Evaluation of Mechanical and Histological Significance of Nano Hydroxyapatite and Nano Zirconium Oxide Coating On the Osseointegration of CP Ti Implants

Abstract

Background: Dental implant considers a unique treatment option for the replacement of missing dentition. The newtrend of implants is looking for materials which accelerate bone formation in bone implant interface and enhanceosseointegration to provide immediate loading directly after placement and decrease the time period which isdisturbs patients and uncomfortable. The aim of the study was to evaluate the effect of nano zirconium oxide (ZrO2)and nano hydroxyapatite (Hap) mixture coating of screw shaped commercially pure titanium (cpTi) implants onbond strength at the bone implant interface with torque removal test and histological analysis in comparison withnon coated implants.Materials and methods: Forty screws were machined from cpTi rods using a lathe machine. Then 20 screws coatedby electrophoretic deposition method by a mixture of nano hydroxyl apatite and nano zirconium oxide, while theother 20 screws remain uncoated. The tibia of 10 adult white New Zealand experimental rabbits was chosen asimplantation site, each rabbit tibia received 2 screws, one coated and the other uncoated. Torque removal test wasperformed to measure the torque required to remove the screw and histological analysis was performed to observethe new bone formation, after 2 and 4 weeks healing intervals.Results: Implant coated with a mixture of nano zirconium oxide and nano hydroxyl apatite showed a significantlyhigher removal torque values compared to uncoated one. There was more new bone formation with coatedimplants for both healing periods.Conclusions: Coating by electrophoresis considers a valuable process to coat metallic implants with a ceramicmaterial and to form a uniform composite layer of coating. Osseointegration improved at bone-implant interfaceassociated with the coated implants, which was illustrated by higher bone formation at the two intervals of time 2weeks and 4 weeks.