The closed hole on the head of the OT Equator attachment and the epithelium connective tissue junction that forms between the surface of the attachment and the outer soft tissues restrict or prevent any inflammatory phenomena, mucositis, and in many cases peri-implantitis and peri-implant bone resorption.
Here you can see two cases where the effectiveness of the barrier is demonstrated.
"The uncomfortable truth: neither the specific dimensions of these tissues nor their stability dependent on time and even the influence of the ecosystem were determined scientifically. We are faced with a biological barrier, nothing more and nothing less."
(Walton - Int. J. Prosthodontics - 2011)