Surface treatment of cpTi with micro-arc oxidation and glow discharge plasma: characterization and multispecies biofilm development

Author(s)

Adaias Oliveira Matos

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2016-02-26

Examining board members

Valentim Adelino Ricardo Barão; Daniela Micheline dos Santos; Antônio Pedro Ricomini Filho

• Advisor: Valentim Adelino Ricardo Barão

Abstract

The role of different surface treatments to control biofilm formation on the substrate of titanium is scarce. Surface treatments of the titanium-based implants have been used to improve osseointegration but the control of biofilm proliferation remains a challenge. In this study we synthetized biofunctional titanium surfaces through micro-arc oxidation (MAO) and glow discharge plasma (GDP) and tested the development of a three-species periodontopatogenic biofilm onto the treated commercially-pure titanium (cpTi) surfaces. Machined and sandblasted surfaces were used as controls. The surfaces of the discs were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy, X-ray diffraction, wettability, surface free energy and measurement of surface roughness. A multispecies biofilm composed of Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum was developed onto cpTi discs for 16.5 h (early biofilm) and 64.5 h (mature biofilm). The number of viable microorganisms and the composition of the extracellular matrix (proteins and carbohydrates) were determined. The biofilm structure was analyzed by SEM. Data were analyzed using analysis of variance and Tukey HSD test (?=.05). MAO treatment produced oxide films rich in calcium and phosphorus with a volcano appearance while GDP treatment produced silicon-based smooth thin-film. Plasma treatments were able to increase the wettability of cpTi (p<.05). An increase of surface roughness (p<.05) and formation of anatase and rutile structures were noted after MAO treatment. GDP had the greatest surface free energy (p<.05) while maintaining the surface roughness compared to the machined control (p>.05). Plasma treatment did not affect the viable microorganisms counts (p>.05), but the counts of F. nucleatum was lower for MAO treatment at adhesion phase (p<.05). The extracellular matrix composition was similar among groups (p>.05), excepted for GDP that had the greatest carbohydrates content (p>.05). Plasma treatments seems to be a viable and promising technology to treat bone-integrated dental implants as improved surface properties was achieved while controlling biofilm proliferation (AU)

• FAPESP's process: 13/26145-5 - Surface treatment of cpTi with plasma electrolytic oxidation and glow discharge plasma: characterization and multispecies biofilm development
• Grantee: Adaias Oliveira Matos
• Support Opportunities: Scholarships in Brazil - Master