ABSTRACT
BACKGROUND:Nanosilver has significant antibacterial properties, and nanohydroxyapatite has good biological activity and mechanical strength, while their mixture cannot only promote bone formation but also have antibacterial properties. OBJECTIVE:To observe the effect of nanosilver and nanohydroxyapatite mixed filing on the osseointegration of immediate implants. METHODS: Nine New Zealand white rabbits were randomly divided into experimental group (n=6) and control group (n=3) after four incisors from the upper and lower jaw were extracted. The mixture of nanosilver and nanohydroxyapatite was filed into the tooth socket in the experimental group, while nanohydroxyapatite was filed into the tooth socket in the control group. Titanium screw was immediately implanted into both groups. The intact maxila and mandibular specimens were harvested at the 4th, 8th, and 12th weeks after operation. Gross observation, X-ray bone density analysis, torque test and histological observation were conducted. RESULTS AND CONCLUSION:The gray value and maximum torque value of regenerated osseous tissue at different time points in experimental group were significantly higher than those in the control group (P < 0.05). Within 12 weeks of implantation, the bone formation rate and maturity of new bone tissue were higher in the experimental group compared with the control group, and no inflammatory cel infiltration occurred. At the 4th week after implantation, there was a large amount of inflammatory cel infiltration, and few inflammatory existed at the 8th week after implantation. These results demonstrate that compared with nanohydroxyapatite alone, the mixture of nanosilver and nanohydroxyapatite shows better antibacterial effect, biocompatibility and osteoinductive ability, which may accelerate osseointegration and promote osteogenesis.