Design and applications of barrier membranes for guided bone regeneration.

Despite the placement of millions of dental implants annually, one-quarter to one-half of cases require concurrent guided bone regeneration (GBR), where a recent meta-analysis of 100 studies reported an approximately 26% complication rate that exposes the structural and biological limits of current barrier membranes. Conventional collagen and PTFE-based membranes function predominantly as passive occlusive barriers, lacking the bioactivity, controllable degradation, and immunomodulatory capacity demanded by the dynamic alveolar microenvironment, in which up to 50% of ridge width can be lost within 12 months post-extraction. Addressing this gap requires reframing GBR membranes as programmable interfaces. This review presents a three-lens framework - alveolar-bone-specific osteoimmune biology, metabolically active and stimuli-responsive material platforms, and translational bottlenecks - to systematically chart the field. We synthesize recent advances across four next-generation material families (polymer composites, biodegradable Mg/Zn alloys, MXene-based systems, and citrate-based polymers), four hierarchical structural strategies (bilayer, Janus, gradient, and 4D-printed architectures), and complementary functionalization strategies that include surface chemistry tailoring, bioactive ion release, and stimuli-responsive triggers, explicitly mapping how each modulates mechanical retention, degradation kinetics, antibacterial activity, and macrophage M1-to-M2 polarization. We further evaluate the clinical performance of these material platforms in alveolar ridge augmentation and identify platform-specific post-market follow-up endpoints required for regulatory translation. Finally, we articulate six open mechanistic questions and a near-term agenda integrating artificial intelligence/machine learning-driven design, microfluidic oral-microenvironment models, and standardized large-animal alveolar protocols. This framework repositions GBR membranes toward programmable, osteoimmune-active regenerative platforms, charting an actionable path from bench to clinic.