Advancing dental implants:Bioactive and therapeutic modifications of zirconia

Zirconium-based implants have gained popularity in the dental implant field owing to their corrosion resistance and biocompatibility,attributed to the formation of a native zirconia(ZrO_(2))film.However,enhanced bioactivity and local therapy from such implants are desirable to enable the earlier establishment and improved long-term maintenance of implant integration,especially in compromised patient conditions.As a result,surface modification of zirconium-based implants have been performed using various physical,chemical and biological techniques at the macro-,micro-,and nano-scales.In this extensive review,we discuss and detail the development of Zr implants covering the spectrum from past and present advancements to future perspectives,arriving at the next generation of highly bioactive and therapeutic nano-engineered Zr-based implants.The review provides in-depth knowledge of the bioactive/therapeutic value of surface modification of Zr implants in dental implant applications focusing on clinical translation.

Fresh or aged:Short time anodization of titanium to understand the influence of electrolyte aging on titania nanopores

Electrochemical anodization(EA)is a simple and cost-effective technique to fabricate controlled nanostructures on Ti substrates,such as TiO_(2)nanotubes and nanopores.Electrolyte aging of organic EA electrolytes(repeated EA using non-target Ti before EA of target Ti)is recognized to influence the characteristics of the anodized nanostructures.However,there is limited information about how surface topography and electrolyte aging dictate the formation and characteristics of the anodized nanostructures.In the current study,short-time EA(starting at 10 s)of micro-machined Ti substrates was performed with electrolytes of various ages(fresh/unused,15 h aged and 30 h aged),followed by evaluation of the TiO_(2)nanopores(TNPs)characteristics in terms of topography,chemistry,stability and protein adhesion.The results showed that aligned TNPs were obtained earlier(120 s)with fresh electrolyte as compared to the aged electrolyte EA(600 s).Interestingly,TNPs fabricated using fresh electrolyte(at lower EA times)showed favorable wettability,protein adhesion capacity and mechanical properties compared with aged electrolyte counterparts.The findings of the study demonstrate how nanopore formation differs between fresh and aged electrolytes when performing EA of micro-machined Ti,which provides an improved understanding of electrolyte aging and its influence on anodized nanostructures.

Hierarchical dual-porous hydroxyapatite doped dendritic mesoporous silica nanoparticles based scaffolds promote osteogenesis in vitro and in vivo

Biomaterial based scaffolds for treating large bone defects require excellent biocompatibility and osteoconductivity.Here we report on the fabrication of hydroxyapatite-dendritic mesoporous silica nanoparticles(HA-DMSN)based scaffolds with hierarchical micro-pores(5µm)and nano-pores(6.4 nm),and their application for bone regeneration.The in vitro studies demonstrated good biocompatibility of dissolution extracts,as well as enhanced osteogenic potential indicated by dose-dependent upregulation of bone marker gene expression(osteocalcin gene(OCN),osteopontin gene(OPN),collagen type I alpha 1 gene(CoL1A1),runt-related transcription factor 2 gene(RUNX2),and integrin-binding sialoprotein gene(IBSP)),alkaline phosphatise(ALP)activity,and alizarin red staining.The in vivo studies showed that HA-DMSN scaffolds significantly increased bone formation in a rat cranial bone defect model after 4 weeks healing.Our study provides a simple method to fabricate promising inorganic scaffolds with hierarchical pores for bone tissue engineering.