Periodontal disease destroys teeth-supporting bone. In some instances, this destruction results in bone defects with bacterial-conducive morphology. In these cases, thorough debridement is not enough to control the inflammatory condition. Depending on the angle and size of the bone defect as well as other factors, the periodontist will either reshape this defect to be non-bacterial conducive or will attempt to regenerate the lost bone through Guided Tissue Regeneration.