The microbial flora in the natural dentition sulcus/pocket and the implant crevice/pocket is very similar in both health and disease. In health, coccal forms predominate, and in disease, large numbers of Gram-negative pathogens are associated with both tooth and implant. It has also been demonstrated that the bacteria in the partially edentulous implant case may be more pathogenic (especially Gram-negative rods and spirochetes) than in the fully edentulous case, indicating a possible seeding mechanism from tooth pocket to implant crevice. Detoxification procedures involving the use of tetracycline and citric acid prior to regenerative procedures with the use of barrier membranes and grafting materials are necessary, and the same problems attendant to premature exposure of the barrier membrane(s) in the natural dentition situation apply to the implant case. It is apparent that periodontitis = peri-implantitis in etiology and therapy.