## 1 Introduction  
The success rate of dental implants depends on osseointegration, which is initiated by cell adhesion when the implant surface meets the surrounding tissue [1; 2; 3; 4; 5; 6; 7]. Ossoeintegration failure is characterized by the instability or loosening of the implant, perimplantitis, and bone resorption [1; 8; 9; 10; 11]. Ossoeintegration is accomplished through two phases involving primary or mechanical stability, which is recognized after implant placement, and secondary or biological stability related to the healing process [12]. As such, it is crucial to perform various surface modifications to the implant where osseointegration occurs.  
Dental implants generally use titanium (Ti) material, which has mechanical and biocompatible properties, yet these are insufficient to cause this material to be well-accepted and not considered as a foreign object, which leads to rejection by the body [9; 10; 13]. It is believed that the improvement of the mechanical, physical, and biological properties of the implant material, through surface modification, can overcome these obstacles to promote better bone contact to the implant surface, which in sequence can accelerate the osseointegration [14; 15]. Of the various implant surface modifications, the sandblasted, large-grit, and acid-etched (SLA) surface treatment method is most often used to elevate the mechanical and physical properties of the implant, while biochemical methods can enhance the biological properties in the form of increased adhesion and cell migration by immobilization or delivery of various proteins, enzymes, or peptides on the implant surface [4; 13; 16; 17].  
The current study focuses on surface functionalization using peptides that allow the adhesion of cells to the implant surface, which has previously been treated by an innovative dip-coating technique (IDCT) [13]. In our previous study, surface modification with IDCT involved the application of polymer pluronic F127 (PF127), which acts as a scaffold with its amphiphilic properties and which not only improves wettability but also exhibits antibacterial action to induce the healing process [13; 18]. However, the weak interaction with cells, and the lack of protein adsorption, were to be the shortcomings of the polymer that could have a negative impact on cell adhesion to the implant surface [16; 19]. Several in vivo studies have displayed that type I collagen containing the amino acid sequence Arg-Gly-Asp (RGD) was useful to speed up fixation between the implant and the surrounding bone, and lead to the acceleration of osseointegration by enhancing cell adhesion, differentiation, and extracellular matrix (ECM) secretion [15; 17]. Therefore, this study used Arg-Gly-Asp (RGD) peptide to mediate cell adhesion to the scaffold. The ability of RGD peptides to bind with integrin receptors leads to increased cell adhesion and its functions [6; 20]. It was reported that the tetrapeptide Gly-Arg-Gly-Asp (GRGD) peptide sequence derived from fibronectin will bind to integrins and other ECM proteins [5]. Moreover, the GRGD peptide was also reported to be useful in modifying the Ti implant surface [21]. As mentioned above, the present study aimed to evaluate the IDCT-Ti implant coated with GRGD peptide in promoting osteoblast behavior to increase osseointegration.