Evaluation of photocatalytic and antibacterial activity of TiO2 on commercially pure titanium surface deposited by magnetron sputtering

Author(s)

Heloisa Navarro Pantaroto

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2017-02-22

Examining board members

Valentim Adelino Ricardo Barão; Elidiane Cipriano Rangel; Carolina Steiner Oliveira

• Advisor: Valentim Adelino Ricardo Barão

Abstract

The health of periimplant tissues is of utmost important for long-term success of prosthetic rehabilitation treatment and depends on abutments that support the gingival health. Surface treatments of abutments have been studied to promote periimplant health and antimicrobial properties. A photocatalytic compound such as titanium dioxide (TiO2) has been incorporated into some surface treatments due to its supposed antibacterial activity, which remains uncertain on oral biofilm. Therefore, the aim of this study was to investigate the photocatalytic antibacterial potential of TiO2 films through radiofrequency magnetron sputtering treatment on commercially pure titanium (cpTi) discs. The studied groups were: (1) cpTi machined (control group); (2) A-TiO2 (anatase crystalline phase); (3) M-TiO2 (mixture of anatase and rutile crystalline phases); (4) R-TiO2 (rutile crystalline phase). Discs¿ surfaces were characterized in terms of morphology (scanning electron microscopy - SEM), crystalline phase (X-ray diffraction analysis -XRD), chemical composition (energy dispersive spectrometry - EDS), hardness and elastic modulus (nanoindentation), roughness (perfilometer) and surface free energy (SFE) (goniometer). Photocatalytic potential was evaluated using the Methylene Blue (MB) degradation assay. The antibacterial potential was investigated by the adhesion (16.5 h) of a multi-species biofilm (16.5 h) composed by Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum followed by UVA light exposure (1h; 2×15 W; ? = 350 nm and intensity = 1.62 mW/cm2). Biofilm morphology analysis (SEM) and colony forming units quantification (CFU) were analyzed. Data were subjected to analysis of variance (ANOVA) and Tukey HSD test (?=0.05). TiO2 films presented thickness of ?300 nm and greater hardness comparing to cpTi. M-TiO2 and R-TiO2 showed higher elastic modulus comparing to A-TiO2 and cpTi surfaces (p<.05). A-TiO2 and R-TiO2 presented smaller values of roughness compared to cpTi and M-TiO2 (p<.05). R-TiO2 presented the smallest SFE (p<.05) when compared to the other groups. A-TiO2 and M-TiO2 films presented superior photocatalytic activity than R-TiO2 on MB degradation (p<.05); however the CFU quantification was similar between cpTi and TiO2 groups regardless of the crystalline phases (p>.05). These findings suggest that despite TiO2 films present a photocatalytic potential, such potential was not enough to promote antibacterial activity on multispecies oral biofilm (AU)

• FAPESP's process: 15/17055-8 - Photocalytic antibacterial effect of TiO2 on commercially-pure titanium surface deposited by magnetron sputtering
• Grantee: Heloisa Navarro Pantaroto
• Support Opportunities: Scholarships in Brazil - Master