The term Guided Tissue Regeneration was coined by Gottlow et al. in1986 to designate techniques that enhance selective cell population on the root surface from fibroblasts and other progenitor cells originating in the periodontal ligament. It has been defined by Chung as the creation of an environment, which following a periodontal flap procedure allows the cells from periodontal ligament to repopulate the debrided root surface area and form new periodontal attachment. This guided tissue regeneration (GTR) concept led to the use of different materials in periodontal regenerative therapy. The first material clinically used in periodontal surgery, allowing regeneration of cementum, periodontal ligament and alveolar bone, was cellulose acetate laboratory filter. Thus, for the first time periodontal regeneration as a response to GTR was histologically verified. Since that time, membranes from different materials for achieving periodontal regeneration have been developed and modified.