Statement of the problem:

The alveolar ridge undergoes various remodeling processes following tooth extraction, but the ridge resorption continues over time, resulting in hard and soft tissue loss which complicates prosthodontic rehabilitation whether by dental implants or tooth supported prosthesis.

Aim of the study:

The aim of the study is to assess the influence of the different time intervals on the healing of the demineralized dentin graft in alveolar ridge preservation (ARP) procedures.

Materials and methods:

30 patients with hopeless teeth requiring extraction in maxillary non molar areas and requiring replacement with dental implants, will be enrolled and recruited from the outpatient clinic, faculty of dentistry, ain shams university according to the inclusion criteria. They will be randomly allocated into three equal groups. Group A (n=10) alveolar ridge preservation will be done with demineralized dentin graft and re-entry at 12 weeks, group B (n=10) alveolar ridge preservation will be done with demineralized dentin graft and re-entry at 18 weeks and group C (n=10) alveolar ridge preservation will be done with demineralized dentin graft and re-entry at 24 weeks. Radiographic assessment will be done using CBCT to the arch of interest and another cone beam will be done prior to the implant placement at 11, 17 and 23 weeks based on the study group and a volumetric assessment will be done with digital subtraction. At the respective times core biopsy will be taken for the histological assessment, and the implant placement will be done with the implant primary stability recorded using Ostell. Postoperative medication will be prescribed to the patient and postoperative instructions will be explained in detail. Follow-up will be performed. Data collected will be tabulated and statistically analyzed.

Inclusion Criteria:

• Systemically free patients (American Society of Anesthesiologists I; ASA I)
• Age range 20 - 50.
• Non-molar maxillary teeth indicated for extraction.
• Patients with extraction sockets having intact bony walls, or no more than one bony wall dehiscence not extending more than 50% of the total bone height

Exclusion Criteria:

• Teeth to be extracted or adjacent teeth associated with acute infections.
• Smokers.
• Patients with other conditions that may affect the treatment [uncontrolled diabetes mellitus (HbA1c >7.0), liver or kidney failure, any active oral or systemic acute infections, currently receiving chemo-or radiotherapy or a history of radiotherapy in the head and neck area, severe hematologic disorders].
• Pregnant and lactating females.
• Patients with history of lack of compliance to dental visits and unwillingness or inability to sign the informed consent.