Abstract
Background:
In the field of periodontology pathogenic mechanism, the periodontium is subjected to a range of pathological conditions leading advanced stages to bone resorption at the alveolar crest and subsequent detachment of the periodontal ligament with different degrees of furcation involvement and finally tooth loss. Therapy aims at restoring the lost parts of the periodontium by different regenerative procedures.

Aim:
The aim of the present study was to evaluate using the bio-absorbable amniotic membrane as guided tissue regeneration (GRT) combined with bone autograft as guided bone regeneration (GBT) in dogs affected with advanced degree III furcation in marrow dogs.

Methods:
The study was performed on 18 mandibular right premolar teeth units (6 dogs) affected with experimentally induced advanced furcation involvement (III degree- key hole). The left mandibular affected premolar teeth assigned as a control. Therapy was by using the amniotic membrane of dogs as GTR and iliac bone marrow autogenous graft as GBR. Serial post-operative radiographs were monthly performed to assess recovery. The dogs were sacrificed 3 months after reconstruction surgery to collect tissue biopsies for histopathology.

Results:
Healing processed uneventfully in 8 operated teeth units expressed by the presence of merged dense connective tissue with the periodontal ligament. The alveolar bone showed marked osteoblastic activity. The other 10 operated teeth units exhibited granulomas affecting the apical part of the teeth (6 teeth) and delayed healing with poor connective tissue bond (4 teeth).

Conclusion:
Reconstruction surgical technique using autogenous bone marrow grafting (GBR) combined with a bio-absorbable amniotic membrane barrier of dogs (GRT)was a promising as a salvage treatment of advanced degree III of furcation defects in dogs.

Key words: Furcation degree III defect; Guided tissue regeneration; Guided bone regeneration; Amniotic membrane barrier; Periodontal disease.