Titanium Implants after Alkali Heating Treatment with a [Zn(OH)₄]²⁻ Complex: Analysis of Interfacial Bond Strength Using Push‐Out Tests

BACKGROUND: Clinical demands for stronger and faster bone bonding to implants have motivated the development of chemically and topographically modified surfaces capable of chemical bonding. This study presents a new one-step alkali heat treatment performed with a solution containing [Zn(OH)(4)](2-) complex as an alternative to the conventional NaOH solution. PURPOSE: The objective of this work is to assess the effect of a Zn-modified surface chemistry on bone-implant shear strength using a rabbit model. MATERIALS AND METHODS: The study was conducted on mechanical-grinded and smooth surfaces of Ti cylindrical implants. The topographical structure, chemical surface composition, and structural properties of the chemically modified titanium surface were studied by scanning electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffractometry. Implant-bone shear strength was evaluated by push-out tests undertaken at 4, 12, and 24 weeks after insertion in rabbit femora. RESULTS: Implants with smooth and rough surfaces chemically-modified with a solution containing [Zn(OH)(4)](2-) complex demonstrated significantly stronger bone fixation than nonmodified implants at all healing times (p < 0.05). CONCLUSIONS: The obtained results suggest that biochemical bonding at the bone-implant interface, stimulated by the Zn(2+) ion release in combination with mechanical interlocking definitively improved the implant fixation.