The Effect of Various Implant Coatings on Bone Formation and Cell Adhesion-In Vitro Study

Implant coatings play a crucial role in enhancing bone-implant integration and cellular adhesion. Despite numerous advancements in surface modifications, the comparative effect of various coatings on bone formation and cell adhesion remains inadequately explored. This study aims to evaluate the influence of different implant coatings on osteoblast activity and bone formation under in vitro conditions.

Titanium implants were coated with hydroxyapatite (HA), titanium dioxide (TiO₂), and bioactive glass using a plasma-spraying technique. Uncoated titanium implants served as controls. Osteoblast-like cells (MG-63) were seeded onto the implants, and assays were conducted to measure cell proliferation, alkaline phosphatase (ALP) activity, and mineralized nodule formation. A bone formation simulation was performed using a bone-like extracellular matrix culture system. Data were analyzed using ANOVA with a significance level of P < 0.05.

The HA-coated implants showed the highest cell proliferation rate (58% increase compared to control), followed by TiO₂-coated implants (42%) and bioactive glass (38%). ALP activity was significantly elevated in the HA group (21.5 ± 1.2 U/L) compared to TiO₂ (17.8 ± 1.0 U/L), bioactive glass (16.3 ± 0.8 U/L), and control (12.9 ± 0.7 U/L). Mineralized nodule formation was most prominent in the HA group, with a mean area of 230 ± 15 μm², compared to 180 ± 12 μm² in TiO₂, 160 ± 10 μm² in bioactive glass, and 120 ± 8 μm² in controls.

Hydroxyapatite-coated implants demonstrated superior cell adhesion and bone formation potential compared to other coatings. These findings underscore the importance of HA as a preferred coating material for enhancing implant integration and bone healing in vitro. Further studies are recommended to evaluate these coatings under clinical conditions.