[A study on the stability of miniscrew on different loading time as orthodontic anchorage].

PURPOSE: To evaluate the stability of the miniscrew on different loading time as orthodontic anchorage.

METHODS: 2 healthy adult male Beagle dogs were used in this study. 48 mini-implants were implanted into the maxilla and mandible of the dogs. The miniscrews were divided into 8 different groups,1 group was loaded 0g as control group and the others were loaded 200g forces as experimental groups. 200g forces were loaded on the corresponding mini-implant anchorages immediately after implantation and at the time of 1w,2w,3w,4w,5w and 6w after implantation. The dogs were sacrificed at 12w after implantation. Histological progresses of implant-bone interfaces was examined with light microscope. Blue deposition and contact ratio were calculated and analyzed using SPSS13.0 software package.

RESULTS: Fibrous and osseous-integration was noted in the interface, there was no significant difference in bone deposition ratio and bone contact ratio.

CONCLUSION: Different force loading time does not affect the stability of the mini-implant anchorage.