ORIGINAL ARTICLE Photofunctionalization and non-thermal plasma activation of titanium surfaces Anders Henningsen 1,2 & Ralf Smeets 1 & Philip Hartjen 1 & Oliver Heinrich 1 & Roman Heuberger 3 & Max Heiland 4 & Clarissa Precht 1 & Claudio Cacaci 5 Received: 27 March 2017 /Accepted: 12 July 2017 /Published online: 20 July 2017 # Springer-Verlag GmbH Germany 2017 Abstract Objective The aim of this study was to compare UV light and non-thermal plasma (NTP) treatment regarding the improve- ment of physical material characteristics and cell reaction on titanium surfaces in vitro after short-term functionalization. Materials and methods Moderately rough (Ra 1.8–2.0 μm) sandblasted and acid-etched titanium disks were treated by UV light (0.05 mW/cm 2 at λ = 360 nm and 2 mW/cm 2 at λ = 250 nm) or by NTP (24 W, -0.5 mbar) of argon or oxygen for 12 min each. Surface structure was investigated by scan- ning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy (XPS). Hydrophilicity was assessed by dynamic contact angle measurement. Cell attach- ment, viability, cell proliferation and cytotoxicity were assessed in vitro using murine osteoblast-like cells. Results UV irradiation or NTP treatment of titanium surfaces did not alter the surface structure. XPS analysis revealed a significantly increased oxidation of the surface and a decrease of carbon after the use of either method. NTP and UV light led to a significant better cell attachment of murine osteoblasts; significantly more osteoblasts grew on the treated surfaces at each time point (p < 0.001). Conclusions UV light as well as NTP modified the surface of titanium and significantly improved the conditions for murine osteoblast cells in vitro. However, results indicate a slight advantage for NTP of argon and oxygen in a short time inter- val of surface functionalization compared to UV. Clinical relevance UV light and NTP are able to improve surface conditions of dental implants made of titanium. Keywords Dental implants . Ultraviolet rays . Plasma gases . Titanium . Cell adhesion . Osteoblasts Introduction In 1981, Albrektsson et al. showed that surface conditions of titanium implants are a fundamental factor for successful osseointegration [1]. Topographical, biological and chemical conditions determine the surface characteristics of dental im- plants. Despite a low specific weight, titanium has excellent mechanical properties and a good corrosion resistance due to the dense oxide layer. The oxide layer (mainly TiO 2 ) is an essential precondition for successful osseointegration [2]. Present-day dental implants have an optimized surface topog- raphy and some have an optimized surface chemistry. Biologically and pharmaceutically modified surfaces are still subjects of recent research [3]. Until now, no evidence has been shown for any particular type of dental implant to be superior concerning long-term success [4]. However, higher bone-implant-contact (BIC) values and better bone apposition were demonstrated on implants with rough surfaces compared to smooth surfaces, including stimulation of cell migration and proliferation [5]. BIC values in modern implants normally vary between 65 and 73% but do not reach the ideal 100% [6]. Clarissa Precht and Claudio Cacaci contributed equally. * Anders Henningsen a.henningsen@uke.de 1 Department of Oral and Maxillofacial Surgery, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany 2 Department of Oral and Maxillofacial Surgery, German Armed Forces Hospital, Lesserstrasse 180, 22049 Hamburg, Germany 3 RMS Foundation, Bischmattstraße 12, 2544 Bettlach, Switzerland 4 Department of Oral and Maxillofacial Surgery, Charité University Hospital, Augustenburger Platz 1, 13353 Berlin, Germany 5 Implant Competence Centrum, Weinstr. 4, 80333 Munich, Germany Clin Oral Invest (2018) 22:1045–1054 DOI 10.1007/s00784-017-2186-z