Histological and Histomorphometric Assessment With Inflammatory Profile Analysis of Bone Tissue After Horizontal Ridge Augmentation Using Customized Porous Zirconia Shell

Overview

The goal of this clinical study is to learn whether a custom-made porous zirconia shell can support good-quality new bone when widening the lower back jaw before dental implant placement. The study includes adults whose jawbone in this area is too narrow for implants (Seibert Class I defects). The main question it aims to answer is: What is the quality of the new bone formed under a porous zirconia shell, and how much inflammation does the tissue show? Participants will: * Receive gum treatment and a CBCT scan before surgery * Have bone augmentation surgery, in which a digitally designed porous zirconia shell is fixed over a mixture of their own bone and bovine bone graft * Return after 2 weeks for suture removal and a check of the wound * Return after 6 months for a CBCT scan, removal of the shell, collection of a small bone sample (biopsy), and dental implant placement

Horizontal bone loss in the posterior mandible often prevents dental implant placement. The Khoury technique uses thin autogenous cortical bone plates to rebuild the ridge, but harvesting these plates causes donor-site morbidity, is technically demanding, and is limited by available bone. Zirconia is biocompatible, mechanically strong and osteoconductive, and has shown low inflammatory response. However, it has not been studied as a shell replacing autogenous bone plates. In this single-arm study, 10 adults with Seibert Class I defects in the posterior mandible will first receive non-surgical periodontal therapy. Compliance will be checked after 1 month. A zirconia shell with 1.5 mm pores will be digitally designed from each patient's CBCT scan, milled on a 5-axis machine, then cleaned and sterilized. Under local anesthesia, buccal and lingual full-thickness flaps will be raised and the recipient bone decorticated. Autogenous bone chips will be harvested from the mandibular body with a bone chip maker and mixed 1:1 with xenograft. The shell will be fixed over the graft with 3-4 buccal screws. The flaps will be advanced and closed with a double-layer suture. After 6 months, the shell will be removed, a core biopsy will be taken, and an implant will be placed. The biopsies will be fixed in 10% formalin and analyzed histologically, histomorphometrically and for tissue inflammatory response.