TƯƠNG QUAN GIỮA IMPLANT TỨC THÌ VÀ XƯƠNG Ổ RĂNG NANH HÀM DƯỚI

Abstract

Introduction: Immediate implant placement, defined as inserting an implant directly after tooth extraction, offers multiple advantages such as reduced treatment time and minimized post-extraction alveolar bone resorption. However, this approach may compromise primary stability due to reduced available bone. The mandibular canine region is considered high-risk for complications because of limited bone volume and unique anatomical characteristics, where implants often need to be placed deeper into the mandible. Therefore, the aim of this study was to evaluate the spatial correlation between prosthetically-driven immediate implant placement and the mandibular canine socket on cone-beam computed tomography (CBCT), focusing on the degree of encroachment into surrounding bony walls (buccal, lingual, mesial, distal). Methods: A cross-sectional study was conducted on 34 CBCT scans of patients aged 18 years or older with intact mandibular canines. A virtual implant (Straumann, 3.3 mm diameter) was positioned according to the prosthetic-driven axis. Measurements were taken from the implant surface to the buccal (B), lingual (L), mesial (M), and distal (D) bony walls at three reference levels: level 0 (implant platform), level 4 (4 mm apical to platform), and level 8 (8 mm apical). Negative values indicated perforation of buccal/lingual plates or invasion of mesial/distal walls. Results: No negative values were observed for buccal or lingual measurements, confirming that implants did not perforate in the bucco-lingual direction. Mean distances at L0 and B0 were 3.13 mm and 4.13 mm, respectively. However, implants showed a tendency to invade mesial and distal walls. At level 8 mm, mean mesial wall encroachment was -0.03 mm. Conclusion: Prosthetically-driven immediate implant placement in the mandibular canine socket did not result in buccal/lingual cortical plate perforation but tended to encroach upon mesial and distal walls. Virtual implant planning using CBCT is essential prior to surgery to evaluate socket morphology and adjust implant positioning, thereby minimizing surgical risks.