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Made available in DSpace on 2022-05-01T10:19:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Implant-related infections at the early healing period are considered one of the main risk factors in implant failure. Designing coatings that control bacterial adhesion and have cell stimulatory behavior remains a challenging strategy for dental implants. Here, we used plasma electrolytic oxidation (PEO) to produce antimicrobial coatings on commercially pure titanium (cpTi) using bioactive elements (calcium and phosphorus) and different copper (Cu) sources: copper acetate (CuAc), copper sulfate (CuS), and copper oxide (CuO); coatings containing only Ca and P (CaP) served as controls. Cu sources drove differential physical and chemical surface features of PEO coatings, resulting in tailorable release kinetics with a sustained Cu ion release over 10 weeks. The antibacterial effects of Cu-containing coatings were roughness-dependent. CuAc coating exhibited optimal properties in terms of its hydrophilicity, pores density, and limited surface roughness, which provided the most robust antibacterial activity combined with appropriate responses of human primary stem cells and angiogenic cells. Our data indicate that Cu source selection largely determines the functionality of Cu-containing PEO coatings regarding their antibacterial efficacy and cytocompatibility. Department of Prosthodontics and Periodontology Piracicaba Dental School University of Campinas (UNICAMP) Faculdade de Ciências Odontológicas (FCO) Dental Research Division Guarulhos University Laboratory of Technological Plasmas Institute of Science and Technology São Paulo State University (UNESP) Regenerative Biomaterials Dentistry Radboudumc Laboratory of Technological Plasmas Institute of Science and Technology São Paulo State University (UNESP) CAPES: 001 FAPESP: 2017/01320-0 FAPESP: 2018/14117-0 CNPq: 304853/2018-60

PURPOSE To investigate the influence of nonthermal plasma (NTP) treatment on the tensile bond strength between heat-polymerized acrylic resin for ocular prostheses and silicone reliner, with and without the use of an adhesive primer. MATERIALS AND METHODS One-hundred and sixty-four acrylic resin specimens were fabricated and randomly distributed into four groups according to the type of surface treatment: Sofreliner Primer, NTP, Sofreliner Primer + NTP, and NTP + Sofreliner Primer. Two specimens interposed with relining material (Sofreliner) formed one test sample to perform the tensile bond strength tests, before (initial) and after storage (final) in saline solution (37°C, 90 days, n = 10). Surface characterization was performed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The failure type was classified as cohesive, adhesive, or mixed. The data were analyzed statistically using the two-way ANOVA and Tukey test, as well as the chi-squared test (α = 0.05), Bonferroni correction (α = 0.005), and Spearman correlation coefficient (α = 0.05). RESULTS The SEM and EDS analyses showed the presence of a thin, homogenous organic film in the groups treated with NTP. The NTP + Sofreliner Primer group presented the largest bond strength mean values in the initial period (p < 0.05). Sofreliner Primer and NTP + Sofreliner Primer groups presented the first and second largest tensile bond strength mean values in the final period (p < 0.05), respectively. NTP + Sofreliner Primer group also had the largest number of cohesive (70%, initial) and mixed (90%, final) failures. CONCLUSIONS The NTP treatment performed before the primer application enhanced the bond between the acrylic resin ocular prosthesis and the Sofreliner silicone-based reliner, even after 90 days of immersion in saline solution.

Made available in DSpace on 2020-12-12T02:36:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-04 Polymicrobial infections are one of the most common reasons for inflammation of surrounding tissues and failure of implanted biomaterials. Because microorganism adhesion is the first step for biofilm formation, physical-chemical modifications of biomaterials have been proposed to reduce the initial microbial attachment. Thus, the use of superhydrophobic coatings has emerged because of their anti-biofilm properties. However, these coatings on the titanium (Ti) surface have been developed mainly by dual-step surface modification techniques and have not been tested using polymicrobial biofilms. Therefore, we developed a one-step superhydrophobic coating on the Ti surface by using a low-pressure plasma technology to create a biocompatible coating that reduces polymicrobial biofilm adhesion and formation. The superhydrophobic coating on Ti was created by the glow discharge plasma using Ar, O2, and hexamethyldisiloxane gases, and after full physical, chemical, and biological characterizations, we evaluated its properties regarding oral biofilm inhibition. The newly developed coating presented an increased surface roughness and, consequently, superhydrophobicity (contact angle over 150°) and enhanced corrosion resistance (p < 0.05) of the Ti surface. Furthermore, proteomic analysis showed a unique pattern of protein adsorption on the superhydrophobic coating without drastically changing the biologic processes mediated by proteins. Additionally, superhydrophobic treatment did not present a cytotoxic effect on fibroblasts or reduction of proliferation; however, it significantly reduced (≈8-fold change) polymicrobial adhesion (bacterial and fungal) and biofilm formation in vitro. Interestingly, superhydrophobic coating shifted the microbiological profile of biofilms formed in situ in the oral cavity, reducing by up to ≈7 fold pathogens associated with the peri-implant disease. Thus, this new superhydrophobic coating developed by a one-step glow discharge plasma technique is a promising biocompatible strategy to drastically reduce microbial adhesion and biofilm formation on Ti-based biomedical implants. Department of Prosthodontics and Periodontology Piracicaba Dental School University of Campinas (UNICAMP), 901 Limeira Avenue Department of Oral Health and Diagnostic Sciences University of Connecticut Health Center, 263 Farmington Avenue Dental Research Division Guarulhos University, 88 Eng. Prestes Maia Street Laboratory of Technological Plasmas Institute of Science and Technology São Paulo State University (UNESP), 511 Três de Março Avenue Laboratory of Technological Plasmas Institute of Science and Technology São Paulo State University (UNESP), 511 Três de Março Avenue

Made available in DSpace on 2019-10-06T15:57:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Universidade Estadual Paulista This study developed an experimental quaternary titanium (Ti) alloy and evaluated its surface properties and electrochemical stability. The viability for a biofunctional surface treatment was also tested. Ti-35Nb-7Zr-5Ta (wt%) alloy was developed from pure metals. Commercially pure titanium (cpTi) and Ti-6Al-4V were used as controls. All groups had two surface conditions: untreated (machined surface) and modified by plasma electrolytic oxidation (PEO) (treated surface). The experimental alloy was successfully synthesized and exhibited β microstructure. PEO treatment created a porous surface with increased roughness, surface free energy, hardness and electrochemical stability (p < 0.05). For the machined surfaces, the Ti-Nb-Zr-Ta alloy presented the lowest hardness and elastic modulus (p < 0.05) and displayed greater polarization resistance relative to cpTi. Only PEO-treated cpTi and Ti-Al-V alloys exhibited anatase and rutile as crystalline structures. The β experimental Ti-Nb-Zr-Ta alloy seems to be a good alternative for the manufacture of dental implants, since it presents elastic modulus closer to that of bone, feasibility for surface treatment, electrochemical stability and absence of toxic elements. University of Campinas (UNICAMP) Piracicaba Dental School Department of Prosthodontics and Periodontology, Av. Limeira, 901 Institute of Biomaterials Tribocorrosion and Nanomedicine (IBTN) Faculdade de Ciências do Tocantins (FACIT), Av. José de Brito, 730 Centro Universitário Tocantinense Presidente Antônio Carlos (UNITPAC), Av. Filadélfia, 568 São Paulo State University (UNESP) Engineering College Laboratory of Technological Plasmas, Av. Três de Março, 511 Univ. Estadual Paulista (UNESP) Araraquara Dental School Department of Dental Materials and Prosthodontics, R. Humaitá São Paulo State University (UNESP) Engineering College Laboratory of Technological Plasmas, Av. Três de Março, 511 Univ. Estadual Paulista (UNESP) Araraquara Dental School Department of Dental Materials and Prosthodontics, R. Humaitá FAPESP: 2016/11470-6 FAPESP: 2017/01320-0