Experimentelle Untersuchung zur Alveolarkammaugmentation mit Poly-(D,L-)Laktid-Membranen

Abstract

The objective of this experimental investigation was to assess the regeneration of alveolar bone defects using a rigid synthetic barrier system (PDLLA) in a shell technique with natural bone mineral (NBM) respectively a mix with autologous bone (AB). Four saddle-type defects were prepared in each lower jaw of six foxhounds. The outer contours of two groups were reconstructed using poly-(d,l-)lactide-pins welded to a 0,1mm poly-(d,l-)lactide-membrane (PDLLA) by ultrasound vibration. For augmentation the defects were filled using either a natural bone mineral (NBM) or a mix of NBM and autologous bone (AB), covered by a native collagen membrane (CM). The third defect was augmented using NBM, AB and CM, while the fourth site was left untreated. At 14 weeks, dissected blocks were processed for histological and histomorphometrical analysis. Histological analysis showed a very good osseointegration of NBM. A few dislocated particles caused a resorption of bone. No resorptions were found at shell technique augmented defects. Regenerated bone values were increased in all guided bone regeneration (GBR) groups [NBM+PDDL+CM (17,94mm2) > NBM+AB+PDDL+CM (16,52mm2) > NBM+AB+CM (14,76mm2)] when compared with the untreated control sites (6,45mm2). The difference between the PDLLA group and the control group was statistically significant (NBM+AB+PDLLA+CM – control: p=0,043; NBM+PDLLA+CM – control: p=0,017). Comparing the defect sites with healthy reference sections all GBR groups showed an almost complete regeneration. [NBM+AB+PDDL+CM (112,20%) > NBM+PDDL+CM (99,79%) > NBM+AB+CM (99,60%) > control (46,61%)]. The differences between the GBR group and the controls were significant [NBM+AB+PDLLA+CM – control: p=0,006; NBM+PDLLA+CM – control: p=0,028; NBM+AB+CM – control: p=0,028). Analyzing the density, no significant differences could be found in all groups. All GBR procedures investigated comparably supported bone regeneration, the application of PDDL may show a higher rigidity of the augmentation with less complications caused by movements of particles. AB may not improve healing at NBM+PDDL+CM-treated sites.