Immunohistochemical analysis of blood vessels in peri-implant mucosa: a comparison between mini-incision flapless and flap surgeries in domestic pigs

Abstract

AimThe aim of this experimental study is to compare the effect of mini-incision flapless versus flap technique of implant placement on the amount of vascular structures and blood vessel elements in peri-implant soft tissue, using immunohistochemical analysis. MethodThe experiment was conducted on five domestic pigs. Each animal received six implants in mandible according to the split-mouth design. On one randomly chosen jaw side, mini-incision flapless surgery was performed, whereas on the opposite jaw side, flap was raised. After 3months of implant healing through submerged approach, the experimental animals were sacrificed and samples for immunohistochemical analyses were taken from the buccal side of peri-implant mucosa next to the neck of implants, from three levels. The study outcome was the presence of vascular structures and elements of the blood vessels in the peri-implant mucosa per microscopic field, estimated through ordinal scores from 0 to 2. Effects of surgical approach, site of implantation, and their interaction on vascular scores of peri-implant mucosa were assessed by Brunner and Langer nonparametric analysis of longitudinal data. ResultsStatistically significant effect of surgical approach on vascularity of peri-implant mucosa has been revealed in the second mucosal layer, where flapless approach provided higher vascularity compared with flap approach (P=0.002). In the remaining two layers, surgical approach did not affect mucosal vascularity significantly (layer 1: P=0.071; layer 3: P=0.433). ConclusionThe flapless surgical implant placement approach using mini-incision provides better vascularization of peri-implant mucosa after 3months of healing compared with flap surgery.