Study On Histological Alterations Of Different Part Of The Jaw Bones Surrounding Microscrew Implant For Anchorage

Obtaining and controlling adequate anchorage is a requirement for achieving successful results during orthodontic treatment. Traditional orthodontic anchorage have played a very important role, but they are not enougth when dental elements lack quantity or quality, extraoral devices are impractical or noncompli-ance during treatment is likely. The growing demand for orthodontic treatment method that require minimal compliance,particularly by adults, and the importance placed on esthetic considerations by all patients have led to the development of implant technology.Microscrew implant have been used in resent years for anchorage in orthodontic treatment. However opinions about the histological alterations of micro-screw implant with jaw bones were varied. The aim of this study was,through the animal experiment, to observe histological alterations of the different part of the tissue surrounding microscrew implant loaded with 1. 96N horizontal force for eight weeks, and to discuss the healing mode of jaw after insertion of microscrew implant .Material and MethodsMaterial;Three male crossbred dogs. Twelve microscrew implant and affiliated appliances. Blade microtome. Scanning electron microscope.Methods;The microscrew implant were inserted in the vicinity of upper canines of three crossbred dogs respetively, two microscrew implant in one side of each dog were chosed randomly. They were loaded with a horizontal force of 1.96N immediately by superelastic nickel - titanium coil spring. Two unloaded mi-croscrew implant in the other side served as control group. The force were adjusted every two weeks. These dogs were sacrificed at eight weeks. The jaw bones of each dog were fixed, decalcified and sectioned. These sections were observed under optical microscope and scanning electron microscope.ResultAfter insertion and orthodontic loading, no mobility of the implants was observed.The interface between cervical of implant and bone was filled with fibrous tissue, while the middle and apex parts of implant almost completely contacted with bone, few fiber bundles was found between implant and bone.But in specific slice among experimental group there were fibrous tissue from cervical to apex and there was no difference between each part.ConclusionWhen the force was loaded instantly, histologic analyses showed that there was a uniform intimate bone —implant contact in the middle and apex parts,but not in cervical part because fibrous tissue was present there.