Management of Retrograde Peri-Implantitis Using Guided Bone Regeneration.

Retrograde peri-implantitis (RPI) is characterized by atypical and often progressive bone loss at the periapex of a dental implant. Although RPI reportedly has a lower prevalence than marginal peri-implantitis, if left untreated it can lead to loss of dental implants. In this clinical case series, two patients with different presentations of RPI were treated with guided bone regeneration (GBR) using bone graft and collagen membrane. Longterm follow-up showed clinical and radiographic improvements that resulted in radiographic bone fill and reduced probing depths around implants. Observations reported herein suggest that GBR in defects caused by RPI is an effective treatment option.