## 4 Discussion  
The concept of surface finish or topography on the biological response to an implant was studied by [PERSON] et al. [102]. The chemical and physical surface properties [103] such as surface topography and roughness, surface chemistry, and surface energy affect the initial cell response at the cell-material interface, enhance cell proliferation and differentiation, and eventually affect the rate and quality of new tissue formation. Surfaces with high wettability can influence the bonding strength, promote protein adsorption, and enhance cell adhesion compared with hydrophobic surfaces. However, surface modification techniques appear to affect the wettability, hydrophobicity, and surface charge of certain implants and alter the extent of protein adsorption [18; 19]. For the past years, UV light treatment has been applied to enhance the biological properties of the titanium surface by altering its surface chemistry without altering the surface topography. The use of UV light to condition the implant surface has emerged from the knowledge of the photocatalytic degradation properties of TiO\({}_{2}\) based on the photo-induced hydrophilicity and decomposition reaction described above [32]. The effect of photofunctionalization on different surfaces was evaluated by many researchers, and the production of superhydrophilic surfaces with increased and accelerated bone-implant integration was demonstrated in in vitro [21; 22; 93] and in vivo [58; 73; 87; 96; 98] studies. The following paragraphs aim to provide a brief and crucial overview of the adhesion behaviors of osteoblast cells on superhydrophilic surfaces following UV photofunctionalization. The effects of UV photofunctionalization on osteoblasts are summarized in Table 2. The wettability values are also highlighted in this table. These studies (although not an exhaustive list) suggest that the UV-light exposure of biomaterials (titanium) enhances the migration, attachment, and proliferation of osteoblasts and its lineage. From this table, it can be seen that different types of osteoblasts may show a similar positive response toward the UV-enhanced surface. In contrast, however, [PERSON] et al. [93] found that primary human alveolar osteoblast morphology and initial attachment were not affected by bioactivation via UV photofunctionalization, but were influenced by surface topography. Similar results were also reported by [PERSON] et al. [104]. As seen in their experiments, no differences were observed in the morphology of osteoblasts or in their induction and activity when primary human  
Figure 3: Therapès® SuperOsseo, (Ushio Inc., Tokyo, Japan). osteoblast cells were subjected to implants with UV light surface activation. As they assumed that the indifferent morphology was due to the lack of stimulatory factors in the growth media used to culture the already differentiated osteoblasts, the negligible effect of UV light could be related to the dissimilarities of TiUnite surface treatment. The TiUnite by Nobel Biocare Implant System has an anodized coating of TiO\({}_{2}\) layers with \(S_{\text{a}}\) and \(S_{\text{dr}}\) values of 1.1 \(\upmu\)m and 37%, respectively. Hence, their study supported the findings of [PERSON] et al. [38], who demonstrated that the proliferation and differentiation of cells derived from human mandibular bone were enhanced by the surface roughness of the titanium implant. Furthermore, [PERSON] [13] reported that implants with rough surfaces offered more significant advantages than those with smoother surfaces, especially in compromised bone. In addition, [PERSON] et al. [105] showed that the argon-plasma-treated surface was superior to the UV-treated surface of the same topographical specimens. These findings could encourage future research on the utilization of a surface conditioning tool other than UV technology without altering the surface topography. The success of early- and late-stage osseointegration in association with surface conditioning with UV light was also established via various animal experiments.