History and Overview
- Barrier membranes for bone regeneration first described in orthopaedic research in 1959.
- Theoretical principles of guided tissue regeneration developed by Melcher in 1976.
- Research on potential for alveolar bone regeneration using guided bone regeneration in the 1980s.
- GBR principle examined by Dahlin et al. in 1988 on rats.
- Selective ingrowth of bone-forming cells improved with membrane, confirmed by Kostopoulos and Karring in 1994.
- Four stages for successful bone and tissue regeneration: primary closure, angiogenesis, space creation and maintenance, stability of the wound.
- Normal healing process after tooth removal takes 40 days.
- Chronic periodontitis results in breakdown of connective tissues and supporting bone.
- GTR surgery aims to regenerate periodontal tissues.
- GTR has greater effect on probing measures compared to open flap debridement.

Application and Current Treatments
- Barrier membranes first used in 1982 for regeneration of periodontal tissues via GTR.
- GBR technique uses barrier membrane to cover bone defect and create secluded space.
- Barrier membrane criteria: biocompatible, excludes unwanted cell types, allows tissue integration, creates and maintains space, easy to trim and place.
- Surgical techniques for bone reconstruction of severely resorbed maxilla using different types of bone substitutes.
- Non-resorbable titanium-reinforced d-PTFE membranes recommended for higher predictability.
- Conventional treatments for destructive periodontal disease unable to restore damaged bone and connective tissue support.
- GTR may be able to achieve regeneration and improve upon conventional surgical results.
- Two types of barrier membranes available: resorbable and non-resorbable.
- Main types of non-resorbable membranes: e-PTFE, high-density polytetrafluoroethylene, titanium mesh, and titanium-reinforced PTFE.
- Expanded polytetrafluoroethylene (e-PTFE) membrane commonly used in bone regeneration in the 1990s.
- Main types of resorbable membranes: synthetic polymers and natural biomaterials.
- Resorbable membranes can be obtained from bovine or porcine or dermis.
- Emdogain has been shown to improve probing attachment levels and periodontal pocket depth reduction.
- Resorption rates of resorbable membranes range from six to 24 weeks.
- No need for a second surgery to remove the resorbable membrane.

Importance of Guided Bone and Tissue Regeneration
- Promotes healing of regenerated tissues
- Prevents disruption to the healing process
- Enhances stability of augmented bone
- Improves facial bone thickness in the aesthetic zone
- Success depends on factors like presence of osteoblasts and sufficient blood supply

Synthetic Resorbable Membrane as an Alternative
- Synthetic resorbable membrane (e.g., Powerbone Barrier Membrane)
- Ideal alternative to collagen material
- Comparisons with collagen membrane in clinical trials
- Simultaneous use with dental implant placement
- Effective in maintaining stability of augmented bone

Factors Affecting Success of Guided Regeneration and Studies/Research
- Presence of osteoblasts at the site
- Sufficient blood supply
- Stabilization of the graft during healing
- Soft tissue not under tension
- Importance of proper conditions for successful regeneration
- Larsen P, Ghali GE (2004) - Principles of Oral and Maxillofacial Surgery
- Hurley LA et al. (1959) - Role of soft tissues in osteogenesis
- Melcher AH (1976) - Repair potential of periodontal tissues
- Wang HL, Boyapati L (2006) - Principles for predictable bone regeneration
- Liu J, Kerns DG (2014) - Mechanisms of guided bone regeneration

Clinical Applications and Techniques
- Guided tissue regeneration for periodontal infra-bony defects
- New attachment formation in periodontium through guided tissue regeneration
- Guided bone regeneration in severely resorbed maxilla
- Healing of bone defects using membrane technique
- Regeneration and enlargement of jaw bone using guided tissue regeneration