Abstract: BACKGROUND: Stem cell mesenchyme within reactive soft tissues has the potential to promote tissue regeneration. Demineralized dentin matrix, which has good biocompatibility, can be used as a scaffold material for the site preservation surgery to promote the attachment, proliferation, and differentiation of osteoblasts.
OBJECTIVE: To evaluate the changes in alveolar bone height and width after 6 months of site preservation with demineralized dentin matrix after 1 month of extraction of affected teeth with preservation of reactive soft tissues.
METHODS: A total of 38 patients with 62 extraction sites were included. One month after the extraction of the affected teeth with preservation of reactive soft tissues, demineralized dentin matrix was used to perform site-preservation surgery. Cone-beam CT was taken preoperatively, immediately postoperatively, and 6 months postoperatively to measure the proximal-medial bone height, central bone height, distal-medial bone height, buccal bone height, lingual bone height, and alveolar bone height, and alveolar bone width. Extraction defects were categorized as one-, two-, three-, or four-wall defects based on the number of alveolar fossa bone walls remaining after tooth extraction. Changes in bone volume were compared preoperatively, immediately postoperatively, and 6 months postoperatively.
RESULTS AND CONCLUSION: No wound infection occurred at any site during bone healing. Compared with preoperative data, there was a significant increase in alveolar bone height and bone immediately postoperatively (P < 0.05); there was also an increase in alveolar bone height but no change in alveolar bone width 6 months postoperatively (P > 0.05). Compared with the immediate postoperative period, alveolar bone width was increased by (1.253±2.896) mm 6 months postoperatively, but there was no change in alveolar bone height (P > 0.05). The bone height of the four bone defect types was significantly increased immediately and 6 months postoperatively (P < 0.05), and no changes in the bone width were observed (P > 0.05). Compared with the preoperative data, there was the least increase in proximal-medial bone volume in one-wall bone defects at 6 months postoperatively (P < 0.05) and the most increase in proximal-medial bone volume in two-wall bone defects (P < 0.05). These findings indicate that demineralized dentin matrix applied to site preservation can effectively prevent and slow down alveolar bone resorption after tooth extraction, and can rebuild the alveolar bone contour where resorption has occurred to a certain extent; preservation of reactive tissues applied to demineralized dentin matrix site preservation after tooth extraction can achieve wound closure with good clinical efficacy; demineralized dentin matrix applied to the alveolar socket site preservation with one-, two-, three-, and four-wall defects shares similar effects. However, demineralized dentin matrix is more effective for site preservation when applied to extraction sockets with intact bone walls.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: imaging research, site preservation, demineralized dentin matrix, reactive soft tissue, bone wall defects