Evaluation of Bone Gain Using Customized 3D Zirconia Barrier Versus Titanium Mesh

After a tooth is extracted, the alveolar process undergoes an inevitable dimensional change as part of the post extraction remodeling process. The alveolar process is reduced both in the vertical and the horizontal dimension. Therefore, Bone augmentation procedures have been employed to address this issue. A number of bone grafting materials and membranes have been used including resorbable and non-resorbable membranes. It is well-established that non-resorbable membranes produce greater bone augmentation than resorbable ones in terms of their ability to generate new bone. However, their complications make them a less popular option in everyday clinical practice.

Zirconia surfaces show prominent osteo-conductivity, also it has low affinity to bacterial plaque, small amounts of inflammatory infiltrate and good soft-tissue integration. Therefore, this study aims to introduce customized-3D zirconia barriers as a predictable alternative to titanium mesh with horizontal bone gain used as primary outcome.

A randomized clinical trial designed to evaluate the amount of bone gained clinically and radiographically using customized 3D printed zirconia barrier compared to titanium mesh with 26 sites with combined ridge defect total sample size, 13 sites per arm. Once patient preparation is completed and the radiographs are acquired, the patient will be assigned into an arm in the study to allow for barrier manufacturing.

For the zirconia group from the pre-operative CBCT a 3D model of the alveolar jawbone will be created. A 0.4-0.5 mm-thick barrier will then be designed. It will be designed to cover the planned bone graft and extended a few millimeters wider than the graft perimeter. The barrier will be milled and sintered, after milling and finishing, the zirconia meshes will be cleaned, dis-infected and sterilized. At the time of the surgery and after administration of anesthesia, the full thickness flap of the atrophic area will be elevated adjacent to the defect site. Autogenous bone particulate will be harvested. Autogenous bone will be harvested by using an auto-chip maker (ACM) bur, autogenous bone chips that collected with ACM bur will be mixed with a xenograft at 50:50 ratio. A try-in of the barrier will be performed before grafting the area to verify whether its adaptation to the recipient site will be correct. A part of the graft will be placed into the atrophic area and the other part of it was placed into the inner side of the barrier. The barrier will be then placed and according to the clinical situation, two or three fixation screws were tightened at 10 N/cm.

The titanium mesh group, an aluminum foil will be adapted to the defect site and used as a guide for trimming the titanium mesh and ensure its adequate fit. The titanium mesh will be polished to prevent dehiscence or premature exposure. It will then stabilize over the particulate graft by 2 mm titanium mini screws at the labial and palatal sides. Releasing incisions of the flaps will be the next step in the procedure. Then, suturing was performed with single and horizontal mattress sutures.

The patient will be instructed to take antibiotics, antiseptic mouth rinse, anti-inflammatory drugs and instructed to apply an ice pack to the treated area for the first 24 hours and to avoid any brushing or trauma to the surgical site for one week.

After 6 months of a healing period a post-operative CBCT will be performed to assess the effectiveness of the GBR procedure, and then Dental implants will be placed according to the bone dimensions. The osteotomy will be initially done using a 4 mm-diameter trephine bur, instead of the pilot drill to acquire a core biopsy. Sequential drilling will then take place until the correct osteotomy size is created for the implant size

Inclusion criteria

• Age: 20-70 years.
• Bone width less than 4mm
• Vertical bone height less than 9mm
• Periodontally sound neighboring teeth
• Patients with sound vertical occlusal bite dimension
• Good oral hygiene (full mouth plaque control record [PCR] < 25%,full mouth bleeding on probing (BOP) < 25% .
• Patients demonstrating understanding and commitment to the post-operative care regime and the study follow up timeline.
• Good general health (including participants with well-controlled systemic disease)

Exclusion criteria

• Pathological lesions (abscess-cyst-acute infection) in the defect site
• Systemic diseases that would interfere with bone metabolism
• Uncontrolled diabetic patients
• Ongoing treatment or a history of recent chemotherapy or radiotherapy
• Poor oral hygiene after hygienic phase (Plaque control record over 30%) or Active periodontal disease