Selection Criteria: This review employed manual and electronic searches across three databases (MEDLINE, EMBASE, and CENTRAL), with the latest search conducted in July 2023. Inclusion criteria encompassed clinical studies involving adults aged 18 and above, with a minimum follow-up period of 12 months after implant surgery and prostheses loaded within 1 week of implant placement. Specifically, the studies focused on immediate implant placement with simultaneous guided bone regeneration (GBR) during implant surgery, emphasizing reporting changes in marginal bone level. On the other hand, expert opinions, case series with fewer than 10 patients, and animal or in vitro studies were excluded from consideration. Additionally, clinical trials involving patients classified as ASA III with uncontrolled systemic diseases and studies lacking adequate information to identify survival criteria or failing to report the longest follow-up with the same patient population were excluded.

Two reviewers independently screened the title and abstract, collected data, and assessed the risk of bias in relevant papers. Any disagreements were resolved through discussion with a third reviewer. The included studies underwent quality assessment, with the Cochrane risk-of-bias tool (RoB 2) applied to randomized controlled trials (RCTs), the Newcastle-Ottawa Scale employed for cohort and case-control studies, and the Case Series Critical Appraisal Tool utilized to evaluate the quality of case series.

Key Study Factor: A review of studies included edentulous or partially edentulous patients treated with an immediate implant placement protocol. The efficacy of bone augmentation around an immediately placed implant with gap-filling sites (a gap between the implant surface and the buccal-approximal bone wall) compared with augmented sites exhibiting gap with dehiscence/fenestration was assessed.

Main Outcome Measure: Marginal bone level change (MBLc) measured on a periapical radiograph was defined as the primary outcome; Implant insertion was chosen as the baseline time.

Pink esthetic score, gingival recession, and Implant Survival rate were secondary outcomes.

Main Results: The review included a total of 25 studies, which consisted of 5 randomized controlled trials, 6 prospective studies, 7 retrospective studies, and 12 case series. These studies examined a collective total of 692 implants that were immediately placed.

Among the studies that focused on bone grafting in the gap between the implant and the surrounding bone wall, the analysis found that the average marginal bone loss was 0.73 mm ± 1.52 mm (ranging from -1.50 to 0.26 mm) for a total of 475 implants. Eight studies showed improvements in the pink esthetic score, and the weighted cumulative implant survival rate (ISR) was determined to be 98.99% based on 622 implants. Regarding studies on gap augmentation with dehiscence or fenestration, the average MBLc was 1.19 mm ± 0.26 mm across 30 implants. The weighted cumulative ISR for these cases was 97.25% out of 70 implants.

Conclusion: Immediate implant placement with simultaneous filling of the gap with a bone graft has decreased bone loss and enhanced the healing of surrounding soft tissues compared to cases where the gap is not filled. Moreover, implants with gap filling have exhibited a higher rate of survival. However, additional research is needed to determine the consistent advantages of placing provisional prostheses simultaneously when augmenting bone defects around the implants.