Effect of Hafnium Coating on Osseointegration of Titanium Implants: A Split Mouth Animal Study

Vaishnavi Rajaraman,S Rajeshkumar,Padma Ariga,Karthik Ganesh,Deepak Nallaswamy,Dhanraj Ganapathy,Domenico Acierno

doi:10.1155/2021/7512957

Abstract

The behaviour of hafnium as surface coating in biological environments has not been studied. Little is known about osseointegration of hafnium-coated titanium implants. Thus, further studies of hafnium coating under biological conditions are required in order to determine the suitability of this material, as a surface coating for biomedical application. The aim of the study is to analyse the difference between hafnium-coated titanium and uncoated titanium by evaluating the osseointegration ability of hafnium metal and mechanism of which promotes better bone integration. The study was conducted with a split mouth design on 16 Wistar Albino rats of both sexes, at the age of 6-7 months, weighing 2526.5 ± 74.4 g . Self-tapping titanium osteosynthesis screws ( 4 mm × 2 mm ) (LeForte System Bone Screw®) were implanted in the mandible of rats: Group A (pure titanium screws, n = 12 ) and Group B (hafnium-coated screws, n = 12 ). The implanted screws’ stability was checked and noted with a specially customised torque apparatus during insertion and removal of implant. The tissue sections were then processed for hematoxylin and eosin and Masson’s trichrome for bone and connective tissue examination, after 4 and 8 weeks of placement. Hafnium coating appears to have offered similar biocompatibility (aspartate transaminase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) enzyme assay), statistically significant improvement (independent Student’s t -test, p < 0.05 ) in insertion torque ( 25.42 ± 3.965 ) and removal torque ( 29.17 ± 2.887 ) than commercially pure titanium with insertion torque ( 22.08 ± .575 ) and removal torque ( 25.42 ± 2.575 ). Hafnium coating in the rat mandible showed promising osseointegration with good tissue biocompatibility. Further human trials of hafnium-coated implants are needed to understand the biological behaviour better to enhance clinical performance.

Highlights

Tissue engineering is a novel and well-proven approach for repair and reconstruction of bone defects
Tantalum is shown to be promising in bone defect repair, its elastic modulus is much higher than that of human bone tissue and prone to stress shielding effect [15–25]
Hafnium belongs to the same period and block as tantalum, in the periodic table [26–32]

Summary

Introduction

Tissue engineering is a novel and well-proven approach for repair and reconstruction of bone defects. An ideal implant material should have properties that include biocompatibility, corrosion resistance, elastic modulus, and favour bone anchorage [1–14]. In various studies conducted till date, tantalum has revealed superior properties fulfilling criteria required for an implant which include excellent chemical stability, body fluid resistance, biological inertia, and remarkable osteoconductivity. Tantalum is shown to be promising in bone defect repair, its elastic modulus is much higher than that of human bone tissue and prone to stress shielding effect [15–25]. We wanted to evaluate alternative elements that may have the potential to offer equivalent or superior osseointegration. One such element of interest is hafnium. Hafnium belongs to the same period and block as tantalum, in the periodic table [26–32]

Objectives

Methods

Conclusion