Immediate versus delayed single-tooth implant placement in bony defect sockets in the aesthetic zone: Is an intact buccal wall necessary?

Abstract

A commentary on: Meijer H J A, Slagter K W, Gareb B, Hentenaar D F M, Vissink A, Raghoebar G M. Immediate single-tooth implant placement in bony defect sites: a 10-year randomized controlled trial. J Periodontol 2025; 96: 151-163.

Design: This single-center, 10-year randomized controlled trial (RCT) was conducted at the University Medical Center Groningen (UMCG), the Netherlands, to compare immediate and delayed implant placement in patients with a failing tooth in the aesthetic region and a buccal bony defect of ≥5 mm. Forty patients were randomly assigned to either the Immediate Group (immediate implant placement with bone grafting and delayed provisionalization) or the Delayed Group (ridge preservation followed by delayed implant placement and provisionalization). Cone beam computed tomography (CBCT) was used preoperatively to assess palatal bone availability. Surgical procedures were standardized and performed by a single experienced oral and maxillofacial surgeon, while prosthetic procedures were completed by a single prosthodontist. Patients were followed up for 10 years to assess marginal bone levels (MBL), buccal bone thickness (BBT), soft tissue changes, aesthetic outcomes, patient satisfaction, and biological and technical complications.

Case selection: Patients with a compromised tooth in the maxillary aesthetic zone and a buccal bone defect of ≥5 mm following extraction were included. Patients were excluded if they met any of the following criteria: poor oral hygiene, inadequate mesio-distal space for implant placement, presence of periodontal disease, smoking, an American Society of Anesthesiologists (ASA) score of ≥II, or a vertical bony defect of less than 5 mm in the labial socket wall after tooth extraction.

Data analysis: The primary outcome, change in marginal bone level, was analyzed using a per-protocol strategy. Normally distributed data were summarized using means and confidence intervals and compared with the independent samples t-test, while non-normally distributed data were described using medians and interquartile ranges and compared using the Mann-Whitney U test. To check the robustness of the findings, sensitivity analyses were conducted, including an intention-to-treat analysis. For outcomes with repeated measurements, multivariable linear mixed-effect models were utilized to examine differences between the treatment groups over time. All statistical analyses were performed using the R software (version 4.0.5), and a p-value less than 0.05 was the criterion for statistical significance.

Results: After 10 years, the mean marginal bone level change was -0.71 ± 0.59 mm in the Immediate Group and -0.36 ± 0.39 mm in the Delayed Group, with no statistically significant difference between them (p = 0.063). Secondary outcomes showed no significant variations between the two groups.

Conclusions: Immediate implant placement with bone augmentation in postextraction sockets with buccal bony defects ≥5 mm yielded similar long-term outcomes to delayed implant placement after ridge preservation in the aesthetic zone, with no significant differences in bone stability, clinical performance, aesthetics, or patient satisfaction over 10 years.