This scoping review was conducted following the methodological framework outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The aim was to systematically chart the literature on (1) factors contributing to dental implant failure and (2) techniques used for implant retrieval or explantation. The review did not include quality assessment or meta-analysis, as the objective was to map the extent, range, and nature of the available evidence.

The Search was done using the following PCC framework.

Population (P): Studies which reported patients with dental implants, including those experiencing implant failure for any cause (e.g., peri-implantitis, overload, systemic conditions, medication effects)

Concept (C): Implant failure characteristics and the techniques used for explantation or retrieval of failed dental implants (e.g., trephine burs, reverse torque, piezo, laser, electrochemical)

Context (C): All study designs (e.g., observational studies, clinical trials, case reports, reviews) published in English from 1983 to 2025, across all care settings and geographical regions

A total of 1,014 records were identified across PubMed, Scopus, and Web of Science. After removal of 602 duplicates, 412 records underwent title and abstract screening, of which 24 were excluded for not meeting the inclusion criteria. The final number of studies included in this review was 388. A summary of the screening process is provided in the PRISMA flow diagram (Figure 1).

The included studies were published between 1983 and 2025, demonstrated a clear and consistent growth in publications related to dental implant failure and retrieval techniques with a steady increase observed from 2015 onwards. Fewer than five studies were published annually before 2000, followed by a moderate increase between 2001 and 2010. The peak publication period was between 2019 and 2023, accounting for 62% of the included literature. This reflects an increase in global research activity and clinical interest in implant failure mechanisms and minimally invasive retrieval strategies (Figure 2).

The distribution of study types was as follows: •

Observational studies (cohort, cross-sectional, case series): 264 studies (68%)

The most frequently cited biological cause of implant failure was peri-implantitis, characterized by inflammation, bleeding on probing, and radiographic bone loss (5–10). Several studies emphasized the lack of uniform diagnostic criteria, with thresholds for marginal bone loss ranging from 2 mm to 3.5 mm (8, 11, 12).

Poor plaque control and inadequate maintenance protocols were strongly correlated with peri-implant disease (13–15). Residual cement was also highlighted as a peri-implant irritant in both case reports and systematic reviews (16, 17).

Systematic reviews have linked poorly controlled diabetes mellitus to an increased risk of peri-implantitis (18, 19). However, well-controlled diabetes does not appear to significantly compromise peri-implant bone stability, as crestal bone levels in type 2 diabetic patients with strict glycemic control were found to be comparable to non-diabetic patients (20).

Smoking is another significant risk factor, with moderate-certainty evidence supporting its association with peri-implantitis (21). Furthermore, studies suggest a dose-dependent relationship between smoking and implant failure, with patients smoking more than 20 cigarettes per day facing a higher risk (22).

Additionally, nicotine impairs vascularization and wound healing, further compromising implant integration (23). A meta-analysis also reported that smoking significantly increases marginal bone loss around implants, further contributing to peri-implant disease progression (24).

Systemic conditions such as diabetes mellitus, especially when poorly controlled, were significantly associated with early and late implant failures (15, 25, 26). Several systematic reviews noted increased failure rates in patients with elevated HbA1c levels (13, 27).

Exposure to bisphosphonates, SSRIs, and proton pump inhibitors was linked to altered bone metabolism and decreased implant survival (28–30). Although findings were inconsistent across studies, the pharmacological effects on osseointegration and bone remodeling remain a growing concern.

While some systematic reviews suggest that low-dose antiresorptive therapy for osteoporosis does not significantly increase implant failure risk (5, 21, 31, 32), others remain inconclusive on its impact (33, 34). However, multiple studies have reported cases of medication-related osteonecrosis of the jaw (MRONJ) in patients with dental implants (35, 36).

Radiotherapy negatively affects implant treatment outcomes (37).

Another meta-analysis yielded inconclusive results on the influence of chemotherapy on osseointegration due to the limited number of available studies. Most of these studies lacked specificity, included only a small number of cases, and were conducted without a control group, making definitive conclusions challenging (38).

Although no definitive radiation dose threshold exists for implant success, patients receiving less than 38 Gy for head and neck cancer may safely undergo implant placement (39).

Mechanical overload due to prosthetic misfit, occlusal discrepancies, or bruxism was a major contributor to implant failure in 40 studies (14, 40–43). Improper torque control, inadequate stress distribution, and parafunctional habits were commonly cited in retrospective analyses.

A small subset of studies also reported implant–abutment connection fractures and fixture fractures, particularly in narrow-diameter implants under posterior load (44–46).

Several failures were attributed to poor surgical technique, including overheating of bone, proficiency in maintaining sterility, executing proper flap techniques, ensuring precise, steady insertion, lack of primary stability, selecting sites with insufficient bone and immediate placement in infected sockets (1, 47–49). Inadequate site preparation, especially in dense bone types, was associated with early implant mobility and fibrous encapsulation.

Implant positioning errors, shallow placement, facial positioning, improper axial inclination, negatively affects aesthetics and complicates oral hygiene maintenance (50). The use of computer-guided implant placement has been shown to improve precision and minimize errors during surgery (51, 52). In cases where implants are malpositioned, corrective procedures such as prosthetic compensation, guided bone regeneration, or implant removal and reinstallation may be necessary (50, 53).

Although titanium allergies are rare, with an estimated prevalence of 0.6%, they have been linked to unexplained implant failures. Among patients who underwent preoperative patch testing, 2.7% exhibited a positive reaction to titanium (54).

The most frequently cited factor in implant failure across study types was peri-implantitis. Consistently associated with marginal bone loss, inflammation, and ultimately loss of osseointegration, peri-implantitis featured in over 150 studies in this review. However, variation in diagnostic criteria—particularly the thresholds for acceptable bone loss and clinical probing parameters—complicates cross-study interpretation. Despite advances in implant surface technologies and maintenance strategies, the prevalence of peri-implant inflammation suggests an ongoing clinical challenge.

The role of plaque control, patient compliance, and maintenance protocols was emphasized in both observational data and systematic reviews. Studies noted that failure was more likely in patients who lacked regular follow-up or professional cleaning, underscoring the importance of preventive strategies in implant maintenance (71).

Our review highlights a growing body of literature examining how systemic conditions, especially poorly controlled diabetes mellitus and osteoporosis adversely affect implant outcomes. Elevated HbA1c levels were consistently associated with increased risk of peri-implant bone loss and failure, aligning with findings from multiple meta-analyses.

The influence of medications such as bisphosphonates, SSRIs, and PPIs on implant survival has emerged as a major area of interest over the last decade. Although findings are not always consistent, several included studies suggest that such medications may impair bone metabolism, potentially reducing osseointegration or increasing susceptibility to marginal bone loss. These observations support the need for personalized risk assessment during treatment planning.

Mechanical stress emerged as another critical determinant of implant survival. Factors such as prosthetic misfit, inadequate occlusal control, and bruxism were strongly associated with complications such as screw loosening, implant fractures, and prosthetic decementation. Particularly in posterior regions, the application of excessive or poorly distributed forces was reported as a common precursor to mechanical failure.

Studies further identified that improper prosthetic design including cantilevered extensions and non-axial loading can introduce deleterious stress patterns. These findings reinforce the importance of biomechanically sound restorative planning and suggest that even well-integrated implants are vulnerable to mechanical abuse over time.

Despite the large number of studies on implant placement and failure, only 14 articles in the included sample described techniques for implant retrieval or explantation. The most commonly reported method was the use of trephine burs, which, although effective, entails removal of peri-implant bone and often necessitates additional grafting procedures. This technique, however, remains a well-validated option (94% success), particularly when other methods fail or bone removal is acceptable.

Newer, minimally invasive approaches—such as reverse-torque devices (284 implants; 87.7% success, piezoelectric systems, and laser-assisted explantation—are being introduced, but evidence for their comparative effectiveness remains sparse. Success rates reported for these newer techniques ranged from 70% to 100%, but most studies had small sample sizes, short follow-up, and lack of control groups.

The absence of randomized controlled trials or standardized outcome measures limits our ability to determine the optimal approach for implant retrieval. Moreover, a few studies reported patient-centered outcomes, such as pain, healing time, or reimplantation success following retrieval.

This review's strengths include a comprehensive search strategy across three major databases, inclusion of all relevant study types, and adherence to PRISMA-ScR guidelines.

However, several limitations must be acknowledged: