The Bacterial Anti-Adhesive Activity of Double-Etched Titanium (DAE) as a Dental Implant Surface.

Morena Petrini,Emanuela Di Campli,Adriano Piattelli,Alessandra Giuliani,Simonetta D’Ercole,Giovanna Iezzi,Silvia Di Lodovico

doi:10.3390/ijms21218315

Abstract

This work aimed to compare the capability of Streptococcus oralis to adhere to a novel surface, double-etched titanium (DAE), in respect to machined and single-etched titanium. The secondary outcome was to establish which topographical features could affect the interaction between the implant surface and bacteria. The samples’ superficial features were characterized using scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS), and the wetting properties were tested through sessile methods. The novel surface, the double-etched titanium (DAE), was also analyzed with atomic force microscopy (AFM). S. oralis was inoculated on discs previously incubated in saliva, and then the colony-forming units (CFUs), biomass, and cellular viability were measured at 24 and 48h. SEM observation showed that DAE was characterized by higher porosity and Oxygen (%) in the superficial layer and the measurement of the wetting properties showed higher hydrophilicity. AFM confirmed the presence of a higher superficial nano-roughness. Microbiological analysis showed that DAE discs, coated by pellicle’s proteins, were characterized by significantly lower CFUs at 24 and 48 h with respect to the other two groups. In particular, a significant inverse relationship was shown between the CFUs at 48 h and the values of the wetted area and a direct correlation with the water contact angle. The biomass at 24 h was slightly lower on DAE, but results were not significant concerning the other groups, both at 24 and 48 h. The DAE treatment not only modifies the superficial topography and increased hydrophilicity, but it also increases the Oxygen percentage in the superficial layer, which could contribute to the inhibition of S. oralis adhesion. DAE can be considered a promising treatment for titanium implants to counteract a colonization pioneer microorganism, such as S. oralis.

Highlights

The acidified surfaces (Figure 1B,C) are characterized by a porous structure composed of the random arrangement of furrows of various sizes
The Pearson analysis showed that the percentage of porosity was directly correlated with the wetted area (r = 0.861, p < 0.01) and inversely with the water contact angle (WCA) (r = −0.906, p < 0.01)
atomic force microscopy (AFM) demonstrated that the double etching treatment enhanced the formation of a nano-roughness surface, and average roughness roughness average (Ra) remained under 0.2 μm

Summary

Introduction

The study of variables that could affect the early and late failures of dental implants is fundamental for developing useful tools to prevent or treat the disease. Superficial treatments of dental implants have been shown to increase the surface in contact with the bone, promote osseointegration, accelerate the loading protocols, and decrease early failure rates [1,2]. The peri-implant zone is an active environment of ~1 mm in width. The interactions between the implant and the bone are continuously mediated by cell-signaling pathways (such as the Wnt-β catenin pathway), influencing the bone remodeling process [3]. Superficial micro-porosities, increasing titanium’s wettability, can affect cellular adhesion, diffusion, migration, proliferation, and differentiation [4,5,6]

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Discussion

Conclusion