Prognostic factors for alveolar regeneration:: effect of tissue occlusion on alveolar bone regeneration with guided tissue regeneration

Objectives: Design criteria for guided tissue regeneration (GTR) devices include biocompatibility, cell occlusion, space-provision, tissue integration, and ease of use. The objective of this study was to evaluate the effect of cell occlusion and space-provision on alveolar bone regeneration in conjunction with GTR. Methods: Routine, critical-size, 6 mm, supra-alveolar, periodontal defects were created in 6 young adult Beagle dogs. Space-providing ePTFE devices, with or without 300-mum laser-drilled pores were implanted to provide for GTR. Treatments were alternated between left and right jaw quadrants in subsequent animals. The gingival flaps were advanced for primary intention healing. The animals were euthanized at week 8 post surgery. The histometric analysis assessed regeneration of alveolar bone relative to space-provision by the ePTFE device. Results: A significant relationship was observed between bone regeneration and space-provision for defect sites receiving the occlusive (beta=0.194; p<0.02) and porous (beta=0.229; p<0.0004) GTR devices irrespective of treatment (p=0.14). The bivariate analysis showed that both space-provision and device occlusivity significantly enhanced bone regeneration. Hence, sites receiving the occlusive GTR device and sites with enhanced space-provision showed significantly greater bone regeneration compared to sites receiving the porous GTR device (p=0.03) or more limited space-provision (p=0.0002). Conclusions: Cell occlusion and space-provision may significantly influence the magnitude of alveolar bone regeneration in conjunction with guided tissue regeneration.