This review addresses the different aspects of the use of titanium and its alloys in the production of dental implants, the most common causes of implant failures and the development of improved surfaces capable of stimulating osseointegration and guaranteeing the long-term success of dental implants. Titanium is the main material for the development of dental implants; despite this, different surface modifications are studied aiming to improve the osseointegration process. Nanoscale modifications and the bioactivation of surfaces with biological molecules can promote faster healing when compared to smooth surfaces. Recent studies have also pointed out that gradual changes in the implant, based on the microenvironment of insertion, are factors that may improve the integration of the implant with soft and bone tissues, preventing infections and osseointegration failures. In this context, the understanding that nanobiotechnological surface modifications in titanium dental implants improve the osseointegration process arouses interest in the development of new strategies, which is a highly relevant factor in the production of improved dental materials.

Titanium is usually used in the manufacturing of metal implants due to its biocompatibility and high resistance to corrosion. A structural and functional connection between the living bone and the surface of the implant, a process called osseointegration, is mandatory for avoiding prolonged healing, infections, and tissue loss. Therefore, osseointegration is crucial for the success of the implantation procedure. Osseointegration is a process mediated by bone-matrix progenitor cells’ proteins, named integrins. In this study, we used an in silico approach to assemble and test peptides that can be strategically used in sensitizing TiO₂ implants in order to improve osseointegration. To do so, we downloaded PDB structures of integrins α5β1, αvβ3, and αIIbβ3; their biological ligands; and low-cost proteins from the Protein Data Bank, and then we performed a primary (integrin-protein) docking analysis. Furthermore, we modeled complex peptides with the potential to bind to the TiO₂ surface on the implant, as well as integrins in the bone-matrix progenitor cells. Then we performed a secondary (integrin–peptide) docking analysis. The ten most promising integrin–peptide docking results were further verified by molecular dynamics (MD) simulations. We recognized 82 peptides with great potential to bind the integrins, and therefore to be used in coating TiO₂ implants. Among them, peptides 1 (GHTHYHAVRTQTTGR), 3 (RKLPDATGR), and 8 (GHTHYHAVRTQTLKA) showed the highest binding stability during the MD simulations. This bioinformatics approach saves time and more effectively directs in vitro studies.

Objetivo: Avaliar in vitro a atividade de Staphylococcus aureus e Candida albicans em bases de próteses convencionais à base de polimetilmetacrilato de metila com nanopartículas de prata incorporadas a sua composição. Métodos: Foi realizado um estudo experimental laboratorial com resinas acrílicas autopolimerizáveis comercialmente disponíveis, Vipi Flash/VIPI e JET/Clássico. Foram confeccionados 80 corpos de prova, divididos em 16 grupos (n = 5), referentes ao tipo de resina, tratamento (incorporação e imersão na solução de nanopartículas de prata) e microrganismo inoculado. As nanopartículas foram sintetizadas com ácido polimetacrílico, nitrato de prata e irradiadas com luz ultravioleta de baixa potência (~8W) por 6 horas, e as suas concentrações idealizadas pelo método de microdiluição em placas para determinação da concentração mínima inibitória frente aos microrganismos selecionados. Verificou-se ação bactericida e fungicida com concentração inicial de 25% e após fator de diluição 12,5%. Resultados: Houve dificuldade de incorporação das nanopartículas na resina acrílica, que pode decorrer da alteração da proporção 3:1 recomendada pelo fabricante ou pela redução ou inativação da ação da nanopartícula de prata pela interação com o polimetilmetacrilato. VIPI com inclusão de nanopartícula obteve menor aderência de biofilme de Candida albicans. Conclusão: A nanopartícula de prata mostrou-se eficaz na sua ação de controle de Candida albicans e Staphylococcus aureus no método de imersão, entretanto, a sua ação antimicrobiana foi comprometida após inclusão nas resinas acrílicas.

Silver nanoparticles (AgNPs) have received great attention because of their unique characteristics and applications from basic to applied sciences. Recently, studies have also shown applications as larvicides against Aedes aegypti larvae [1], which generates great interest in public health due to the annual outbreaks Zica virus in Brazil, being associated with the recent cases of infants born with microcephaly. We synthesized AgNP, using polymethacrylic acid (PMAA) as a stabilizing and reducing agent catalyzed by ultraviolet radiation. The synthesis is clean, quick and low cost and average size of 10nm. Their use as nanolarvicide against Aedes aegypti in laboratory and field simulation will be reported. To check efficiency as larvicide the AgNPs were performed pilot bioassays, in which 20 fourth-instar larvae were placed in 100 ml of water with small concentrations of AgNPs (0.02 to 1.1 ppm). It was observed the mortality of the larvae from 6h and maximum expression of 24h exposure. The values LC50 and CL90 are 0.027, 0.044 ppm, respectively were recorded after 24 hours of exposure [2]. For the simulated field test, the initial efficacy, estimated by larval mortality in the first 96 hours after application of the product, was performed using 50 young instar-L1/recipient (20 liters). It was observed 100% mortality of the larvae in L1-instar in 96h of exposure of the nanoparticles. The persistence of mortality of the larvae in the L1-instar was observed up to the present moment by five months of exposure of the nanoparticles. [1]N. Sap-Lam et al., “UV irradiation-induced silver nanoparticles as mosquito larvicides,” in Journal of Applied Sciences 10(23), pp. 3132–3136 (2010) [2]Carvalho et al.; "Exploiting silver nanoparticles with PMAA against aedes aegypti larvae development: potential larvicidal activity" In Colloidal Nanoparticles for Biomedical Applications XIII, SPIE, San Francisco, pp. 23 (2018)