Detailed process of bone remodeling after achievement of osseointegration in a rat implantation model.
Osseointegration is regarded as the most appropriate implant-bone interface in dental implantation. However, damaged bone with empty osteocytic lacunae driven by implant cavity preparation remains even after the completion of osseointegration. Although previous studies have suggested the occurrence of bone remodeling around implants, information on its detailed process is meager. Our study aimed to examine the fate of bone around titanium implants after the establishment of osseointegration on an animal model using the rat maxilla. Titanium implants were inserted into prepared bone cavities of the rat maxilla. Bone formation and maturation processes were evaluated by double staining for alkaline phosphatase and tartrate-resistant acid phosphatase, immunohistochemistry for bone matrix proteins, vital staining with calcein, and elemental mapping with an electron probe microanalyzer. Bone with empty osteocytic lacunae or pyknosis remained between the intact preexisting and newly formed woven bones at post 1 month. It gradually decreased to disappear completely by active bone remodeling with a synchronized coordination of alkaline phosphatase-positive osteoblasts and tartrate-resistant acid phosphatase-reactive osteoclasts at post 3 months, thickening to be replaced by compact bone. Dynamic labeling showed two clear lines in the newly formed bone around the implant through this experimental period. Electron probe microanalyzer analysis demonstrated chronologically increased levels of Ca and P in the newly formed bone identical to those in the surrounding bone at post 2.5 months. These findings indicate that continuous bone remodeling after the achievement of osseointegration causes replacement of the damaged bone by compact bone as well as an improvement in bone quality. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.
Haga
Maiko
M
Division of Oral Health in Aging and Fixed Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Fujii
Noritaka
N
Nozawa-Inoue
Kayoko
K
Nomura
Shuichi
S
Oda
Kimimitsu
K
Uoshima
Katsumi
K
Maeda
Takeyasu
T
D000818:Animals; D016723:Bone Remodeling / Q000502:physiology*; D020007:Implants, Experimental; D008297:Male; D008437:Maxilla / Q000166:cytology / Q000502:physiology; D023421:Models, Animal; D016348:Osseointegration / Q000502:physiology*; D010010:Osteoclasts / Q000166:cytology / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar