Dental implants have revolutionized restorative dentistry and are the most effective method to replace missing teeth and provide a long-term solution to restoring dental function and aesthetics. Dental implants have changed the treatment plan for people suffering from tooth loss. However, like other medical procedures, they are not immune to complications.^[1] Dental implants have been widely accepted as a treatment for many edentulous patients, with a survival rate of 89.4% after 10 years and a success rate of 90%.^[2,3] Among the different procedures for dental implant placement, two main techniques have emerged: immediate loading (IL) and non-IL (NIL). While both are effective, they differ significantly in application, timing, and patient outcomes.^[4] The loading time in single-implant restorations has become a major focus of dental implantology, and long-term clinical outcomes are at the center of this debate.

IL, where the implant is restored shortly after placement, offers distinct advantages, including shorter treatment time and immediate esthetic improvements, which increase patient satisfaction.^[5] One of the main prerequisites for implant success is acceptable initial stability both during implant placement and after implant loading. The need for adequate bone volume and density, longer or wider implants, and the suggested 3–6-month delay before implant loading support this fundamental principle.^[6] The debate between immediate and NIL protocols for single-implant restorations is a research and clinical focal point. Understanding the nuances of each technique is critical for dental professionals to optimize patient care and implant success. However, there are still concerns about achieving initial stability and ensuring proper osseous integrity under IL conditions.^[7]

This approach aims to reduce the time the patient has to remain edentulous, and it has gained popularity due to its convenience and potential to increase patient satisfaction.^[8] This technique invests in the initial stability of the implant and is usually used in cases where the bone has desirable quality and quantity, and the implant has sufficient initial stability.^[9] The successful outcome of IL largely depends on achieving adequate initial stability during implant placement, often being determined by the bone quality and quantity and implant insertion torque.^[10] For this reason, IL is used more in patients with good bone density, such as the anterior mandible, where the bone has better quality.^[11]

However, the long-term success of immediately loaded implants is often questioned due to the potential risks associated with premature loading, which may compromise the osseointegration process and increase the likelihood of implant failure.^[12] To reduce this risk, clinicians should carefully assess the biomechanical environment and use techniques such as multiple implant splinting or implants with surface modifications that enhance osseous integrity. Studies have shown that when appropriate patient selection criteria are met, IL can achieve a success rate comparable to the delayed loading protocol.^[13]

In contrast, nonimmediate or delayed loading involves a recovery period ranging from 3 to 6 months before the prosthetic restoration placement. This conventional method assumes that a stress-free treatment environment allows for optimal osseointegration and thus improves the stability and long-term success of the implant.^[14] This period allows for osseointegration, a process in which the implant integrates with the jawbone, providing a stable and secure base for the prosthesis. Despite the predictability and success of NIL, it increases the duration of treatment and requires multiple visits, which can be unpleasant for patients.^[15] This approach is considered the gold standard, especially when patients present with poor bone density, insufficient bone volume, or systemic conditions that may interfere with the treatment.

Delayed loading provides a more predictable environment for implant success, as the long treatment phase allows the bone-implant interface to fully mature before any functional stress is applied.^[16] Research has shown that this method significantly reduces the risk of premature implant failure, especially in cases where the initial stability of the implant may not be ideal at the time of implantation.^[17] In addition, delayed loading is often preferred in cases where bone grafting or reconstructive procedures are performed, as these procedures require a longer treatment period to achieve sufficient bone volume and density for successful implant integration. Research shows that the delayed protocol allows the surrounding bone to adapt and regenerate around the implant and causes stronger and more stable long-term results.^[18] Although the longer treatment time may be considered a disadvantage, the delayed loading protocol has consistently demonstrated high survival rates and long-term success among different groups of patients.^[19]

The choice between immediate and NIL is influenced by several factors, including the patient’s oral health, bone density, and implant site.^[9] IL may be preferred in cases where esthetics is the main concern, and the patient needs a quicker solution.^[20] However, implant failure is a concern, especially if the implant has not achieved sufficient initial stability during implantation. Since immediate and NIL methods have advantages and challenges, dental professionals should consider them carefully to ensure optimal results.^[21] With the progress of research, the decision-making process for choosing the appropriate implant loading protocol is increasingly guided by evidence-based practices and individual patient care.^[22]

It is necessary to research immediate and delayed loading of dental implants to advance clinical practices and improve patient outcomes in implant dentistry. Furthermore, it is essential to assess the immediate and delayed loading of dental implants to modify treatment protocols and address the limitations of each approach. While both techniques have shown high success rates, their long-term effects vary depending on individual patient characteristics, such as bone quality, systemic health, and the presence of risk factors such as smoking or bruxism. Further investigations could help determine which loading protocol is most appropriate for different clinical scenarios and ensure optimized implant survival and success rates in a larger patient population.^[23] In addition, IL is becoming increasingly popular as patients seek faster and more convenient treatment options. However, comprehensive research should confirm its long-term effectiveness compared to delayed loading, especially in complex cases involving compromised bone conditions or multiple missing teeth.^[24]

Despite the success of both loading protocols, there is considerable variability in how they are applied to different patient populations and clinical scenarios. Understanding the biomechanical and biological factors that influence the success of each approach is essential to optimize treatment protocols and minimize the risk of implant failure. Research can help clarify specific conditions under which IL is appropriate, particularly in patients with compromised bone quality or those undergoing complex procedures such as bone grafting.^[18] IL requires high initial stability; however, the exact threshold and conditions for this stability are still debated. Studies that examine factors such as implant design, surface modifications, and surgical techniques provide essential data to improve the predictability of IL outcomes.^[25] Similarly, examining how different qualities of bones, such as maxilla or mandible, respond to immediate or delayed loading will inform clinicians on how to customize treatment plans for individual patients.^[26] In addition, with the development of implantology, there is a need for evidence-based guidelines that inform clinicians when to choose immediate versus delayed loading based on patient-specific factors and implant characteristics.^[27]

In addition, the demand for faster and more beautiful results increases as more patients seek implant treatment to replace missing teeth. IL offers the potential to reduce treatment time, increase patient satisfaction, and improve functional outcomes, but its widespread acceptance must be supported by rigorous, long-term research. Comparative studies investigating the success rates, complications, and long-term stability of implants under both protocols can provide valuable data to help clinicians normalize the benefits of immediate restoration with the risk of failure in different clinical contexts.^[28] Research is also needed to examine the economic implications of both protocols because IL, if successful, may reduce the number of visits and overall treatment costs, benefiting patients and healthcare systems.^[29] In summary, further research on loading protocols will improve clinical decision-making and the predictability of results and ultimately enhance patient care in implant dentistry.

In a systematic review of clinical trials, Cochran et al. concluded that delayed loading is particularly effective in complex cases or suboptimal bone conditions, highlighting its reliability in extending the implant life.^[21] Chaushu et al. compared immediate and delayed loading in a clinical study on single-tooth implants. Their findings showed that IL did not negatively affect implant survival or success rate compared to delayed loading, supporting IL under appropriate clinical conditions.^[30]

In a systematic review and meta-analysis, Pigozzo et al. evaluated and compared the clinical outcomes of immediate and early loading protocols for single-tooth implants. IL refers to placing the dental restoration on the implant within 48 h of surgery, whereas early loading occurs after a short recovery period but before the typical 3 to 6-month restoration time. This analysis included numerous studies and showed that immediate and early loading protocols indicated high implant survival rates and satisfactory functional results. There was no significant difference in implant success, marginal bone loss, or soft tissue health between the two techniques, indicating that immediate and early loading protocols can be effectively and safely employed in appropriate cases and provide flexibility in treatment plans.^[31]

Gjelvold et al. conducted a randomized clinical trial comparing the clinical outcomes of immediate and delayed loading of single-tooth implants over 5 years. This study showed that immediate and delayed loading procedures have high survival rates (100% and 95.8%, respectively) with no significant difference in marginal bone loss or aesthetic outcomes, suggesting that IL can be as effective as delayed loading in the long term.^[32]

Zhao et al. performed a systematic review and meta-analysis on the long-term results of immediate versus NIL in single-implant restorations. This review included 10 randomized controlled trials. The results revealed that IL showed predictable and reliable results, with no significant difference in implant failure rates or marginal bone loss compared to NIL. This study emphasized that careful case selection is critical to the success of IL protocols.^[33]

This umbrella review aimed to fill the knowledge gap by systematically evaluating and comparing the long-term clinical outcomes of immediate versus NIL in single-implant restorations. By examining critical parameters such as implant survival rate, marginal bone loss, prosthetic complications, and patient-reported outcomes, this review provides valuable insights to clinicians and researchers, guides clinical decision-making, and highlights areas for future research. This comprehensive approach ensures that the nuances of each loading protocol are fully understood, ultimately helping to improve patient outcomes and advance the field of dental implantology.

The results of this umbrella review were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Based on the Figure 1, this review provides a comprehensive summary of the evidence and identifies areas of agreement, disagreement, and gaps in the literature to guide clinical decision-making in implant dentistry.

This umbrella review combined findings from various systematic reviews and meta-analyses comparing immediate and nonimmediate single-implant loading outcomes. As Figure 2 show, a total of 24 systematic reviews with a cumulative sample size of 8063 patients and 18,373 implants were included in the study.

The findings of this review confirm that both IL and NIL protocols offer successful long-term outcomes for single-implant restorations, with comparable survival rates and soft-tissue responses. This is consistent with previous studies, such as Buser et al. (2017), which found no significant difference in implant survival between the two protocols after long-term follow-up.^[16] In both IL and NIL, proper osseointegration and soft-tissue health were maintained, emphasizing that both approaches can lead to stable and predictable outcomes when managed correctly. These findings align with the conclusions of various meta-analyses, including those by Pjetursson et al. (2008), who demonstrated similar success rates for both loading protocols over extended periods, regardless of the approach used.^[38]

One of the key advantages of IL highlighted in our study is its ability to deliver faster results and higher patient satisfaction. This finding is consistent with the work of Carosi et al. (2023), who reported that IL significantly shortened treatment times without compromising implant survival or aesthetics.^[39] However, as we noted, IL requires strict clinical conditions to ensure success, such as adequate bone density and initial implant stability. In contrast, studies like those by Chen et al. (2020) and Pjetursson et al. (2008) have emphasized that NIL is a more predictable option, especially for patients with compromised bone quality or when a more conservative approach is desire.^[40,38] NIL allows for more time for osseointegration before functional loading, which can reduce the risk of early complications, such as implant mobility or failure, in less-than-ideal clinical scenarios.

Ultimately, the choice between immediate and NIL should be individualized based on the patient’s specific clinical circumstances, as emphasized in several studies. For instance, Lemos et al. (2016) suggested that the decision should be based on factors such as bone quality, the level of initial implant stability, and the patient’s overall health.^[41] Our findings support this notion, as we observed that NIL is particularly suitable for cases where low-risk procedures or poorer bone quality are concerns. While IL can provide faster outcomes and improved patient satisfaction, NIL remains a reliable and safe choice for ensuring long-term implant success, especially in patients with more challenging clinical conditions. The ability to tailor the loading protocol to the patient’s needs is critical for achieving optimal outcomes.

The present study reports the improvements made in immediate or delayed loading of dental implants with more accuracy. New findings indicate the role of bone density, implant surface changes, and patient-specific characteristics in the success rates of both protocols. In addition, new implant materials and designs have facilitated faster osseointegration and early stability, thereby increasing the possibility of IL. This research provides clinicians with updated evidence-based guidelines to select an appropriate loading protocol. Therefore, this study would inform physicians of correct clinical decision-making regarding loading protocols. Such findings enable clinicians to confidently recommend IL at patients’ requests for faster restoration but with careful case selection to ensure long-term success. Conversely, delayed loading remains a reliable option for complex cases, balancing rapid recovery with clinical predictability and safety.