With the development of regeneration technology,intentional replantation(IR)has gradually become the important treat-ment.Some affected teeth that are difficult to be cured by conventional methods,such as refractory periapical periodontitis,radicular groove and combined periodontal-endodontic lesions,can be preserved through IR.IR is effective in the treatment of teeth with severe periodontal destruction.This article reviews the historical development,clinical operation and influencing factors,and provides refer-ence for exploring the treatment plan of IR for a single tooth with severe periodontal destruction and the preservation of patients'natural dentition.

Platelets, small cell fragments in the blood that prevent bleeding, are closely associated with hemostasis and thrombosis and play an important role in the inflammatory response. Periodontitis is a chronic inflammatory disease caused by periodontopathogenic bacteria, resulting in local and systemic inflammatory responses that are associated with many systemic diseases. In recent years, several animal and human studies have demonstrated the correlation between periodontitis and platelets from three aspects: gingiva, and gingival crevicular fluid, and found that activated platelets play a very important role in the development and progression of periodontitis. Porphyromonas gingivalis and inflammatory mediators S100A8/A9 activate platelets, which then combine with leukocytes to form platelet-leukocyte aggregates. These aggregates can migrate into periodontal tissue, producing proinflammatory cytokines, thereby promoting the development and progression of periodontitis. Available studies also suggest that initial periodontal therapy reduces platelet activation and platelet-leukocyte aggregate formation, which may reduce the risk of cardiovascular diseases (CVDs) in patients with periodontitis. Additionally, studies found that antiplatelet drugs can inhibit periodontal inflammation and promote periodontal tissue repair and that P. gingivalis-induced expression of CD40L on platelets may be an important mediator between periodontitis and CVD. These reports suggest that platelets can serve as novel therapeutic targets for the treatment of periodontitis. This review aims to discuss the current literature on the correlation and interaction mechanisms between periodontitis and platelets.