Description

This study aims to evaluate the radiographical and histomorphometrical differences between the allogenic dentin matrix and the autogenous partially demineralized dentin matrix (APDDM) in ridge preservation after tooth extraction in the aesthetic zone.

Research Procedure:

Patients will be selected from the outpatient clinic of the Oral Medicine and Periodontology Department, Faculty of Dentistry, Cairo University. General operative procedures: The patients who fulfil the inclusion criteria will be enrolled. The nature of the study will be explained to each patient as follows: as well as the importance of compliance with pre- and post-operative instructions.

and follow-up visits. Each patient will be asked to sign an informed consent form. After enrolment, periodontal and radiographic examination and Patients with badly unrestorable teeth in the aesthetic zone will be identified.

These patients will undergo mesio-distal distance between adjacent teeth. corono-apical height of bone, presence of labial undercut, dehiscence, or fenestration and relation to adjacent teeth measurements using transgival probing technique, and a preapical radiograph, or CBCT. Initial Therapy: The initial therapy will consist of periodontal treatment. (phase I therapy), including supra-gingival scaling and subgingival debridement if needed, adjustment of faulty restoration, and polishing. The mechanical plaque Control instructions for each patient include brushing and interdental cleaning.

techniques.

• Atraumatic extraction:
• Local anaesthesia will be administered via buccal and palatal infiltration prior to any surgical procedure.
• In both groups, flapless atraumatic tooth extraction will be performed. which includes an intrasulcular incision using a 15c blade, then a The periotome is inserted between the root and the surrounding bone in a wedging action on all sides around the root. Afterwards, a small A straight elevator will be used to luxate the root and the remaining root. Forceps will be used to deliver it. Lucas Curette will be used to clean the extraction socket of any apical pathology and granulation tissue.
• In the intervention group, 2) Group 1 (an allogeneic dentin matrix) will be used.

Preparation of the allogenic dentin matrix.

Steps of Allogenic Dentin Processing:

Washing with distilled water for 30-120 mins Soft and pulp tissues are to be removed from the dental root, then washed with distilled water for about 30 minutes to about 2 hours.

Quick Freezing with Liquid Nitrogen at 160 oC for 30-120 min Then grind to a particle size of 300-800 µm.

The dental root will be processed by quick-freezing and crushing into powder, whose average particle diameter is about 200 mm to about 1,500 mm. The powder may be washed with distilled water for about 30 minutes to about 2 hours to remove contaminants and residual soft tissue.

Ultrasonic cleaning cycles: 1st with distilled water for 5-10 minutes, 2nd with 5-7% hydrogen peroxide 10-30 minutes, then 3 minutes with distilled water for 5-10 minutes at 60-80 The powder will be cleaned using three cycles of ultrasonic cleaning, each of which consists of the following steps: a first washing step in which the powder will be cleaned using ultrasonic technology for about five to ten minutes in sterilised or clean water; a second washing step in which the powder will be cleaned using ultrasonic technology for about ten to thirty minutes in hydrogen peroxide solution; and a third washing step in which the powder will be cleaned using ultrasonic technology for about five to ten minutes in pure water.

Defatting with Chloroform Methanol Solution 1:0.5 for 3-12 hours The powder washed in the above-described step will be primarily degreased using a chloroform-methanol solution where the ratio between the chloroform and methanol is about 1:0.5 to about 1:2 by weight for about 3 hours to about 12 hours.

Demineralization with 0.5 N HCL for 10-60 min The above-mentioned powder that has been principally degreased will be delimed (demineralized) for 10 minutes to an hour in an aqueous solution of about 0.5N hydrochloric acid that has a volume that is 5-10 times more than that of the powder.

Dehydration with Neutral Ethyl Alcohol for 30 minutes, then Defatting with Chloroform Methanol Solution 1:0.5 for 3-12 hours The deli powder will next be dehydrated for up to two hours with neutral ethyl alcohol. The dehydrated powder may undergo a second degreasing step using a chloroform-methanol solution with a chloroform-to-methanol weight ratio of about 1:0.5 to about 1:2 over a duration of about 3 hours to about 12 hours.

Washing with normal saline and freeze drying, then sterilisation using ethylene oxide gas The degreased, delimed, and dehydrated powders are then freeze-dried, and the freeze-dried powders are then sterilised using ethylene oxide gas.

In the control group, the partially demineralized dentin graft will be prepared as follows: The extracted tooth will be decontaminated and cleaned with a diamond. under abundant irrigation with physiological water. All filling materials (gutta-percha, composite, luting cements, etc.) will be removed with the outmost care. Subsequently, the tooth will be cut into fragments (5 × 5 mm). and will be dried using air and ground with the Tooth Transformer device. following the manufacturer's protocol. Dentin particles will be obtained with a dimension of 400-800 μm.

• Alveolar ridge preservation:
• After socket debridement, each socket will be carefully filled with dentin graft.

Once the grafts are properly adapted to the sockets, they will be covered with collagen membranes extending 2 mm in the envelope prepared between the periosteum.

and the bony borders of the socket (360° around). The wound will be secured using 5/0 proline interrupted sutures, not with the intention to close the wound, but simply to keep the graft and membranes are stable in position. After a 6-month healing period, at the moment of the implant placement, a A biopsy from the core of the grafted site will be obtained using a 2-mm trephine.

bur. The biopsy will be immediately fixed in 10% neutral buffered formalin and then dehydrated through baths of progressively more concentrated water (from 50 to 100%) alcohol and subsequently embedded in paraffin. Finally, a tissue A section of 4 μm thick will be prepared and stained with hematoxylin-eosin for histological analysis.

Late implant placement:

• After complete bone healing of the extraction socket, 6 months following tooth extraction and late implant placement will be performed.
• Local anaesthesia in which Septocaine (Articaine hydrochloride, 4%) with 1:100000 Epinephrine) will be administered via buccal and palatal infiltration prior to any surgical procedure. For both groups, a triangular flap design will be used. which involves a midcrestal horizontal incision with an intrasulcular incision on each distal tooth to the edentulous area. Then, two vertical releases Incisions will be made at the line angles of the adjacent teeth. This will be followed by full-thickness flap elevation.
• The implant osteotomy will then be prepared using sequential drilling according to to the manufacturer's instructions to allow implant placement in proper 3D prosthetic. Finally, the implant will be inserted into the prepared osteotomy.

  Outcome

Radiographic bucco-lingual ridge width loss. Radiographic palatal vertical bone changes. Radiographic buccal vertical bone changes. Percentage of new vital bone formation. Percentage of residual bone graft. Implant Primary Stability. The results were directly postoperative and 6 months postoperatively.