The effect of guided tissue regeneration procedures on the healing of osseo
us defects was studied in Sprague-Dawley rats. A full thickness flap was re
flected and two 5 mm defects were made in the calvaria of 17 rats. A resorb
able membrane was placed over one defect in each animal, while the remainin
g defect sewed as a control, After 3, 5, or 7 wk, healing of the osseous de
fects was evaluated histologically. There was no statistical difference in
bone regeneration between experimental and control sites at any time period
.