Orientador: Maria José Hitomi Nagata / Banca: Álvaro Francisco Bosco / Banca: Sonia Regina Panzarini Barioni / Resumo: Este estudo avaliou histomorfometricamente o processo de cicatrização em defeitos de fenestração periodontal, criados cirurgicamente em cães e tratados com Plasma Rico em Plaquetas (PRP) associado ou não ao uso de barreira de membrana. Defeitos de fenestração periodontal com 5 mm de diâmetro foram cirurgicamente criados nos caninos superiores de 12 cães. Os dentes foram divididos em 4 grupos: C (controle) - defeito preenchido somente com coágulo sangüíneo; M - defeito preenchido com coágulo sangüíneo e protegido com uma membrana de politetrafluoretileno expandido (PTFE-e) com reforço de titânio; PRP - defeito preenchido com PRP; PRP/M - defeito preenchido com PRP e protegido com uma membrana de PTFE-e com reforço de titânio. Os animais foram eutanasiados após 4 semanas. Medidas lineares e de área da cicatrização periodontal foram avaliadas e calculadas como porcentagem do defeito original. Os dados foram submetidos à análise estatística (análise de variância, p < 0,05). Nenhum espécime regenerou-se completamente com osso ou cemento. Formação de novo cemento foi significativamente maior nos Grupos PRP e PRP/M quando comparados ao Grupo C. Observou-se, também, significativa maior formação de novo cemento no Grupo PRP/M que no Grupo M. Dentro dos limites deste estudo, pode-se concluir que o PRP favoreceu a formação de novo cemento. A Regeneração Tecidual Guiada (RTG) não proporcionou efeitos adicionais ao uso do PRP no tratamento de defeitos de fenestração periodontal em cães. / Abstract: This study histomorphometrically analyzed the healing of periodontal fenestration defects surgically created in dogs and treated with Platelet-Rich Plasma (PRP) with or without a barrier membrane. A 5 mm diameter periodontal fenestration defect was made in each upper canine of 12 dogs. The teeth were divided into 4 groups: C (control) - defect filled with blood clot only; M - defect filled with blood clot and covered by a titanium-reinforced expanded polytetrafluoroethylene membrane (ePTFE); PRP - defect filled with PRP; PRP/M - defect filled with PRP and covered by a titanium-reinforced ePTFE. All animals were euthanized at 4 weeks post-operative. Linear and area measurements of periodontal healing were evaluated and calculated as a percentage of the original defect. Data were statistically analyzed (analysis of variance, p < 0.05). No defect completely regenerated with either bone or cementum. Cementum formation was significantly greater in groups PRP and PRP/M when both groups were compared to Group C. A significant greater cementum formation was also observed in Group PRP/M than in Group M. Within the limits of this study, it can be concluded that the PRP favored cementum formation. Guided Tissue Regeneration (GTR) did not promote any additional benefit to the use of PRP in the treatment of periodontal fenestration defects in dogs. / Mestre

O princípio da regeneração tecidual guiada (RTG) baseia-se na utilização de membranas biocompatíveis com a finalidade de impedir a migração dos tecidos conjuntivo e epitelial para a ferida, permitindo que células do ligamento periodontal repovoem a superfície radicular e regenerem o aparato de inserção do dente. A RTG tem sido utilizada em diversas situações clínicas para facilitar o reparo de defeitos ósseos e periodontais, sendo as membranas de politetrafluoretileno expandido (e-PTFE) as mais utilizadas. O objetivo deste estudo foi avaliar a biocompatibilidade in vitro de uma nova membrana do compósito de poli(vinilideno-trifluoretileno)/titanato de bário (P(VDF-TrFE)/BT). Para isso, osteoblastos, fibroblastos e queratinócitos, células com as quais a membrana entrará em contato durante o processo de RTG, foram cultivados sobre membranas de P(VDF-TrFE)/BT e PTFE (controle). Os seguintes parâmetros foram avaliados: 1) adesão celular por contagem em hemocitômetro; 2) proliferação celular por MTT e 3) adesão e morfologia celular por fluorescência, para as linhagens osteoblástica, fibroblástica e de queratinócitos; 1) medida do conteúdo de proteína total; 2) medida da atividade de fosfatase alcalina (ALP) e 3) formação de matriz mineralizada, para as linhagens osteoblástica e fibroblástica; 1) imunolocalização de ALP por fluorescência; 2) detecção histoquímica in situ da atividade de ALP e 3) expressão dos genes Runx2, Colágeno I (COL I), Ostepontina (OPN), ALP, Sialoproteína óssea (BSP), Osteocalcina (OC), Bax, Bcl-2 e Survivina (SUR) por PCR em tempo real, para a linhagem osteoblástica; 1) expressão dos genes Periostin (PRT), Periodontal Ligament Specific 17 (PDLs17), Calcium-binding protein (S100A4), Fibromodulina (FBM), Bax, Bcl-2 e SUR por PCR em tempo real, para a linhagem fibroblástica e 1) expressão dos genes Involucrina (IVL), Queratina 1 (QRT-1), Queratina 10 (QRT-10), Queratina 14 (QRT-14), Bax, Bcl-2 e SUR por PCR em tempo real, para a linhagem de queratinócitos. Os dados quantitativos foram submetidos ao teste estatístico Mann-Whitney (nível de significância: 5%). A adesão de células osteoblásticas foi semelhante entre P(VDF-TrFE)/BT e PTFE em 30 min, 2 e 4 h (p>0,05). A proliferação de células osteoblásticas foi maior em culturas crescidas sobre o P(VDF-TrFE)/BT em 1, 7 e 10 dias (p<0,05). A epifluorescência indicou que as células osteoblásticas estavam aderidas e mais espraiadas sobre o P(VDF-TrFE)/BT em 30 min, 4 e 24 h. A imunofluorescência revelou presença de ALP apenas em culturas crescidas sobre o P(VDF-TrFE)/BT em 7 e 14 dias. O conteúdo de proteína total foi semelhante entre as duas membranas em 10 dias (p>0,05) e maior sobre o P(VDF-TrFE)/BT em 7 e 14 dias (p<0,05). Não houve diferença estatisticamente significante para atividade de ALP em 7 dias (p>0,05), entretanto em 10 e 14 dias (p<0,05) a atividade de ALP foi maior em culturas sobre o P(VDFTrFE)/ BT. A detecção histoquímica in situ revelou atividade de ALP apenas em culturas crescidas sobre o P(VDF-TrFE)/BT, tanto aos 7 quanto aos 14 dias. A formação de matriz mineralizada ocorreu apenas em culturas crescidas sobre o P(VDF-TrFE)/BT. A expressão dos genes Runx2, COL I, OPN, ALP, BSP, OC, Bax e SUR foi maior em células cultivadas sobre o P(VDF-TrFE)/BT em 7 e 14 dias (p<0,05). Não houve expressão de Bcl-2 em culturas sobre as duas membranas. A adesão de células fibroblásticas foi semelhante entre P(VDFTrFE)/ BT e PTFE em 30 min (p>0,05) e maior sobre o P(VDF-TrFE)/BT em 2 e 4 h (p<0,05). A proliferação de células fibroblásticas foi estatisticamente semelhante entre as duas membranas em 3 dias (p>0,05) e maior em culturas crescidas sobre o P(VDF-TrFE)/BT em 1 e 7 dias (p<0,05). Os ensaios de fluorescência direta revelaram que as células fibroblásticas estavam aderidas sobre as duas membranas, porém em estágios mais avançados de espraiamento sobre o P(VDF-TrFE)/BT em 30 min, 2 e 4 h. O conteúdo de proteína total foi maior sobre o P(VDF-TrFE)/BT em 10, 14 e 21 dias (p<0,05). Não se observou atividade de ALP em culturas fibroblásticas sobre as membranas de P(VDF-TrFE)/BT e PTFE aos 7 dias. Contudo, em 14 dias (p>0,05) a atividade de ALP foi semelhante entre as duas membranas e em 21 dias (p<0,05) foi estatisticamente significante em culturas crescidas sobre o P(VDF-TrFE)/BT. Aos 21 dias não se notou formação de matriz mineralizada em ambas as membranas. A expressão dos genes PRT, PDLs17, S100A4, FBM, Bax e SUR foi maior em culturas sobre o P(VDF-TrFE)/BT em 7 e 14 dias (p<0,05). A expressão de Bcl-2 foi maior em células fibroblásticas cultivadas sobre o PTFE em 7 e 14 dias (p<0,05). A adesão de queratinócitos foi semelhante entre P(VDF-TrFE)/BT e PTFE em 30 min, 2 e 4 h (p>0,05). A proliferação de queratinócitos foi estatisticamente semelhante entre as duas membranas em 4, 7, 10 e 14 dias (p>0,05) e maior sobre culturas crescidas sobre P(VDF-TrFE)/BT em 1, 17 e 21 dias (p<0,05). Por fluorescência direta notou-se que células cultivadas sobre ambas as membranas exibiam morfologia predominantemente arredondada em 30 min, 4 e 24 h. A expressão do gene IVL foi semelhante em culturas crescidas sobre as duas membranas em 7 dias (p>0,05) e maior sobre o P(VDF-TrFE)/BT em 14 dias (p<0,05). Os genes QRT-1, QRT -10 e QRT -14, Bax e SUR estavam mais expressos em culturas sobre o P(VDF-TrFE)/BT em 7 e 14 dias (p<0,05). A expressão de Bcl-2 foi maior em queratinócitos crescidos sobre o PTFE em 7 dias (p<0,05) e semelhante entre as duas membranas em 14 dias (p>0,05). Por favorecer eventos relacionados ao desenvolvimento tecidual, como a adesão, proliferação e diferenciação celular, a membrana de P(VDF-TrFE)/BT pode representar uma boa alternativa ao PTFE para procedimentos de RTG. / The principle of guided tissue regeneration (GTR) is based on the use of physical barrier to isolate periodontal defects of the gingival connective and epithelial tissues so that bone, periodontal ligament, and cementum can be regenerated from their own cells. RTG procedure has been used in many clinical situations to promote bone and periodontal regeneration. Membranes of expanded polytetrafluoroethylene (e-PTFE) are the most commonly used material for GTR. However, several membranes have been tested to be applied in GTR. The purpose of this study was to evaluate the in vitro biocompatibility of the membrane of poly(vinylidene-trifluoroethylene/barium titanate (P(VDF-TrFE)/BT) composite. For that, osteoblasts, fibroblasts and keratinocytes, cells that will interact with the membrane during RTG, were culture P(VDF-TrFE)/BT and PTFE (control) membranes for up to 21 days. The following parameters were evaluated: 1) cell adhesion by counting in hemocytometer, 2) cell proliferation and 3) cell morphology by fluorescent labeling, for osteoblastic, fibroblastic and keratinocyte lineages; 1) total protein content; 2) alkaline phosphatase (ALP) activity and 3) mineralized bone-like nodule formation, for osteblastic and fibroblastic lineages; 1) immunolocalization of ALP by fluorescent labeling; 2) histochemistry detection in situ of ALP activity and 3) gene expression of Runx2, Collagen I (COL I), Ostepontin (OPN), ALP, Bone Sialoprotein (BSP), Osteocalcin (OC), Bax, Bcl-2 and Survivin (SUR) by real-time PCR, for osteoblastic lineage; 1) gene expression of Periostin (PRT), Periodontal ligament specific (PDLs17), Calcium-binding protein (S100A4), Fibromodulin (FBM), Bax, Bcl-2 and SUR by real-time PCR, for fibroblastic lineage; 1) gene expression of Involucrin (IVL), Keratin-1 (QRT-1), Keratin-10 (QRT-10), Keratin-14 (QRT- 14), Bax, Bcl-2 and SUR days by real-time PCR, for keratinocyte lineage. Data were submitted to Mann-Whitney test (level of significance: 5%). The adhesion of osteoblastic cells was similar between P(VDF-TrFE)/BT and PTFE at 30 min, 2 and 4 h (p>0.05). Cell proliferation was higher in ostegenic cultures grown on P(VDF-TrFE)/BT at 1, 7 and 10 days (p<0.05). Epifluorescence showed that osteoblastic cells grown on P(VDF-TrFE)/BT were more adhered and spread compared to PTFE at 30 min, 4 and 24 h. Immunofluorescence revealed the presence of ALP only in osteogenic cultures grown on P(VDF-TrFE)/BT at 7 and 14 days. Total protein content was similar between the membranes at 10 days (p>0.05) and higher on the P(VDF-TrFE)/BT at 7 and 14 days (p<0.05). There was no differences in ALP activity at 7 days (p>0.05). However, ALP activity was higher in osteogenic cultures on the P(VDF-TrFE)/BT at 10 and 14 days (p<0.05). The histochemistry reveals that only ostegenic cultures grown on P(VDF-TrFE)/BT had ALP activity in situ at 7 and 14 days. Bone-like nodule formation occurred only in cultures on the P(VDF-TrFE)/BT at 21 days. Gene expression of Runx2, COL I, OPN, ALP, BSP, OC, Bax and SUR was higher in cultures grown on P(VDF-TrFE)/BT at 7 and 14 days (p<0.05). There was no expression of Bcl-2 in cultures on both membranes. The adhesion of fibroblastic cells was similar between P(VDFTrFE)/ BT and PTFE at 30 min (p>0.05) and greater in fibroblastic cultures on P(VDFTrFE)/ BT at 2 and 4 h (p<0.05). Cell proliferation was similar in fibroblastic cultures grown on both membranes at 3 days (p>0.05) and higher in cultures on P(VDF-TrFE)/BT at 1 and 7 days (p<0.05). Epifluorescence showed that fibroblastic cells grown on P(VDF-TrFE)/BT were more adhered and more spread compared to PTFE at 30 min, 4 and 24 h. Total protein content was greater on P(VDF-TrFE)/BT at 10, 14 and 21 days (p<0.05). There was no ALP activity in fibroblastic cultures grown on both membranes at 7 days. The ALP activity was similar between P(VDF-TrFE)/BT and PTFE at 14 day (p>0.05) and higher on P(VDFTrFE)/ BT at 21 days (p<0.05). Bone-like nodule formation was not observed in fibroblastic cultures on both membranes at 21 days. Gene expression of PRT, PDLs17, S100A4, FBM, Bax and SUR was higher in cultures on the P(VDF-TrFE)/BT at 7 and 14 days (p<0.05). Bcl- 2 expression was higher in fibroblastic cultures on the PTFE at 7 and 14 days (p<0.05). Keratinocyte adhesion was similar for P(VDF-TrFE)/BT and PTFE at 30 min, 2 and 4 h (p>0.05). Keratinocyte proliferation was statistically similar on both membranes at 4, 7, 10 and 14 days (p>0.05) and higher in cultures grown on P(VDF-TrFE)/BT at 1, 17 and 21 days (p<0.05). Keratinocytes displayed a round morphology and was not observed any evidence of cell spreading at 30 min, 4 and 24 h. The gene expression of IVL was similar in cultures grown on P(VDF-TrFE)/BT and PTFE at 7 days (p>0.05) and higher on the P(VDF-TrFE)/BT at 14 days (p<0.05). Genes expression of QRT-1, QRT-10, QRT-14, Bax and SUR was greater in keratinocytes grown on P(VDF-TrFE)/BT at 7 and 14 days (p<0.05). Bcl-2 expression was higher in keratinocytes cultured on PTFE at 7 days (p<0.05) and similar on both membranes at 14 days (p>0.05). Our study indicates that P(VDF-TrFE)/BT membrane promote events related to tissue development/regeneration, such as cell adhesion, proliferation and differentiation. Thus, the membrane of P(VDF-TrFE)/BT could be used as an advantageous alternative to PTFE in GTR procedures.

Orientadores: Francisco Humberto Nociti Junior, Marcio Zaffalon Casati / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-05T21:22:40Z (GMT). No. of bitstreams: 1 Goncalves_PatriciaFurtado_D.pdf: 1584484 bytes, checksum: 320d77faa174f7b65746904c2c6166c6 (MD5) Previous issue date: 2006 / Resumo: Tendo sido demonstrada a possibilidade de preservação do cemento como forma alternativa de tratamento da doença periodontal, o presente estudo teve como objetivo avaliar o efeito do cemento dental na regeneração periodontal. Foram utilizados nove cães, sem raça definida, que receberam ligaduras de fio de algodão nos terceiros pré-molares inferiores, bilateralmente, para produzir lesões de bifurcação classe III. Após o levantamento de retalhos mucoperiosteais, os defeitos foram aleatoriamente escolhidos para receber um dos seguintes tratamentos: (A) remoção do tecido de granulação e uma cuidadosa raspagem e alisamento radicular, utilizando curetas e brocas, objetivando a remoção dos depósitos duros e moles e do cemento radicular, e polimento radicular com taças de borracha e pasta profilática; (B) somente a remoção do tecido de granulação e polimento radicular com taças de borracha e pasta profilática, objetivando a preservação do cemento radicular. Em ambos os grupos, os defeitos foram tratados com o princípio da Regeneração Tecidual Guiada (membranas reabsorvíveis - RESOLUT XT®) e os retalhos foram posicionados coronariamente e suturados. Após quatro meses os animais foram sacrificados para uma análise histomorfométrica. No grupo B, houve uma maior extensão (3,59±1,67 e 6,20±2,26mm para os grupos A e B, respectivamente; p=0,004) e espessura (18,89±9,47 e 52,29±22,48µm para os grupos A e B, respectivamente; p=0,001) de novo cemento, uma maior extensão de novo osso (1,86±1,76 e 4,62±3,01mm para os grupos A e B, respectivamente; p=0,002), além de uma maior extensão de regeneração periodontal, quando comparado ao grupo A (p<0,05 ¿ Wilcoxon). Observou-se ainda, no grupo B, uma menor formação de tecido epitelial/conjuntivo sobre a superfície radicular (2,77±0,79 e 1,10±1,48mm para os grupos A e B, respectivamente; p=0,009), além de uma maior porcentagem de preenchimento da área do defeito (80,95±17,46 e 94,50±10,27 para os grupos A e B, respectivamente; p<0,05), com uma maior proporção de novo osso e uma menor proporção de tecido epitelial/conjuntivo (p<0,05). Dentro dos limites deste estudo, conclui-se que o cemento dental pode modular a regeneração periodontal / Abstract: The aim of the present study was to histometrically evaluate, in dogs, the effect of root cementum on periodontal regeneration. Nine mongrel dogs were used to obtain bilateral chronic class III furcation defects by placing cotton ligatures around both third mandibular premolars. The teeth were randomly assigned to receive one of the following treatments: (A) Scaling and root planning, by means of hand and rotatory instruments, in order to remove soft and hard deposits as well as all root cementum; (B) Removal of only soft microbial deposits, by polishing the root surface with rubber cups and polishing paste, aiming at maximum root cementum preservation. Both groups were treated with Guided Tissue Regeneration (GTR), with the use of resorbable poliglycolic-lactic-acid membranes (RESOLUT XT®) covering the buccal e lingual aspects of the furcation defect, and the flaps coronally positioned. Four months after the treatment, the animals were sacrificed and the histological sections obtained. Data analysis showed that a superior length (3.59±1.67 vs. 6.20±2.26mm; p=0.004) and a thicker layer (18.89±9.47 vs. 52.29 ±22.48µm; p=0.001) of new cementum were observed for group B (p<0.05). Additionally, group B presented and a superior length of new bone (1.86±1.76 vs. 4.62±3.01mm; p= 0.002) and less soft tissue along the root surface (2.77±0.79 vs. 1.10±1.48mm; p=0.009), and a larger proportion of periodontal regeneration when compared to control (p<0.05). A larger area of new bone (p=0.018) and a smaller area of soft tissue (p=0.024) were also observed for group B (p<0.05 - Wilcoxon). Within the limits of this study, it can be concluded that root cementum may modulate periodontal regeneration / Doutorado / Periodontia / Doutor em Clínica Odontológica

Orientadores: Enilson Antonio Sallum, Antonio Wilson Sallum / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-26T05:10:48Z (GMT). No. of bitstreams: 1 Pereira_SergioLuisdaSilva_D.pdf: 3339204 bytes, checksum: 5e8546b985b4441bbc62f16e7bbb50a7 (MD5) Previous issue date: 1999 / Resumo: O objetivo deste trabalho foi comparar, histológica e histometricamente, o processo de cura de defeitos tipo deiscência tratados pela técnica de regeneração tecidual guiada (RTG) com membranas reabsorvíveis de ácido poliláctico e não reabsorvíveis de politetrafluoroetileno expandido (PTFE-e). Seis cães adultos fêmeas de raça indefinida foram utilizados. Defeitos ósseos tipo deiscência foram criados cirurgicamente nas raízes distais dos terceiros e quartos pré molares mandibulares de ambos os lados e expostos ao acúmulo de placa por 3 meses. Após este período, os defeitos foram aleatoriamente designados para um dos tratamentos: RTG com membrana reabsorvível de ácido poliláctico (Grupo 1), RTG com membrana não reabsorvível de PTFE-e (Grupo 2), raspagem e alisamento radicular manual com acesso cirúrgico (Grupo 3) e não tratado (Grupo 4). Após 3 meses do segundo procedimento cirúrgico, os cães foram sacrificados e os espécimes processados para permitir análise histológica e histométrica, incluindo. os seguintes parâmetros: extensão linear do epitélio sulcular e juncional, adaptação do tecido conjuntivo, novo cemento, extensão vertical do novo osso e nova área óssea. Uma extensão linear de novo cemento estatisticamente superior (P<0.05) foi observada nos sítios tratados pela RTG, independente do tipo de membrana utilizada, em comparação com o Grupo 3. Não houve diferença estatisticamente significante entre o Grupo 1 e 2 em todos os parâmetros avaliados, exceto em relação à área de novo osso. O grupo 1 apresentou uma área de novo osso estatisticamente superior a dos outros grupos (P<0.05). Dentro dos limites deste estudo pôde-se concluir que ambas as membranas foram igualmente efetivas em promover nova formação cementária e que a membrana reabsorvível de ácido poliláctico (não-suturada) providenciou uma maior área óssea em relação à membrana não reabsorvível de PTFE-e / Abstract: The goal of this investigation was to compare histollogically and histometrically the healing process of dehiscence-type defects treated by guided tissue regeneration (GTR) with resorbable polylactic acid membranes and nonresorbable ePTFE membranes. Six mongrel dogs were used. Buccal osseous dehiscences were surgically created on the distal roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one ofthe treatments: GTR with resorbable membrane (GTR1), GTR with nonresorbable membrane (GTR2), open flap debridement (OFD) and non-treated control (NTC). After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone (vertical component) and new bone area. A superior length of new cementum was observed in the sites treated by GTR, regardless of the type of barrier used (P<0.05), in comparison with OFD. No statistically significant differences were found between GTRl and GTR2 in all the parameters with the exception ofbone area. GTRl presented a greater bone area (P<0.05) when compared to GTR2, OFD and NTC. Within the limits of this study, it can be concluded that both batriers are equally effective for new cementum formation. The resorbable membrane (non-sutured) may provide a better osseous response than the nonresorbable membrane / Doutorado / Periodontia / Doutor em Clínica Odontológica

Experimental grade III furcation defects were developed bilaterally at the second and fourth premolars in 18 conditioned, laboratory-source, adult Beagles and maintained for 12 weeks. All defects were treated with debridement and mucoperiosteal flap repositioning alone, or with the addition of autologous fibrinogen, Resolut® barrier membrane, or autologous fibrinogen and Resolut® barrier membrane. The defects were analyzed by digital subtraction radiography, histopathologic, and histomorphometric analysis of healing at 1, 3, and 6 months post-treatment to determine: percent increase in defect bone volume, height and area, and length of periodontal regeneration along the perimeter of the defect. Comparisons at post-treatment intervals indicated significantly (P < 0.05) greater healing of debridement and autologous fibrinogen treated defects at 3 months, however by 6 months there were no significant differences in defect healing for all histomorphometric parameters. Defects receiving Resolut® were associated with significantly less root ankylosis. Defects receiving debridement alone had significantly greater increases in bone volume, as calculated with digital subtraction radiography, at 6 months post-treatment compared with groups receiving Resolut®. There was a significant correlation between regenerated bone area, bone volume, and periodontal regeneration for all treatments at 3 and 6 months post-treatment. In this study autologous fibrinogen and Resolut® barrier membrane did not enhance the amount of periodontal healing compared with debridement only. However, Resolut® treated defects were essentially absent of root ankylosis. Therefore, canine periodontitis causing grade III furcation involvement may respond equally well to conservative periodontal surgery compared with guided tissue regenerative techniques. However, the prevention of root ankylosis may provide a substantial benefit favoring this latter methodology. / Master of Science

60 % of school children have some form of untreated tooth decay or have suffered trauma to the front teeth which results in pulp damage. If left untreated, these teeth are susceptible to premature fracture/loss under daily stresses. In cases of adolescent tooth loss, teenagers cannot get dental implants until after the growth spurts; their only option is using removable dentures which lowers their quality of life. Conventional endodontic treatment (root canal treatment) is used in cases of pulp necrosis, but cannot be performed in immature permanent teeth due to major differences in tooth anatomy. Currently the American Dental Academy has approved a procedure called Regenerative Endodontic Treatment (RET) for such cases, but the outcomes are still unpredictable and the method is largely unreliable. One issue that we are trying to address in this work is the regeneration of the pulp-dentin complex (PDC), specifically the interface. Endeavors in regenerating either pulp or dentin have been successful individually, but the interface region is the anatomical and physiologic hallmark of the PDC and has not been addressed. We have proposed a biomimetic scaffold to facilitate early stage stratification of these different tissues and allow recapitulation of their interface. Tissue engineering principles and biomaterial processing techniques were used simultaneously to encourage dental pulp stem cells into mineralize selectively only on one side. This effectively allows the scaffold to serve as the interface region between the hard dentin and the soft vascular pulp. / Bioengineering

Yes / Nanodiamonds (NDs) have been used in various fields of medicine such as drug delivery, tissue regeneration and gene therapy. Although there has been research carried out investigated the potential of these remarkable materials in dentistry, to date no review has been published to summarize the studies conducted. Due to their target cell specificity, small size and fluorescence they have also been found to be usefulness in dentistry. Main applications of NDs in dentistry and medicine include guided tissue regeneration, reinforcement of polymers and drug delivery to treat infections and cancers. Recent research also suggests that NDs can also be used as bioactive or antibacterial dental implant coatings. However, to date, the research conducted on their biocompatibility is limited and inconclusive. Hence, substantially more in vitro and in vivo studies are required to envisage the future of NDs in dentistry. It is hoped that in the next decade these promising materials will find a variety of uses in routine dentistry.

Yes / Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies.

Orientador: Álvaro Francisco Bosco / Banca: Maria José Hitomi Nagata / Banca: Valdir Gouveia Garcia / Banca: Mário Taba Júnior / Banca: Marcio Zaffalon Casati / Resumo: O objetivo do presente estudo foi avaliar histológica e histometricamente a cicatrização de defeitos de deiscência periodontal associados ao aplainamento radicular tratados com enxerto de tecido conjuntivo subepitelial (ETC) ou Membrana Bioabsorvível (MB), cada qual comparado ao tratamento com Retalho Posicionado Coronal (RPC). Foram utilizados 12 cães, divididos em dois grupos de 6. Defeitos de deiscência óssea (6x8 mm) e o aplainamento radicular foram realizados nos caninos superiores e os grupos divididos, seguindo um modelo de boca dividida de acordo com o tratamento. Os caninos esquerdos serviram como controle (RPC), onde o retalho foi somente posicionado coronalmente. Os caninos direitos receberam os tratamentos com ETC ou MB. Após 3 meses pósoperatórios os animais foram submetidos à eutanásia e os blocos processados para análise histológica e histométrica. Os parâmetros histométricos avaliados incluíram extensão de tecido epitelial (TE), extensão da nova inserção de tecido conjuntivo (NITC) e extensão da aposição de tecido conjuntivo (ATC), extensão de novo cemento (NC) e extensão de novo osso (NO). Histologicamente, o grupo MB mostrou significativamente maiores NC, NO e NITC (4.12±1.24; 2.44±0.78; 1.80±0.39, respectivamente) em comparação ao grupo RPC (1.04±0.43; 0.93±0.23; 0.71±0.45, respectivamente) (P<0.05) e significativamente menor ATC (0.29±0.33) comparado aos grupos RPC (2.79±1.74) e ETC (2.62±1.52) (P<0.05). A NITC no grupo ETC (0.71±0.36) foi significativamente menor, enquanto a ATC (2.62±1.52) e TE (1.70±0.53) foram significativamente maiores comparado ao grupo MB (1.80±0.39; 0.29±0.33; 1.00±0.35, respectivamente) (P<0.05). Dentro dos limites deste estudo, concluiuse que o grupo MB mostrou melhores resultados histológicos de nova inserção de tecido conjuntivo, formação de novo osso e novo cemento em relação aos grupos RPC e ETC. / Abstract: The aim of the present study was to evaluate histologically and histometrically the healing of periodontal dehiscence defects associated to root planing treated with subepithelial connective tissue graft (CTG) or Bioabsorbable Membrane (BM), each one compared to the treatment with Coronally Positioned Flap (CPF). Twelve dogs were used, divided into two groups of six elements. Bone dehiscence defects (6x8 mm) and root planing were accomplished in the upper canine and the groups were divided, following a model of divided mouth according to the treatment used. Left canine were used as control (CPF), where the flap was only coronally positioned. Right canine received treatments with CTG or BM. After three postoperative months, the animals were euthanized and the blocks were processed for histological and histometrical analysis. The evaluated histometric parameters included lenght of epithelial tissue (TE), new attachment (NACT) and connective tissue aposition (CTA), new cementum (NC), and new bone (NB). Histologically, group BM showed significant higher values of NC, NO and NITC (4.12±1.24; 2.44±0.78; 1.80±0.39, respectively) in comparison to the group CPF (1.04±0.43; 0.93±0.23; 0.71±0.45, respectively) (P<0.05) and significant lower values of ATC (0.29±0.33) in comparison to the groups CPF (2.79±1.74) and CTG (2.62±1.52) (P<0.05). NITC in group CTG (0.71±0.36) was significantly lower, while ATC (2.62±1.52) and TE (1.70±0.53) were significantly higher in comparison to group BM (1.80±0.39; 0.29±0.33; 1.00±0.35, respectively) (P<0.05). Within the limits of this study, it can be concluded that group BM showed better histological results of connective tissue new attachment, new bone and new cementum formation in comparison to groups CPF and CTG. / Doutor

The American Heart Association (AHA) estimates that at least one American will die from a coronary event every minute, costing over $150 billion in 2008 alone. Regenerating the myocardium of patients that survive the initial infarction has proven to be an elusive goal. A variety of factors - including the loss of contractile cells, inflammatory response following infarction, cardiac hypertrophy, and lack of suitable cues for progenitor cells - causes fibrosis in the heart and loss of cardiac function. This dissertation examines three drug delivery strategies aimed at improving conditions for cardiac regeneration: polyketal microspheres as non-inflammatory drug delivery vehicles; surface functionalization of microparticles with nitrilotriacetic acid-nickel (NTA-Ni) for non-covalent tethering of proteins; and using Hoechst-inspired ligands for targeting extracellular DNA in necrotic tissue.