Application of a novel resorbable membrane in the treatment of calvarial defects in rats.

Diplen-Gam (DG) is a novel absorbable guided bone regeneration (GBR) membrane. This study was designed to evaluate the capacity of bone repair of DG compared with that of Bio-Gide (BG). Critical size defects were created in both sides of the calcarium of 36 Sprague-Dawley rats. Defects were assigned to six groups and each group was subjected to one of the following treatments: (A1) unfilled defects, (A2) Bio-Oss (BO) grafts, (B1) DG membrane, (B2) BG membrane, (C1) DG membrane + BO grafts and (C2) BG membrane + BO grafts. The animals were killed at 2, 4, 8 and 12 weeks after the operation. The defects and surrounding tissues were examined by gross observation and X-ray examination. The paraffin sections were subjected to HE (hematoxylin and eosin) staining and IHC (immunohistochemistry) for bone morphogenetic protein-2 (BMP-2). The X-rays showed that, at 12 weeks, the DG and BG group exhibited more new bone formation than CSD blank group did; the BG group exhibited more new bone formation than the DG group did (t = 5.240, P = 0.035), the BG + BO group showed no significant differences in bone formation compared with the DG + BO group (t = 1.246, P = 0.339). By IHC staining, BMP-2-positive results could be seen inside the DG membrane, on the surface of the new bone, and inside the new bone. It can be suggested that BG membrane achieved better effects in guided bone regeneration compared with DG membrane. No significant differences were found between the two membranes in their bone healing ability when they are used with BO. Therefore, DG membrane shows clinical effectiveness, but should be used in combination with bone substitute.