In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices

Haude et al. BMC Oral Health (2024) 24:558 https://doi.org/10.1186/s12903-024-04230-9 BMC Oral Health Open Access RESEARCH In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices Sandra Haude1†, Rutger Matthes1†, Vinay Pitchika1, Birte Holtfreter1, Rabea Schlüter2, Torsten Gerling3, Thomas Kocher1 and Lukasz Jablonowski1* Abstract Background We investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface. Methods Discs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs. Results Treatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy. Conclusion AP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device. Keywords Air polishing, Biofilm, Cold plasma, Anodised titanium, Peri-implantitis, Surface treatment † Sandra Haude and Rutger Matthes contributed equally to this work. *Correspondence: Lukasz Jablonowski 1 Department of Restorative Dentistry, Periodontology, Endodontology, Preventive Dentistry and Paediatric Dentistry, Dental School, University Medicine Greifswald, Walther-Rathenau-Str. 42a, Greifswald D - 17475, Germany 2 Imaging Center of the Department of Biology, University of Greifswald, Greifswald, Germany 3 ZIK Plasmatis, Leibniz-Institute for Plasma Science and Technology e.V. (INP), a member of the Leibniz Research Alliance Leibniz Health Technology, Greifswald, Germany © The Author(s) 2024. 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The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Haude et al. BMC Oral Health (2024) 24:558 Background The treatment of peri-implantitis is still a major problem and there are no generally accepted treatment guidelines. A recent Cochrane review did not find any debridement method superior to any other method in removing the biofilm [1] and no method was able to achieve clinically predictable, stable results over time [2–4]. The removal of biofilm from the exposed implant surface is regarded as the cornerstone of peri-implantitis therapy [1]. The exposed rough implant surface in combination with implant threads makes non-surgical treatment unpredictable [5, 6]. Today’s standard treatment for severe peri-implantitis is to expose the implant surface by a surgical flap and to remove the biofilm from the exposed implant surfaces [7]. Air powder devices showed the best cleansing capability of all mechanical methods. However, in-vitro studies have shown that up to 40% of the exposed surface remained untreated even during optimal access, especially in the undercuts of the implant threads [8–10]. The local use of antiseptic agents, air abrasives or lasers for decontamination of the implant surface during a surgical intervention did not improve the treatment outcomes compared with mechanical debridement combined with topical saline rinsing [11–13]. The rough implant surface and the implant threads provide ‘’protected areas’’ to the biofilm, inaccessible to conventional mechanical therapy. Therefore, surface decontamination is the critical step for the resolution of inflammation. Treatment of machined surfaces as originally devised by Brånemark displayed the best tendency for clinical healing, followed by sand-blasted, acid-etched surfaces, whereas TiUnite® surfaces showed less successful healing, which could be due to its unique surface characteristics (Fig. 1) [12, 14]. Fig. 1 The TiUnite® surface is manufactured by spark anodisation in an electrolytic solution which produces an inner layer without pores and an outer layer with numerous pores with diameter and depth between ≤ 4 microns and ≤ 10 microns [15]. Black bar 2 μm Page 2 of 12 Physical plasma is formed when a gas is ionised. Plasma at atmospheric pressure is electrically neutral, composed of ions, electrons, vacuum ultraviolet and ultraviolet irradiation, free radicals, and chemically reactive neutral particles with a short lifespan and generates heat. Plasma inactivates planktonic bacteria in a dose-dependent anti-microbial effectivity [16, 17] and hydrophilises the exposed surface [18]. Plaque removal with cold jet plasma devices in combination with a brush or an air polishing device rendered sand-blasted, acid-etched titanium discs conducive for complete coverage with osteoblastic cells [19, 20]. Because of the complete coverage with cells, we appraised these treatment methods as successful. A new in-vitro study from our lab revealed that the topographically demanding anodised titanium surface used could not be treated as successfully as a sandblasted, acid-etched surface, used in a previous study [21]. Cold atmospheric pressure plasma devices (CAP) should not generate temperatures higher than 40 °C for treatment in or on patients [22, 23]. In our lab, we performed a series of studies with different pla (...truncated)