Effects of micro/nano strontium‐loaded surface implants on osseointegration in ovariectomized sheep

Abstract

Background Poor osseointegration of dental implants often occurs in osteoporotic patients and processed implant surfaces could help to improve the dilemma. Purpose This study aimed to compare the effects of different titanium (Ti) surfaces on bone‐implant osseointegration in ovariectomized (OVX) sheep. Materials and Methods Four groups were included: smooth titanium (ST) was merely polished Ti; micro titanium (MT) was treated with hydrofluoric acid (HF) for 30 minutes; strontium‐loaded nano titanium (NT‐Sr) was formed by magnetron sputtering; strontium‐loaded micro/nano titanium (MNT‐Sr) was fabricated by HF etching combined with magnetron sputtering. The biological responses were evaluated by human bone marrow‐derived mesenchymal stem cells (hBMMSCs) experiments in vitro. Osseointegration was evaluated in vivo after each surface implant was inserted into OVX sheep’ mandibles. Results The numbers of adhered and mineralized hBMMSCs increased significantly in the MNT‐Sr group. The bone‐implant contact and the maximal pull‐out force increased significantly with MNT‐Sr surface. The bone volume ratio and trabecular number of the MNT‐Sr group were significantly higher than others, whereas trabecular separation decreased. Conclusions These results indicated that an MNT‐Sr surface promotes the differentiation of hBMMSCs in vitro and enhances bone‐implant osseointegration in vivo, which may be a promising option for clinical implants in osteoporotic patients.

Gradient nanostructured titanium stimulates cell responses in vitro and enhances osseointegration in vivo

“…Zhu et al (40) implanted bioceramics with nano/micro surface into the long bone defect of Beagle dogs, and tight osseointegration was observed at 12 weeks after surgery, while there were still gaps between the implant surface and bone in the control group. In addition, Liu et al (41) implanted strontium-loaded micro/nano Ti into the mandible of ovariectomized sheep, and the results showed the BV/TV and the Tb.N of nano/micro surfaces are significantly higher and Tb.sp is lower than those in other groups. The improved bone tissue morphology parameters in the animal model indicate that GNS Ti may be further applied in the field of dental implants.…”

Local tissue effects and peri‐implant bone healing induced by implant surface treatment: an in vivo study in the sheep

“…Considering the current experimental conditions and results, it is therefore assumed that both REF and TEST implants would achieve long-term stability. However, by positively affecting coronal BIC results both at 4 weeks and 13 weeks compared to the REF implant, it is supposed by the authors that the surface treatment applied to the TEST implant may be of interest for improving osseointegration of implants in bone of poor quality such as osteoporotic bone (19).…”

“…To our knowledge, very few in vivo studies assessed the combined influence of micro and nanofeatures on dental implant osseointegration, and these were only conducted either on small animals (16,17) or for very short periods (18). Recently, Liu et al (2019) studied screw-shaped cylinders implanted for three months in osteoporotic sheep mandibulars and found higher biomechanical parameter values for surfaces presenting micro/nanofeatures (19). However, no assessment of the neo-bone formation, of fibrosis, nor of the bone texture was conducted in this study.…”

Biofunctional Elements Incorporated Nano/Microstructured Coatings on Titanium Implants with Enhanced Osteogenic and Antibacterial Performance

“…[53,[89][90][91][92] An in vivo test of Sr-loaded nano/microstructured implants (MNT-Sr) has been performed on ovariectomized sheep and MNT-Sr exhibits enhanced osseointegration. [93] Compared with rats and rabbits, sheep have some advantages in imitating humans. Sheep are docile, easy to handle, and large enough for serial sampling and have hormone profiles, mineral metabolism, and bone structures similar to humans.…”