titanium [1]. Biocompatibility and prevention of inflammation around applied devices are essential for long term effectiveness [2]. The medical implant should be benign concerning the patients and should not cause a vicious immunological response. Commercially pure titanium (CpTi) is considered to be an ideal biocompatible dental material because of its surface properties as a result of the spontaneous growth of a stable and inert oxide layer [3]. CpTi is used primarily for endosseous dental implant applications [4]. Ooseeintegration of dental implants is described as a direct bone-to-implant contact [5]. Nowadays, it is an indispensable condition that an implant has to be a good bioinert material and also must have appropriate adhesion properties [6; 7]. Ooseeintegration has four stages: hemostasis, inflammatory, proliferative, and remodeling. The very first step of the hemostasis phase is the development of a layer of a water-based solution containing inorganic and organic components that are essential for the osseeintegration process [8]. Several works in literature present enhanced osseeintegration with hydrophilic implant surface in native bone [9; 10; 11]. [PERSON] et al. demonstrated improved osseeintegration of titanium implants with hydrophilic surface in areas augmented with deproteinized bovine bone grafts and biphasic hydroxyapatite/beta-tricalcium phosphate grafts [12]. It was shown that, on a hydrophilic surface, a drop of water-based solution or blood spreads easily. CpTi is hydrophilic, thus it is essential that any modification of the surface should not decrease hydrophilicity. While many medical devices are embedded in the body and covered by tissues of the organ, dental implants are placed trans-gingivally, creating a potential gateway for bacteria to penetrate. This is a constant threat to developing inflammation called mucositis and periimplantitis [13]. The antibacterial feature of the implant surface at this gateway area can help to prevent this inflammation process [14]. One method of adding an antibacterial feature to the implant surface is silver layering [15; 16; 17]. Despite numerous investigations, the antibacterial effect of silver is still not fully understood, but it has long been a well-known and used material in medicine. Numerous studies prove that using silver nanoparticles (AgNPs) for layering significantly increases the antibacterial properties of the implants [18; 19]. Silver ions tend to bond to sulphur, oxygen, and nitrogen [20] and thus to cell walls, membranes, DNA, enzymes, therefore altering their original functions [21; 22]. On AgNP-Ti surfaces, reactive oxygen species are also generated to achieve additional antibacterial effects [18]. Surfaces with silver nanoparticles release silver ions that correlate with the surface. In a previous study, we demonstrated this antibacterial effect on a titanium surface covered by silver nanoparticles [23]. On the other hand, silver can be cytotoxic to human tissues by altering mitochondrial, DNA, membrane, and enzyme functions [24]. These mechanisms are the same as for bacteria, but for eukaryotic cells, a higher silver ion concentration is needed for comparable toxic effects. This opens up a therapeutic window for antibacterial treatment [25]. Controlling the diameter of the nanoparticles controls the total silver surface to release ions, thus the amount of ion can be controlled by the particle diameter. This paper focuses on how the different sizes of silver nanoparticles affect the viability of human dental pulpal stem cells. Surface modification by using nanoparticles has an important role in the field of various research, especially in material science and medical applications [26; 27; 28; 29]. By modifying the steps of surface treatment described in our previous study [23], we created surface configurations covered by differently sized silver nanoparticles. By culturing cells, their viability on the different surface configurations was investigated and compared.