Evaluation of Two Alloplastic Biomaterials in a Critical-Size Rat Calvarial Defect Model

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Oral and Maxillofacial Surgery

Background:

• Critical-size bone defects pose significant challenges in regenerative medicine.
• Alloplastic biomaterials are investigated for their potential to enhance bone regeneration.
• Understanding the in vivo performance of biomaterials is crucial for clinical application.

Purpose of the Study:

• To evaluate the bone regeneration capacity of deproteinized bovine bone mineral (DBBM) with a collagen membrane (CM) and poly-(lactic-co-glycolic-acid) (PLGA)-coated bioceramics (β-TCP and HA:β-TCP).
• To assess the construct integrity and retention of these alloplastic biomaterials in a critical-size rat calvarial defect model.

Main Methods:

• A critical-size calvarial defect (Ø8 mm) was created in 80 rats, randomized into treatment groups: sham surgery, DBBM + CM, PLGA-coated pure phase β-tricalcium phosphate (β-TCP), or PLGA-coated 60% hydroxyapatite (HA):40%β-TCP.
• Animals were analyzed at 2 and 6 weeks post-surgery.
• Microcomputed tomography (μCT) assessed mineralized tissue volume and biomaterial displacement; histological analysis evaluated new bone formation.

Main Results:

• No significant differences in total mineralized tissue volume were observed among groups.
• DBBM + CM showed increased horizontal displacement at 2 weeks, but not at 6 weeks.
• Histological analysis revealed comparable new bone formation across all groups, including the sham surgery control, at 6 weeks.

Conclusions:

• The tested alloplastic biomaterials exhibited adequate construct integrity and retention in the critical-size calvarial defect.
• Limited new bone formation was observed with all tested biomaterials, similar to the control group.
• Further research may be needed to enhance the osteogenic potential of these materials for bone regeneration.