Surface Modification of Titanium Using Nano-Hydroxyapatite: A Comparative Microhardness Study

Background and aim Surface modification of titanium implants is essential to enhance their mechanical and biological performance. Nano-hydroxyapatite has emerged as a promising biomimetic material capable of improving surface characteristics and potentially optimizing implant success. The aim of this study was to evaluate the effect of nano-hydroxyapatite on the surface microhardness of titanium discs. Methods This in vitro experimental study included 30 commercially pure titanium discs allocated into control (artificial saliva) and experimental (nano-hydroxyapatite) groups (n = 15 each). Baseline surface microhardness was measured using a Vickers microhardness tester (Shimadzu Corporation, Kyoto, Japan). The experimental group received nano-hydroxyapatite twice daily for 14 days, while the control group was maintained in artificial saliva. Posttreatment microhardness was assessed, and changes in the Vickers hardness number (VHN) were calculated. Data were analyzed using independent and paired t-tests, with significance set at p < 0.05. Results Baseline microhardness values were comparable between the control (224.57 ± 6.76 VHN) and experimental groups (223.13 ± 7.32 VHN) (p = 0.582). Posttreatment, the experimental group showed a significant increase in microhardness (241.65 ± 7.34 VHN), whereas the control group demonstrated a slight decrease (222.01 ± 7.53 VHN). The mean change in VHN was +18.52 ± 3.54 in the experimental group and -2.55 ± 2.73 in the control group, with a highly significant intergroup difference (p < 0.001). Conclusions Within the limitations of this study, nano-hydroxyapatite surface modification significantly improved the microhardness of titanium. This suggests enhanced surface durability and potential for better clinical performance. Clinically, such modifications may improve resistance to wear and deformation under load-bearing conditions. Additionally, improved surface characteristics may promote superior osseointegration, contributing to the long-term success of dental implants.