Reosseointegration Following Regenerative Therapy of Tissue-Engineered Bone in a Canine Model of Experimental Peri-Implantitis

BackgroundDue to the existence of inflammation and limited osteogenesis on the precontaminated implant surface, reosseointegration is difficult to realize by current therapies. Tissue-engineering strategy has been proved quite effective in intractable bone defect situation. PurposeThis study was designed to see whether the adoption of tissue-engineered bone complex of adipose-derived stem cells (ASCs) and bone morphogenetic protein-2 (BMP-2) gene delivery would work efficiently in the correction of experimental peri-implantitis. MethodsAll premolars in both side of mandibular were removed from six beagle canines three months before implant placement. Typical peri-implantitis were then induced by three month ligature placement. After the implementation of identical anti-bacterial and mechanical debridement therapy, the shaped peri-implant defect were stuffed with four groups of constructs, as A: beta tricalcium phosphate (-TCP); B: -TCP with ASCs; C: -TCP with enhanced green fluorescent protein gene transduced ASCs (AdGFP-ASCs); and D: -TCP with bone morphogenetic protein-2 gene-modified ASCs (AdBMP-2-ASCs). Systematic radiographic, micro-CT, and histomorphometrical assessments were performed. ResultsAfter six months of healing, more bone formation and reosseointegration was found around the implant of groups B and C than group A. And group D further promoted the new bone height and reosseointegration percentage. Moreover, sequential fluorescence labeling tells that group D exhibited the quickest and strongest bone formation on the cleaned implant surface during the entire observation period as compared to the other three groups. ConclusionsThese data demonstrated that tissue engineered bone of ASCs, BMP-2 gene delivery, and -TCP could exert powerful therapeutic effect on peri-implantitis as expected, which may suggest a feasible way to maintain the stability and masticatory function of dental implant.