Improving the functionality and reducing revision rates are important driving forces in the development of orthopaedic implants. FibMat is a fibrinogen based matrix developed towards commercialisation by the company Optovent AB. This matrix can be coated on implants and act as a local drug delivery system for bisphosphonates (BPs). BPs are drugs inhibiting bone resorption, and applied with FibMat to improve stability of implants in bone, e.g. when fixing bone fractures. In this thesis, FibMat loaded with BP (FibMat/BP) was coated on stainless-steel screws and titanium screws in order to investigate some technology properties relevant to its clinical applicability. Bone-mimicking materials were used to study scrape-off effect upon insertion. The coagulation properties of fibrinogen as well as the structural properties of BPs were studied after exposure to gamma radiation. The screws were coated with FibMat and BP (alendronate and 14C-alendronate) using standard coupling techniques. The total amount and distribution of BP after insertion was measured by liquid scintillation and autoradiography. Coagulation assays were performed in order to determine the coagulation properties of fibrinogen, exposed to doses up to 35 kGy, mixed with thrombin. The structural properties of four different BPs (alendronate, pamidronate, zoledronate and ibandronate), exposed to doses up to 35 kGy were analysed by transmission infrared spectroscopy. The results show that FibMat/BP coating on porous stainless-steel screws is virtually unaffected by insertion into bone materials. The anodised, planar titanium screws are more affected by the insertion process, but an even BP distribution in the cancellous material is indicated. The coagulation assays show that gamma-irradiated fibrinogen has a slower coagulation process compared to non-irradiated fibrinogen and form interrupted network unable to clot. The chemical structures of the BPs seem unaffected by exposure to gamma irradiation. In conclusion, the FibMat/BP is a promising technology for local distribution of BP in conjunction with bone implants.

<p>Improving the functionality and reducing revision rates are important driving forces in the development of orthopaedic implants. FibMat is a fibrinogen based matrix developed towards commercialisation by the company Optovent AB. This matrix can be coated on implants and act as a local drug delivery system for bisphosphonates (BPs). BPs are drugs inhibiting bone resorption, and applied with FibMat to improve stability of implants in bone, e.g. when fixing bone fractures. In this thesis, FibMat loaded with BP (FibMat/BP) was coated on stainless-steel screws and titanium screws in order to investigate some technology properties relevant to its clinical applicability. Bone-mimicking materials were used to study scrape-off effect upon insertion. The coagulation properties of fibrinogen as well as the structural properties of BPs were studied after exposure to gamma radiation.</p><p>The screws were coated with FibMat and BP (alendronate and 14C-alendronate) using standard coupling techniques. The total amount and distribution of BP after insertion was measured by liquid scintillation and autoradiography. Coagulation assays were performed in order to determine the coagulation properties of fibrinogen, exposed to doses up to 35 kGy, mixed with thrombin. The structural properties of four different BPs (alendronate, pamidronate, zoledronate and ibandronate), exposed to doses up to 35 kGy were analysed by transmission infrared spectroscopy.</p><p>The results show that FibMat/BP coating on porous stainless-steel screws is virtually unaffected by insertion into bone materials. The anodised, planar titanium screws are more affected by the insertion process, but an even BP distribution in the cancellous material is indicated. The coagulation assays show that gamma-irradiated fibrinogen has a slower coagulation process compared to non-irradiated fibrinogen and form interrupted network unable to clot. The chemical structures of the BPs seem unaffected by exposure to gamma irradiation. In conclusion, the FibMat/BP is a promising technology for local distribution of BP in conjunction with bone implants.</p>

Osteoclasts are multinucleated cells found exclusively in bone and are derived from the haematopoietic cells of monocytes/macrophage lineage. The cell-to-cell interaction between osteoblastic/stromal cells and osteoclast precursor cells is necessary for osteoclastogenesis. Receptor Activator of NF-κB ligand (RANKL) was identified as a membrane-bound TNF ligand family member that is the ‘master’ cytokine expressed on osteoblastic/stromal cells, which stimulate osteoclastogenesis through cell-to-cell contact with osteoclast precursors. RANKL is considered to be a factor that is necessary and sufficient for the induction of osteoclastogenesis (Lacey, et al., 1998). RANKL is a type II transmembrane cytokine of the TNF ligand superfamily and has an active TNF-like core domain at the extracellular domain. This active TNF-like core domain is thought to be the region through which it binds to it’s active receptor, RANK, for the activation of signal transduction pathways for the initiation of processes leading to osteoclastogenesis (Lacey, et al., 1998; Li, et al., 1999). It was hypothesized that any change in the active TNF-like core domain might affect the ability of RANKL binding to RANK and consequently affect the activation of signal transduction pathways and osteoclastogenesis. Hence, this thesis sought to investigate the effects of changes in the active TNF-like core domain by truncation mutation on the ability of RANKL binding to RANK and consequently affect the activation of signal transduction pathways and osteoclastogenesis. A cDNA fragment encoding the full-length TNF-like core domain of rat RANKL (rRANKL) (aa160-318) was cloned into the bacterial expression pGEX vectors and stably expressed in Eschechia coli as a fusion protein with the C-terminus of glutathione S-transferase (GST). Four mutants (aa160-302, aa160-268, aa239-318 and aa246-318) were also generated by truncation mutation in the TNF-like core domain, and cloned into the pGEX vector to produce GST-rRANKL mutants. The proteins were over-expressed and affinity purified to 95% in purity. GST-rRANKL (160-318) containing the full length TNF-like core domain was able to induced osteoclastogenesis in spleen cells in the presence of M-CSF and in RAW264.7 cells in the absence of M-CSF. It was also found to activate mature osteoclast activity in vitro, ex vivo and in vivo. It has the highest binding affinity to RANK and the greatest potency for NF-κB activation as well as the induction of osteoclastogenesis compared to the truncated mutants. Mutants generated by truncation of the TNF-like core domain revealed that the TNF-like core domain is important for the interaction with the RANK, for high binding affinity, NF-κB activation and induction of osteoclastogenesis. In general, the truncated mutants not only displayed a reduction in the binding affinity to RANK, but also a reduction in NF-κB activation, and significantly reduced potency in the induction of osteoclastogenesis. Interestingly, mutant GST-rRANKL (160-268) showed a higher affectivity than the other mutants did, in that it had greater binding affinity to RANK, and in NF-κB activation than the rest of the truncated mutants. Mutants GST-rRANKL (239-318) and GST-rRANKL (246-318) on the other hand, showed little potency in the induction of osteoclast formation, however, might have an inhibitory effect through competition with full length GST-rRANKL (160-318) as well as inducing a response in vivo resulting in an increase in the serum calcium level. In conclusion, this thesis demonstrated that the TNF-like core domain of RANKL is active, and imperative in the binding to RANK, activating signal transduction pathways and induction of osteoclastogenesis. Changes in the active TNF-like core domain affected the ability, affinity and efficiency of RANKL binding to the receptor, RANK and consequently affected the activation of signal transduction pathways and osteoclastogenesis.

Orientador: Paulo Sérgio Perri de Carvalho / Resumo: As vantagens do tratamento do edentulismo total mandibular com implantes osseointegráveis e função oclusal precoce são bem conhecidas. Recentemente, um interesse crescente pelos benefícios dessa modalidade terapêutica envolveu o edentulismo parcial em várias regiões da boca. No entanto, protocolos bem definidos para a mandíbula posterior com função oclusal precoce não foram devidamente testados e aprovados. O objetivo desta investigação foi avaliar a eficácia clínica de um protocolo cirúrgico, protético e radiográfico para o tratamento da mandíbula posterior, com implantes osseointegráveis e função oclusal precoce. Treze pacientes com edentulismo parcial posterior, uni ou bilateral, foram tratados em clínica particular. Cinqüenta e dois implantes foram inseridos em 17 áreas mandibulares, com classes I, II e III de Kennedy. Os implantes utilizados foram MKIII e MKIV, com superfície lisa e foi empregada técnica cirúrgica padronizada para inserção dos implantes. A função oclusal precoce foi obtida com próteses parciais fixas instaladas com uma média de 7 dias da inserção dos implantes.O tempo de observação clínica variou entre 12 e 26 meses, com média de 19 meses. O nível do osso marginal foi determinado com medidas nas imagens digitalizadas de radiografias convencionais padronizadas. A taxa cumulativa de sobrevivência foi de 98,1% e a perda óssea marginal média, nos primeiros seis meses, foi de 1,02mm e 1,07mm para um ano de observação. A taxa da sobrevivência das próteses foi de 100%. Considerando os limites deste estudo, o protocolo testado para tratamento da mandíbula posterior com função oclusal precoce e implantes osseointegráveis parece viável para aplicação clínica em bases rotineiras, No entanto, estudos multicêntricos e a longo prazo devem ser conduzidos para confirmar ou refutar os resultados obtidos. / Abstract: The early occlusal loading of Osseointegrated implants in mandibular totally edentulous patients have been shown to be a successful and an advantageous approach. Recently, this treatment modality evolved to the treatment of partially edentulous patients. However protocols for treating those cases were neither tested nor approved. The objective of this investigation was to evaluate the clinical efficacy of a surgical, a prosthetic and a radiographic protocol idealized for the treatment of the posterior mandible with early occlusaly loaded osseointegrated implants. Thirteen partially edentulous patients in the posterior mandibleunilaterally or bilaterally, were treated in a private practice setting. Fifty two fixtures were placed in seventeen mandibular areas class I, II and III accordingly to Kennedy's classification. Machined MKIII and MKIV implants were placed utilizing standardized surgical technique. Early loading conditions were obtained with the placement of fixed partial dentures installed in average seven days after fixtures installation. The clinical observation time varied between 12 and 26 months with an average of 19 months. The marginal bone levels were determined from digital images derived from standardized conventional radiographs. A mean marginal bone loss of 1.02mm was noted in the first six months of observation and a mean marginal bone loss of 1.07 mm after 12 months under the evaluated conditions. The cumulative survival rate of 98.1% and 100 % were found for implants and prostheses respectively. Within the limits of this study, it can be concluded that the tested protocol for the treatment of the posterior mandible with osseointegrated implants under early occlusal loading condition seemed to be a viable clinical alternative for routine application. Nevertheless, additional studies including a multicenter design and longer evaluation periods are necessary to substantiate these findings. / Doutor

Made available in DSpace on 2014-06-11T19:32:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2004Bitstream added on 2014-06-13T18:43:56Z : No. of bitstreams: 1 pinto_avs_dr_araca.pdf: 1496770 bytes, checksum: c9fd8c4da9c28379a95d5da49951a5df (MD5) / 3i Implant / As vantagens do tratamento do edentulismo total mandibular com implantes osseointegráveis e função oclusal precoce são bem conhecidas. Recentemente, um interesse crescente pelos benefícios dessa modalidade terapêutica envolveu o edentulismo parcial em várias regiões da boca. No entanto, protocolos bem definidos para a mandíbula posterior com função oclusal precoce não foram devidamente testados e aprovados. O objetivo desta investigação foi avaliar a eficácia clínica de um protocolo cirúrgico, protético e radiográfico para o tratamento da mandíbula posterior, com implantes osseointegráveis e função oclusal precoce. Treze pacientes com edentulismo parcial posterior, uni ou bilateral, foram tratados em clínica particular. Cinqüenta e dois implantes foram inseridos em 17 áreas mandibulares, com classes I, II e III de Kennedy. Os implantes utilizados foram MKIII e MKIV, com superfície lisa e foi empregada técnica cirúrgica padronizada para inserção dos implantes. A função oclusal precoce foi obtida com próteses parciais fixas instaladas com uma média de 7 dias da inserção dos implantes.O tempo de observação clínica variou entre 12 e 26 meses, com média de 19 meses. O nível do osso marginal foi determinado com medidas nas imagens digitalizadas de radiografias convencionais padronizadas. A taxa cumulativa de sobrevivência foi de 98,1% e a perda óssea marginal média, nos primeiros seis meses, foi de 1,02mm e 1,07mm para um ano de observação. A taxa da sobrevivência das próteses foi de 100%. Considerando os limites deste estudo, o protocolo testado para tratamento da mandíbula posterior com função oclusal precoce e implantes osseointegráveis parece viável para aplicação clínica em bases rotineiras, No entanto, estudos multicêntricos e a longo prazo devem ser conduzidos para confirmar ou refutar os resultados obtidos. / The early occlusal loading of Osseointegrated implants in mandibular totally edentulous patients have been shown to be a successful and an advantageous approach. Recently, this treatment modality evolved to the treatment of partially edentulous patients. However protocols for treating those cases were neither tested nor approved. The objective of this investigation was to evaluate the clinical efficacy of a surgical, a prosthetic and a radiographic protocol idealized for the treatment of the posterior mandible with early occlusaly loaded osseointegrated implants. Thirteen partially edentulous patients in the posterior mandibleunilaterally or bilaterally, were treated in a private practice setting. Fifty two fixtures were placed in seventeen mandibular areas class I, II and III accordingly to Kennedy’s classification. Machined MKIII and MKIV implants were placed utilizing standardized surgical technique. Early loading conditions were obtained with the placement of fixed partial dentures installed in average seven days after fixtures installation. The clinical observation time varied between 12 and 26 months with an average of 19 months. The marginal bone levels were determined from digital images derived from standardized conventional radiographs. A mean marginal bone loss of 1.02mm was noted in the first six months of observation and a mean marginal bone loss of 1.07 mm after 12 months under the evaluated conditions. The cumulative survival rate of 98.1% and 100 % were found for implants and prostheses respectively. Within the limits of this study, it can be concluded that the tested protocol for the treatment of the posterior mandible with osseointegrated implants under early occlusal loading condition seemed to be a viable clinical alternative for routine application. Nevertheless, additional studies including a multicenter design and longer evaluation periods are necessary to substantiate these findings.

Orientador: Carlos Rossa Junior / Banca: Luis Carlos Spolidório / Banca: Silvana Regina Perez Orrico / Banca: Dagmar Ruth Stach Machado / Banca: Paula Cristina Trevilatto / Resumo: Embora a doença periodontal tenha origem infecciosa, ela se caracteriza por uma complexa resposta imune-inflamatória, com a participação de células residentes e não-residentes, produzindo diversas citocinas e mediadores biológicos. A principal característica da doença periodontal destrutiva é a reabsorção do osso alveolar, a qual é uma consequência frequentemente irreversível do processo patológico e das citocinas produzidas pela resposta do hospedeiro. Citocinas específicas atuam diretamente no controle da remodelação óssea, denominadas RANKL (Receptor activator of NF-kB ligand) e OPG (Osteoprotegerin,). RANKL é uma proteína produzida por fibroblastos, osteoblastos, condrócitos, células mesenquimais e células T e B ativadas e sua ligação com o seu receptor RANK (Receptor activator of NF-kB) em células precursoras de osteoclastos é necessário e suficiente para a ativação, diferenciação e sobrevivência de osteoclastos maduros. OPG, a outra proteína envolvida nesta modulação, serve como um falso receptor para RANKL, impedindo dessa forma a ligação RANKL-RANK e levando a uma menor ativação de osteoclastos. Assim, o balanço entre RANKL e OPG é o atual paradigma para a modulação da remodelação óssea. FK-506 (tacrolimo) é uma droga imunossupressora usada para prevenir rejeição de enxertos afetando a ativação de linfócitos T por meio da modulação da via da calcineurina, inibindo a ativação de NFAT e de NF-kB. Estudos prévios demonstraram que o uso de tacrolimo em ratos diminui a resposta inflamatória e reabsorção óssea em modelo experimental de indução de doença periodontal. A proposta deste estudo foi avaliar os efeitos da administração sistêmica do tacrolimo sobre a expressão de RANKL e OPG na doença periodontal induzida em ratos e determinar in vitro, se o tratamento de células residentes do periodonto com tacrolimo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Periodontitis is a well-characterized infectious disease with a complex immune-inflammatory response. In response to the bacterial presence, many resident and non-resident cells into the peridontium produce many cytokines and biologic mediators, causing tissue destruction and alveolar bone loss. These cytokines are the key-factor in osteoclast-mediated bone resorption. The expression ratio between two cytokines is fundamental to bone resorption process: RANKL (Receptor activator of NF-kB ligand) that is necessary to osteoclast differentiation, activation and survival, and OPG (Osteoprotegerin) that acts as the endogenous inhibitor of RANKL by functioning as its decoy receptor. RANKL is expressed by fibroblasts, osteoblasts, chondrocytes, mesenchymal cells and T and B lymphocytes. OPG is secreted primarily by osteoblastic cells, bone marrow stromal celss and fibroblasts and it counter regulates the excessive bone loss antagonizing the RANKL-binding to its receptor RANK in osteoclast precursor cells. The ratio between RANKL and OPG is the current paradigm for modulation of coupled bone turnover. FK-506 is an immunossupressive drug used to reduce and to prevent the risk of organ transplant rejections. It acts affecting T lymphocyte activation by calcinaurin pathway modulation inhibiting NFAT and NF-kB translocation to the nucleus. Previous studies showed that animals with experimental periodontitis treated with FK-506 exhibited less bone resorption and inflammatory infiltrate. The purpose of this study was evaluated effects of FK-506 systemic administration over RANKL and OPG expression in animals with experimental periodontitis; and determines if FK-506-treated periodontium resident cells can affect IL-1- and LPS-induced RANKL and OPG expression. In the in vivo study, two experimental periodontitis models were used (LPS and ligature) in rats. In the test group the animals received dail... (Complete abstract click electronic access below) / Doutor

Trata-se de estudo comparativo para avaliar a atividade dos medicamentos nimesulida, Arnica TM, Arnica 6CH comparados com H2O no tratamento da Doença Periodontal experimental induzida por ligadura em ratos. Esta doença se caracteriza por processo inflamatório que pode evoluir até ao ligamento periodontal e tecido ósseo provocando perda óssea. Mediadores produzidos pelo hospedeiro e substâncias do biofilme são responsáveis pelos danos que podem levar até a perda do elemento dentário. O objetivo deste trabalho foi desenvolver estudo exploratório descritivo para analisar, aprofundar e comparar os efeitos das medicações citadas, investigando possíveis inovações no tratamento da doença periodontal. A metodologia consistiu em: 1) colocação, sob anestesia, da ligadura no primeiro molar inferior esquerdo. 2) administração diária por gavagem de H2O (controle) (1&#x3BC;l/g), nimesulida (1&#x3BC;l/g, de uma suspensão com 5mg/ml), Arnica TM (8&#x3BC;l/300g) ou Arnica 6CH (3,21&#x3BC;l/300g) durante 14, 21 e 28 dias a quatro grupos de ratos Wistar (n=30/ grupo); 3) eutanásia e coleta de material para análises histológica, da perda óssea e RT-PCR (alvos: TNF-&#x3B1;, COX-2, IL-6, OPG e RANKL); 4) análise estatística paramétrica realizada por ANOVA a um ou dois critérios, seguida do teste de Tukey, ou por análise não paramétrica por Kruskal-Wallis, seguido do método de Dunns, nível de significância de 5%. Quanto à perda óssea, não houve diferença estatística entre os grupos e nenhum dos tratamentos foi capaz de contê-la. Os escores para o infiltrado inflamatório não mostraram diferença significativa entre os grupos nos períodos estudados. Quanto ao escore geral, que envolve intensidade do infiltrado inflamatório, migração do epitélio juncional, integridade do cemento e da crista óssea alveolar, não houve diferença significativa entre os grupos nos períodos. Na expressão do RNAm para as citocinas vimos para o TNF-&#x3B1; não haver diferença significativa entre os grupos, quando se analisou isoladamente os períodos de 14 e 28 dias. No entanto, no período de 21 dias, houve redução significativa no grupo nimesulida comparado ao grupo Arnica 6CH (&#x2217;p<0,05). Para a COX-2, não houve diferença significativa quanto à expressão do RNAm entre os grupos, analisando isoladamente cada período de estudo, sendo nítida a redução desta expressão no grupo Arnica 6CH em todos os períodos; para a IL-6, OPG e RANKL não houve diferença significativa quanto à expressão do RNAm entre os grupos nos períodos estudados. No entanto, no grupo Arnica 6CH nota-se tendência nítida para o aumento da expressão do RNAm para OPG, ao longo do tempo. Comparando com o grupo H2O a ação de cada medicamento quanto à expressão do RNAm para todas as citocinas, considerando o conjunto dos 3 períodos, vê-se redução significativa para a expressão de RNAm para COX-2 e RANKL após o tratamento com Arnica 6CH (&#x2217;p<0,05). O mesmo pode ser visto para a nimesulida quando se estuda a expressão do RNAm para RANKL (&#x2217;p<0,05). No estudo ficaram destacados os efeitos biológicos da Arnica 6CH sobre a leitura e transcrição do DNA, notadamente sobre genes relacionados à perda óssea, o que vislumbra a possibilidade de sua utilização terapêutica. / This is a comparative study to evaluate the activity of nimesulide medicines, Arnica TM, Arnica 6CH compared with H2O in the treatment of experimental periodontal disease induced by ligation in rats. This disease is characterized by an inflammatory process that may progress to the periodontal ligament and bone tissue leading to bone loss. Mediators produced by the host and biofilm substances are responsible for the damage that can lead to tooth loss. The aim of this exploratory and descriptive study was to analyze, deepen and compare the effects of the mentioned medications, investigating possible innovations in the treatment of periodontal disease. The methodology consisted of: 1) placing under anesthesia ligature in the first lower left molar. 2) daily administration by gavage H2O (control) (1&#x3BC;l/g), nimesulide (1&#x3BC;l/g, a suspension of 5 mg / ml), Arnica TM (8&#x3BC;l/300g) or Arnica 6CH (3,21&#x3BC;l/300g) for 14, 21 and 28 days to four groups of Wistar rats (n = 30 / group); 3) euthanasia and collection of material for histological, bone loss and RTPCRanalysis (targets: TNF-&#x3B1;, COX-2, IL-6, OPG and RANKL); 4) parametric statistical analysis performed by ANOVA to one or two criteria, followed by Tukey test, or nonparametric analysis by Kruskal-Wallis, followed by Dunns method, 5% significance level. Regarding the bone loss, there was no statistical difference between the groups and none of the treatments was able to contain it. The scores for the inflammatory infiltrate showed no significant difference between the groups in the study periods. Regarding the general score, which involves intensity of the inflammatory infiltrate, migration of the junctional epithelium integrity of the cement and the alveolar bone crest, there was no significant difference between groups in the periods. At the mRNA expression for the cytokines we saw for TNF-&#x3B1; no significant difference between groups when analyzed separately periods of 14 and 28 days. However, in the 21day period, there was significant reduction in nimesulide group compared to the Arnica 6CH group (&#x2217; p <0.05). For COX-2, there was no significant difference in mRNA expression between the groups, separately analyzing each study period, being sharper reduction of this expression in Arnica 6CH group in all periods; for IL-6, OPG and RANKL no significant difference in mRNA expression between the groups in the study periods. However, it is noted in the Arnica 6CH group a clear tendency to increase of the mRNA expression for OPG over time. Comparing with H2O group action of each medicine on the mRNA expression for all cytokines, considering the set of three periods, we see a significant reduction in mRNA expression for COX-2 and RANKL after treatment with Arnica 6CH (&#x2217; p <0.05). The same can be seen for nimesulide when studying the mRNA expression for RANKL (&#x2217; p <0.05). In the study were highlighted the biological effects of Arnica 6CH about reading and transcription of the DNA, notedly about genes related to bone loss, which envisions the possibility of its therapeutic use.

Orientadores: Francisco Humberto Nociti Junior, João Batista Cesar Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-12T22:34:14Z (GMT). No. of bitstreams: 1 Bossolan_AnaPaulaOliveiraGiorgetti_M.pdf: 2279288 bytes, checksum: 5a228c75e99aaefdca7d50013fbc0c84 (MD5) Previous issue date: 2009 / Resumo: O objetivo do presente estudo foi avaliar a influência da inalação da fumaça de cigarros sobre o processo de reparo ósseo alveolar em ratos. Foram utilizados 40 ratos Wistar adultos aleatoriamente divididos em: Grupo CONTROLE - 20 animais que não foram expostos à fumaça de cigarros (FC) e Grupo TESTE - 20 animais que foram expostos à FC. Todos os animais tiveram seus 1°s e 2°s molares (M) inferiores extraídos, sendo que as exposições à FC iniciaram-se 3 dias antes das extrações mantendo-se até o sacrifício (3, 7, 10 e 14 dias). Após cada sacrifício, os alvéolos dentais dos 1°sM foram curetados e o tecido obtido armazenado. Os alvéolos dos 2°s M foram processados para avaliação histométrica. A reação de PCR (Polymerase Chain Reaction) em tempo real quantificou a expressão dos genes: fosfatase alcalina (ALP), proteína óssea morfogenética (BMP)-2, BMP-3 e BMP-7, ligante ativador do receptor do fator ?B (RANKL), osteoprotegerina (OPG) e v-ATPase V0 subunidade d2 (Atp6v0d2). Histometricamente, a inalação da fumaça de cigarros influenciou negativamente o preenchimento ósseo apenas no 7º dia mostrando diferença estatisticamente significante para os parâmetros tecido medular e defeito remanescente (p<0,05). Em relação à expressão gênica, a análise dos dados demonstrou que no grupo controle houve diminuição nos níveis de RNAm ao longo do tempo de Atp6v0d2, BMP-3 e na razão entre RANKL/OPG . Os níveis de RNAm para ALP, BMP-2 e BMP-7 mostraram-se aumentados. Já no grupo teste, esses padrões de expressão gênica se invertem, pois houve aumento nos níveis de RNAm de Atp6v0d2 e na razão entre RANKL/OPG. Desta forma, conclui-se que a inalação da fumaça de cigarros pode modular o padrão de reparo ósseo alveolar observado histometricamente, provavelmente devido ao efeito observado sobre a expressão de genes envolvidos nesse processo. / Abstract: The aim of the present study was to evaluate the effect of cigarette smoke inhalation on wound healing of molar extraction socket. A total of 40 male Wistar rats were randomly assigned to one of the following groups: Control Group - 20 animals not exposed to cigarette smoke inhalation (CSI) and Test Group - 20 animals exposed to CSI for 3 days before the surgery until sacrifice (3, 7, 10, 14 days). After sacrifice, the mandible was removed and the specimens processed either for histometric analysis (2nd molar sockets) or for gene expression analysis (1st molar sockets) by Real Time polymerase chain reaction (PCR). The expression of alkaline phosphatase (ALP), bone morphogenetic protein (BMP) -2, BMP-3 and BMP-7, receptor activator of nuclear factor ?B ligand (RANKL), osteoprotegerin (OPG) and v-ATPase V0 subunit d2 (Atp6v0d2) was assessed. Histometrically, data analysis showed that CSI negatively affected bone formation on the 7th day showing a lower amount of non-mineralized tissue and higher wound area (p<0.05). As for gene expression, data analysis demonstrated a trend of lower mRNA levels over time for Atp6v0d2, BMP-3 and RANKL/OPG ratio in the control group. Whereas, ALP, BMP-2 and BMP-7 mRNA levels were increased. Data analysis additionally demonstrated that this pattern was modified by CSI. Cigarette smoke exposure resulted in an increase in Atp6v0d2 mRNA levels and in RANKL/OPG ratio. Within the limits of the present study, it can be concluded that cigarette smoke inhalation may affect the post-extraction socket healing pattern, probably due to the observed effect on the expression of bone remodeling-associated genes in the sites of tooth extraction. / Mestrado / Periodontia / Mestre em Clínica Odontológica

A osteoporose é uma epidemia mundial, exprime altas taxas de morbidade e mortalidade, resultando também em altos custos sociais. O exame de densitometria óssea por emissão dupla de raios-X (DXA) é o exame padrão ouro para o diagnóstico da doença. Porém, o alto custo e a disponibilidade de equipamentos, dificultam o acesso ao exame, principalmente nos países pobres e nos emergentes. Triar melhor, e mais precocemente os pacientes para realizar o DXA, é uma estratégia fundamental no combate a essa enfermidade. A radiografia panorâmica vem sendo utilizada na rotina do atendimento odontológico no mundo todo, e tem sido empregada como um método de triagem eficiente de pacientes com baixa densidade mineral óssea. O objetivo deste estudo foi analisar as paredes corticais do canal da mandíbula para a avaliação de possíveis alterações causadas pela osteopenia /osteoporose, na expectativa de indicar ou não a correlação entre a qualidade óssea mandibular e a qualidade óssea sistêmica. A amostra constituiu-se por 52 mulheres, com idade superior a 45 anos (56.4 ± 8.4 anos) divididas em três grupos de acordo com o exame de DXA: Grupo N (n= 26) normal nos três sítios (antebraço, quadril e coluna); Grupo E (n= 18) com osteopenia nos três sítios e Grupo O (n= 8) com osteoporose nos três sítios. Os resultados demonstraram que houve diferenças significativas na quantidade relativa de pixels pretos na região de ramo (R) do canal da mandíbula (p < 0.05) entre as médias verdadeiras quando comparada entre os grupos da amostra. Nas regiões do canal da mandíbula próximo ao forame mentual (FM) e no ângulo (A) e na análise da quantidade de fragmentos os testes estatísticos não evidenciaram a existência de diferenças significativas, apesar dos valores relativos apontarem uma tendência à maior reabsorção das paredes no grupo O e E em relação ao Grupo N. Concluiu-se que a análise das corticais do canal da mandíbula por meio da quantidade de pixels pretos pode ser um instrumento útil ao cirurgião-dentista na avaliação de baixa densidade mineral óssea. / Osteoporosis is a worldwide epidemic, expresses high morbidity and mortality, resulting also in high social costs. The bone densitometry by dual-energy X-ray absorptiometry (DXA) is the gold standard test for diagnosing the disease. However, its high cost and viability are restricted, especially in poor countries and emerging. Screening better and earlier patients to perform DXA, is a key strategy in combating this disease. Panoramic radiography has been used in routine dental care around the world, and has been employed as an efficient method of screening patients with low bone mineral density. The aim of this study was to analyze the cortical walls of the mandibular canal to evaluate possible changes caused by osteopenia / osteoporosis, hoping to indicate or not the correlation between mandibular bone quality and systemic. 52 women were included aged over 45 years (56.4 ± 8.4 years) were divided into three groups according to the DXA exam: Group N (n = 26) normal in three sites (forearm, hip and spine), Group E (n = 18) with osteopenia at the three sites and Group O (n = 8) with osteoporosis in the three sites. Significant differences were found between relative amount of black pixels in the region of the branch (R) of the mandibular canal (p <0.05) and the mean true when compared among groups of samples. In regions of the mandibular canal near the mental foramen (MF), angle (A) and analysis of the amount of fragments statistical tests did not show the significant differences, despite the figures suggest a trend to higher absorption in the walls the E group and to the detriment of group N. It was concluded that the analysis of the cortical the mandibular canal by the number of black pixels may be a useful to the dentist in the evaluation of low bone mineral density.

Para testar a hipótese de que a desmineralização in situ das superfícies de contato enxerto-leito, e a forma como o enxerto é estabilizado ao leito, podem influenciar os mecanismos envolvidos na consolidação do enxerto, fragmentos ósseos de 10 mm de diâmetro foram removidos das metáfises proximais tibiais de 36 coelhos (Oryctolagus Cuniculus) e transplantados para uma área adjacente. Na tíbia esquerda dos animais, as superfícies de contato do enxerto e do leito hospedeiro foram desmineralizadas com ácido cítrico pH 1,0 por 3 minutos antes dos enxertos serem fixados ao leito. Na tíbia direita, o transplante do bloco ósseo não foi precedido de desmineralização. Metade dos enxertos foi imobilizada sobre o leito pela superposição de uma membrana não reabsorvível de politetrafluoretileno colada com cianoacrilato ao leito à distância da interface enxerto-leito. A outra metade dos enxertos foi fixada por um parafuso de titânio no centro do enxerto. Assim, foram formados 4 grupos de estudo: membrana (M), membrana + ácido (MA), parafuso (P) e parafuso + ácido (PA). Três animais de cada grupo forneceram espécimes para análise microscópica quantitativa e qualitativa aos 15, 30 e 45 dias de pós-operatório. A análise qualitativa demonstrou que não houve formação óssea na interface em nenhum espécime aos 15 dias e que nos demais períodos, em todos os grupos, a quantidade de tecido ósseo neoformado na interface e seu estágio de maturação aumentaram com o tempo. Ambos os métodos de fixação empregados foram eficientes em manter os enxertos em posição, porém a membrana promoveu menor reabsorção da estrutura do enxerto. A análise quantitativa computadorizada revelou que, aos 30 dias, os grupos MA e PA apresentaram maior área de formação óssea na interface (71,34 ± 12,03%; 56,74 ± 2,15% respectivamente) em relação aos grupos M e P (51,75 ± 11,02%; 43,95 ± 4,05% respectivamente) e superfícies de consolidação óssea mais extensas (93,41 ± 5,95%; 93,73 ± 4,96% respectivamente) do que os grupos sem tratamento ácido (73,49 ± 7,7%; 73,77 ± 11,77% respectivamente para M e P), sendo essas diferenças estatisticamente significantes (p<0,05). Aos 45 dias de pós-operatório, os grupos MA e PA (71,18 ± 8,9%; 58,97 ± 3,97% respectivamente) apresentaram resultados superiores aos grupos M e P (59,78 ± 11,28%; 46,08 ± 3,53% respectivamente) em relação à área de neoformação óssea na interface, porém essa diferença não foi significativa. Concluiu-se que a desmineralização ácida das superfícies contactantes nos enxertos ósseos autógenos em bloco na tíbia de coelhos promoveu a osteogênese na interface enxerto-leito e acelerou a consolidação dos enxertos. Além disso, quando o tratamento ácido foi associado ao uso de membrana como método de fixação, a consolidação e grau de reabsorção óssea foram otimizados. / In order to test the hypothesis that the demineralization \"in situ\" of contacting surfaces of bone graft/bone bed and the fixation method used for graft stabilization can influence the mechanisms involved in the consolidation of the graft, bone fragments of 10 mm in diameter were removed from the proximal tibial metaphysis of thirty-six male rabbits (Oryctolagus Cuniculus) and transplanted to an adjacent area. In the left tibia of the animals, the contacting surfaces of the graft and host bed were demineralized with citric acid pH 1.0 for 3 minutes before the grafts were fixed to the receptor bed. In the right tibia, the bone block transplantation was not preceded by demineralization. Half of the grafts were immobilized on the bone bed by a nonresorbable polytetrafluoroethylene membrane glued with cyanoacrylate adhesive to the host bed distant from the bone graft-bone bed interface. The other half of the grafts were fixed by a titanium screw in the center of the graft. Thus, four groups were formed: membrane (M), membrane + acid (MA), screw (P) and screw + acid (PA). Three animals from each group provided specimens for quantitative and qualitative microscopic analysis at 15, 30 and 45 days postoperatively. Qualitative analysis showed no significant bone formation at the interface in any specimen of the groups at 15 days and on the other periods in all groups, the amount of newly formed bone at the interface as well as the stage of bone maturation increased with time. Both fixation methods were effective in maintaining the graft in position, but the membrane resulted in less resorption of the graft. Quantitative analysis, performed by means of a computer program for image analysis, showed that at day 30, groups MA and PA, showed greater area of bone formation at the interface (71.34 ± 12.03%; 56.74 ± 2 15%) than groups M and P (51.75 ± 11.02%, 43.95 ± 4.05%) and more osseointegrated bone surfaces (93.41 ± 5.95%, 93.73 ± 4.96%) than those without acid treatment (73.49 ± 7.7%, 73.77 ± 11.77%), and these differences were statistically significant. At 45 days postoperatively MA and PA groups (71.18 ± 8.9%, 58.97 ± 3.97%) showed better results than the M and P groups (59.78 ± 11.28%, 46 , 08 ± 3.53%) compared to the area of new bone formation at the interface and osseointegrated surfaces, but these differences were not significant. It was concluded that the acid demineralization of contacting surfaces in autogenous onlay bone grafts in the tibia of rabbits promotes osteogenesis in bone graft-host bed interface and accelerates the consolidation of the grafts. Furthermore, the association of this surface treatment to the use of membrane/cyanoacrylate fixation method, optimizes the results regarding consolidation and degree of bone graft resorption.