## 1 Introduction  
Soft tissue integration is a challenge in implant-prosthetic treatment, and attention has shifted to the portion between the peri-implant soft tissue and the transmucosal component [1,2]. Although titanium-based implants facilitate osseointegration with the host bone [3], the limited number of gingival fibroblasts around implants may reduce the healing and regeneration of the connective tissue, with the risk of bacterial exposure [4].  
Only a small proportion of gingival fibroblasts (GFs) are found in the tissues around implants (3-5%), with significantly lower cell counts than around healthy periodontal connective tissue (approximately 15%) [5]. The limited GFs may reduce the healing and regeneration of the connective tissue (6-12 weeks are normally needed for peri-implant connective tissue maturation), which can result in bacterial exposure. In sum, soft tissue integration around Ti implants is mainly achieved through the physical \"adaptation\" of the peri-implant mucosa, rather than through biological \"integration\" around the natural tissue (such as teeth), which forms an effective barrier protecting the underlying structures [6]. The lack or weakness of transmucosal sealing can cause the rapid progression of peri-implant diseases; consequently, the application of surface treatments that enhance the \"adaptation\" of the soft tissues may represent an effective clinical strategy for the long-term prevention of peri-implant diseases [5].  
Cellular functions can be enhanced and modulated by surface modifications on a macro-, micro- and nano-scale [7]. Electrochemical anodization to produce controlled TiO\({}_{2}\) nanotubes/nanopores seems to be a popular technique for augmenting the bioactivity of Ti-based orthopedic and dental implants [8]. However, further research is needed to understand the effect of such surface treatments upon the soft tissues [9].  
The biological response to an implanted device is determined by the interaction between the implant materials and the tissues in contact with them. This response is controlled by multiple regenerative pathways that condition the implantation outcome depending on the activation or/and development of immune, coagulation, angiogenic or collagen synthesis processes [10]. The contact of the implant with proteins from tissues and fluids leads to the adsorption of a protein layer on the implant surface [11]. The material surface parameters, such as wettability, roughness or chemistry, play a key role in this protein adsorption phenomenon [12]. Likewise, the activation of regenerative processes and the formation of the provisional extracellular matrix are determined by the protein layer, with the subsequent induction of cellular and tissue responses [13,14].  
The aim of this study was to evaluate the potential of Ti anodized surfaces to improve soft tissue healing around dental implant abutments. For this purpose, the anodized surfaces were evaluated in vitro with both macrophages and fibroblasts to analyze their regenerative and inflammatory potentials. Additionally, to achieve a better understanding of how these dental abutment surfaces affect the initial soft tissue regenerative process, the proteomic adsorption patterns on the anodized Ti surfaces were characterized using nLC-MS/MS. The null hypothesis underlying this study is that the anodization of Ti surfaces does not produce any significant differences in biological responses, in particular, in cell behavior (inflammatory or regenerative) or in protein adsorption patterns, compared to non-anodized control surfaces.