Decontamination of Ti Oxide Surfaces by Using Ultraviolet Light: Hg-Vapor vs. LED-Based Irradiation

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Mercury (Hg)-vapor lamps emitting C-range Ultraviolet (UVC) light are known for hydrocarbon decontamination and antimicrobial effects on titanium surfaces.
• Surface modification of titanium dental implants is crucial for improving their performance and biocompatibility.

Purpose of the Study:

• To compare the effectiveness of mercury (Hg)-vapor lamps and Light Emitting Diodes (LEDs) for photofunctionalization of titanium dental implant surfaces.
• To investigate the surface chemistry modifications induced by UVC irradiation from both Hg-vapor lamps and LEDs.

Main Methods:

• Titanium dental implants were irradiated for 12 minutes using a mercury (Hg)-vapor lamp (λ = 254 nm) and Light Emitting Diodes (LEDs) (λ = 278 nm).
• X-ray Photoelectron Spectroscopy (XPS) was utilized to analyze the surface chemical composition (carbon, oxygen, titanium) before and after UVC treatment.

Main Results:

• Both UVC technologies demonstrated a reduction in surface hydrocarbons, decreasing from approximately 26 to 23.4 atomic percent (at.%).
• Simultaneously, an increase in the surface concentration of oxygen and titanium was observed following UVC irradiation.
• LED-based UVC photofunctionalization proved as effective as Hg-vapor lamps in removing hydrocarbons from titanium surfaces.

Conclusions:

• LED-based UVC technology is a viable and effective alternative for the decontamination of titanium dental implants.
• Given increasing global mercury restrictions, LEDs present a promising, mercury-free solution for surface photofunctionalization, maintaining efficacy comparable to traditional Hg-vapor lamps.