Immunohistochemical characteristics of regenerated bone after surgical therapy of advanced ligature-induced peri-implantitis defects.

This study seeks to assess and compare immunohistochemical characteristics of regenerated and pristine bone areas following surgical therapy of advanced peri-implantitis. At ligature-induced peri-implantitis defects, the intrabony component was filled with a natural bone mineral (NBM), and the supracrestal component was treated by either an equine bone block (EB) or implantoplasty. NBM and EB were soak-loaded with rhBMP-2 or sterile saline. Membrane (i.e., native collagen) protected sites were submerged for 12 weeks. Osteocalcin (OC) and transglutaminase 2 (TG2; angiogenesis) antigen reactivity was assessed within the augmented-(AA) and pristine bone (PB) areas at non-exposed sites (n = 39 defects). In all groups investigated, mean OC (AA, 0.5 ± 0.4 to 1.9 ± 2.9 %/PB, 1.7 ± 2.6 to 3.5 ± 6.5 %) and TG2 (AA, 0.6 ± 0.5 to 1.3 ± 1.5 %/PB, 0.5 ± 0.5 to 1.6 ± 1.9 %) values within AA did not significantly differ from those values assessed within PB (P > 0.05, respectively). AA formed in different treatment groups may not be considered as qualitatively (i.e., OC and TG2) compromised bone.