## 1 Introduction  
Calcium phosphate (CaP) coatings are osteeconductive and are widely used in orthopedics and dental implants to increase osseointegration between the implant and hard bone [1]. In previously study, [PERSON] et al. reported that the calcium phosphate (CaP) coating formed on the porous titanium surface can reduce the healing time by early enhance osseointegration in the body [2]. CaP can be divided into hydroxyapatite (HA), octacalcium phosphate (OCP), amorphous calcium phosphate (ACP), and dicalcium phosphate (DCPD), according to the calcium-to-phosphorus (Ca/P) ratio [3,4]. HA is the main component of human body tissues and enamel on the surface of the teeth. After HA is implanted into a hard bone defect, the surface of the material will form a chemical bond with the hard bone tissue to improve osseointegration [5]. However, the poor biodegradability of HA results in a rather slow induction of hard bone growth after implantation [6]. Therefore, the previous literature used metal ions instead of calcium ions to reduce the crystallinity and increase the degradation rate of HA. The substitution of cobalt ions not only reduces crystallinity but also acts as a hypoxia mimic, which can activate hypoxia-inducible factor (HIF)-1\(\alpha\) in mesenchymal stem cells to help angiogenesis [7]. Previous studies showed that cobalt-substituted hydroxyapatite (CoHA) has good biological activity and can induce bone growth [8]. There are many methods for forming HA coatings such as sol-gel [9], plasma spraying [10], and laser-assisted biomimetic (LAB) [11; 12]. LAB is a method of immersing a substrate in a supersaturated CaP solution and irradiating the sample with an Neodymium-dopedYttriumAluminiumGarnet laser (Nd-YAG, 200 mJ pulse\({}^{-1}\) cm\({}^{-2}\)). The surface of the sample converts absorbed light energy into heat energy, which induces CaP to rapidly form a coating [13; 14]. LAB can also be used on polymer and titanium surfaces [14; 15; 16]. [PERSON] et al. reported the use of a high-energy laser (1 Kw mm\({}^{-2}\)) to form a CaP coating on the surface of titanium immersed in a CaP solution. The biocompatibility test with a human osteosarcoma cell line (MG-63) showed good cell adhesion [17]. [PERSON] et al. found that near-infrared (NIR; \(\lambda\) = 1064 nm) laser pulses can replace ultraviolet (UV, \(\lambda\) = 355 nm) laser pulses used by LAB to avoid using too high of an energy, which can damage the surface of a sample [13]. In addition, surface treatment of titanium test pieces was proven to increase the pores on the surface of the material, thereby increasing the effect of osseointegration [11; 18]. Clinical dentistry will also increase the success rate of surgery through the modification of the implant surface [19]. Surface treatment methods include plasma spray, sand-blasting, anodic treatment, and chemical etching. Among these, the modification methods of alkali treatment and acid treatment are relatively simple and can be applied to complex-shaped structures to produce many uniform nano-level holes on the surface [20; 21]. Anodic oxidation treatment (with TiO\({}_{2}\) nanotubes (TNTs)) can form an oxide film on the surface of titanium to improve biocompatibility and can attract apatite to the surface to promote the regeneration of hard bones [22]. This study investigated whether changes in the surface morphology and elemental composition of titanium after different surface treatment procedures (anodization, alkali treatment, and acid treatment) will affect LAB coatings. In addition, we used CaP and CoHA solutions with the LAB method to observe whether the structure and composition of the mineralized layer on the surface were affected, and we analyzed cell viability to evaluate the biocompatibility of test pieces. Finally, test pieces were immersed in simulated body fluid (SBF) for 7 days, and the surface morphology, crystal structure, and elemental composition were analyzed as evaluations of biological activities.