Dental Implant Healing Screws as Temporary Oral Drug Delivery Systems for Decrease of Infections in the Area of the Head and Neck

Figures & data

Figure 1 Scanning electron microscopy (SEM) of the dental implant that was removed from the mandible bone due to chronic infection which developed soon after the surgery and could not be treated with conventional antibiotics. (A) Magnification of 30x does not show evident cause of implant failure, whereas magnification of 100x (B) and 500x (C) show bacterial biofilm persisting between implant screw threads. Source: own test results.

Table 1 Characterization of ZnO+0.1% Ag Nanoparticles

Sample	Specific Surface Area by Gas Adsorption, as±σ (m^2/g)	Skeleton Density by Gas Pycnometry, ρs±σ (g/cm^3)	Average Particle Size from SSA BET, d±σ (nm)	Average Crystallite Size from Nanopowder XRD Processor Demo, d±σ (nm)	Average Crystallite Size, Scherrer Formula, Based on XRD, da, dc (nm)
ZnO+0.1% Ag	37.7 ± 0.1	5.34 ± 0.02	30 ± 1	28 ± 9	27a, 33c

Abbreviations: ZnO, zinc oxide; Ag, silver; a_s, specific surface area; ρ_s, skeleton density; SSA, specific surface area; BET, Brunauer Emmett Teller; d, diameter; σ, standard deviation; g, gram; m, metre; cm, centimeter; nm, nanometer.

Figure 2 SEM image of ZnO+0.1% Ag nanoparticles used as implant coating (A–C). Images B(1) and B(2) as well as images C(1) and C(2) are images of identical areas of the sample that were taken using different detectors. (1) - SEM images taken with the InLens detector. (2) - SEM images taken with the AsB detector.

Abbreviations: InLens, immersion lens detector; AsB, angle selective backscatter detector; ZnO, zinc oxide; Ag, silver; SEM, Scanning electron microscopy.

Figure 3 (A) Size distributions of particles/agglomerates of ZnO+0.1%Ag in human saliva suspension obtained by DLS method. (B) Crystallite size distribution of ZnO+0.1%Ag obtained by Nanopowder XRD Processor Demo, pre.α.ver.0.0.8, © Pielaszek Research.

Abbreviations: d, diameter; DLS, dynamic light scattering; XRD, X-ray diffraction; ZnO, zinc oxide; Ag, silver; a.u., arbitrary unit; nm, nanometer.

Figure 4 Comparison of SEM images of a pure implant abutment (A–C) and an implant abutment coated with ZnO+0.1% Ag (D–L).

Abbreviations: Ag, silver; ZnO, zinc oxide; nm, nanometer; µm, micrometer.

Figure 5 Elemental EDS mapping of a pure implant abutment (A–C) and an implant abutment coated with ZnO+0.1%Ag (D–F). There is a visible island coating of ZnO+0.1%Ag on the implant abutment surface.

Abbreviations: Ag, silver; Al, aluminum; Ti, titanium; ZnO, zinc oxide; Zn, zinc; µm, micrometer.

Figure 6 Qualitative EDS analysis of: (A) the clean implant surface consisting of C, Ti, Al and V; (B) surface of the modified implant abutment coated with ZnO+0.1%Ag. (1) - SEM image for EDS analysis area. (2) - EDS spectra.

Abbreviations: Al, aluminum; C, carbon; Ti, titanium; O, oxygen; Zn, zinc; µm, micrometer; cps/eV, counts per second per electron-volt; V, vanadium.

Figure 7 The example of AFM 3D images (10 μm x 10μm) of implant surfaces: (A) upper part of the pure abutment, (B) lower part of the pure abutment, (C) upper part of ZnO+0.1%Ag coated implant abutment, (D) lower part of ZnO+0.1%Ag coated implant abutment.

Figure 8 Example of contact angle analysis results (A) of the pure implant abutment surface and (B) of the implant abutment surface after modification with ZnO+0.1%Ag.

Figure 9 Absorbance test indicating a significant reduction in bacterial adhesion on the titanium surface modified with nanoparticles (p<0.005).

Figure 10 SEM image of the retrieved abutments after microbiological studies showing significantly more bacterial biofilm attached on the control implants (A–E) than those modified with ZnO+0.1%Ag NPs (F–J).