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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.
51

Suppression of osteoblast activity by disuse is prevented by low magnitude mechanical loading through a bone morphogenic protein-dependent Mechanism

Patel, Mamta Jashvantlal 15 January 2008 (has links)
Musculoskeletal pathologies associated with decreased bone mass, including osteoporosis and disuse-induced bone loss, affect millions of Americans annually. Many pharmaceutical treatments have slowed osteoporosis, but there is still no countermeasure for bone loss observed in astronauts. Additionally, high magnitude and low frequency impact has been recognized to increase bone and muscle mass under normal but not microgravity conditions. However, a low magnitude and high frequency (LMHF) mechanical load experienced in activities such as postural control has also been shown to be anabolic to bone. While several clinical trials have demonstrated that the LMHF mechanical loading normalizes bone loss in vivo, the target tissues and cells of the mechanical load and underlying mechanisms mediating the responses are unknown. As such, the objectives of this project are to analyze cellular and molecular changes induced in osteoblasts by LMHF loading and to investigate the utility of a LMHF mechanical load in mitigating microgravity-induced bone loss. The central hypothesis of the project is that simulated microgravity or disuse conditions induce bone loss by inhibiting expression of genes critical in regulating bone formation, osteoblast differentiation, and subsequent mineralization while a LMHF mechanical load prevents these effects. To test this hypothesis, we developed an in vitro disuse system using the Random Positioning Machine (RPM). For the first time, we reported systemic gene expression studies in 2T3 preosteoblasts using the RPM disuse system showing that 140 genes were altered by RPM exposure with over two-fold statistically significant changes. Moreover, we also utilized an independent simulator called the Rotating Wall Vessel (RWV) to partially validate the in vitro disuse systems and to confine the list of genes to those most critical in regulating bone formation. After comparative studies, we constricted the list to 15 commonly changed genes, three of which were not only decreased with disuse but also increased with mechanical loading in vivo. Furthermore, we employed the RPM disuse system to evaluate the mechanism by which a LMHF load mitigates bone loss. Exposure of osteoblasts to the RPM decreased both ALP activity and mineralization even in the presence of bone morphogenic protein 4 (BMP4), and the LMHF mechanical loading prevented the RPM-induced decrease in both markers. Mineralization induced by LMHF mechanical loading was enhanced by treatment with BMP4 and blocked by the BMP antagonist noggin, suggesting a role for BMPs in this response. In addition, LMHF mechanical loading rescued the RPM-induced decrease in gene expression of ALP, runx2, osteomodulin, parathyroid hormone receptor 1, and osteoglycin. These findings show that osteoblasts directly respond to LMHF mechanical loading, potentially leading to normalization or prevention of bone loss caused by disuse or microgravity conditions. The mechanosensitive genes identified here provide potential targets for pharmaceutical treatments that may be used in combination with LMHF mechanical loading to better treat osteoporosis, disuse-induced bone loss, or microgravity-induced bone loss.
52

Long chain polyunsaturated fatty acids and their possible interaction with phytoestrogens : impact on bone and bone cell function in vivo and in vitro : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University, Palmerston North, New Zealand

Poulsen, Raewyn Carol January 2007 (has links)
Inflammation is a major contributor to postmenopausal bone loss. Various long chain polyunsaturated fatty acids (LCPUFAs), particularly those of the n-3 family, are known to have anti-inflammatory activity and may have a role in minimising postmenopausal bone loss. The objectives of this thesis were to determine whether some LCPUFAs have greater bone-protective effects than others; to identify some of the mechanisms of action of LCPUFAs in bone and to explore the possibility that combined treatment with LCPUFAs and phytoestrogens offers greater bone-protective effects than either treatment alone. Using the ovariectomised rat model for postmenopausal bone loss, the relative effectiveness of eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and gamma-linolenic acid (GLA, 18:3n-6) in minimising bone loss post-ovariectomy was investigated. GLA exacerbated bone loss post ovariectomy in rats. In vitro, treatment of MC3T3-E1/4 osteoblast-like cells with GLA resulted in greater membrane-bound RANKL expression suggesting a possible stimulatory effect of GLA on osteoclastogenesis and osteoclast activity. EPA had no effect on overall bone mass in vivo. DHA significantly ameliorated ovariectomy-induced bone loss possibly by increasing plasma IGF-1 concentration, modulating vitamin D metabolism and, as observed in a second study, by increasing the concentration of gamma-carboxylated osteocalcin. In vitro both EPA and DHA reduced the prostaglandin E2 (PGE2)-induced increase in membrane-bound RANKL expression in MC3T3-E1/4 osteoblast-like cells. However as RANKL-independent pathways are believed to be largely responsible for the ovariectomy-induced increase in osteoclastogenesis in vivo, inhibition of RANKL expression may not significantly contribute to the prevention of ovariectomy-induced bone loss. In a second study in ovariectomised rats, combined treatment with DHA and 17β-oestradiol was associated with significantly higher femur bone mineral content than either treatment alone. However, no beneficial effects of combined treatment with DHA and either of the phytoestrogens genistein or daidzein, on bone mass were apparent. In vitro, co-treatment of TNF-α - exposed MC3T3-E1/4 cells with DHA and 17β-oestradiol was associated with a higher cell number compared to either treatment alone indicating a protective effect of combined treatment against the cytotoxic and/or anti-proliferative effects of TNF-α. In contrast, combined treatment of MC3T3-E1/4 cells with DHA and genistein, but not daidzein, was associated with significantly lower cell number than either treatment alone. As genistein, but not daidzein, is a tyrosine kinase inhibitor, this may indicate that DHA requires tyrosine kinase activity for its protective effect on cell number in TNF-α - exposed osteoblasts. Whether DHA itself is bioactive in bone cells or whether lipid mediators formed from DHA are responsible for the observed bone-protective effects is unknown. Using lipid mediator lipidomic analysis, the presence of DHA-derived lipid mediators in bone marrow in quantities known to be physiologically significant in other tissues was confirmed. Further research into the effects of these lipid mediators in bone and confirmation of the mechanisms of action of DHA in bone cells is required. This thesis demonstrates that consumption of DHA provides some protection against ovariectomy-induced bone loss in vivo and mitigates the effects of inflammation on RANKL signalling and osteoblast cell number in vitro. The bone-protective effects of DHA are complemented by co-treatment with 17β-oestradiol but may be inhibited by co-treatment with the phytoestrogens daidzein or genistein.
53

Regenerative matrices for oriented bone growth in craniofacial and dental repair /

Patterson, Jennifer. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 176-207).
54

Influência de drogas quimioterápicas na evolução da periodontite experimental em ratos /

Novaes, Vivian Cristina Noronha. January 2017 (has links)
Orientador: Juliano Milanezi de Almeida / Coorientador: Valdir Gouveia Garcia / Banca: Edilson Ervolino / Banca: Letícia Helena Theodoro / Banca: Erivan Clementino Gualberto / Banca: Estevam Augusto Bonfante / Resumo: Objetivo: Este estudo avaliou comparativamente a influência dos quimioterápicos 5-fluotouracil (5-FU) e Cisplanina (CIS) para tratamento de câncer no periodonto saudável, sobre a evolução da periodontite experimental (PE) e as funções hepáticas e renais de ratos portadores de PE submetidos ao tratamento com os quimioterápicos 5-FU ou CIS. Materiais e Métodos: foram utilizado 90 ratos machos distribuídos em 6 grupos. Grupo SPE-SS (n = 15): animais que receberam injeções de 0,5 ml de solução salina 0.9% (SS) sem indução da PE (grupo Sham). Grupo PE-SS (n = 15): animais que receberam injeções s de 0,5 ml de SS e indução da PE após a primeira injeção. Grupo SPE-5FU (n=15): animais que receberam injeções de 5-Fluorouracil (5- FU) sem indução da PE. Grupo PE-5FU (n = 15): animais que receberam injeções de 5- FU e indução da PE após a primeira injeção. Grupo SPE-CIS (n = 15): animais que receberam injeções Cisplatinas (CIS) sem indução da PE. Grupo PE-CIS (n = 15): animais que receberam injeções de CIS e indução da PE após a primeira injeção. Para indução da PE foi adaptado um fio de algodão número 24 ao redor dos primeiros molares inferiores direito e esquerdo. Decorridos 07, 15 e 30 dias após a primeira injeção intraperitoneal (SS ou quimioterápicos) os animais foram eutanaziados. Foi realizada coleta sanguínea para análises hematológia e bioquímicas de aspartato aminotransferase (AST), alamina aminotransferase (ALT), creatinina e uréia previamente as injeções e aos 07 e 30 dias, ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objective: This study evaluated the influence of chemotherapy with 5-fluorotouracil (5- FU) and Cisplanin (CIS) for the treatment of cancer in healthy periodontium, on the evolution of experimental periodontitis (EP), and liver and kidney function of rats with EP treated with chemotherapeutic agents. Materials and Methods: 90 male rats were distributed in 6 groups. Group SPE-SS (n = 15): animals that received injections of 0.5 ml of 0.9% saline solution (SS) without PE induction (Sham group). Group PE-SS (n = 15): animals that received injections s of 0.5 ml of SS and induction of PE after the first injection. Group SPE-5FU (n = 15): animals receiving injections of 5-Fluorouracil (5- FU) without induction of PE. Group PE-5FU (n = 15): animals receiving injections of 5- FU and induction of PE after the first injection. SPE-CIS group (n = 15): animals that received Cisplatin injections (CIS) without PE induction. PE-CIS group (n = 15): animals that received CIS injections and PE induction after the first injection. For EP induction a cotton thread number 24 was fitted around the first right and left lower first molars. After 07, 15 and 30 days after the first intraperitoneal injection (SS or chemotherapeutic) the animals were euthanized. Blood samples were collected for hematological and biochemical analyzes of AST, ALT, creatinine and urea before injections and at 07 and 30 days. The mandibles containing the mandibular first molars were collected and processed according to the proposed analyzes. For the photometric analysis, alveolar bone loss (ABL) around the lower first molar was evaluated. For the analysis of computerized microtomography (μCT) the percentage of bone tissue volume (PBTV) in the furcation region was evaluated. The contralateral hemimandibula were used for histomorphometric and immunohistochemical analyzes in the furcation region... / Doutor
55

Optimized Kava compound treatment reduced porphyromonas gingivalis-induced alveolar bone loss

Alshammari, Abdulsalam Khulaif 25 October 2017 (has links)
BACKGROUND: The aim of this study was to assess the effects of a modified Kavain-derived compound, Kava-241, on periodontal destruction in a periodontitis-induced murine model. METHODS: The study involved 49 mice divided into three groups: control, diseased, and treatment. Diseased mice were infected with P. gingivalis via oral gavage over a 15-day period to mimic periodontal infection. Treated mice received Kava-241 treatment after disease induction over the same period. Bone loss and inflammatory cell activity was assessed by a morphometric analysis of the left mouse maxillae and a histomorphometric analysis of TRAP and H&E stained tissue sections of the right mouse maxillae. RESULTS: Infected group showed significantly increased alveolar bone loss and inflammatory cells throughout the experimental period in comparison to the untreated control groups. The Infected mice that received Kava-241 showed a significant decrease in inflammatory cell activity in periodontal connective tissues as compared to mice that did not receive any treatment. In periodontal connective tissues, treated mice showed significant decreases of 61.9% and 41.6% of polymorphonucleocyte and monocyte cell counts, respectively, compared to untreated mice. Furthermore, the mice that received treatment post-infection showed a statistically significant decrease in alveolar bone loss. Histomorphometric analysis demonstrated 72.7% and 37.0% reductions of epithelial down-growth and bone loss respectively. Morphometric analysis demonstrated a 46.7% reduction of bone loss in treated mice compared to controls. CONCLUSION: Our results demonstrate modification of Kava could yield a more effective and safer therapeutic compound in the treatment of periodontal inflammation and bone loss.
56

Avaliação do efeito do álcool em baixas concentrações na perda óssea alveolar em ratos wistar

Liberman, Diego Nique January 2009 (has links)
A relação entre o álcool e as doenças periodontais destrutivas tem sido avaliada em humanos através de estudos transversais e longitudinais na última década. As investigações apontam para resultados conflitantes sobre a influência do consumo de bebidas alcoólicas na progressão da periodontite. Em quatro estudos recentes realizados em ratos Wistar, o consumo de álcool com concentrações entre 10% e 30% esteve associado a uma maior perda óssea alveolar. Nestes estudos, os métodos de avaliação da perda óssea alveolar em estudos de modelo animal tem sido realizados de formas distintas, impedindo uma comparação direta em investigações que utilizaram diferentes concentrações de álcool. Contudo, a literatura tem correlacionado o consumo de concentrações moderadas de bebidas alcoólicas com uma melhora no sistema imunológico e uma redução em marcadores inflamatórios sistêmicos, reduzindo a ocorrência de eventos cardiovasculares e aterosclerose. O mecanismo de atuação do álcool nestes parâmetros parece ser ambíguo e dependente da dose, do padrão de consumo e de características individuais variáveis. Os resultados conflitantes sobre a relação entre consumo de bebidas alcoólicas e doença periodontal podem sugerir esse padrão bifásico do álcool. Não existem estudos em modelo animal que avaliaram o impacto da administração de concentrações menores de álcool sobre a perda óssea alveolar. A discussão acerca de metodologias adequadas para estudos em animais e interpretação dos resultados encontra-se limitada em poucos estudos. A presente tese propôs-se a avaliar o impacto do consumo de álcool numa concentração de 5% na destruição periodontal em um modelo de periodontite induzida por ligaduras em ratos Wistar. Uma comparação entre dois métodos distintos para a quantificação da perda óssea alveolar também foi realizada. Através de uma avaliação morfométrica, tanto linear quanto de área, verificou-se que os ratos que receberam etanol em uma concentração de 5% apresentaram uma menor perda óssea do que os ratos do grupo controle em dentes que não receberam ligadura (0.32±0.07 e 0.37±0.07 respectivamente;p=0.04). Apesar da menor perda óssea apresentada pelos ratos do grupo teste também nos dentes que haviam recebido ligadura, tais diferenças não foram estatisticamente significantes (0.78±0.14 e 0.84±0.18 respectivamente;p=0.14). Um valor de Correlação de Pearson de 0.98 foi encontrado estre os métodos de avalição de perda óssea alveolar lineares e de área, indicando de uma correlação quase perfeita.Sendo assim, ambos os métodos revelaram eficazes na detecção de alterações na crista óssea alveolar.Os resultados do presente estudo revelam que o consumo de álcool em concentrações moderadas (5%) pode inibir a perda óssea alveolar em ratos Wistar. / The relationship between alcohol and periodontal disease have been evaluated in humans throughout cross-sectional and longitudinal studies in the last decade. The investigations have led to conflicting results about the influence of alcohol drinking on periodontitis progression. In four studies with Wistar rats, alcohol consumption in concentrations ranging between 10% to 30% was associated with greater alveolar bone loss. In these studies,different methods of bone loss evaluation have been used in animal model studies and it turns difficult to make a direct comparison between investigations that utilized different alcohol concentrations. However, the literature has associated moderate alcohol consumption with improvement in immunological status and reduction in inflammatory markers, reducing cardiovascular events and atherosclerosis. The mechanisms by which alcohol influences these parameters seems to be ambiguous and dependent of dose, pattern of consumption and individual characteristics. The conflicting results between beverage consumption and periodontal disease may suggest the biphasic pattern of alcohol. There aren’t studies in animal models that evaluated the impact of low alcohol concentrations on alveolar bone loss. Discussion about methodological issues and results interpretation in relation to studies in animals are restricted to few studies. The aim of the present thesis was to evaluate the impact of alcohol consumption in a concentration of 5% on periodontal breakdown in a ligature periodontitis-induced model. Also, a comparison between two distinct methods for bone loss assessment was evaluated. Linear and area morphometric evaluation revealed that rats receiving ethanol 5% presented less alveolar bone loss than rats in control group in unligated teeth (0.32±0.07 and 0.37±0.07 respectively;p=0.04). Despite the fact that rats in test group presented less alveolar bone loss even in ligated teeth when compared to controls,differences were no statistically significantly (0.78±0.14 and 0.84±0.18 respectively;p=0.14).A value of 0.98 were found in Pearson’s Correlation between linear and area morphometric methods of evaluating alveolar bone loss indicating an almost perfect correlation. Both methods were reliable for detecting alterations in alveolar bone crest. The results of the present study revealed that alcohol consumption in moderate concentrations (5%) may inhibit alveolar bone loss in Wistar rats.
57

Avaliação radiográfica longitudinal da altura e aspecto da crista óssea alveolar em molares decíduos

Vizzotto, Mariana Boessio January 2009 (has links)
Este estudo teve como objetivo analisar, longitudinalmente, a distância entre a junção cemento-esmalte (JCE) - crista óssea alveolar (COA) e o aspecto da COA em radiografias interproximais de molares decíduos. As radiografias foram digitalizadas e separadas de acordo com as variáveis: grupo etário, momento da avaliação (primeiro e segundo momento), característica radiográfica da superfície proximal (hígida→hígida; hígida→não-hígida; nãohígida→ não-hígida), dente e sistema de atendimento. As mensurações da distância entre a JCE-COA foram realizadas na distal do primeiro molar e/ou na mesial do segundo molar inferior no programa Image Tool. O aspecto radiográfico da COA foi classificado em escores e para sua inspeção foi realizado exame visual da crista na sua totalidade (região 74/75 e 84/85). Como resultados da distância JCE-COA, pôde-se constatar que houve interação entre as seguintes variáveis: avaliação-grupo etário, grupo etáriodente, avaliação-condição radiográfica da superfície proximal e grupo etáriocondição radiográfica da superfície proximal. Observou-se que a distância da JCE-COA aumentou significativamente com o evoluir da idade, principalmente no primeiro molar inferior decíduo. Ainda, houve aumento significativo das médias quando comparado o grupo de superfícies hígidas→hígidas com o de não-hígidas→não-hígidas. Em relação ao aspecto radiográfico da COA, não se obteve associação deste com a condição radiográfica da superfície proximal, bem como com o grupo etário. Desta forma, pode-se concluir que o tempo é um fator relevante para o aumento da distância da JCE-COA e que a existência de superfícies não-hígidas podem representar indicativo de risco à perda óssea alveolar. / The present study is a longitudinal radiographic assessment of the distance between the cemento-enamel junction (CEJ) - alveolar bone crest (ABC) and the aspect of ABC in bitewings of deciduous molar. Radiographs were digitized and divided into age groups, moment of evaluation (first and second), radiographic proximal surface condition (sound→sound; sound→unsound; unsound→unsound), tooth and form of service. The CEJ-ABC distances were measured on the distal site of the first deciduous molar and/or the mesial site of the second lower deciduous molar, using the Image Tool software. For the ABC analysis, the data was regrouped in regions (74/75 and 84/85) and a qualitative assessment by visual inspection was conducted. The results revealed interactions between the following variables: evaluation-age, age-tooth, evaluation-proximal surface condition, and age-proximal surface condition. It has been detected that CEJ-ABC distances have significantly increased with time, particularly in terms of assessment of primary lower first molars. Yet, this increase is greater in unsound when compared to sound surfaces. No relationship was observed between crest score and age groups, as well with the condition of the proximal surface. Therefore, this study suggests that time is a relevant factor in terms of increasing of CEJ-ABC mean distances and that the presence of unsound surfaces might be a sign of risk of alveolar bone loss.
58

Estudo comparativo de perda e reparação óssea alveolar em camundongos submetidos ao deslocamento mucoperiostal expostos e não expostos à radiação X

Lermen, Cláudio Afonso January 2007 (has links)
Esta pesquisa teve como objetivo estudar o efeito da radiação X, em baixas doses, nos processos de perda e reparação óssea alveolar em camundongos submetidos à cirurgia de retalho mucoperiostal. O processo de perda óssea alveolar é um fenômeno comum em todos os indivíduos, entretanto, sabe-se que o descolamento da mucosa nesta região estimula tal fenômeno. Sabendo dos efeitos biológicos da radiação X sobre os tecidos, procurou-se analisar a possível interferência de ação da mesma como agente adicional a este processo. Foram utilizados 72 camundongos CF 1 Mus Domesticus divididos em grupo teste (expostos à quatro doses semanais de 0,002C/Kg de radiação) e controle (não expostos à radiação). Os resultados mostraram, segundo análises estatísticas, utilizando o teste Kruskal Wallis e teste U de Mann- Whitney, que não houve diferença significativa, considerando p= 0,05, em relação a perda e reparação óssea alveolar entre o grupo teste e controle. Pôde-se concluir que dose de radiação compatível com exames de investigação por imagem, por um período de quatro semanas, não altera os padrões de reabsorção e reparação óssea alveolar em camundongos submetidos à cirurgia de retalho mucoperiostal. / This research aims to study the effects of x-radiation, in low doses, to the alveolar bone loss and repair processes in mice submitted to chirurgical mucoperistal flap. Alveolar bone loss is common to all individuals, but it is known that the displacement of the mucosa stimulates the phenomenon. In order to analyze x-radiation as an additional agent to this process of loss and repair, 72 CF 1 Mus Domesticus mice were divided into experimental group (exposed to radiation) and test group (not exposed to radiation) at a dose of 0,002C/Kg. The results showed no significant difference in alveolar bone loss and repair comparing the experimental and the test groups, considering p = 0,05. It is possible to conclude, therefore, that low doses of radiation during a period of four weeks does not alter the patterns of alveolar bone loss and repair in mice submitted to chirurgical mucoperistal flap.
59

Comparação dos tratamentos cirúrgico e não cirúrgico da perimplantite : análise clínica de 3 meses de um ensaio controlado randomizado

Costa, Ricardo dos Santos Araujo January 2017 (has links)
As doenças perimplantares (DPi) vêm sendo consideradas umas das maiores causas de perdas tardias de implantes dentários e nenhum dos tratamentos já propostos na literatura mostrou ser eficiente a ponto de se tornar a primeira escolha terapêutica. Considerando que a definição correta do tratamento depende invariavelmente do entendimento da etiopatogenia, ocorrências e diagnóstico das DPi, o objetivo da presente tese foi abordar as DPi através de uma ampla revisão dos seus conceitos e da apresentação de dados clínicos preliminares de três meses de um ensaio clínico controlado randomizado comparando os resultados dos tratamentos cirúrgico (C) e não cirúrgico (NC) da perimplantite. Foram incluídos implantes apresentando um ou mais sítios com profundidade de sondagem perimplantar (PSi) ≥ 5mm, com presença de sangramento submucoso (SSi) e/ou supuração e apresentando perda óssea radiográfica (PO) ≥ 3mm. O tratamento não cirúrgico incluiu debridamento mecânico com curetas de teflon e irrigação com solução salina, assim como o tratamento cirúrgico, com acesso por retalho mucoperiostal. Não foram utilizadas técnicas ressectivas e nem implantoplastia. A amostra foi randomizada de maneira estratificada para o hábito de fumar e a presente análise, de 3 meses de acompanhamento após o tratamento, se refere à amostra de 22 indivíduos (29 implantes), sendo 12 (17 implantes) no grupo C e 10 (12 implantes) no NC. No início do estudo não foram observadas diferenças significativas entre os grupos para variáveis demográficas e clínicas, exceto nas condições periodontais de índice de placa visível (IPV) (NC 22,3±14,08 / C 40,2±19,9) e sangramento a sondagem (NC 15,9±10,2 / C 31,8±15,9). Após três meses de tratamento, não houve desistências e, considerando o pior sítio do implante, os dois tratamentos reduziram significativamente as medidas de PSi (NC 5,8±0,27 para 4,3±0,55mm / C 5,9±0,29 para 5,0±0,28mm), os dois grupos apresentaram redução de SSi mas apenas no grupo C foi significativa, diminuindo de 100% para 53%. Não houve diferenças entre os níveis de perda de inserção clínica (PIi). Em uma análise multivariada para identificar os preditores de sucesso dos tratamentos, implantes com PSi basal > 6 mm apresentaram piores reduções de PSi, SSi e PIi, o histórico de periodontite dificultou a redução de PSi enquanto indivíduos com 5 ou mais implantes e reabilitados com próteses cimentadas apresentaram piores reduções de SSi. A taxa de sucesso dos tratamentos foi de 33% no grupo NC e 17% para o grupo C sem diferenças estatísticas. Conclui-se que ambos os tratamentos diminuíram sinais inflamatórios embora sem a demonstração de diferenças entre eles, e que preditores de risco ao sucesso do tratamento devem ser investigados. / Peri-implant diseases (PiD) have been considered the major causes of late loss of dental implants, and none of the proposed treatments in the literature demonstrated to be efficient to become the first therapeutic choice. Considering that the correct definition of treatment depends invariably on the understanding of the etiopathogenesis, occurrence and diagnosis of PiD, the aim of the present theses was to approach PiD through a 9oné99ono f its concepts and presenting preliminary clinical data of 3 months from a randomized controlled 9oné9 comparing surgical (ST) and non-surgical (NST) treatments of peri-implantitis. Implants presenting pocket depth (PD) ≥5mm and bleeding on probing (Bosshardt et al.) with radiographic bone loss ≥3 mm were included in the study. NST included mechanical debridement of the implant with Teflon curets and irrigation with saline solution, whereas ST included the debridement with mucoperiostal flap. Ressective surgery and implantoplasty were not applied. The sample was randomized by stratification according to smoking habit, and the present 3-months analysis after treatment referes to 22 individuals (29 implants), 12 (17 implants) in ST and 10 (12 implants) in the NST group. At basliene, no significant differences were observed between groups for demographic and clinical variables, except for periodontal conditions of teeth in regards to visible plaque (NST 22.3±14.08% and ST 40.2±19.9%) and BOP (NST 15.9±10.2% and ST 31.8±15.9%). After 3 months, there were no drop-outs and, considering the worst site of each implant, the two treatments reduced significantly mean PD (NST 5.8±0.27mm to 4.3±0.55mm and ST 5.9±0.29mm to 5.0±0.28mm. Both groups presented reduction in BOP, but only in the ST the reduction was significant, decreasing from 100% to 53%. There were no significant differences in clinical attachment loss after 3 months in the two groups. In a multivariable analysis to identify predictors of treatment success, implants with baseline PD >6mm presented lower reduction in PD over 3 months, as well as BOP and CAL. Previous history of periodontitis lead to higher PD and individuals with more then 5 implants and rehabilitated with bonded prosthesis had higher BOP over time. It can be concluded that both treatments reduced signs of inflammation although without significant differences between them, and baseline PD, number of implants, history of periodontitis and type of prosthetic fixation may be used as predictors of clinical outcomes of peri-implantitis treatment.
60

Efeito da cerveja sobre a doença periodontal induzida em ratos Wistar

Lourenci, Rafael Nascimento January 2017 (has links)
Evidências científicas têm apontado para inúmeros benefícios do consumo baixo/moderado de cerveja sobre a saúde dos indivíduos. Uma recente meta-análise com mais de 290.000 pessoas confirma a redução no risco de doenças cardiovasculares tanto para o vinho, como também para a cerveja, desde que consumido em doses baixas ou moderadas. A essas substâncias têm se atribuído efeitos antioxidantes e anti-inflamatórios, bem como ações na função vascular. Uma vez que as doenças periodontais apresentam uma natureza infecto-inflamatória, é lícito supor que o consumo de cerveja possa trazer benefícios para os tecidos periodontais. Para isso, o presente estudo abordou de forma prospectiva a ação da cerveja rica ou não em lúpulo sobre a perda óssea alveolar (POA) em modelo animal. Para isso, 64 ratos Wistar machos com 60 dias foram utilizados, divididos em 8 grupos experimentais. Após a eutanásia, o padrão de destruição óssea foi avaliada morfometricamente nos diferentes grupos experimentais Para os grupos submetidos a indução de POA por meio de ligadura, menores médias de destruição periodontal foram encontradas nos grupos expostos a cerveja, especialmente no que se refere a face palatina (p<0.01) e a média de POA no dente (p<0.01). Já na comparação entre os grupos que não sofreram indução de POA, a média de destruição periodontal foi estatisticamente menor somente na face palatina do grupo que recebeu cerveja com alto teor de lúpulo (p=0.01), quando comparada ao controle. Além disso, os ratos expostos a cerveja com alto teor de lúpulo apresentaram uma menor ocorrência de periodontite quando comparado aos demais grupos experimentais. Concluiu-se que o consumo de cerveja enriquecida com lúpulo parece trazer um efeito protetor sobre a POA induzida ou não por meio de ligadura em modelo animal. Além disso, a presença de lúpulo na cerveja pode ser benéfica na diminuição da ocorrência de periodontite experimental. / Effects of a low/moderate consumption of beer on human health has been reported. A recent meta-analysis confirms an important reduction in cardiovascular risk as much for wine as for a beer. Vascular improvement and antioxidant/anti-inflammatory effects should be related with this point. Periodontal diseases have an infectious-inflammatory nature. Therefore, beer consumption can benefits the periodontal health. For that, the aim of the present study was assessed the effect of beer enriched with hops on alveolar bone loss (ABL) in animal model. Sixty-four, 60-days-old, male Wistar rats in 8 experimental groups were stratified. After euthanasia, the ABL in the different experimental groups was evaluated. The groups that were not ligature-induced presented less ABL in beer group, especially regarding the palatal face (p <0.01) and mean of ABL in the tooth (p <0.01). In the comparison between groups that did not undergo ABL induction by ligature, mean periodontal destruction was statistically lower in the group that received beer with high hops concentration (p = 0.01) when compared to control group. In addition, the rats that were exposed to beer with high hops concentration to experienced less occurrence of periodontitis than others groups. It can be concluded that the consumption of beer enriched with hops seems protect to ABL induced or not by ligature. In addition, lower occurrence of experimental periodontitis was experienced in the enriched hops beer group.

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