A Novel 3D Titanium Surface Produced by Selective Laser Sintering to Counteract Streptococcus oralis Biofilm Formation

Simonetta D’Ercole,Cigdem Atalayin Ozkaya,Adriano Piattelli,Silvia Di Lodovico,Giovanna Iezzi,Luigina Cellini,Morena Petrini,Carlo Mangano

doi:10.3390/app112411915

Abstract

The topography of implant surfaces influences the interaction relationship between material and bacteria. The aim of this work was to characterize a novel 3D titanium surface, produced using Selective Laser Sintering (SLS), and to compare the bacterial interaction with machined and double acid etching (DAE) discs. The surface was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), and Energy Dispersive X-ray Spectrometry (EDX). The wettability was measured using the sessile method. The microbiological investigation consisted in the cultivation of a bacterial pioneer, Streptococcus oralis, on titanium surfaces, previously covered by human saliva in order to form the acquired pellicle. Then, colony forming units (CFUs), biofilm biomass quantification, analyses of viable and dead cells, and SEM observation were determined after 24 h of S. oralis biofilm formation on the different discs. A significantly higher nano-roughness with respect to the other two groups characterized the novel 3D surface, but the wettability was similar to that of machined samples. The microbiological assays demonstrated that the 3D discs reported significantly lower values of CFUs and biofilm biomass with respect to machined surfaces; however, no significant differences were found with the DAE surfaces. The live/dead staining confirmed the lower percentage of living cells on DAE and 3D surfaces compared with the machined. This novel 3D surface produced by SLS presented a high antiadhesive and antibiofilm activity.

Highlights

Three-dimensional printing is an additive manufacturing technology (AM) that represents an alternative method of production with respect to traditional casting and subtractive methods for producing tridimensional tools
colony forming units (CFUs) and biofilm biomass with respect to machined surfaces; no significant differences were found with the double acid etching (DAE) surfaces
With respect to the traditional process of fabrication, 3D printing represents an economic alternative that minimizes the amount of material wasted, reduces the number of steps needed in production, and influences the technician’s ability to produce high-quality products [3]

Summary

Introduction

Three-dimensional printing is an additive manufacturing technology (AM) that represents an alternative method of production with respect to traditional casting and subtractive methods for producing tridimensional tools. This novel technology permits freeform fabrication, so in the biomedical field, custom-made tools can be fabricated, starting from patients records, such as X-rays or CT-scans [1,2]. With respect to the traditional process of fabrication, 3D printing represents an economic alternative that minimizes the amount of material wasted, reduces the number of steps needed in production, and influences the technician’s ability to produce high-quality products [3]. In power bed fusion techniques, a high energetic beam, such as LASER, can be used to sinter (selective laser sintering, SLS) or melt (selective laser melting, SLM) different layers of metal powder deposited consecutively, based on a computer-aided design (CAD) project

Objectives

Methods

Results

Discussion

Conclusion