LAUSR

Micro-implant stability has always been the focus of orthodontic clinical research.In the experiment, the morphological changes of bone tissue around the micro-implants in self-tapping and assisting implantation were investigated to explor the effect of different implantation on the osseointegration of micro-implants in order to provide some theoretical basis for c linical practice. Six adult male Beagle dogs were selected,three implants were implanted into the left and right maxillary bone of Beag le d gs at the 0th, 4 th and 6 week, respectively. One side to self-tapping implantation, the opposite side to assisting implantation. At the 8 th week of the experiment, the animals were sacrificed and the micro-implant-bone tissue specimens with the healing time of 8w, 4w and 2 were obtained.The specimens were stained with Toluidine Blue(TB) and photographed under 100X, 200X microscope. Morphology of microimplant-bone interface cells was observed under light microscope. In self-tapping group, there were some fibrous tissues surrou nding the micro-implants at the 2 th week, the formation of osteoblasts and osteoid was observed at the 4 th we k, the wavy and lamellar bone tissues were seen at the 8 th week.In assisting group,more collagen fibers were deposited around the micro-implant at the 2th week, there were a large number of osteoid-like cells, and the collagen was gradually replaced by the bone tissue at the 4 th week, the osteoblasts were active and the osteoblasts were linear arrange and form a laminate bone at the 8 th week.Whether implanted self-tapping or assisted implantation, micro-implant-bone interface reconstruction can occur. If the clinical need for early loading force, micro-implant try to choos e selftapping implantation. By appropriately prolonging the healing time, the initial stability of the micro-implant under assistive implantation can be improved.