Background: Guided bone regeneration is frequently performed to augment deficient alveolar ridges. Although many materials may be used for these procedures, the outcome is usually predictable. In this report, we present an unusual reaction to a frequently used commercially available xenograft material.
Methods: A 36-year-old African American male was referred for restoration of edentulous space #8. Examination confirmed a ridge inadequate for implant placement without augmentation. A staged approach was chosen, with augmentation by a mixture of autogenous bone and anorganic bovine bone with platelet-rich plasma and a bioabsorbable collagen membrane. Healing was uneventful, although after 4 months, upon flap reflection, no regenerated hard tissue was found. The tissue at the site was submitted for histology, and the site was regrafted with an allograft/xenograft mixture and covered by a bioabsorbable collagen membrane. Wound healing was uneventful, and a histologic core was obtained at implant placement 5 months later.
Results: The initial histologic specimen consisted of a fibrous connective tissue matrix supporting islands of the anorganic bovine bone. The majority of the graft material demonstrated an intimate association with multinucleated foreign body-type giant cells. The histologic core obtained at the second procedure consisted of trabeculae of viable lamellar bone and associated fibrous connective tissue without a significant inflammatory cell infiltrate. Scattered particles of anorganic bovine bone were present, but no foreign body-type giant cells were identified.
Conclusion: Failure of commonly used materials for guided bone regeneration is rare; however, different batches of materials may elicit varying immune responses in the recipient.