Maxillary Sinus Floor Augmentation Using Xenograft: Gene Expression and Histologic Analysis

Area of Science:

• Oral surgery
• Regenerative medicine
• Biomaterials science

Background:

• Anorganic bovine bone (ABB) is widely used for maxillary sinus floor augmentation (MSFA).
• Clinical success of ABB in MSFA is documented, but molecular mechanisms of bone healing remain unclear.
• Understanding gene expression in bone remodeling and inflammation is crucial for optimizing regenerative therapies.

Purpose of the Study:

• To investigate gene expression profiles related to bone remodeling and inflammation following MSFA using ABB.
• To compare gene expression levels between grafted and non-grafted maxillary bone sites.
• To correlate molecular findings with histological evidence of bone healing.

Main Methods:

• Gene expression of RUNX2, RANKL, OPG, MMP-9, TRAP, and IL-1β was quantified using RT-PCR.
• The RANKL/OPG ratio was analyzed to assess bone remodeling potential.
• Histological analysis examined bone formation and integration of ABB particles.
• Bone samples were collected 6 months post-MSFA or tooth extraction.

Main Results:

• No significant differences in gene expression levels for RUNX2, RANKL, OPG, MMP-9, TRAP, or IL-1β were observed between groups.
• The RANKL/OPG ratio did not differ significantly between the MSFA and control groups.
• Histology revealed viable bone-lining cells, osteocytes within new bone, and close contact between residual ABB particles and newly formed bone.

Conclusions:

• ABB particles do not appear to influence the expression of key genes involved in bone remodeling and inflammation after 6 months of healing in MSFA.
• Histological findings support that ABB acts as a scaffold, facilitating new bone formation without impeding the healing process.
• ABB demonstrates biocompatibility and osteoconductive properties, contributing to successful bone regeneration in MSFA.