Removal torque for bone-cement and titanium screws implanted in rabbits.

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Tissue Engineering

Background:

• Bone defect repair often involves implantable devices.
• Biocompatibility and osseointegration are critical for implant success.
• Titanium and polymethyl methacrylate are common orthopedic implant materials.

Purpose of the Study:

• To compare the osseointegration and stability of titanium and polymethyl methacrylate implants in a rabbit tibia model.
• To evaluate the effect of implantation duration on implant stability.

Main Methods:

• Screw-shaped implants made of commercially pure titanium and polymerized methyl methacrylate were surgically placed into the tibias of rabbits.
• Animals were divided into two groups, with implants removed after 5 weeks and 9 months.
• Implant stability was quantified using removal torque measurements.

Main Results:

• Titanium implants exhibited significantly greater removal torque compared to polymethyl methacrylate implants at both 5-week and 9-month intervals.
• Higher removal torque indicates enhanced osseointegration and mechanical stability for titanium implants.
• The observed differences suggest varying biocompatibility and biological response between the two materials.

Conclusions:

• Commercially pure titanium demonstrates superior osseointegration and stability over polymethyl methacrylate in a rabbit tibia model.
• The findings support the use of titanium for orthopedic implants requiring robust bone integration.
• Lower biocompatibility of polymethyl methacrylate may limit its application in load-bearing bone applications.