Long-term behaviour of active glasses in sheep mandibular bone

Area of Science:

• Biomaterials Science
• Dental Materials
• Bone Regeneration

Background:

• Bone defects in dentistry require effective regenerative materials.
• Bioglass materials offer potential for bone repair due to their bioactive properties.

Purpose of the Study:

• To evaluate the in vivo performance of Hench's formula glass (A) and a new bioactive glass (AKRA 15) for dental bone defect repair.
• To compare the bone integration and material degradation of these glasses over 12 months.

Main Methods:

• Implantation of glass granules into sheep mandibular bone defects.
• Analysis using microradiography, optical microscopy, and scanning electron microscopy (SEM).
• X-ray microprobe analysis to determine elemental changes within the bone-implant interface.

Main Results:

• Glass A granules degraded over 12 months with limited bone growth observed.
• AKRA 15 granules showed some bone integration, with distinct ionic exchange patterns.
• Sodium and silicon ions decreased, while calcium and phosphorus ions initially increased then decreased in both materials.
• Potassium ions appeared in AKRA 15 implants after 4 months.

Conclusions:

• Hench's formula glass (A) showed limited efficacy in promoting bone regeneration in this model.
• The new bioactive glass (AKRA 15) demonstrated potential for bone repair, indicated by ionic exchange and some bone apposition.
• Further investigation into AKRA 15's composition and ion release profile is warranted for dental applications.