Comparative histomorphometric analysis of maxillary sinus augmentation with absorbable collagen membrane and osteoinductive replaceable bony window in rabbits

Purpose The aim of this animal study was to evaluate, through histomorphometric evaluation, bone regeneration in rabbit maxillary sinuses with absorbable collagen membranes and osteoinductive replaceable bony windows over bone grafts. Materials and methods Bilateral sinus augmentation procedures were performed in 16 adult male rabbits. The rabbits were randomly assigned to 4 groups of 4 rabbits each. Rectangular replaceable bony windows were made with a piezoelectric thin saw insert. In control group, grafted β-tricalcium phosphate (β-TCP) was covered by absorbable collagen membranes. In experimental groups, β-TCP was grafted and covered by replaceable bony windows. The rabbits were killed at 1, 2, 4, and 8 weeks postoperatively. The augmented sinuses were stained with hematoxylin-eosin and Masson trichrome stains and examined, under light microscopy, for newly formed bone and soft tissue changes in the maxillary sinuses. Results Histologically, significantly higher and faster new bone formation was observed in the augmented sinuses of the experimental groups, receiving homologous replaceable bony windows than in those of the control group receiving collagen membranes. Conclusion This study demonstrates that, for augmentation, the use of the homologous replaceable bony window over bone graft material on the maxillary sinus accelerates bone regeneration.