Immunohistochemical detection to evaluate the biological role of Ti implants coated by a combination of fibronectin protein and hydroxyapitate (EPD)‎ : in vivo study

Abstract EN

Background : physicochemical and biochemical coating techniques that are investigated now a day to enhance bone regeneration at the interface of titanium implant materials.

The combination, however, of both organic and inorganic constituents is expected to result into truly bone-resembling coatings and as such to a new generation of surface-modified titanium implants with improved functionality and biological efficacy.

This research was conducted to study the expression of osteocalcin and growth hormone receptor as bone formation markers in coated and uncoated implant in interval periods (3days, 1, 2and 6 weeks).

Materials and methods: Commercially pure titanium (CpTi) implants coated with hydroxyapatite by EPD method and with fibronectin protein, were placed in the tibia of (16) New Zeland white rabbits, immunohistochemical tests for detection of expression of osteocalcin and growth hormone receptor were performed on all the implants of both control and experimental groups (3days, 1, 2 and 6 weeks) healing intervals.

Mechanical test (torque removal test) was performed as an indicator for the presence of osseointegration and as a test for the mechanical property of bone-implant interface to be primarily propping the interface machanics.

Results : the removal torque mean values in all studied groups uncoated and coated were increasing with advancing time (higher at 6 than 2 weeks periods) and coated implant showed high value in comparsion to control.

Result shows that Immunohistochemical findings revealed high positive expression range from strong to moderate for osteocalcin and growth hormone receptor in coated implant in comparison to uncoated.

These results indicating that a mixing of bioactive HA ceramic and FN increased the activity of coated layer which improved the bone formation and maturation in bone-implant interface and enhance mechanical interlocking with bone.

Conclusions : the present study concludes that organic and inorganic surface modification for titanium implant surface by HA and FN enhances bone formation and increase osseointegration.