Objectives Surgical endodontics (hemisection) commonly involves the alveolar bone socket and the periradicular tissue. In today's era, optimizing the bone healing process is updated by using bone graft induction. This study explores the mechanisms of bone healing of the alveolar bone socket post-dental extraction of Wistar rats after administration of a bovine tooth graft (hydroxyapatite bovine tooth graft [HAp-BTG]). Materials and Methods Fifty Wistar rats were randomly selected into two groups, control and treatment, and into five subgroups on days 3, 7, 14, 21, and 28. The postextraction socket was filled with polyethylene glycol (PEG) as the control and PEG + HAp-BTG as the treatment group. On days 3, 7, 14, 21, and 28, Wistar rats were sacrificed, mandibles were taken, paraffin blocks were made, cut 4 µm thick, and made into glass preparations for microscopic examination. The variable analysis was performed by staining hematoxylin-eosin for osteoblasts (OBs) and osteoclasts (OCs) and immunohistochemistry for runt-related transcription factor 2 (RUNX2), osterix (OSX), osteocalcin (OCN), bone morphogenic protein (BMP) 2. We analyzed the expressed cell count per microscope field. Results In general, the number of cell expressions in the treatment group was significantly higher and faster, except for significantly lower OC. The high variables peak occurred on day 14 for RUNX2 and OCN, on day 7 for OSX, while OB significantly increased on day 21 and remained until day 28. The decrease of OC cells occurred on day 7 and remained low until 28 days. BMP2 was first dominantly induced by HAp-BTG, then the others. Conclusion HAp-BTG can induce higher and faster bone healing biomarkers. BMP2 is the dominant first impacted. On the 28th day, it did not significantly express the suppression of OC by OB, which entered the bone formation and remodeling step.

Background:The failure of endodontic treatment commonly caused by imperfect obturation, periodontalperiradicular lesions, untreated root canals, and some other factors. The failure may trigger the occurrence of secondary infections due to persistent. bacteria.One of the abnormalities that appear after endodontic treatment is a periapical abscess.Endodontic failure can be overcome by endodontic retreatment, apical surgery, or extraction. During an endodontic retreatment, endodontic instruments are used to remove the root canal filling material and to repeat the steps of endodontic treatment to achieve the apical patency. Purpose: This case report presents management to overcome the failure of previous endodontic treatment with nonsurgical endodontic retreatment. Case: A 66 years old male patient came with a dull pain of tooth no 16 and uncomfortable when used for chewing since 2 months after endodontic treatment. The episodic swelling appeared since 3 months ago which then deflated.The objective examination showed a positive response to bite test and percussion test. Intraoral periapical radiograph confirmed an underfilled root canal, and a periapical radiolucency with a diffuse border on palatal root. Case Management: Based on the patient's history taking, radiographic, and clinical examination,endodontic retreatment was done and followed by porcelain fused to metal crown restoration. Conclusion: Endodontic retreatment is the appropriate treatmentoption to overcome the failure of the previous endodontic treatment that accompanied with a periapical lesion and to preserve its function in stomatognatic system.