Biological responses of anodized titanium implants under different current voltages

Area of Science:

• Biomaterials Science
• Orthopedic Research
• Surface Engineering

Background:

• Titanium's stable oxide layer promotes biocompatibility and osseointegration.
• Anodic oxidation is a key surface modification technique for titanium implants.
• Understanding the impact of varying oxidation voltages is crucial for optimizing implant performance.

Purpose of the Study:

• To investigate how high anodic oxidation voltages affect titanium implant surface properties.
• To evaluate the biological response, specifically bone tissue integration, in rabbit tibiae.
• To determine the optimal voltage for enhanced osseointegration.

Main Methods:

• Commercially pure titanium (Grade II) screw-shaped implants with microthreads were anodized at 300 V, 400 V, 500 V, and 550 V.
• Surface characteristics (morphology, roughness, oxide layer thickness) were analyzed.
• Implants were inserted into rabbit tibiae, with removal torque tests and histomorphometric analysis performed after 1 and 3 months.

Main Results:

• Increasing anodic oxidation voltage above 300 V rapidly increased oxide layer thickness and pore size.
• Surface roughness increased up to 500 V, then decreased at 550 V.
• Implants oxidized at 500 V (Group III) showed significantly higher removal torque after 1 month compared to lower voltages.
• Groups III and IV exhibited significantly greater bone-to-implant contact ratios after 3 months compared to Group I.

Conclusions:

• Anodic oxidation voltage significantly influences titanium implant surface characteristics and osseointegration.
• Voltages around 500 V appear optimal for enhancing early bone integration and implant stability.
• Higher oxidation voltages (500 V and 550 V) promote superior bone-to-implant contact in the long term.