DOI: 10.14457/tu.the.2019.1629
title: Clinical evaluation of 3D printed nano-bioengineered bone graft for alveolar ridge preservation: a randomized controlled trial

description: After tooth loss, edentulous patients suffer from time-dependent ridge reduction. This ultimate negative sequel of tooth loss poses major problems including insufficient retention, pain, difficulties with eating, speech and altered facial appearance. Dental implants have been shown to provide excellent support for both fixed and removable prosthesis. Nevertheless, the success rate depends on the quality and quantity of available bone. The application of a bone graft and/or membrane may help to foster selective cells and tissue repopulation to restore the alveolar bone quality and quantity. A wide variety of bone substitutes have been applied over the last five decades. The aim of this study was to evaluate the clinical efficacy of Novel 3D printedporous nano-hydroxyapatite bone graft material in comparison to commercial bone graft material (NanoBone®) in alveolar ridge preservation prior to implant replacement. Materials and Methods: Thirty patients were randomized into two treatment groups following tooth extraction from incisor to premolar area. In the test group, the alveolar socket was filled with 3D printed porous nano-hydroxyapatite bone graft while in the control group, NanoBone® was used. In both groups, a non-resorbable PTFE membrane (cytoplast®) was applied to seal the extracted socket. Clinical early response was recorded on PI, GI, PPD, Keratinized tissue, buccal bone thickness, palatal/lingual bone thickness, CBCT, and intraoral scanned for evaluating dimensional changes of soft tissue at 1, 2, 4 weeks. After 4 months, prior to implant placement, the ridge dimensional changes were re-evaluated by using intraoral scanner and CBCT. Finally, trephine biopsy was performed at the grafted site for histological and histomorphometric analysis. In addition, implant insertion torque was recorded while stability of implant was also measured by using AnyCheck at the time of implant placement and before insertion of crown restoration. Results: The postoperative healing after extraction and preservation was uneventful in all patients. After 4 months, the mean value of ridge dimensional changes in the control group was 0.013009±0.004404 whereas the test group was 0.015475±0.008061. The mean value of bone dimensional changes from baseline to 4 months before implant placement in control group was 0.006357±0.003145 whereas in test group was 0.007148±0.004734. The histological results showed new bone formation in the apical part of the biopsy samples, which, in some areas, were in direct contact with both 3D printed nano-hydroxyapatite and NanoBone® particles. The coronal part of the biopsies was occupied by a dense fibrous connective tissue surrounding both control and test particles. Results of histomorphometric analysis found the mean of new bone formation in the control group was 30.80±12.08% whereas 32.56±15.84% in the test group. The mean of fibrous connective tissue constituted 32.96±8.34%, the residual graft material was 17.31±9.40% and other was 18.92±5.30% in the control group whereas the test group had the mean of fibrous connective tissue was 31.97±12.78%, the residual graft material was 17.27±13.14% and other was 18.19±7.44%. The comparative of all measurements in both groups from extraction time to 4 months follow up before implant placement was not statistically significant (p&gt;0.05, an independent sample t-test). In addition, the bone quality of the grafted site when placing the implant showed efficient implant stability test (IST mean values 75.4 in control group and 75.6 in test group) in 10 patients withoutthe need of additional bone graft surgery. Conclusion: Overall results indicated that novel 3D printed nano-hydroxyapatite granules could be potentially used as an alternative bone graft material for alveolar ridge preservation.