• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 568
  • 164
  • 20
  • 18
  • 18
  • 17
  • 17
  • 11
  • 10
  • 9
  • 9
  • 8
  • 4
  • 4
  • 2
  • Tagged with
  • 815
  • 815
  • 518
  • 484
  • 154
  • 137
  • 127
  • 114
  • 101
  • 85
  • 80
  • 77
  • 75
  • 74
  • 60
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Criteria to Maintain Periodontally-involved Teeth versus Extract and Replace with Implants: A Delphi Study

Gordon, Ross January 2017 (has links)
No description available.
322

Análise microbiológica da peri-implantite induzida por ligadura em diferentes superfícies de implantes osseointegrados: estudo em cães /

Shibli, Jamil Awad. January 2000 (has links)
Orientador: Elcio Marcantonio Junior / Banca: Izabel Yoko Ito / Banca: Roberto Fraga Moreira Lotufo / Resumo: A microbiota presente na peri-implantite induzida por ligadura, em diferentes superfícies de implantes osseointegrados, foi analisada em 6 cães adultos machos. 36 implantes osseointegrados (9 Ticp: titânio comercialmente puro; 9 TPS: titânio plasma spray; 9 HA: hidroxiapatita; 9 superfícies tratadas com ácidos) foram inseridos e distribuídos igualmente 3 meses após exodontia de todos os pré-molares inferiores. Após um período de 3 meses de osseointegração, os implantes receberam os cicatrizadores. Decorridos 45 dias de cicatrização, amostras peri-implantares foram colhida, utilizando pontas de papel, no período 0 e após a colocação de ligaduras com fio de algodão, nos períodos 20, 40 e 60 dias. A contagem total de microrganismos (CTM) e a proporação de A. actinomycetemcomitans, Bacteroides forsythus, P. gingivalis, P. intermedia, Campylobacter sp, Capnocytophaga sp., Fusobacterium sp., Peptostreptococcus micros, bastonetes anaeróbios Gram-negativos, Streptococcus beta-hemolíticos, Eikenella corrodens e Candida sp. foram analisadas. Não houve diferença da CTM entre as diferentes superfícies (p>0,05). A Pg não foi detectada no tempo 0; nos tempos 20 e 40 foi detectada em 12 implantes (4 Ticp, 4 HA, 2 TPS e 1 Sup. Trat. com ácidos) e no período 60 dias, em 9 (2 Ticp, 3 HA, 2 TPS e 1 Sup. Trat. com ácidos), tendo menor afinidade à superfície tratada com ácidos. Pi foi detectada em 5 implantes (2 Ticp, 2 HA e 1 Sup. Trat. com ácidos) no período 0 e em 100% dos implantes nos demais períodos. Fusobacterium sp. foi detectado em todos os períodos, tendo uma maior afinidade à HA. Streptococcus beta-hemolíticos foi detectado em 6 implantes (3 Ticp, 1 TPS e 2 HA) no período 0 e 30, 26 e 24 implantes respectivamente nos períodos 20, 40 e 60. Campylobacter sp. e Candida sp. foram detectadas em baixas proporções. Os demais microrganismos não... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: The microbiota associated with ligature-induced peri-implantitis, in different dental implants surfaces, was investigated by cultivation on enriched non-selective and various selective solid media, in 6 mongrel dogs. 36 dental implants (9 Ticp: titanium commercially pure; 9 TPS: titanium plasma spray; 9 HA: hidroxiapatite; 9 surfaces acid-etched) were placed in a similar distribution in all dogs 3 months after extraction of all premolars in mandible. Following a healing period of 3 months, healing abutments were installed and 45 days after cotton ligatures were placed and oral-cleaning procedures abolished for 2 months to induce vertical bone loss of about 40%. Microbial samples were with paper points on day of ligature placement and after 20, 40 and 60 days. The total number of cultivable bacteria and proportions of A. actinomycetemcomitans, Bacteroides forsythus, P. gingivalis, P. intermediate, Campylobacter sp., Capnocytophaga sp., Fusobacterium sp., Peptostreptococcus micros, Enteric Gram-negative rods, beta-hemolytic Streptococcus, Eikenella corrodens and Candida sp. were analyzed. No significant microbiological differences were observed among the different surfaces (p>0,05). Pg was not detected in the time 0; already in the times 20 and 40 were detected in 12 dental implants (4 Ticp, 4 HA, 2 TPS and 1 acid-etched surface) and in the period 60 days, in 9(2 Ticp, 3 HA, 2 TPS and 1 acid-etched surface), tends smaller affinity to eh surface with acids-etched surface. Pi was detected in 5 implants (2 Ticp, 2 HA and 1 acid-etched surface) in the period 0 and in 100% of implants in other periods. Fusobacterium sp. was detected in all the periods, tends a larger affinity to HA. Beta-hemolytic Streptococcus was detected in 6 implants (3 Ticp, 1 TPS and 2 HA) in the period 0 and 30, 26 and 24... (Complete abstract, click electronic address below). / Mestre
323

[en] RESISTANCE ANALYSIS OF FIXED ZIRCONIA BRIDGES APPLIED IN SCREWED DENTAL PROSTHESIS / [pt] ANÁLISE DA RESISTÊNCIA DE PONTES FIXAS EM ZIRCÔNIA APLICADAS EM PRÓTESES DENTÁRIAS APARAFUSADAS

JOSE ALEX GONCALVES DE GALIZA 10 March 2015 (has links)
[pt] Esse trabalho teve como objetivo principal avaliar a resistência à falha da infraestrutura de uma prótese parcial fixa em zircônia de três elementos e aparafusada sobre implantes, através de análise de tensões por elementos finitos e determinação da resistência à fadiga da estrutura. Como objetivo secundário, foram avaliadas as distribuições das tensões nos demais componentes da prótese. Na análise de tensões, dois modelos distintos foram gerados, sendo o primeiro com prótese, implantes e parafusos similares àqueles adotados na clínica odontológica. Um segundo modelo, usado como controle, adotou uma geometria simplificada. As cargas mastigatórias foram aquelas usuais da literatura especializada e a análise por elementos finitos foi realizada através do programa Ansys Workbench 14.5. Os resultados das distribuições de tensões mostraram semelhanças entre os dois modelos, com pequenas variações relacionadas às geometrias empregadas. As tensões calculadas ficaram abaixo dos limites de resistência mecânica da zircônia e das ligas de titânio. No cálculo da vida em fadiga da prótese de zircônia um modelo analítico foi adotado prevendo uma vida infinita para o componente. / [en] The main goal of this work was to evaluate the failure resistance of a zirconia fixed partial denture of three elements screwed on implants by means of a finite element stress analysis and the determination of the fatigue strength of the structure. As a secondary objective, the stress distributions in the other components of the prosthesis were evaluated. In order to promote the stress analysis, two different models were generated, the first making use of prosthesis, implants and screws similar to those adopted in the dental clinic. A second model, used as control, adopted a simplified geometry. The masticatory loads were those presented usually in the literature and finite element analysis was performed making use of Ansys Workbench 14.5 program. The stress distribution results showed similarity in both models, with small variations related to the adopted geometries. The calculated stresses were smaller than the ultimate strength of the zirconia and titanium alloys. Concerning the fatigue life of the zirconia prosthesis an analytical model was adopted and estimated an infinite life for the component.
324

Analise biomecanica do efeito da esplintagem e da conexao protetica em implantes extra-curtos

Oliveira, Bernardo Rodrigues de 23 July 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-27T18:09:04Z No. of bitstreams: 1 bernardorodriguesdeoliveira.pdf: 2133637 bytes, checksum: 47ab328fa9df384a7ac20ae3a65afe38 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-10-01T18:04:40Z (GMT) No. of bitstreams: 1 bernardorodriguesdeoliveira.pdf: 2133637 bytes, checksum: 47ab328fa9df384a7ac20ae3a65afe38 (MD5) / Made available in DSpace on 2018-10-01T18:04:40Z (GMT). No. of bitstreams: 1 bernardorodriguesdeoliveira.pdf: 2133637 bytes, checksum: 47ab328fa9df384a7ac20ae3a65afe38 (MD5) Previous issue date: 2018-07-23 / O objetivo deste estudo foi avaliar a distribuicao da tensao em implantes extra-curtos inseridos em mandibula com atrofia ossea, utilizando-se diferentes tipos de conexao protetica (Cone Morse – CM e Hexagono Externo – HE) associadas a duas tecnicas de confeccao das coroas proteticas (separadas ou esplintadas). Um segmento de mandibula tridimensional foi construido com base em imagem de tomografia computadorizada. Foram modeladas quatro configuracoes de dois implantes extracurtos na regiao de primeiro e segundo molares inferiores, variando-se as conexoes e as coroas proteticas. Os modelos foram carregados com forca mastigatoria normal. Os valores de tensao principal maxima (σmax), minima (σmin), cisalhamento (τ) e deformacao maxima (εmax) foram analisados para o tecido osseo e os valores da tensao equivalente de von Mises (σvM) para as estruturas dos implantes, parafusos e pilares proteticos. As conexoes CM apresentaram maiores picos de tensao frente as conexoes HE para implantes, pilares proteticos, parafusos proteticos e tecido osseo. A simulacao da esplintagem das coroas, independente do tipo da conexao, apresentou menores picos de tensao quando comparado aos grupos com coroas separadas, tanto para implantes, quanto para pilares proteticos, parafusos proteticos e tecido osseo. A conexao HE apresentou melhor comportamento biomecanico quando comparada a conexao CM, independente da realizacao de esplintagem das coroas proteticas. A esplintagem das coroas proteticas, em regiao posterior de mandibula atrofica, parece permitir melhor distribuicao das tensoes para o sistema protese/implante e tecido osseo. O tipo de conexao exerceu influencia no comportamento biomecanico do sistema protese/implante, observando-se melhores resultados quando da associacao da conexao HE com esplintagem das coroas. / The aim of this study was to evaluate the stress distribution on extra-short implants in cases of mandibular bone atrophy, with the use of different implant-abutment connections (Morse Taper - MT and External Hexagon – EH), associated with two crown designs (single-unit or splinted). A three-dimensional segment of the mandible was constructed, based on a computed tomography image. Four configurations of two extra-short implants in the mandibular first and second molar region were modeled, with variations in the implant-abutment connections and crown designs. The models were loaded with normal masticatory force. The values of maximum (σmax), minimum (σmin) principal, shear stress (τ) and maximum strain (εmax) were analyzed for the bone tissue and the values of equivalent von Mises stress (σvM) for the structures of the implants, prosthetic screws and abutments. The MT connections showed the highest peaks of stress when compared to EH connections for implants, prosthetic abutments, prosthetic screws and bone tissue. Splinted crowns, irrespective of the implantabutment connection, showed lower peaks of stress when compared with the groups with single-unit crowns, both for implants and for abutments, prosthetic screws and bone tissue. The EH showed better biological behavior when compared with MT, irrespective of crown designs. Splinted crowns in the posterior region of the atrophied mandible appeared to allow better distribution of stresses to the prosthesis/implant system and bone tissue. The implant-abutment connection had an influence on the biomechanical behavior of the prosthesis/implant system, with better results being observed with the association of the EH connection with splinted crown.
325

Bone regeneration in novel porous titanium implants

Khouja, Naseeba, 1981- January 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The objective of this study was to evaluate the in vivo performance of the novel press-fit dental implant fabricated via electron beam melting (EBM, Southern Methodist Univ.) and compare it to a commercially-available porous-coated press-fit dental implant (Endopore, Innova Corp.). Twelve cylindrical shaped implants 3 mm in diameter x 5 mm long were made by EBM (Southern Methodist Univ.) using Ti6Al4V ELI alloy. Twelve commercial implants (Endopore, Innova Corp.) of the same geometry were used as controls. Samples were implanted in rabbit tibia and retrieved six weeks postoperatively. Six specimens from each implant type were embedded undecalcified, sectioned, and stained with toluidine blue (Sigma) for histomorphometry analysis. Bone-to-implant contact (BIC) was measured. On the six remaining samples from each implant type, the mechanical properties were evaluated by pushout test on a material testing machine. The samples were loaded at a loading rate of 1 mm/min. The pushout strength was measured and the apparent shear stiffness was calculated. The results were analyzed with a paired-t test. The histology shows osteointegration of surrounding bone with both implant types. Bone was found to grow into the porous space between the beads. Both the Endopore (Innova Corp.) and the EBM (Southern Methodist Univ.) showed similar BIC. The mean BIC for the Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implant were 35 ± 6% and 32 ± 9%, respectively. It failed to reach statistical significance (p > 0.05). The peak pushout force for Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implants were 198.80 ± 61.29 N and 243.21 ± 69.75 N, respectively. The apparent shear stiffness between bone and implant for the Endopore (Innova Corp.) and EBM (Southern Methodist Univ.) implants were 577.36 ± 129.99 N/mm; and 584.48 ± 146.63 N/mm, respectively. Neither the peak pushout force nor the apparent shear stiffness of the implants was statistically different between the two groups (p > 0.05). The results suggest that the implants manufactured by EBM (Southern Methodist Univ.) perform equally well as the commercial implant Endopore (Innova Corp.) in this current animal model.
326

Oral hälsorelaterad livskvalitet hos patienter med dentala implantat : en enkätstudie / Oral health- related quality of life in patients with dental implants : a questionnaire study

Vahlberg, Virpi January 2012 (has links)
Syfte: Syftet med denna enkätstudie var att kartlägga hur dental implantatbehandling påverkar livskvaliteten avseende upplevd tuggförmåga, smak, talet, utseendet och munhygienvanor samt själförtroendet. Material och metod: En empirisk enkätstudie med kvantitativ ansats utfördes på tre olika tandkliniker i Stockholm under perioden feb - april 2012. Enkät med följebrev och frankerat svarskuvert sändes ut genom konsekutivt urval till 83 patienter. Fyrtio patienter varav 15 män och 25 kvinnor, med medelåldrar 66,5 år (34 – 89 år), valde att delta i studien. Analys av svaren utfördes i statistikprogrammet IBM® SPSS® 19. Resultat: Andelen deltagare som upplevde en förbättring i upplevd tuggförmåga uppgick till 42,5 %, talet och smaken upplevdes inte ha förändrats av 85,0 % efter implantatbehandling. Vad gäller utseendet upplevde 27,5 % att det hade blivit bättre och 62,5 % att det inte var någon förändring. Det var 22,5 % som upplevde att självförtroendet hade blivit bättre, medan 75,0 % av deltagarna inte upplevde en förändring i självförtroendet efter implantatbehandlingen. Majoriteten (85,0 %) av deltagarna tyckte inte att deras sociala liv hade förändrats efter behandlingen, medan 7,5 % av patienterna rapporterade att det hade blivit bättre. I resultatet kunde noteras att 17,5 % av patienterna tyckte att det var enklare/lättare att utföra munhygienen medan 75,0 % upplevde ingen förändring med att utföra munhygien efter implantatbehandlingen. Konklusion: En förbättring i oral hälsorelaterad livskvalitet avseende alla studerade faktorer kunde ses hos en del patienter efter implantatbehandling. Flertalet patienter upplever dock ingen förändring i oral hälsorelaterad livskvalitet. / Purpose: The purpose of this survey study was to identify how dental implant treatment affects quality of life regarding chewing ability, taste, speech, appearance, oral hygiene habits, and self-confidence. Materials and methods: An empirical survey study with quantitative data was performed on three different dental clinics in Stockholm during the time period Feb - April 2012. Questionnaire with a covering letter and stamped envelope was sent to a consecutive sample of 83 patients. Participants, 40 patients, 15 men and 25 women, mean age 66.5 years (34 - 89), voluntarily chose to participate in the study. Analyses of responses were performed in statistical software IBM ® SPSS ® 19. Results: The proportion of participants who experienced an improvement in perceived chewing ability was 42,5 %, speech and the taste was perceived not to have changed by 85,0 % after dental implant treatment. Regarding the appearance, 27,5 % said it had improved and 62,5 % that there was no change. There were 22,5 % who felt that their self- confidence had improved, while 75,0 % of participants did not experience a change in self- confidence after dental implant treatment. The majority (85,0 %) of participants did not think their social life had changed after treatment, while 7,5 % of patients reported that it had become better. The result could be noted that 17,5 % of patients found it simpler/ easier to perform oral hygiene while 75,0 % experienced no change in the performance of oral hygiene after dental implant treatment. Conclusion: An improvement in oral health- related quality of life for all studied factors could be observed in some patients after dental implant treatment. Most patients experience no change in oral health- related quality of life after dental implant treatment.
327

NC-gestützte Fertigung von Bohrschablonen für die dentale Implantation

Ellmann, Daniel, Klar, Andreas, Sembdner, Philipp, Holtzhausen, Stefan, Schöne, Christine, Stelzer, Ralph 10 December 2016 (has links) (PDF)
Einleitung Bei Zahnverlust ist das Setzen eines Implantates eine gängige und etablierte Behandlungsmethode. Zahnimplantate bieten für den Patienten viele Vorteile. Im Vergleich zum Einsatz einer klassischen Brücke müssen keine Nachbarzähne beschliffen werden. Gesunde Zahnsubstanz bleibt erhalten. Der künstliche Zahn sitzt fest und sicher im Kiefer und bietet Schutz vor Knochenverlust. Ein Implantat leitet die beim Kauen entstehenden Kräfte gleichmäßig in den Kieferknochen. Ein weiterer Vorteil ist die Sicherstellung der natürlichen Funktionen wie Kauen, Sprechen oder Lachen. Somit trägt implantatgetragener Zahnersatz erheblich zur Verbesserung der Lebensqualität bei. Zur Planung des chirurgischen Eingriffs und dem eigentlichen Setzen des Implantates sind die Zahnärzte und Zahntechniker auf Softwarelösungen angewiesen, welche nicht nur die Möglichkeit der Befundung, Analyse und Diagnostik bieten, sondern gleichermaßen die Informationen liefern, die erforderlich sind, um mit Hilfe eines Computers die Fertigung einer Bohrschablone zu planen (CAM-System) und mittels CNC-Fertigung herzustellen.
328

Avaliação clínica de implantes restaurados com conectores de titânio ou zircônia: estudo longitudinal de 3 anos / Clinical evaluation of restored implants with titanium or zirconia abutments: longitudinal study of 3 years

Pereira, Alice Ramos de Freitas 15 January 2018 (has links)
Os implantes dentários representam uma opção de tratamento com alta previsibilidade de sucesso e sobrevivência. Os excelentes resultados geralmente estão relacionados à estabilidade da crista óssea e à saúde dos tecidos peri-implantares de suporte. O material utilizado para confecção do conector protético parece ter um papel importante no resultado clínico dos implantes em longo prazo. O objetivo deste estudo foi avaliar longitudinalmente parâmetros clínicos dos tecidos peri-implantares em pacientes reabilitados com próteses unitárias cimentadas sobre conectores de titânio ou zircônia. Foram selecionados 20 participantes que foram reabilitados com implantes dentários e coroas protéticas cimentadas sobre conectores de zircônia (n=10; região anterior da maxila) ou conectores de titânio (n=10; região posterior da maxila/mandíbula). Os parâmetros clínicos: profundidade de sondagem, nível clínico de inserção, recessão gengival, sangramento à sondagem e reabsorção óssea marginal foram coletados nos períodos T0 = baseline (instalação da prótese), T1 = 12 meses, T2 = 24 meses e T3 = 36 meses de função mastigatória. Nenhuma complicação clínica foi observada em ambos os conectores, com taxa de sucesso de 100%. Tanto os materiais avaliados quanto os períodos de investigação propostos apresentaram efeito relativo significante nos parâmetros clínicos avaliados (p < 0,05). Não houve diferença significante em relação à reabsorção óssea marginal total, entre os dois materiais, após 36 meses. Os resultados sugerem manutenção da saúde peri-implantar ao longo do tempo, em ambos os grupos / Dental implants represent a treatment option with high success and survival predictability. The great results usually are related to bone crest stability and peri-implant supporting tissues health. The material used to produce the prosthetic connector seems to play an important role on the long term of implant clinical outcome. The objective of this study was to evaluate longitudinal clinical parameters of peri-implant tissues in patients rehabilitated with unitary prostheses cemented on titanium or zirconia connectors. Were selected twenty participants rehabilitated with dental implants and cemented crowns on zirconia connectors (n = 10, anterior maxilla) or titanium connectors (n = 10, posterior maxilla/ mandible). The clinical parameters: probing depth, connective tissue attachment level, gingival recession, bleeding on probing and marginal bone resorption, were collected in the periods of masticatory function: T0 = baseline (prosthesis installation), T1 = 12 months, T2 = 24 months and T3 = 36 months. No clinical complication was observed in both connectors, with a 100% success rate. The evaluated materials and the investigated periods had a significant relative effect on the clinical parameters evaluated (p < 0.05). There was no significant difference on the total marginal bone resorption between the two materials, after 36 months. The results suggests maintenance of peri-implant health over time, in both groups
329

[en] EXPERIMENTAL STUDIES OF DIFFERENT SURFACE TREATMENTS APPLIED TO TITANIUM DENTAL IMPLANTS / [pt] ANÁLISE DE DIFERENTES PROCESSOS SUBTRATIVOS UTILIZADOS NO TRATAMENTO DA SUPERFÍCIE DE IMPLANTES ODONTOLÓGICOS DE TITÂNIO CP

RICARDO VIEIRA BATHOMARCO 12 April 2004 (has links)
[pt] Apesar do titânio e suas ligas serem amplamente empregadas na implantodontia e os resultados das experiências clínicas comprovarem que estes materiais apresentaram excelente biocompatibilidade, existem dúvidas quanto às propriedades físico-químicas ideais das superfícies dos implantes de titânio para se obter uma osseointegração adequada. Todavia, os padrões para definir as propriedades superficiais dos implantes odontológicos ainda não estão definidos na literatura. Estas características são importantes, uma vez que a osseointegração é fortemente dependente da ligação das células com a superfície do implante. Este trabalho tem como objetivo analisar três processos subtrativos utilizados no tratamento da superfície de implantes osseointegráveis de titânio comercialmente puro a saber: abrasão - jateamento, erosão - ataque químico e combinação das duas. Estes métodos permitem avaliar as propriedades físicas e químicas superficiais de cilindros de titânio tratados através destes processos tais como: morfologia superficial, topografia e molhabilidade (ângulo de contato). Foi possível, também, identificar os parâmetros e métodos vinculados que otimizam as condições superficiais para este fim. / [en] Titanium alloys are widely used in dental implants in virtue of clinical evidences of the excellent biocompatibility performance shown by this alloys. However, there are still a number of unanswered questions regarding the ideal physicochemical properties of titanium surfaces used in dental implants aiming at an appropriate integration with the bone. Furthermore, in the literature there are not still available standards defining superficial properties of dental implants. These characteristics are a fundamental importance since biocompatibility is strongly depended upon the connections between host cells and the titanium surface implant. The present work has as objective the analysis of three processes use for surface treatments of dental implants based on titanium of commercial purity, namely mechanically- induced erosion, chemical etching and the combination of both. Such methods applied to titanium cylinders, have permitted one to estimate more closely their physical and chemical surfaces properties, such as surface morphology, surface topology and contact angle (wet ability). It is also identified the factors and methods allowing to obtain the optimal surface conditions for this purpose.
330

Avaliação da passagem de micro-organismos por meio da interface entre implantes e conectores protéticos com parafusos convencionais planos e experimentais cônicos pela técnica DNA-Checkerboard / Evaluation of microorganisms leakage through the interface between implants and prosthetic connectors with conventional plane and experimental conical screws by DNA-Checkerboard technique

Santos, Carla Gabaldo Pessoa dos 03 March 2017 (has links)
Apesar da confiabilidade e da sobrevivência relacionadas aos tratamentos com implantes, falhas das reabilitações orais implanto-suportadas ainda são persistentes. Estas falhas podem causar tanto danos mecânicos -como o afrouxamento do parafuso de retenção devido à instabilidade das conexões- quanto danos biológicos -como as reações inflamatórias nos tecidos peri-implantares devido à ocorrência de infiltração bacteriana através da interface implante/pilar e a consequente colonização do interior dos implantes e seus componentes. Os mecanismos responsáveis por estas falhas mecânicas/biológicas dos sistemas de implantes não estão totalmente elucidados, e modificações nos modelos das conexões protéticas e dos parafusos de retenção vêm sendo desenvolvidas com o intuito de aumentar a estabilidade das conexões e minimizar estas intercorrências. Entretanto, a literatura relativa à configuração ideal destas modificações e seus fatores determinantes envolvidos ainda é inconclusiva. Assim, os objetivos do presente do estudo foram avaliar microbiologicamente por meio da técnica de hibridização DNA-Checkerboard, a ocorrência de infiltração bacteriana do meio externo para o interior dos implantes através das diferentes interfaces implante/pilar em dois diferentes sistemas de conexão de implantes, hexágono externo (HE) e triângulo interno (TI), com parafusos de retenção de pilares planos convencionais e parafusos experimentais cônicos. Quarenta e oito implantes dos dois tipos de conexão foram analisados, sendo estes HE ( n = 24) ou TI (n = 24). Os pilares foram fixados a implantes com parafusos convencionais ou parafusos cônicos experimentais. Após a incubação em saliva, a hibridização DNA Checkerboard foi utilizada para identificar e quantificar até 38 espécies bacterianas na área interna dos implantes. Para análise estatística utilizou-se o teste de Kruskal-Wallis seguido de pós-testes de Bonferroni para comparações múltiplas. Vinte e quatro das trinta e oito espécies estudadas, incluindo patógenos putativos periodontais, foram encontradas colonizando as superfícies internas dos implantes HE e TI. Peptostreptococcus anaerobios (P = 0,003), Prevotella melaninogenica (P <0,0001) e Candida dubliniensis (P <0,0001) apresentaram diferenças significativas entre os diferentes grupos. As médias de contagem microbiana total (× 104, ± DP) para cada grupo foram registradas como: G1 (0,27 ± 2,04), G2 (0 ± 0), G3 (1,81 ± 7,50) e G4 (0,35 ± 1,81). As diferentes geometrias das conexões de implantes e parafusos apresentaram distintos níveis de penetração microbiana através da interface implante-pilar. Os implantes ligados com parafusos de pilar de cabeça cônica experimental apresentaram contagens menores de micro-organismos quando comparados com os parafusos convencionais. / Despite the reliability and high success rates related to treatment with implants, failures of implant-supported oral rehabilitation are still persistent. These failures can cause both mechanical damage, such as loosening the retaining screw connections due to instability, as biological damage, such as inflammatory reactions in periimplants tissues due to the occurrence of bacterial leakage along the implant/abutment interface and the subsequent colonization of the subsequent colonization of the internal/inner parts of the implants and components. The mechanisms responsible for these mechanical/biological failures of implant systems are not fully elucidated, and changes to the models of prosthetic connections and retaining screws have been developed in order to increase the stability of connections and minimize these problems. However, the literature related to these changes and its impact on the implant-components stability is still inconclusive. The objective of this study was to evaluate microbiologically by the DNA-Checkerboard hybridization, the occurrence of bacterial leakage from the external environment to the interior of the implant through these different implant/abutment interface. For the study will be evaluated two different implant connections, one external hexagonal (EH) and other internal triangle (IT), with either conventional and experimental tapered screws abutment. Forty-eight two-part implants with external hexagon (EH; n = 24) or tri-channel internal (TI; n = 24) connections were investigated. Abutments were attached to implants with conventional flat-head or experimental conical-head screws. After saliva incubation, Checkerboard DNA-DNA hybridization was used to identify and quantify up to 38 bacterial colonizing the internal parts of the implants. Kruskal-Wallis test followed by Bonferroni\'s post-tests for multiple comparisons was used for statistical analysis. Twenty-four of thirty-eight species, including putative periodontal pathogens, were found colonizing the inner surfaces of both EH and TI implants. Peptostreptococcus anaerobios (P = 0.003), Prevotella melaninogenica (P < 0.0001), and Candida dubliniensis (P < 0.0001) presented significant differences between different groups. Means of total microbial count (×104 , ±SD) for each group were recorded as follows: G1 (0.27 ± 2.04), G2 (0 ± 0), G3 (1.81 ± 7.50), and G4 (0.35 ± 1.81). Differences in the geometry of implant connections and abutment screws have impacted the microbial leakage through the implant-abutment interface. Implants attached with experimental conical-head abutment screws showed lower counts of microorganisms when compared with conventional flat-head screws.

Page generated in 0.0737 seconds