[Impact of dental implant insertion method on the periimplant epithelial seal--experimental study on dogs]

There is a controversial opinion among implantologists on the method of dental implantation that provides more favourable response of soft and bone tissues. The aim of this study was to pathohistologicaly compare the influences of one- and two-phase implant surgical methods on the periimplant epithelial tissues.

The experiment was performed on 10 dogs. Eight weeks following tooth extractions implants were inserted using one phase method on the right side of the mandible, and two-phase method on the left one. Three months after implantation the animals were sacrificed. Contact regions of epithelial and subepithelial tissues and implants were pathohistologicaly examined, the elements of analysis were scored and compared.

Epithelial tissue was not found in the two samples of one-phase implants, while in the remainder of samples the structure of basal membrane was preserved, massive inflammatory infiltrate was found in one, and partial necrosis was found in three samples. Epithelial tissue was not found in the three samples of two-phase implants, in three samples the structure of basal membrane was intact, while in three remained samples the membrane could not be detected; moderate inflammatory infiltrate was found in four samples and massive inflammatory infiltrate in both two remained samples; tissue necrosis, which was observed in the half of the samples, was complete. In subepithelial gingival tissues around one-phase implants the number of blood vessels was increased in three samples, accompanied by the thickening and dilatation of vascular walls, proliferation of blood elements, altered vascular walls and inflammatory cell infiltrate was found in four samples.

On the base of the analized characteristics of epithelial and subepithelial tissues in contact with dental implants, one-phase method of implantation showed a more favorable tissue response.