Surface Roughness Optimization of CP Titanium for Improved Osseointegration in Dental Implants

Introduction: Surface topography plays a critical role in optimizing titanium implants for enhanced osseointegration—a phenomenon first described by Prof. Brånemark in 1952. His pioneering discovery led to dental implants with a surface roughness (Ra) of approximately 0.15 µm achieved through electropolishing. Advances in bone fixation have since introduced various surface treatments to improve implant roughness favouring cell adhesion. This study investigates the roughness of commercially pure (CP) titanium treated with electrochemical oxidation coatings to assess their suitability for dental applications.

Methods: CP titanium specimens (n=6) underwent surface coating via a proprietary electrochemical oxidation (ECO) of Biocera Medical (WO 2020/049299) in phosphate–zirconate electrolyte with four different concentrations of zinc (Zn) additive: Type 1 (Zr-P), Type 2 (Zr-P-Zn (L)), Type 3 (Zr-P-Zn (M)), and Type 4 (Zr-P-Zn (H)). Surface roughness of applied zirconia–Titania ceramic enriched with P and Zn was measured using a Keyence digital microscope (4 readings per sample) and three-dimensional parameters (Sa, Sq, Sz) following ISO 25178.

Results: Coated titanium surfaces demonstrated increased roughness compared to uncoated titanium (Sa = 0.45 ±0.07 µm). Coating Type 1 had a minimal impact on roughness (Sa = 0.49±0.09 µm), while Types 2, 3, and 4 increased the mean Sa values to 0.63±0.07 µm, 0.66±0.05 µm, and 0.72±0.10 µm, respectively. The roughness is not homogeneous, following lines for uncoated Ti while it is more spotted for coated samples, as observed on 3D Sa maps.

Conclusions: Electrochemical oxidation coatings enriched with Zn increased the roughness of CP Ti surfaces. The higher roughness of Types 2–4 may enhance osseointegration by promoting cell attachment and therefore would improve titanium’s surface properties for dental implants. Further research will expand the analysis of coating properties with SEM/EDS imaging, nano-indentation, and biological performance.