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  • 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.
71

Análise microestrutural de sítios ósseos implantares da maxila reconstruídos com enxerto autógeno e xenógeno = Micro-computed tomography of maxillary implant sites reconstructed with autogenous and xenogenous bone graft / Micro-computed tomography of maxillary implant sites reconstructed with autogenous and xenogenous bone graft

Vasconcelos, Karla de Faria, 1983- 26 August 2018 (has links)
Orientador: Frab Norberto Boscolo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T19:08:05Z (GMT). No. of bitstreams: 1 Vasconcelos_KarladeFaria_D.pdf: 5688492 bytes, checksum: d9b11160adfcddce4c94ac1cd818c1e3 (MD5) Previous issue date: 2015 / Resumo: O conhecimento da microarquitetura óssea desempenha importante papel no sucesso das reconstruções ósseas e posterior reabilitação com implantes dentários. Os objetivos dessa pesquisa foram: 1. Avaliar a microarquitetura óssea de sítios da maxila, que foram reconstruídos com enxertos ósseos, autógeno e xenógeno e 2. Avaliar tridimensional e bidimensionalmente a formação óssea na superfície dos parafusos de fixação (BIC-Bone-to-implant contact). Doze amostras contendo parafusos de fixação recobertos por 0,5 a 1mm de osso humano foram removidas com auxílio de uma broca trefina, após seis meses da colocação de blocos de enxerto em maxila de 8 pacientes, cinco mulheres e três homens, com média de idade entre 50 anos. Sete de sítios xenógenos e cinco de autógenos. As amostras foram avaliadas por meio de imagens obtidas pelo microtomógrafo SkyScan 1173 e por meio da técnica histológica de Stevenels blue e Van Giesen red. Para caracterizar a microarquitetura foram avaliados: a razão volume ósseo/volume tecidual, espessura das trabéculas, distância trabecular, número de trabéculas e densidade de conectividade, em três áreas distintas (enxerto/transição/osso nativo). O cálculo do BIC 2D foi realizado em imagens histológicas e microtomográficas. O BIC 3D foi viabilizado em áreas selecionadas em 17 amostras, entretanto, apenas em imagens adquiridas por microtomografia. Quando os parâmetros da microarquitetura foram comparados entre as áreas, foram observadas diferenças estatísticas (p<0,05) na espessura e distância das trabéculas, entre a área de osso nativo e do enxerto, apenas nas amostras autógenas. As amostras xenógenas não apresentaram diferenças entre as áreas. Quando os dois tipos de enxerto foram comparados entre si, diferenças estatísticas (p<0,05) foram encontradas entre o volume de tecido ósseo, espessura entre as trabéculas e a distância entre as trabéculas. O cálculo do BIC 2D revelou semelhança entre as técnicas (p=0,802) e também entre os tipos de enxerto (p=0,097). Avaliando os valores do BIC 3D, observou-se diferença estatística significante nos valores do BIC entre as diferentes áreas, osso e enxerto, com valores mais altos nas áreas de osso nativo. Esses dados estruturais e observações obtidas a partir de imagens microtomográficas proporcionam valiosa caracterização desses sítios e oportunidade de futuras correlações com estudos de elementos finitos e resultados clínicos / Abstract: The knowledge of bone microarchitecture is an important role in the success of bone reconstructions and following rehabilitation with dental implants. Thus, the main objectives of this study were: 1) To characterize the microarchitecture of implant bone sites reconstructed with bone grafts and 2) To assess in two and three-dimensions the percentage of bone in contact with bone graft fixing screws (BIC-Bone-implant contact). Six months after graft placement of blocks in the maxilla of eight patients (five women and three men, with a mean of 50 years of age) twelve samples containing fixing screws covered by 0.5 to 1 mm of human bone were removed using a trephine drill. Five were from sites that had received autogenous grafts and seven from sites that had received xenogeneic grafts. Samples were evaluated by micro tomography images obtained by the SkyScan 1173 (Bruker, Kontich, Belgium) device and by histological technique with Stevenels blue e Van Giesen red solutions. To characterize the bone microarchitecture, bone volume, trabecular thickness, trabecular distance, trabecular number and connectivity in three distinct areas (graft / transition / native bone) were evaluated. The 2D BIC was performed in histological and microtomography images. The 3D BIC was performed only in images acquired by microtomography in whole sample. When the microtomography bone parameters were compared between areas, statistical differences were noted only in the thickness and distance of the trabecular area between the native bone and autogenous graft (p<0.05). No statistically significant differences were observed between these areas in the xenogenous sample. When the parameters were compared between two types of grafts, statistical differences were found between the bone volume (p<0.05), the trabecular thickness (p<0.05) and trabecular separation (p<0.05).While calculating the BIC 2D revealed similarity when comparing values obtained by both techniques (p=0.802), and both grafts (p=0.097). It was observed statistically significant difference in values of BIC 3D in different areas (bone and graft) (p=0.0021) with the highest values in areas of native bone. The structural data and observations obtained from micro-computed tomography images provided valuable characterization of sites that received bone grafts and the opportunity for future correlations with finite element studies and clinical outcomes / Doutorado / Radiologia Odontologica / Doutora em Radiologia Odontológica
72

Development of Fully Injectable Novel Compositions of Phosphate Cements for Orthopedic Applications

Schulin, Terry James January 2020 (has links)
No description available.
73

The impact of bioactive agents PDGF & BMP on resolution of bony defects

Tilwani, Sunny 30 July 2018 (has links)
Bioactive agents are proteins that regulate cellular activities including cell migration, proliferation, differentiation and matrix synthesis. Over the last decades there has been a focused effort to understand how these agents influence repair or regeneration of bony defects. Platelet derived growth factor (PDGF) has potent chemotactic and angiogenic properties. Bone morphogenetic protein (BMP) is a known factor for osteoblasts. This study evaluated the impact of recombinant human PDGF and BMP-2 on resolution of critical bony defects (2 mm) using mouse calvarial bone cultures. Calvaria from 5-7 day neonatal CD-1 mice were dissected and cultured in Dulbecco’s Modified Eagle’s Medium under sterile conditions. In the first experiment, two different delivery systems to deliver PDGF - freeze-dried bone allograft and beta- tricalcium phosphate were compared. The second experiment analyzed bone formation in response to BMP-2 in the presence or absence of freeze-dried bone allograft. The media was changed every 2 days and the spent media were analysed for calcium release. At the end of three weeks the calvaria were processed for histological observation, biochemical analyses and neutral red staining. The results show higher bone formation in response to BMP-2 than PDGF. The presence of allograft inhibits this response. We found B-TCP to be a better delivery agent for PDGF compared to freeze-dried bone allograft. The histologic assessment showed development of new bone through intramembranous pathway that replicates native bone development in presence of BMP-2. In conclusion our study proves that incorporation of two bioactive agents- PDGF and BMP-2 in an osteoconductive scaffold can induce repair and new bone formation in mouse calvarial bone cultures. / 2020-07-30T00:00:00Z
74

Surface Microtopography Modulation of Biomaterials for Bone Tissue Engineering Applications

Kim, Eun Jung 04 June 2010 (has links)
No description available.
75

Alveolar Ridge Preservation at different anatomical locations – Clinical and Histological evaluation of treatment outcome

Salas, Mabel L. January 2009 (has links)
No description available.
76

Evaluation of peri-implantitis treatment. Retrospective case control study

Perolli, Korab, Abdeljabar, Aos January 2016 (has links)
Tandimplantat utsätts för både tekniska och biologiska komplikationer; de senare innefattar mukosit och periimplantit. Ett stort antal periimplantitbehandlingar har utvärderats, ofta i samband med bensubstitut. Det finns dock ingen konsensus idag om effektiv periimplantitbehandling.Syfte: Syftet med studien är att utvärdera och jämföra om skillnader i behandlingsresultat föreligger när periimplantit behandlas kirurgiskt med bensubstitut eller utan bensubstitut.Material och Metoder: Trettiofyra patienter (22 kvinnor, 12 män) behandlades varav 12 patienter med bensubstitut och 22 patienter utan bensubstitut.Av totalt 198 implantat har 193 utvärderats: Avseende bennivån (100 implantat) Avseende fickdjup (PPD) och blödning vid sondering (BOP) (160 implantat).Resultat: Kirurgisk behandling i form av mekanisk depuration och användning av bensubstitut har bidragit till vinst av bennivån med en statistisk signifikans (p ≤ 0,05). Dessutom kan en statistiskt signifikant förbättring (p ≤ 0,05) av PPD noteras bland patienter som behandlades med bensubstitut jämfört med patienter som behandlats utan bensubstitut.Konklusion: Av de patientfallen i studien är slutsatsen att användning av bensubstitut vid kirurgisk periimplantitbehandling resulterar i betydligt större vinst i bennivå och PPD reducering i jämförelse med endast kirurgisk behandling. Nyckelord: Bensubstitut, Periimplantit, Kirurgisk behandling. / Dental implants are subjected to both technical and biological complications; the latter ones comprise peri-implant mucositis and peri-implantitis. Numerous peri-implantitis treatments have been evaluated, often involving implantation of a bone graft. However, as of today, no consensus exists regarding effective peri-implantitis treatment.Aim: The aim of the study is to retrospectively evaluate if there are differences in treatment results after surgical peri-implantitis treatment with or without a bone graft.Material and Methods: Thirty-four patients (22 female, 12 male) were treated whereas 12 patients were treated with bone graft and 22 patients were treated without bone graft. Out of a total of 198 implants, 193 were evaluated regarding peri-implant bone level (100 implants) and probing pocket depth(PPD) and bleeding on probing (BOP) (160 implants).Results: Surgical treatment including mechanical debridement and implantation of a bone graft contributed to statistical significant (p ≤ 0,05) bone level gain in comparison to the non-grafted group. Additionally, statistically significant (p ≤ 0,05) improvement in PPD could be noted among patients treated with bone graft compared to patients treated without a bone graft.Conclusion: Of the present case series, it can be concluded that implantation of a bone graft during surgical peri-implantitis treatment, results in significant larger bone level gain and PPD reduction comparing to only surgical treatment.Keywords: Bone graft, Peri-implantitis, Surgical treatment.
77

Densitometric Comparison of Autogenous Cancellous Bone Graft and Extracorporeal Shock Wave Therapy in the Tibial Tuberosity Advancement Procedure in Dogs

Barnes, Katherine Hirose 01 July 2015 (has links)
Objectives: To compare optical values in the osteotomy gap created after a Tibial Tuberosity Advancement (TTA) treated with autogenous cancellous bone graft (ACBG), extracorporeal shock wave therapy (ESWT), a combination of ACBG and ESWT, and absence of both ACBG and ESWT using densitometry. Methods: Dogs presenting for surgical repair of a cranial cruciate ligament rupture were randomly assigned to one of four groups; TTA with ACBG (TTA-G), TTA with ACBG and ESWT (TTA-GS), TTA with ESWT (TTA-S), and TTA with no additional therapy (TTA-O). Mediolateral radiographs at 0, 4 and 8 weeks after surgery were evaluated to compare healing of the osteotomy gap via densitometry. An analysis of variance (ANOVA) statistical analysis was used to compare the densitometric values between groups. Results: At 4 weeks after surgery, a significant difference in osteotomy gap density was noted between TTA-GS (8.4 millimeters of Aluminum equivalent [mmAleq]) and TTA-S (6.1mmAleq), and between TTA-GS (8.4 mmAleq) and TTA-O (6.4 mmAleq). There were no significant differences noted between groups at the 8 week recheck. Clinical Significance: There were no significant differences in the osteotomy gap density at 8 weeks after surgery regardless of the treatment modality used. The combination of ACBG and ESWT may lead to increased density of the osteotomy gap in the first 4 weeks after surgery. Densitometry using an aluminum step wedge is a feasible method for comparison of bone healing after TTA in dogs. / Master of Science
78

Avaliação do uso de substituto ósseo sintético associado a membrana de colágeno absorvível na preservação da crista óssea alveolar após extração dentária. Estudo clínico e tomográfico em humanos / Evaluation of synthetic bone substitute use associated with absorbable collage membrane in preserving the alveolar crest after tooth extraction. Clinical and tomographic study in humans

Santos, Felipe Anderson Sousa dos 30 January 2015 (has links)
Objetivo: o objetivo deste ensaio clínico controlado aleatorizado foi avaliar o uso de um substituto ósseo sintético associado a uma membrana de colágeno absorvível na preservação da crista óssea alveolar após extração dentária, por meio de análises clínica e tomográfica em humanos. Metodologia: Quatorze pacientes foram selecionados, cada um apresentando ao menos dois dentes anteriores maxilares indicados para extração: no Grupo Teste (GT), o alvéolo pós-exodontia foi preenchido pelo substituto ósseo sintético Reprobone, e no Grupo Controle (GC) houve o preenchimento do alvéolo apenas por coágulo. Em ambos os grupos os alvéolos foram cobertos por uma membrana absorvível de colágeno (BioMend), que por sua vez foi recoberta por um retalho mucoperióstico fechado oclusivamente. Tomografias computadorizadas do tipo Cone Beam foram realizadas no pós-operatório imediato e após 6 meses do procedimento cirúrgico, e as alterações dimensionais horizontais e verticais das cristas ósseas foram quantificadas. Para a análise estatística intragrupo utilizou-se o teste t pareado; para avaliações intergupo, teste t não pareado. Em todas as comparações foi adotado um nível de significância de 5%. Resultados: A Medida Vertical Vestibular reabsorveu 1,5 mm (ou 21,3%) da medida inicial no Grupo Teste (p<0,05) e 1,8 mm (ou 25,8%) no Grupo Controle (p<0,05). A Medida Vertical Palatina diminuiu 0,3 mm em ambos os grupos (p>0,05). A Altura Máxima reduziu 0,5 mm ou 7,9% no grupo com Reprobone e BioMend quando comparada ao baseline (p>0.05), e 1,1 mm ou 14,8% no grupo com BioMend apenas (p<0,05), sendo esta diferença intergrupo estatisticamente significante (p<0,05). A Medida Horizontal Apical diminuiu 0,2 mm no GT, o equivalente a 2,9% (p>0,05), enquanto que no GC diminuiu 0,5 mm ou 7,3% (p<0,05), não havendo diferença estatisticamente significante entre os grupos. A Medida Horizontal Cervical (MHC) perdeu 0,5 mm ou 7,2% no GT e 1,4 mm ou 15,1 % no GC: a análise intragrupo apontou diferença estatística entre os dados iniciais e após 6 meses para este parâmetro (p<0,05), em ambos os grupos, e também foi encontrada diferença estatisticamente significante na avaliação entre grupos para a MHC. Conclusão: Os resultados obtidos demonstraram que o uso do Reprobone associado à Biomend apresentou benefícios e melhores resultados na manutenção vertical e horizontal do rebordo alveolar em comparação ao uso apenas da membrana colágena. / Objective: The aim of this randomized controlled clinical trial was to evaluate the use of a synthetic bone substitute associated with an absorbable collagen membrane in preserving the alveolar crest after tooth extraction, through clinical and tomography analysis in humans. Methods: Fourteen patients were selected, each featuring at least two front teeth jaws indicated for extraction: in Test Group (TG), the post-extraction sockets were filled by the synthetic bone substitute ReproBone, and the control group (CG) was filling the alveoli only by clot. In both groups, the wells were covered with a resorbable collagen membrane (BioMend), which in turn was covered with a mucoperiosteal flap closed occlusally. CT Cone Beam type were performed in the immediate postoperative period and after 6 months of surgery, and the horizontal and vertical dimensional changes of the bone crests were quantified. For intra-group statistical analysis used the paired t test; to intergupo reviews, unpaired t test. In all comparisons was adopted a 5% significance level. Results: Vestibular Vertical Measure reabsorbed 1.5 mm (or 21.3%) of the original measure in the test group (p <0.05) and 1.8 mm (or 25.8%) in the control group (p <0 , 05). The Measured Vertical Palatine 0.3 mm decreased in both groups (p> 0.05). The Maximum Height reduced 0.5 mm or 7.9% for the ReproBone and BioMend compared to baseline (p> 0.05), and 1.1 mm or 14.8% for the BioMend only (p <0.05 ), statistically significant intergroup difference (p <0.05). Measure the horizontal apical decreased by 0.2 mm WG, equivalent to 2.9% (p> 0.05), whereas the CG 0.5 mm or decreased by 7.3% (p <0.05), not statistically significant difference between groups. The Horizontal Cervical Measure (MHC) lost 0.5 mm or 7.2% in GT and 1.4 mm or 15.1% of CG: the intra-group analysis showed statistical difference between the initial data and after 6 months for this parameter (p <0.05) in both groups, and was also a statistically significant difference between groups in the evaluation for the MHC. Conclusion: The results showed that the use of ReproBone associated with BioMend presented benefits and better results in vertical and horizontal maintenance of alveolar ridge compared to using only the collagen membrane.
79

Avaliação da prevalência, extensão e severidade de reabsorções radiculares em dentes adjacentes à área da fissura labiopalatina / Evaluation of the prevalence, extent and severity of root resorption in teeth adjacent to the cleft lip and palate.

Ponce, Jose Burgos 12 March 2012 (has links)
Objetivo: Avaliar radiograficamente a prevalência, extensão e severidade das reabsorções radiculares nos dentes adjacentes à área da fissura após enxerto ósseo alveolar secundário. Material e Métodos: Foram utilizadas 1458 radiografias (periapicais, oclusais e panorâmicas) de 200 indivíduos com fissura transforame incisivo (uni e bilateral) submetidos à cirurgia de enxerto ósseo, obtidas do acervo do setor de Radiologia do Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo. Resultados: Dos 200 indivíduos avaliados, 33 indivíduos apresentaram reabsorções radiculares externas em algum dente. No total foram observadas 33 reabsorções, 15 estavam presentes nas radiografias pré-enxerto ósseo e 18 somente após o enxerto ósseo. Do total das reabsorções observadas, 30 foram localizadas no terço apical da raiz e 3 no terço cervical, sendo o incisivo central esquerdo o dente mais afetado. Não foram encontradas reabsorções radiculares no terço médio da raiz e nenhuma das reabsorções atingiram más de um terço radicular. Não houve diferença estatisticamente significante entre a idade de realização do enxerto ósseo alveolar e a presença de reabsorção radicular externa; e também em relação ao tratamento ortodôntico. Conclusões: A prevalência de reabsorções radiculares nos dentes adjacentes à área da fissura de pacientes submetidos a enxerto ósseo foi baixa (16,5%). Não foi possível estabelecer uma relação entre a observação de reabsorção radicular de indivíduos submetidos a enxerto ósseo e a presença de tratamento ortodôntico em uma mesma imagem. O terço apical da raiz dos dentes observados foi a localização mais frequente de reabsorções radiculares externas, sendo que nenhuma das reabsorções abarcou mais de um terço da raiz. / Objective: To evaluate radiographically the prevalence, extent and severity of root resorption in teeth adjacent to cleft area after secondary alveolar bone graft. Material and methods: We analyzed 1458 radiographs (periapical, occlusal and panoramic) of 200 patients with complete cleft lip and palate (uni and bilateral) underwent bone graft surgery, obteined from of Radiology department files of the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo. Results: Of 200 patients, 33 individuals had external root resorption of a tooth. In total 33 resorptions were observed, 15 were present on preoperative bone graft radiographs, and 18 only after the bone graft. Of the total of resorption observed, 30 were localed in the apical third of the root and 3 into the cervical third; left central incisor was the most affected tooth. There were no root resorption in the middle third of the root and none of the resorption reached nore than one third. There was no statistically significant difference between the age of the alveolar bone graft surgery and the presence of external root resorption, and also in relation to orthodontic treatment. Conclusions: The prevalence of the root resorption in teeth adjacent to the cleft area in patients who underwent bone graft was low (16,5%). Unable to establish a relationship between the observation of root resorption in patients undergoing bone grafting and orthodontic treatment presence in the same image. The apical third of the root of the teeth observed was the most common location of external root resorption, and none of resorption spanned more than one third of the root.
80

Efeito da laserfototerapia na reparação de osso alveolar humano: análise microtomográfica e histomorfométrica / Effect of laserphototherapy on human alveolar bone repair: microtomographic and histomorphometrical analysis

Romão, Marcia Maria Altavista 06 February 2015 (has links)
A instalação imediata de implante dental na região de molares é crítica, devido a grande perda óssea e da discrepância entre a espessura da crista alveolar e a plataforma do implante. Laserfototerapia (LFT) auxilia na reparação óssea, portanto pode acelerar a instalação do implante. Vinte pacientes foram selecionados para o estudo. Dez pacientes foram submetidos à LFT com laser de diodo de GaAlAs (808nm) no transcirúrgico de exodontia de molares, imediatamente após, e em 24h, 48h, 72h, 96h, 7 e 15 dias. As irradiações foram aplicadas no modo contínuo, em contato e pontual (100mW, 0,04cm2, 075,0J/cm2, 30s por ponto, 3J por ponto, em 5 pontos). O grupo controle (n=10) recebeu o mesmo tratamento, no entanto, o equipamento estava desligado. Quarenta dias depois, espécimes do tecido formado no interior dos alvéolos foram coletados para posterior análise por microtomografia (microCT) e histomorfometria. Dados de ambos os grupos foram comparados pelo test t de Student, enquanto aqueles das diferentes avaliações microtomográficas foram comparados pelo teste de correlação de Pearson (p<0.05). O volume relativo do osso, bem como a área relativa do osso foram significativamente maiores (p<0.001) no grupo laser do que no controle. No grupo controle houve correlação negativa significativa entre número e espessura de trabéculas, e entre número e separação entre trabéculas (p<0.01); entre espessura e separação das trabéculas a correlação foi positiva (p<0.01). O grupo laser mostrou correlação negativa significante entre número e espessura de trabéculas (p<0.01). A Laserfototerapia acelerou o reparo ósseo. Baseado na correlação de Pearson foi possível inferir que o grupo laser apresentou uma distribuição trabecular mais homogênea, com trabéculas menos espessas e mais numerosas, o que pode propiciar a redução do tempo para a instalação do implante. / The immediate dental implant placement in the molars region is critical, because of the high amount of bone loss and the discrepancy between the alveolar crest thickness and the dental implant platform. Laserphototherapy (LPT) improves bone repair thus could accelerate the implant placement. Twenty patients were selected for the study. Ten patients were submitted to LPT with GaAlAs diode laser (808nm) during molar extraction, immediately after, 24h, 48h, 72h, 96h, 7 and 15 days. The irradiations were applied in continuous wave, in contact and punctual mode (100mW, 0.04cm2, 075,0J/cm2, 30s per point, 3J per point, in 5 points). The control group (n=10) received the same treatment; however with the power of the laser off. Forty days later samples of the tissue formed inside the sockets were obtained for further microtomography (microCT) and histomorphometry analyses. Data of both groups were compared by the Student t test, whereas those from the different microCT parameters were compared by the Pearson correlation test (p<0.05). The relative bone volume, as well as the relative area were significantly higher (p<0.001) in the lased than the control group. In the control group there were negative correlations between number and thickness, and between number and separation of trabecula (p<0.01); between thickness and separation of trabecula the correlation was positive (p<0.01). The laser group showed significant negative correlation between the number and the thickness of trabecula (p<0.01). Laserphototherapy accelerated bone repair. By the Pearson correlation test it was possible to infer that the lased group presented a more homogeneous trabecula configuration, with thin and numerous trabecula, which would facilite the reduction of time for the installation of the implant.

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