4° to 20.7°). The average interradicular septal bone height was of 6.9 ± 1.6 mm (range 3.28 to 9.61). Type I root form had the highest incidence at maxillary first premolars sites and has the most alveolar bone available, thus having a higher probability for primary stability. The type III root form is most common in the maxillary second premolar site and has the least amount of alveolar support for immediate implant placement. The angulation and alveolar bone support provided by the palatal root in Type I root form maxillary first premolar sites may provide stability for an immediate implant at an appropriate prosthetic position.

Magister Scientiae Dentium - MSc(Dent) / This study analyzed the dental surgical implant therapy in the past 5 years at Tygerberg Oral Health Centre, UWC Dental School, Cape Town, South Africa. The findings of this study serve as a guideline for the estimation of the prevalence in this dental hospital. The importance of this study was to aid in the establishment of the formalized electronic database for dental implant therapy. The data generated will form a foundational basis for future studies that may be conducted in the field of implantology.

Magister Scientiae Dentium - MSc(Dent) / Purpose This study analyzed the dental surgical implant therapy in the past 5 years at Tygerberg Oral Health Centre, UWC Dental School, Cape Town, South Africa. The findings of this study serve as a guideline for the estimation of the prevalence in this dental hospital. The importance of this study was to aid in the establishment of the formalized electronic database for dental implant therapy. The data generated will form a foundational basis for future studies that may be conducted in the field of implantology. Methodology A retrospective cross-sectional study was conducted at the Tygerberg Oral Health Centre. The data was collected from the implant dental records for the years 2012-2017. Variables measured included the patient demographics such as age, gender, an implant placed by type, length, width, and anatomical location. Frequencies and means of data were generated using IBM SPSS v20.

Thesis (MAud (Interdisciplinary Health Sciences. Speech-Language and Hearing Therapy)--Stellenbosch University, 2008. / Individuals are increasingly undergoing bilateral cochlear implantation in an attempt to benefit from binaural hearing. The main aim of the present study was to compare the speech recognition of children fitted with bilateral cochlear implants, under binaural and monaural listening conditions, in quiet and in noise. Ten children, ranging in age from 5 years 7 months to 15 years 4 months, were tested using the Children’s Realistic Index for Speech Perception (CRISP). All the children were implanted with Nucleus multi-channel cochlear implant systems in sequential operations and used the ACE coding strategy bilaterally. The duration of cochlear implant use ranged from 4 years to 8 years 11 months for the first implant and 7 months to 3 years 5 months for the second implant. Each child was tested in eight listening conditions, which included testing in the presence and absence of competing speech. Performance with bilateral cochlear implants was not statistically better than performance with the first cochlear implant, for both quiet and noisy listening conditions. A ceiling effect may have resulted in the lack of a significant finding as the scores obtained during unilateral conditions were already close to maximum. A positive correlation between the length of use of the second cochlear implant and speech recognition performance was established. The results of the present study strongly indicated the need for testing paradigms to be devised which are more sensitive and representative of the complex auditory environments in which cochlear implant users communicate.