Abstract
The purpose of this study was to examine which type of membrane was the most suitable for guided tissue regeneration (GTR) among three types of polypropylene membranes with the pore size 30.0, 5.0 and 0.6μm. Twelve rabbits and eight dogs were used in this study and the bony cavities were covered with these types of membranes. The histological evaluation was done to observe the grade of bone remodelling. The results were as follows : 1. In the control groups, the new bone tissue grew in a hollow shape. 2. In the groups covered by the membranes with the pore size 30.0μm and 5.0μm, the fibrous connective tissue invaded into the space between the membrane and the new bone tissue which appeared in a hollow shape. In addition, the penetration of cells and fibers into the porous structure of the membranes was noted. 3. In the groups covered by the membrane with the pore size 0.6μm, the new bone tissue grew near the membrane and the bone regeneration was almost completely formed. In addition, there were few cells which penetrated into the porous structure of the membrane. 4. In the groups of rabbits covered by the membrane with the pore size 0.6μm, the membrane appeared to guide the way that the new bone tissue grew. 5. In the groups covered by the membranes with the pore size 5.0μm and 0.6μm, the mineralization of the bone was delayed when they were compared with the control groups and with the groups covered by the membrane with the pore size 30.0μm. This study suggests that the most suitable porous membrane which can be used in the bone augmentation is that which can keep cells and fibers from penetrating into the porous structure of the membrane.
