Subgingival microbiota and immune response modulation of osseointegrable implants / Modulação da microbiota subgengival e resposta imune dos implantes osseointegráveis

ABSTRACT Osseointegrable dental implants are biomaterials made of titanium or other alloys mixed with titanium, which have high biocompatibility and allow osseointegration. However, this process can be modulated by changes in the complex mechanisms between microbiota, immune response and host. The present study aims to present how the immune system-microbiota-host interaction influences the osseointegration process of titanium dental implants and its alloys. A literature review was performed through electronic and manual searches in several databases, including PubMed, LILACS, Google Scholar, SciELO and Web of Science for articles published in the last 20 years in English and Portuguese. The formation of a temporary fibrin matrix on the implants surface after implantation implies the recruitment, adhesion and activity of immune cells at this site, with the release of pro-inflammatory molecules and recruitment of neutrophils. In the second moment, monocytes and macrophages (M1) are recruited, producing, in this step, reactive oxygen species. In the later stage of inflammation, macrophages (M2) help in tissue regeneration with expression of anti-inflammatory cytokines. In addition, the implants surface provides a site for microbial colonization mediated by salivary pellicle and topographical features. Thus, in symbiosis the modulation of the immune response will be favorable to osseointegration. However, the dysbiotic process exacerbates the inflammatory progression modulating the immune response influencing abnormal tissue healing or scar and fibrosis formation, compromising osseointegration. Different conditions of the subgingival microbiota will influence different immunological cascades, generating different cellular responses and positive or negative modulation of the osseointegration process.

RESUMO Os implantes dentários osseointegráveis são biomateriais constituídos de titânio ou outras ligas misturadas com titânio, as quais possuem alta biocompatibilidade e permitem a osseointegração. Esse processo pode ser modulado por alterações nos mecanismos complexos entre microbiota, resposta-imune e hospedeiro. O presente estudo busca apresentar como a interação sistema imune-microbiota-hospedeiro influenciam no processo de osseointegração proveniente de implantes dentários de titânio. Foi realizada uma revisão de literatura através de busca eletrônica e manual em diversas bases de dados, incluindo PubMed, LILACS, Google Acadêmico, SciELO e Web of Science para artigos publicados nos últimos 20 anos em inglês e português. A formação de uma matriz provisória de fibrina na superfície dos implantes após a implantação implica no recrutamento, adesão e atividade das células imunes, com a liberação de moléculas pró-inflamatórias e recrutamento de neutrófilos. No segundo momento, monócitos e macrófagos (M1) são recrutados, produzindo espécies reativas a oxigênio. Já no estágio posterior da inflamação, macrófagos (M2) ajudam na regeneração do tecido com expressão de citocinas anti-inflamatórias. Além disso, a superfície dos implantes oferece um local para colonização microbiana mediada pela película salivar e características topográficas. Assim, em simbiose a modulação da resposta imune vai ser favorável à osseointegração. Contudo, em estado de doença periodontal, o processo disbiótico exacerba a progressão inflamatória modulando a resposta imune influindo em um processo cicatricial comprometendo a osseointegração. Diferentes condições da microbiota subgengival vão influenciar em cascatas imunológicas diferentes gerando respostas celulares diferentes e modulação positiva ou negativa do processo de osseointegração.

The peri-implant ligament: a scoping review

The peri-implant ligament is formed from the interface of bone tissue, through the anchoring of proteins and the surface of the dental implant. In this sense, it is relevant to understand the extent to which this ligament is structured and biomimics the periodontal ligament functions. Aim: The goal of this scoping review is to present and analyze the peri-implant ligament composition and compare the extent to which this ligament is structured and biomimics the periodontal ligament functions. Methods: This scoping review was performed according to the Joanna Briggs Institute methodology for scoping reviews and following the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping review. Two independent researchers searched Pubmed, Cochrane, Embase, Virtual Health Library, Scielo, Scopus, Web of Science, Brazilian Bibliography of Dentistry, Latin American and Caribbean Literature in Health Sciences, Digital Library of Theses and Dissertations from the University of São Paulo and Portal Capes. Studies published in English, Portuguese and Spanish, over the last 21 years (2000-2021). Results: A total of 330 titles were identified and after applying inclusion and exclusion factors, 27 studies were included in this review. All proteins were identified regarding their tissue function and classified into 6 major protein groups. After that this new protein ligament was compared with the periodontal ligament regarding its function and composition. The main proteins associated with osseointegration, and thus, with the peri-implant ligament are recognized as belonging to the periodontal ligament. Conclusion: This scoping review results suggest evidence of the composition and function of the periimplant ligament. However, variations may still exist due to the existence of several modulants of the osseointegration process

Nutritional influences on oral infections: the oral microbiota modulation

Introduction: The oral microbiota has approximately 700 symbiotic microorganisms responsible for oral health homeostasis. However, changes in oral microbiota can generate dysbiotic processes that favor the worsening of infections such as caries and periodontal disease. These oral infections, in addition to systemic involvement, can compromise the teeth integrity as well as oral health. Thus, inadequate nutrition proves to be a risk factor influencing the prevention and treatment of these oral infections. Objective: This study aims to evidence the nutritional influence on the oral microbiota modulation affecting, in the longterm, the gut microbiota, highlighting the use of probiotics and prebiotics in the treatment of oral infections by a literature review. Synthesis of data : Supplements of certain nutrients and the intake of an adequate diet in macronutrients and micronutrients directly influence nutritional status and consequently in the maintenance of oral-systemic homeostasis. In addition, due to microbial multidrug resistance, therapies using probiotics and prebiotics have been adopted as aids to the treatment of oral infections. Conclusion: Personalized Dentistry must integrate multidisciplinary knowledge of attention for health care. This in addition to knowingwhen to refer and work together with a Nutritionist.

Introdução: A microbiota oral possui aproximadamente 700 microrganismos simbiontes responsáveis pela homeostase da saúde bucal. Contudo, alterações na microbiota oral podem gerar processos disbióticos que favorecem o agravamento de infecções como a cárie e a doença periodontal. Essas infecções orais, além do acometimento sistêmico, podem comprometer a integridade dos dentes e também da saúde bucal. Dessa forma, a alimentação inadequada mostra-se um fator de risco que influência na prevenção e no tratamento dessas infecções orais. Objetivo: Este estudo visa evidenciar a influência nutricional na modulação da microbiota oral afetando a longo prazo a microbiota intestinal, destacando o uso de probióticos e prebióticos no tratamento de infecções orais através de uma revisão de literatura. Síntese de dados: A suplementação de determinados nutrientes e a ingestão de uma dieta adequada em macronutrientes e micronutrientes influenciam diretamente no estado nutricional e consequentemente na manutenção da homeostase oral-sistêmica. Além disso, devido à multirresistência microbiana, terapias com probióticos e prebióticos têm sido adotadas como auxiliares no tratamento de infecções orais. Conclusão: A Odontologia Personalizada deve integrar conhecimentos multidisciplinares de atenção à saúde. Isso além de saber quando encaminhar e trabalhar junto com o Nutricionista.