Perigraftitis, an independent biologic complication associated with implants placed in grafted bone.

backgroundPerigraftitis is a recently introduced concept describing biologic complications specifically associated with implants placed in grafted bone. It is characterized by inflammation resulting from bacterial colonization of grafted bone and/or residual graft particulates. Reported cases have been managed by removal of the implant, grafted bone, and surrounding inflammatory tissue, and therefore have not definitively established perigraftitis as an independent disease entity. This report describes a histologically confirmed case of perigraftitis treated successfully without implant removal, supporting its recognition as a distinct pathologic condition.

methodsA 63-year-old healthy, nonsmoking Asian male presented with discomfort, and a foul taste around implant #31, placed in a site previously grafted with deproteinized bovine bone mineral. Examination revealed infection and bone loss that centered on the grafted bone, and the site was diagnosed with perigraftitis. The implant crown was removed, and surgical access was obtained using a laser. Three hard tissue specimens were removed and submitted for histology, revealing numerous graft particulates surrounded by mature necrotic host bone with bacterial aggregates within intertrabecular spaces of all three specimens. The site was thoroughly debrided and allowed to heal without the use of any biomaterials.

resultsThree weeks post-treatment, symptoms had resolved. At 13.5 months post-treatment, crestal bone regeneration up to the implant collar was observed. Vertical implant soft tissue augmentation with a subperiosteal circumferential connective tissue graft was then performed, and the implant crown was reseated following soft tissue healing.

conclusionsThe histologic findings and clinical outcome of this case support the recognition of perigraftitis as an independent disease entity. Further controlled studies are warranted to elucidate the etiopathogenesis, risk factors, and prevalence of perigraftitis, and to optimize its prevention and treatment. KEY POINTS: Perigraftitis may be considered an independent disease entity, distinct from peri-implant mucositis and peri-implantitis. Perigraftitis is an inflammatory response induced by bacterial colonization of grafted bone and/or residual graft particulates, with the implant fixture and its transmucosal components likely providing the pathway for oral bacteria to access and infect the grafted bone. Perigraftitis may be successfully resolved through the removal of the infected grafted bone and associated inflammatory tissue without the need for implant removal. PLAIN LANGUAGE SUMMARY: A patient had discomfort, foul taste, and bone loss around an implant on the lower right jaw that had been placed into grafted bone. The site was diagnosed with perigraftitis, defined as inflammation resulting from infection of the grafted bone. The implant crown was removed, and a laser was used to obtain surgical access. Three hard tissue masses were removed and submitted for biopsy. The site was thoroughly cleaned and allowed to heal naturally. After 3 weeks, the patient reported discomfort and foul taste had resolved. Thirteen and a half months after treatment, bone had regenerated around the implant. Vertical implant soft tissue augmentation was then performed. The implant crown was reseated after soft tissue healing. The tissue biopsy confirmed infection of the grafted bone and the diagnosis of perigraftitis. The treatment outcome supports perigraftitis as an independent disease entity, distinct from peri-implant mucositis and peri-implantitis.