Since the introduction of guided bone regeneration (GBR) using nonresorbable membranes, membrane exposure has been categorized as one of the major complications associated with the procedure. Expanded polytetrafluoroethylene (e-PTFE) has a long history of use in GBR, and now the use of high-density PTFE (d-PTFE) is commonly reported in the literature. The major structural difference between these two materials is their permeability to bacteria: e-PTFE has an open-pore microstructure and is permeable to bacteria, while d-PTFE is not. Thus, there are fundamental differences in the two materials if premature exposure occurs. Protocols for classification and management of exposure specific to e-PTFE have been published and were well-received by clinicians, but these protocols do not necessarily apply to d-PTFE exposures. Because of the fundamental structural differences between these two PTFE materials, a protocol specific to the classification and management of d-PTFE membrane healing complications is required and is thus presented in this paper.
