TEDE Communidade:

Papel de Fusobacterium nucleatum e outras bactérias periodontopatogênicas na carcinogênese, progressão e prognóstico do câncer colorretal: Uma síntese das evidências

Fri, 06 Feb 2026 00:00:00 GMT

Título: Papel de Fusobacterium nucleatum e outras bactérias periodontopatogênicas na carcinogênese, progressão e prognóstico do câncer colorretal: Uma síntese das evidências Autor: LEITE, Hadda Lyzandra Austríaco Primeiro orientador: LOPES, Fernanda Ferreira Abstract: Growing evidence indicates that periodontopathogenic bacteria exert a relevant influence on the carcinogenesis, progression, and prognosis of colorectal cancer (CRC). Among these microorganisms, Fusobacterium nucleatum has been consistently identified in tumor tissues and associated with inflammatory, immunological, and molecular alterations that may impact disease evolution. This thesis aimed to critically synthesize the available evidence on the role of periodontopathogenic bacteria in CRC, integrating mechanistic experimental findings with prognostic evidence from observational studies in humans. The thesis was structured into two scientific articles. The first consisted of a systematic review with meta-analysis of observational studies, conducted according to the PECO strategy, assessing the association between the presence of periodontopathogenic bacteria and survival outcomes in patients with CRC. Searches were performed in PubMed/MEDLINE, Embase, Scopus, and Web of Science, covering the last ten years. Only cohort studies reporting adjusted risk estimates for prognostic outcomes, expressed as hazard ratios (HR), were included. The second article comprised a systematic review of experimental in vitro, in vivo, and organoid studies aimed at elucidating the cellular and molecular mechanisms activated by periodontopathogenic bacteria within the colorectal tumor microenvironment. In Article 1, five observational studies met the eligibility criteria, of which four were included in the quantitative synthesis. The meta-analysis demonstrated a significant association between the presence of periodontopathogenic bacteria and worse survival outcomes in CRC, with a pooled HR of 1.84 (95% CI 1.38–2.46). This association was particularly consistent for Fusobacterium nucleatum, with low heterogeneity across studies. In Article 2, experimental evidence demonstrated that Fusobacterium nucleatum, especially lineages adapted to the colorectal tumor niche, modulates key inflammatory and oncogenic pathways, including NF-κB, β-catenin, and epithelial–mesenchymal transition (EMT), while promoting immune evasion, tumor microenvironment remodeling, and therapeutic resistance through ferroptosis suppression. These mechanisms contribute to tumor progression, metastatic potential, and poorer clinical outcomes. Taken together, the findings of this thesis support the role of periodontopathogenic bacteria as active modulators of colorectal cancer progression and prognosis, highlighting Fusobacterium nucleatum as an emerging prognostic biomarker and potential therapeutic target. The evidence reinforces the importance of integrating microbiome research with inflammation and oncology and underscores the need for prospective studies incorporating microbiological, molecular, and clinical data to develop more personalized strategies for prevention, risk stratification, and treatment of CRC. Instituição: Universidade Federal do Maranhão Tipo do documento: Tese

DISTRIBUIÇÃO ESPAÇO-TEMPORAL DE ELEMENTOS DAS REDES DE ATENÇÃO À SAÚDE E MORBIMORTALIDADE POR CÂNCER DE BOCA: ESTUDO ECOLÓGICO DE BASE NACIONAL

Thu, 22 Jan 2026 00:00:00 GMT

Título: DISTRIBUIÇÃO ESPAÇO-TEMPORAL DE ELEMENTOS DAS REDES DE ATENÇÃO À SAÚDE E MORBIMORTALIDADE POR CÂNCER DE BOCA: ESTUDO ECOLÓGICO DE BASE NACIONAL Autor: BORGES, Marcio Vinicius Campos Primeiro orientador: THOMAZ, Erika Barbara Abreu Fonseca Abstract: Analysis of the spatiotemporal distribution of elements of healthcare networks and morbidity and mortality from oral cancer on a national basis, focusing on aspects of the Health System; Duration of Treatment and Diagnosis; in addition to technical aspects of Oral Neoplasia; such as Disease Staging. Instituição: Universidade Federal do Maranhão Tipo do documento: Tese; Trabalho sob Sigilo. Motivo: A tese foi feita a partir da criação de 2 artigos científicos e embora o 1º artigo já tenha sido publicado, o 2 º artigo necessita de sigilo para envio para publicação. Provável data de Liberação: SEM PRAZO.

EXPLORANDO CONEXÕES ENTRE ALTERAÇÕES ÓSSEAS DEGENERATIVAS E INFLAMATÓRIAS E AS PATOLOGIAS PULPO-PERIAPICAIS

Thu, 29 Jan 2026 00:00:00 GMT

Título: EXPLORANDO CONEXÕES ENTRE ALTERAÇÕES ÓSSEAS DEGENERATIVAS E INFLAMATÓRIAS E AS PATOLOGIAS PULPO-PERIAPICAIS Autor: SILVA, Ana Paula Nóbrega Caetano da Primeiro orientador: SOUZA, Soraia de Fátima Carvalho Abstract: Introduction: Pulpo-periapical pathologies are chronic inflammatory diseases with high global prevalence, mostly resulting from the progression of untreated dental caries. Beyond their local impact, these conditions contribute to the individual's systemic inflammatory burden. Conversely, systemic disorders affecting bone metabolism may modulate the host response to these oral infections. This dissertation investigated the connections between two classes of systemic bone alterations: one degenerative (osteoporosis) and the other inflammatory (rheumatic autoimmune diseases), and pulpo-periapical pathologies. The objectives were to assess the evidence regarding: 1) the association between osteoporosis and the occurrence of pulpo-periapical pathologies; and 2) the association between rheumatic autoimmune diseases and the occurrence of pulpo-periapical pathologies. Methods: This dissertation comprises two systematic reviews and meta-analyses, following the PRISMA 2020 recommendations. Comprehensive searches were conducted in MEDLINE/PubMed, Embase, Scopus, BVS-Bireme, Web of Science, SciELO, and Cochrane Library databases, as well as in the grey literature. Observational studies (cross-sectional, cohort, and case-control) comparing the occurrence of pulpo-periapical pathologies in individuals with osteoporosis (first study) or rheumatic autoimmune diseases (second study) versus healthy control groups were included in both studies. Data were extracted by independent reviewers. Risk of bias was assessed using the Joanna Briggs Institute (JBI) tool, and the certainty of evidence was evaluated using the GRADE system. Meta-analyses were conducted using random-effects models to calculate Odds Ratios (OR) with 95% Confidence Intervals (95% CI). Results: In the first study (Chapter II), the random-effects meta-analysis of six studies identified no significant association between osteoporosis and the presence of pulpo-periapical pathologies (unadjusted OR= 1.65; 95% CI: 0.80 to 3.41; I²=98.5%). The result remained insignificant in the adjusted analysis (OR= 1.96; 95% CI: 0.68 to 5.66). In the second study (Chapter III), the random-effects meta-analysis of thirteen studies demonstrated a positive and significant association between rheumatic autoimmune diseases and pulpo-periapical pathologies. This association was found in both the patient-level analysis (adjusted OR= 1.60; 95% CI: 1.20 to 2.12; I²=95.2%) and the tooth-level analysis (unadjusted OR= 1.74; 95% CI: 1.28 to 2.37; I²=69.4%). In both reviews, the certainty of evidence was classified as "Very Low" (GRADE), mainly due to the high risk of bias in primary studies, high heterogeneity, and imprecision of results. Conclusion: The findings of this dissertation regarding the investigated outcomes yielded contrasting results: in the first study (Chapter II), the systematic review and meta-analysis showed no association between osteoporosis (a degenerative condition) and pulpo-periapical pathologies; however, in the second study (Chapter III), a positive association was observed with rheumatic autoimmune diseases (inflammatory conditions). The biological plausibility of this result suggests the need for an integrated clinical approach for the prevention of pulpoperiapical pathologies in individuals with rheumatic autoimmune diseases. Furthermore, we suggest future longitudinal studies with greater methodological rigor to elucidate possible connections between osteoporosis and endodontic outcomes. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Avaliação clínica e laboratorial do uso de materiais bioativos para preservação de tecido desmineralizado

Fri, 06 Mar 2026 00:00:00 GMT

Título: Avaliação clínica e laboratorial do uso de materiais bioativos para preservação de tecido desmineralizado Autor: DINIZ, Ana Carolina Soares Primeiro orientador: FIRROZMAND, Leily Macedo Abstract: Bioactive materials are an interesting alternative to prevent demineralization and maintenance of dental tissue, since they are able to release remineralizing ions into the environment. The aim of Chapter I was to evaluate the influence of the association of bioactive materials (45S5 and Niobiophosphate -NbG) with resin-modified glass ionomer cement (CIV-MR) regarding the alkalinizing potential, release of fluoride ions, demineralized dentin microhardness and its antimicrobial effect. Methodology: Four experimental groups composed of: RC- Composite Resin; CIV-MR- Resin Modified Glass Ionomer Cement; 45S5- CIV-MR+10%45S5; NbG- CIV-MR+10%NbG were evaluated. The alkalinizing potential and fluoride release of the materials were evaluated at different times, and their effect on microhardness at different depths of dentin. For microhardness, dentin slabs were used, which were subjected to caries induction, performing treatment in one half of the slab and the other half remained as a control. The antimicrobial effect of the different experimental groups was evaluated by analyzing the surfaces of materials exposed to colonies of S. mutans UA159. The two-way, three-way ANOVA and T-tests and post-hoc tests were used for the different outcomes evaluated. Results: The alkalinizing potential and fluoride release was higher for 45S5 (p = 0.000) over 60 days. At a depth of 10μm, 45S5 and NbG showed the highest microhardness values (p <0.001). Regarding acidity of the biofilm, 45S5 presented the highest pH values, and a difference was observed between the different materials and times (p = 0.000). Conclusion: The 45S5 bioactive glass associated with the CIV-MR has greater alkalinizing potential and fluoride release, over time, increasing the microhardness of demineralized dentin, and decreasing the acidity of the biofilm. The objective of Chapter II was to present a pragmatic study that proposes the evaluation of the effectiveness of the association of 45S5 with resin-modified glass ionomer cement (CIV-MR) in retaining and preventing the progression of initial carious lesions in permanent molars. Methodology: A total of 36 patients, aged 8 to 14 years, with at least two permanent molars homologous with ICDAS (International Caries Detection and Assessment System) 3 or 4 will be selected to participate in the clinical study of the split-mouth type. The DMF-T (Decayed, Missed and Filled Teeth index), ICDAS, BOP (Bleeding on probing), and VPI (Visible Plaque Index) will be analyzed. The complementary radiographic exam will be performed to assess the dentin underlying lesion. The selected teeth will be randomly assigned into 2 groups: GIC-MR and GIC-MR + 45S5. Parameters such as retention, the clinical performance of materials, and caries evolution will be evaluated into the two studied groups. A calibrated evaluator will perform clinical, radiographic, and microscopic evaluations at 1, 6, and 12 months of follow-up. The results obtained will be evaluated using the Chi-square test. The intention to treat protocol will be followed. Conclusion: The application of the 45S5 association with the GIC-MR may be a promising alternative material for the prevention of the caries lesions evolution with enamel microcavities. In Chapter III, the objective was to evaluate the retention of resin-modified glass ionomer cement (CIV-MR) associated with 45S5 bioglass and its influence in preventing the progression of moderate caries lesions in permanent molars. Methodology: From a total of 1,161 patients, 31 patients were selected and sixty-two permanent homologous molars with moderate lesions of caries, from patients aged 8 to 14 years, were randomly treated with CIV-MR or CIV-MR associated with the 45S5 bioglass. The index of decayed, missing and filled teeth (DMFT), International Caries Detection and Assessment System (ICDAS), Bleeding on probing (BOP), and Visible Plaque Index (VPI) were recorded and initial radiographic examinations were performed. After 1 month, a clinical and radiographic examination was performed, and the retention and clinical quality of the applied material were assessed. The data were analyzed using the Chi-square test of independence (χ2 = 0.05). Results: After one month, there was a difference in the degree of retention of materials (p = 0.031), with total retention predominating in the CIV-MR group. The CIV-MR showed better clinical performance (anatomical shape, marginal adaptation, superficial texture and marginal discoloration) when compared to the CIV-MR + 45S5 (p <0.05). There was a significant reduction from ICDAS 3 and 4 to ICDAS 0 (fully sealed tooth) and 3 (p <0.05), with no significant difference between groups (p = 0.053). During this period, there was an increase in BOP and VPI. Radiographically, none of the groups showed progression of caries lesions. Conclusion: The materials CIV-MR and CIV-MR + 45S5 showed favorable results in controlling the evolution of caries disease, despite the fact that bioactive materials still need improvements to obtain better retention and quality of the material. Instituição: Universidade Federal do Maranhão Tipo do documento: Tese