When a tooth is removed, the bone around it (called the alveolar ridge) naturally shrinks. This study compares two bone grafting materials to find out which one better preserves bone after molar extraction:

Demineralized Dentin Matrix (DDM): A material made from the patient's own extracted tooth, treated to remove minerals while keeping bone-forming proteins.

Mineralized Plasmatic Matrix (MPM): A mixture of a standard bone substitute and platelet-rich plasma from the patient's blood.

Alveolar ridge resorption is a predictable biological process following tooth extraction, particularly in molar sites where the bone structure is more complex. Maintaining ridge volume is essential for optimal future implant placement and prosthetic rehabilitation. Various grafting materials and biologic enhancers have been used to minimize post-extraction bone loss; however, cost, availability, and biocompatibility remain significant challenges, especially with xenograft and allograft materials.

This randomized clinical trial investigates and compares two autogenous and biologically enhanced approaches for alveolar ridge preservation following molar extraction. The first method utilizes Demineralized Dentin Matrix (DDM) prepared from the patient's own extracted tooth. DDM provides a naturally derived scaffold rich in collagen and bone morphogenetic proteins (BMPs), offering both osteoconductive and osteoinductive potential. The second method uses a Mineralized Plasmatic Matrix (MPM), a combination of a xenograft bone substitute mixed with Platelet-Rich Plasma (PRP), which represents a widely used regenerative option in oral surgery.

The study is designed as a parallel-group, single-blind, randomized clinical trial conducted at the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Cairo University. Eligible adult patients requiring extraction of non-restorable multi-rooted molars will be enrolled and allocated equally into two groups. Both groups will undergo atraumatic extraction followed by immediate socket grafting with either DDM+PRF or MPM+PRP.

Standardized postoperative care will be provided to all participants, and healing will be monitored both clinically and radiographically. Cone-beam computed tomography (CBCT) will be used to evaluate alveolar bone width, height, and density immediately after extraction and at 4 months postoperatively. Pain and soft-tissue healing will also be assessed using validated clinical indices.

The study's primary objective is to determine whether Demineralized Dentin Matrix (DDM) provides superior preservation of alveolar ridge dimensions and bone quality compared to Mineralized Plasmatic Matrix (MPM) in molar extraction sites. The hypothesis tested is that there will be no significant difference between both materials regarding bone preservation and regeneration outcomes.

This trial is expected to provide evidence supporting the clinical viability of using recycled autogenous tooth material as a cost-effective and biocompatible alternative to commercially available xenografts, potentially expanding regenerative options for clinicians and improving access to affordable biologic grafting solutions.

Inclusion Criteria:

- Non-restorable tooth indicated for extraction Multi-rooted teeth Age group of 18 to 55 years Patients free from any systemic disease that may affect bone healing.

Exclusion Criteria:

- Pregnant females Active infection at extraction site Smokers Systemic conditions affecting healing (e.g. diabetes, medications as bisphosphonates...) Poor oral hygiene. Patient with systemic disease that may affect bone healing. o Uncooperative patient.

Single-blind design - participants will not be informed which grafting material (DDM or MPM) was used in their treatment. The operating surgeons and data analysts will be aware of the allocation due to the nature of the procedures.