Volume 8 • 2021 • Issue 1

Guided bone regeneration (GBR) is a therapeutic, surgical modality used in implant dentistry to reconstruct alveolar ridges that are deficient as a result of tooth loss. This procedure is used for ridge augmentation before endosseous dental implant placement when there is insufficient bone volume. Guided Bone Regeneration: Two Case Presentations Vinay Bhide, DDS, MSc(Perio), FRCD(C) A ccording to Dr. Vinay Bhide, a periodontist from Aurora, Ontario, a successful GBR involves three key factors: a “scaffold” provided by particulate bone, the presence of undifferentiated cells from flowing marrow, and the presence of signallingmolecules. Dr. Bhide alsomentions the “PASS” principle for predictable bone regeneration, introduced by Dr. Hom-Lay Wang in 2006 1 : •  P rimary Closure •  A ngiogenesis through cortical perforations •  S pace maintenance provided by membrane •  S tability of wound “But what do we mean by successful regenerative outcomes?” asks Dr. Bhide. “Does it mean regeneration of bone or regeneration of enough bone to put an implant into where you don’t need to do anything more?” Dr. Bhide estimates that in 40 to 50% of cases, although adequate bone is regenerated to place implants, some additional augmentation is required. “Additional augmentation will not put off the restoration,” says Dr. Bhide. “Once the implants go in, you will have to wait the same amount of time, whether you have to add more or not. Also, when we typically go back into a regenerated site, in a lot of cases, the superficial bone tends to be a little bit softer. It is not uncommon for us to have to scrape the superficial bone away, which will take away some of the dimension that we tried to regenerate.” In this article, Dr. Bhide presents two case studies to demonstrate the intricacies of the GBR procedure. Although GBR is a highly predictive procedure in healthy patients (see Patient A ), further augmentation is required in a significant number of cases (see Patient B ). 33 Issue 1 | 2021 |