Antibacterial effect of doxycycline-coated dental abutment surfaces

Abstract

Biofilm formation on dental abutment may lead to peri-implant mucositis and subsequent peri-implantitis. These cases are clinically treated with antibiotics such as doxycycline (Doxy). Here we used an electrochemical method of cathodic polarization to coat Doxy onto the outer surface of a dental abutment material. The Doxy-coated surface showed a burst release in phosphate-buffered saline during the first 24 h. However, a significant amount of Doxy remained on the surface for at least 2 weeks especially on a 5 mA-3 h sample with a higher Doxy amount, suggesting both an initial and a long-term bacteriostatic potential of the coated surface. Surface chemistry was analyzed by x-ray photoelectron spectroscopy and secondary ion mass spectrometry. Surface topography was evaluated by field emission scanning electron microscopy and blue-light profilometry. Longer polarization time from 1 h to 5 h and higher current density from 1 to 15 mA cm(-2) resulted in a higher amount of Doxy on the surface. The surface was covered by a layer of Doxy less than 100 nm without significant changes in surface topography. The antibacterial property of the Doxy-coated surface was analyzed by biofilm and planktonic growth assays using Staphylococcus epidermidis. Doxy-coated samples reduced both biofilm accumulation and planktonic growth in broth culture, and also inhibited bacterial growth on agar plates. The antibacterial effect was stronger for samples of 5 mA-3 h coated with a higher amount of Doxy compared to that of 1 mA-1 h. Accordingly, an abutment surface coated with Doxy has potential for preventing bacterial colonization when exposed to the oral cavity. Doxy-coating could be a viable way to control peri-implant mucositis and prevent its progression into peri-implantitis.

Emerging Applications of Drug Delivery Systems in Oral Infectious Diseases Prevention and Treatment

“…PLGA(Ag-Fe3O4)-coated dental implants [175] Sm 7 inhibited bacteria adherence Ag nanoparticles coated on titanium [179] E coli, Sa showed antibacterial effect and sustained release for 7 days Antibiotics doxycycline-coated abutment surfaces [180] Se 8 inhibited the bacterial growth; showed sustained release for least 2 weeks Tetracycline-containing fibers coated titanium implant [171] Pg, Fn 9 ,Pi 10 , Aa showed inhibition of biofilm and kept releasing for 3 days silica-gentamycin coated titanium implant [170] Sa showed antibacterial effect and sustained release for 14 days Tetracycline loaded nanofibers coated titanium implant [43] Aa, Fn, Pg, Pi Showed anti-bacterial effect Tetracycline loaded titanium [181] Pg showed antibacterial efficiency and sustained release for 15 days Cationic antibacterial agents chlorhexidine hexametaphosphate nanoparticles coated titanium [182] Sg demonstrated antibacterial effect and sustained release of soluble chlorhexidine for 99 days The PIXIT implant containing polysiloxane oligomers and chlorhexidine gluconate [183] Clinic trail controlled bacterial adhesion; reduced the bacterial species involved with long-term failure of dental implant Dimethylaminododecyl Methacrylate(DMADDM) coated dental implant [172] saliva-derived biofilm inhibited biofilm growth and regulated microecosystem Bioactive antibacterial agents Chitosan/P-HAP bi-layers coated titanium implant [184] Sg Demonstrated an appropriate mouse pre-osteoblastic cell response, and significant anti-bacterial activity * The bacterial model were showed in abbreviated form: 1 Such kinds of dual-functional DDS not only show antibacterial effects without affecting biocompatibility, but also help promote bone regeneration, which has excellent application potential. However, long-term drug release and multifunctional dental implant research are still limited.…”

The effect of metronidazole releasing polymer coatings on in vitro biofilm formation

“…Here, the combination of low drug concentrations and topcoat gave inferior results probably, due to the extensively slowed down drug release (Figure 2). Short-term protection from bacterial adhesion with a metronidazole containing coating was already described in different studies [25], [26], however in these cases different coating formulations were used so that these results can not be directly applied to our study. For example Lui et al [18] investigated a metronidazole impregnated calcium phosphate coating on titanium surfaces.…”

Effect of cathodic polarization on coating doxycycline on titanium surfaces

“…95 Surfaces coated with doxycycline by means of cathodic polarization have been demonstrated to exhibit antibacterial properties and to promote bone formation. 94,96 However, the mechanisms behind this electrochemical coating process, in particular the role of titanium hydride formation in binding the biomolecules to the surface, remain poorly understood. A reason for this is that the studies used sandblasted and acid-etched surfaces as a substrate for the modifications, comparable to the Institute Straumann SLA ® surface.…”

“…Cathodic polarization has previously been applied to attach doxycycline to titanium based implant materials in order to promote bone growth and to reduce the risk of infection. 94,96 Even though the effect of these doxycycline coatings has been tested in vitro and in vivo in these studies, the changes induced to the substrate's outermost surface layers by the polarization process are poorly understood. Moreover, the proposed role of a formed hydride layer in the binding of doxycycline to the surface remains unclear.…”

“…The process required a custom made setup with individual current output for each mounted Ti disc. Current density was kept constant at 1 mA/cm 2 and was applied for a polarization time of 3 h, similar to the process parameters used in the studies conducted by Walter et al 94 and Xing et al 96 The effect of different current densities or polarization times was not investigated in this study, as the aim of this study was not the optimization of the process, but the evaluation of the events occurring at these particular process parameters. Furthermore, degradation of the doxycycline molecules was already observed to some extent with the used parameters, and would probably increase with higher current densities or polarization times (see Supporting Information in paper I).…”