For graft extraction site, which combination is indicated?

• A. Collagen Type I and Calcium Apatite Crystals
• B. Collagen Type II and Calcium Phosphate
• C. Gelatin Sponge and Hydroxyapatite
• D. Autograft Bone and Beta-Tricalcium Phosphate

Answer: (A)

In bone grafting for an extraction site, you want a material that provides a biocompatible scaffold for new bone to grow into (osteoconduction) and that has a mineral phase to support mineralization. Collagen Type I is the main organic component of bone and creates a natural, resorbable matrix that supports cell attachment, vascular ingrowth, and remodeling. Pairing it with calcium apatite crystals gives the graft a mineral phase similar to bone mineral, which strengthens the scaffold and guides mineral deposition as new bone fills the defect. This combination effectively substitutes for bone matrix in the socket and supports predictable regeneration.

Cartilage-forming collagen (Type II) isn’t appropriate for bone grafts, since the goal is bone, not cartilage. Gelatin sponge is mainly a hemostatic agent and doesn’t provide a durable osteoconductive scaffold. Hydroxyapatite alone lacks the organic matrix needed for optimal cell adhesion and remodeling. Autograft bone with beta-tricalcium phosphate is a valid option but involves a donor site and more invasiveness, whereas the stated combination offers a ready-to-use, biocompatible scaffold that supports socket preservation without harvesting bone from another site.