Dental implants coated with a durable and antibacterial film

Abstract

Dental implants coated with a durable and antibacterial film Vogel et al. embedded between two layers of PP by means of subsequent plasma polymerization and metal evaporation steps. The double PP/Ag/PP layer can be directly deposited on titanium implants, whose in vivo biocompatibility within soft tissues has been investigated in Ref. 13 .Building up on these previous results, in this article, we investigate the performances of a similar PP/Ag/PP-layered coating material (briefly, PP+Ag) toward the adhesion of bacteria and eukaryotic cells in vitro. In particular, besides HeLa cellular models, the adhesion behavior of fibroblasts and osteoblasts will be addressed. With respect to the original coating procedure, 12,13 physical vapor deposition is used instead of evaporation to deposit the silver nanoparticle layer. The advantage of the physical vapor deposition is a better control and reproducibility of the nanoparticle distribution and a lesser degree of nanoparticle agglomeration. We test the coating layer resistance to sterilization and implantation into bone tissue (Section 3.2), optimize the plasma deposition parameters to guarantee eukaryotic adhesion (Section 3.3) and check the successful bacterial deterrence of the coating in fluorescence microscopy images (Section 3.4). Materials and methods Plasma polymerization and layer formationThe plasma polymerization and deposition of silver nanoparticles are performed in the same plasma reactor chamber. A sample holder with rotating platforms is mounted inside a 125-liter vacuum chamber. The chamber comprises an electrode of rectangular shape and a silver target situated behind a shutter system. Gas inlets for the HMDSO precursor (Wacker, Munich, Germany), argon, oxygen and hydrogen (Linde AG, Pullach, Germany) and a pumping system are connected to the chamber walls. In this study, three different coating layers are investigated: (a) A 2000-nm-thick polymer coating without silver particles, which possesses cell-repelling properties (PP2000); (b) a 100-nm-thick coating without silver particles, which promotes eukaryotic adhesion (PP100) and (c) the same coating including silver nanoparticles to inhibit bacterial growth but not eukaryotic adhesion (PP100+Ag). The coating layers are produced as follows: After decreasing the chamber pressure below 10 −4 mbar, HMDSO and oxygen are injected to a working pressure of 10 −2 to 10 −3 mbar. Applying a power of 160 W for 120 s, the plasma is ignited, and a 50-nm-thick polymer preconditioning layer is formed. The 2000-nm-thick coating is prepared at 120 W and oxygen to HMDSO gas flow ratio of 1:2. On top of the preconditioning layer, either the plasma polymerization is carried on until the desired thickness is reached (e.g. 100 nm for PP100), or an intermediate layer of silver nanoparticles is deposited by applying a power of 200 W for 60 s between the silver target and the chamber walls.With this procedure, we coat sand-blasted and etched titanium dental implant screws (11·5-mm length, 5·5-mm diameter ) as well as titaniu...

Antimicrobial dental implant functionalization strategies —A systematic review

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“…(2016) Creation and Evaluation of Construction Guidelines Using CFD for Low Pressure Plasma Gas Feed-in Systems to Homogenize the range of industrial fields such as aircraft, automotive and medical devices for the application of functional coatings e.g. anti-bacterial, anti-scratch, anti-reflection and enhance wear resistance [1] [2] [3] [4]. Within the PECVD process the substrate allocated in a vacuum chamber is exposed to the influence of the plasma.…”

Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys

“…Bacterial adhesion to the surface of implants may result in peri-implant diseases and cannot always be avoided by sterilization before implantation. AgNPs coating produced a strong antibacterial effect on the titanium surface by inhibiting the adhesion of bacteria (Massa et al, 2014;Matsubara et al, 2015;Mishra et al, 2015;Qin et al, 2015;Vogel et al, 2015). In our study, AgNPs were incorporated to the surface of dental alloys to improve their antibacterial properties, in order to further reduce the incidence of denture stomatitis and peri-implantitis.…”

“…Recently, AgNPs have been used to enhance the antibacterial performance of dental materials (Qin et al, 2015;Vogel et al, 2015). AgNPs were added to composite resins and results demonstrated that, in sufficient concentrations, the presence of nanosilver significantly increased the resins' antibacterial performance (Fan et al, 2011;Ai et al, 2017).…”