A Comparative Study of Marginal Bone Loss in Immediate versus Delayed Implant Placement: A Longitudinal Analysis

Introduction: The timing of dental implant placement – whether immediate after tooth extraction or delayed after a healing period – remains debatable. Immediate implant placement offers the advantage of reducing overall treatment time and preserving soft-tissue contours. Still, it may carry a higher risk of marginal bone loss due to surgical trauma and insufficient healing time. On the other hand, delayed implant placement allows for better bone healing and reduced bone resorption but requires a longer treatment period. This study aims to compare marginal bone loss, implant stability and peri-implant tissue health between immediate and delayed implant placement over a 12-month follow-up. Materials and Methods: Forty patients requiring single-tooth implants in the anterior or premolar regions were randomly allocated into two groups: immediate implant placement ( n = 20) and delayed implant placement ( n = 20). Marginal bone loss was assessed using standardised intraoral radiographs at baseline, 3 months, 6 months and 12 months. Implant stability was measured with the implant stability quotient (ISQ), while peri-implant tissue health was assessed through probing depth and signs of inflammation. Results: At 12 months, the immediate implant group exhibited significantly greater marginal bone loss (1.12 ± 0.25 mm) compared to the delayed implant group (0.85 ± 0.18 mm) ( P = 0.003). Implant stability, measured by ISQ, was lower in the immediate group at 3 months (65.5 ± 2.8 vs. 68.2 ± 3.0, P = 0.04) but showed no significant difference at 12 months. Peri-implant soft-tissue health remained stable in both groups, with no significant differences in probing depth. Both groups achieved a 100% implant survival rate with no major complications. Conclusion: Immediate implant placement showed higher marginal bone loss than delayed placement, although both groups achieved similar implant stability and peri-implant tissue health by the 12-month follow-up. These findings suggest that immediate implant placement, while reducing treatment time, may carry a higher risk of bone loss, highlighting the importance of patient-specific treatment planning.