A retrospective study of 30,959 implants: Risk factors associated with early and late implant loss

Risk factors associated with early implant failure: A retrospective review

PURPOSE

The purpose of this study was to investigate the association between possible risk factors and early implant failure.

PATIENTS AND METHODS

This retrospective cohort study included consecutive patients receiving dental implant treatment in a four-year timeframe. Patient-related variables (age, sex, smoking, and systemic disease), local factors (area, reason for tooth extraction, and bone quality), surgical variables (bone augmentation, time of implant placement, staging, and antibiotic prophylaxis), and implant-related factors (brand, length, and diameter) were analyzed. Bivariate analyses and multivariate logistic regression model were used to determine the variables associated with early implant failure.

RESULTS

The study group comprised 1323 implants in 738 patients with a mean of 1.8 implants/patient of which, 53 failed in 52 patients in the early stage (before final prosthetic loading). According to the multivariate model, smoking (Odds Ratio=1.836, P=0.031), posterior maxillary region (OR=2.958, P=0.006), implantation in place of teeth extracted due to periodontal problems (OR=2.531, P=0.004), bone type IV (OR=2.881, P=0.008), implant in previously augmented site (OR=2.239, P=0.014), and immediate provisional prosthesis (OR=3.418, P=0.019) were associated with a significantly higher risk of early implant failure. Narrow implants showed a significantly higher risk of early failure in bivariate analyses (P=0.012). However, the effect was no longer significant in the multivariate model (OR=2.322, P=0.068).

CONCLUSION

Early implant failure would be more expected in smokers, posterior maxilla, history of periodontal problems, type IV bone, augmented bone, and immediately loaded cases.

Association between prosthesis contour and peri-implantitis in patients compliant with supportive periodontal therapy: A retrospective cohort study

PURPOSE

Poor contour of the implant restoration causes plaque accumulation and increases the risk of peri-implantitis. This study aimed to investigate whether the prosthodontic components of dental implants were associated with the prevalence of peri-implantitis.

METHODS

We enrolled 185 patients with 348 implants who underwent at least 1-year follow-up after the delivery of the prosthesis from February 2010 to January 2021. Demographic data of the patients and implants and the follow-up period were recorded. The emergence angle, type of cervical crown contour, and contour angle were analyzed using annual bite-wing radiographs. Peri-implantitis in this study was diagnosed if the peri-implant bone loss was greater than 2 mm between the bite-wing radiographs taken at baseline and the latest. Chi-square test, two-sample t-test, and multivariate logistic regression were used to investigate the differences and odds ratios between the peri-implantitis and non-peri-implantitis groups.

RESULTS

The incidence of peri-implantitis was 14.9% during a follow-up period of 1509 days after the delivery of the prosthesis for at least 1-year. Based on the prevalence of non-peri-implantitis and after adjusting for confounding factors, the risk factors identified were bone types for implants (native bone vs. alveolar ridge preservation: adjusted odds ratio = 2.43, P = 0.04). Sex, arch, and guided bone regeneration vs. alveolar ridge preservation have the potential for a statistical difference.

CONCLUSIONS

Compared with implants at alveolar ridge preservation sites, implants in the native bone were more prone to peri-implantitis. Further randomized controlled trials are required to determine these associations.

Antimicrobial Potential of Strontium-Functionalized Titanium Against Bacteria Associated With Peri-Implantitis

OBJECTIVES

To explore the antimicrobial potential of strontium (Sr)-functionalized wafers against multiple bacteria associated with per-implant infections, in both mono- and multispecies biofilms.

MATERIALS AND METHODS

The bactericidal and bacteriostatic effect of silicon wafers functionalized with a strontium titanium oxygen coating (Sr-Ti-O) or covered only with Ti (controls) against several bacteria, either grown as a mono-species or multispecies biofilms, was assessed using a bacterial viability assay and a plate counting method. Mono-species biofilms were assessed after 2 and 24 h, while the antimicrobial effect on multispecies biofilms was assessed at Days 1, 3, and 6. The impact of Sr functionalization on the total percentage of Porphyromonas gingivalis in the multispecies biofilm, using qPCR, and gingipain activity was also assessed.

RESULTS

Sr-functionalized wafers, compared to controls, were associated with statistically significant less viable cells in both mono- and multispecies tests. The number of colony forming units (CFUs) within the biofilm was significantly less in Sr-functionalized wafers, compared to control wafers, for Staphylococcus aureus at all time points of evaluation and for Escherichia coli at Day 1. Gingipain activity was less in Sr-functionalized wafers, compared to control wafers, and the qPCR showed that P. gingivalis remained below detection levels at Sr-functionalized wafers, while it consisted of 15% of the total biofilm on control wafers at Day 6.

CONCLUSION

Sr functionalization displayed promising antimicrobial potential, possessing bactericidal and bacteriostatic ability against bacteria associated with peri-implantitis grown either as mono-species or mixed in a multispecies consortium with several common oral microorganisms.

An up to thirty-year retrospective study on the success and survival of single unit and splinted implant-supported crowns in a dental school setting

STATEMENT OF PROBLEM

Studies investigating the survival of implant-supported crowns provided in a dental school setting are sparse.

PURPOSE

The purpose of this retrospective study was to evaluate the success and reasons for failure of single unit and splinted implant-supported crowns provided in a dental school.

MATERIAL AND METHODS

Using the axiUm dental management software program and paper charts, all single unit and splinted implant-supported crowns provided between September 1989 and January 2020 were included for evaluation. Success, survival, and failure were recorded as well as reasons for failure. A Kaplan-Meier survival estimate with an associated P value, a life table analysis, and a log-rank test comparing the survival of single unit and splinted implant-supported crowns were performed.

RESULTS

Over 30 years, 678 implant-supported crowns (586 single unit and 92 splinted) had been provided. Of these crowns, 17 (2.90%) single unit crowns and 5 (5.43%) splinted crowns failed, with most being prosthetic failures for both single units (64.7%) and splinted (80%), rather than biologic failures. A total of 371 single unit (63.3%) and 46 splinted (50.0%) implant crowns were a complete success, and 215 single unit (36.7%) and 46 splinted (50.0%) crowns survived but had some type of complication. The overall implant-supported crown survival rate was 96.8%. The survival distribution of the single unit and splinted implant-supported crowns was not statistically significantly different [χ2(2)=1.285, P=.257].

CONCLUSIONS

Both single unit and splinted implant-supported crowns had high success rates and showed similar survival rates. The most common causes of complications were also similar, with debonding and screw loosening of crowns being the most common complication for both single unit and splinted crowns.

Local risk factors for one-year dental implant loss and late loss in 287 failed implants caused by peri-implantitis or infection after prosthesis loading: a retrospective study

The purpose of this paper was to retrospectively assess the local factors that are likely to be associated with the risks for one-year dental implant loss.A retrospective study was designed and implemented. The sample consisted of patients who underwent an implant loss or removal caused by peri-implantitis or infection after prosthesis loading. The chi-squared test and generalised estimating equations (GEE) were used to explore the potential risk factors for one-year implant loss. A total of 279 patients with 287 failed implants were enrolled in this study. Immediate implant placement exhibited a 3.373 (95% CI: 1.652 to 6.886) significantly increased risk to experience one-year implant loss than early and late implant placement (p = 0.001). In addition, implants loaded during a healing period fewer than two months after implant placement were at 18.139 (95% CI: 8.925 to 36.866) significantly higher risk of one-year implant loss when compared with those that loaded within more than two months after implant placement (p < 0.001). Smokers were 1.866 (OR = 1.866,95% CI: 0.993 to 3.510) times as high risk for one-year implant loss as non-smokers, but there were no significant statistical differences (p = 0.053). Immediate implant placement and early implant loading were considered risk factors for one-year implant loss.

Survival Rates of Short Dental Implants (≤6 mm) Used as an Alternative to Longer (>6 mm) Implants for the Rehabilitation of Posterior Partial Edentulism: A Systematic Review of RCTs

Short dental implants have been proposed as an alternative treatment option to bone regeneration procedures for the rehabilitation of resorbed alveolar ridges. The aim of this paper was to systematically review randomized controlled trials (RCTs) comparing short implants (≤6 mm) and longer implants (>6 mm) in atrophic alveolar ridges in terms of implant survival rates, peri-implant marginal bone loss (MBL), prevalence of peri-implantitis and technical complications. A thorough electronic search was performed until September 2023. RCTs with follow-up of at least 1-year post-loading comparing short implants with rough surfaces to longer implants in the posterior jaws of systemically and periodontally healthy, partially edentulous adults were considered. Studies with incomplete information on the number of patients, follow-up or definition of "short implants" were excluded. The revised Cochrane risk-of-bias tool for randomized trials was used for Risk of bias assessment. Fixed-effects meta-analysis of the selected studies was applied to compare the outcome variables. Random-effect meta-analysis was performed, on the basis of within-study comparisons. In total, 16 articles were selected for meta-analysis and incorporated 408 short implants and 475 longer implants inserted in 317 and 388 patients, respectively. The survival rates of longer implants in pristine or augmented bone were significantly increased compared to short implants (95%CI: 2-5%, p < 0.001). Standard-length implants displayed increased, although non-statistically significant MBL (95%CI: -0.17-0.04, p > 0.05), and prevalence of peri-implantitis (95%CI: 0-5%, p > 0.05). No statistically significant differences were observed between short and long implants in terms of technical complications (implant-level 95%CI: -4-6%, p > 0.05). Short implants represent a promising alternative treatment option for the rehabilitation of posterior jaws to avoid additional bone augmentation procedures. Nonetheless, they should be selected cautiously due to a potentially limited survival rate compared to longer implants. A major limitation of this study is the variability in the included studies regarding sample size, patient profile, type of bone, loading protocol, definition of peri-implantitis, among others. This study received no external funding. The study protocol was registered in PROSPERO (CRD42023485514).

Clinical and radiographic outcomes of implant-supported fixed prostheses with cantilever extension in anterior mandible: A retrospective study

OBJECTIVES

The objective of this study is to analyze the clinical and radiographic outcomes of implant-supported fixed protheses with cantilever extensions (ISFPCs) in the partially edentulous anterior mandible.

MATERIALS AND METHODS

Patients who received anterior mandible implant restoration between January 2016 and December 2021 were included. Patients with two, three, or four continuous missing teeth receiving adjacent implant supported single-unit crowns (ISSCs), ISFPCs, implant-supported fixed protheses without cantilever extensions (ISFPNs) were divided into groups: ISSC+ISSC, ISFPC, ISSC+ISFPC, three-unit ISFPN, ISFPC+ISFPC, or four-unit ISFPN, respectively. We recorded and evaluated survival rates, mechanical and biological complications, peri-implant marginal bone loss (MBL), esthetic outcomes, and patient perceptions. Statistical analysis was performed using linear mixed models (LMM).

RESULTS

The study included 87 patients and 152 implants. No implant loss occurred during an average follow-up of 3.48 ± 1.85 years (range: 1-7 years). According to LMM models, prosthetic type had a statistically significant impact on MBL during follow-up periods, in favor of the ISFPC and ISFPC+ISFPC groups (0.16 ± 0.48 mm vs. 0.51 ± 0.49 mm, p = .034; 0.22 ± 0.49 mm vs. 0.60 ± 0.62 mm, p = .043, respectively). Mechanical and biological complications were relatively low and comparable. The four-unit ISFPC group had higher subjective esthetic scores compared with the ISSC+ISSC group (98.6 vs. 83.8, p < .05), and patients in the ISFPC+ISFPC group expressed greater satisfaction with cleanability than the ISFPN group (98.8 vs. 80.6).

CONCLUSION

ISFPCs offer a highly predictable treatment option in the anterior mandible, characterized by high survival rates, and comparable complication rates, peri-implant bone stability and esthetics to adjacent ISSCs or ISFPNs.

Dental implant failures in Utah and US veteran cohorts

INTRODUCTION

Approximately, 5.5 million dental implants are estimated to be surgically placed in the United States yearly, with an anticipated long-term failure rate ranging from 3% to 10%. At the Salt Lake City Dental Clinic within the Department of Veterans Affairs (VHA), specific protocols have been established to mandate that clinicians present every dental implant case for review by a committee. To understand the effectiveness of this approach, a comparative data analysis was undertaken to compare local dental implant failure data against national VHA data.

METHODS

Leveraging electronic health records of veterans spanning from 2000 to 2021, we gathered procedural records related to dental implant placement or failure, demographic information, and medical history for individuals who received dental care at various dental clinics within the nationwide VHA network. Subsequently, statistical analyses were conducted using mixed-effects Poisson regression models with cluster-robust standard errors. Incident rate ratios (IRRs) for Utah-specific and nationwide cohorts were ascertained.

RESULTS

The Utah VHA dental clinical data showed that there was a slightly lower prevalence of implant failure at 6.7% compared to the national cohort, which had a rate of 6.9%. The implant level failure rates were also low, with 4.20 (confidence interval [CI]: 3.68, 4.81) per 1000 implant placements per year for Utah cohorts. The adjusted IRR indicated a relative 16% reduction in risk among Utah Veterans (IRR 0.84, 95% CI [0.76-0.92]; p < 0.001).

CONCLUSIONS

The stringent protocols in place at Salt Lake City, which integrate evidence-based practices and expert opinion for evaluating patient suitability for dental implant placement and subsequent care, contributed to the reduced risk among Utah Dental Clinic veterans pool compared to veterans of other states.

Analysis of risk factors related to early implant failure: A retrospective study

STATEMENT OF PROBLEM

Factors influencing early implant failure (failure during the healing period) in the rehabilitation and restoration of oral function in partially edentulous patients are unclear.

PURPOSE

The purpose of this clinical study was to investigate several factors that may be associated with early implant failure.

MATERIAL AND METHODS

This retrospective study was conducted on 3247 implants in 2061 patients between 2009 and 2022. Patient-related and surgery-related factors, including smoking; sex; diabetes; bone grafting; implant length, diameter, and design; adjacent teeth; and insertion torque, were manually retrieved and analyzed. Using univariate and multivariate analyses, a generalized estimating equation (GEE) model with chi-squared tests was employed to evaluate factors related to early implant failure (the failure before restoration) (α=.05).

RESULTS

The mean ±standard deviation age of the study patients was 49.2 ±15.0 years (range 18 to 91). Ninety-nine implants (3.05%) failed during the healing period. Three factors were statistically significant regarding early implant failure: smoking (odds ratio [OR]=1.92, P=.008), implant design (tapered implants) (OR=1.84, P=.007), and implant length <10 mm (OR=2.98, P=.011). Factors including diabetes, bone grafting, anatomic location, adjacent teeth (endodontic therapy in the adjacent teeth and the distance between implant and adjacent teeth), healing method, and insertion torque did not exhibit a statistically significant higher early implant failure rate. Ninety-three sites with failed implants received new implants, and 6 of these 93 implants failed during the healing period.

CONCLUSIONS

Within the limitation of sample size, smokers, implant length (<10 mm), and implant design (tapered implant) exhibited higher risk of early implant failure in this retrospective study. Implant insertion torque, healing method, adjacent teeth, and diabetes did not significantly influence the risk of early implant failure.

The cumulative survival rate of sandblasted, large-grit, acid-etched dental implants: a retrospective analysis

PURPOSE

This retrospective study aimed to assess the long-term cumulative survival rate of titanium, sandblasted, large-grit, acid-etched implants over a 10-year follow-up period and investigate the factors affecting the survival rate and change in marginal bone loss (MBL).

METHODS

The study included 400 patients who underwent dental implant placement at the Department of Periodontology of Seoul National University Dental Hospital (SNUDH) between 2005 and 2015. Panoramic radiographic images and dental records of patients were collected and examined using Kaplan-Meier analysis, Cox proportional hazards regression analysis, and multiple regression analysis to determine the survival rates and identify any factors related to implant failure and MBL.

RESULTS

A total of 782 implants were placed with a follow-up period ranging from 0 to 16 years (mean: 8.21±3.75 years). Overall, 25 implants were lost, resulting in a cumulative survival rate of 96.8%. Comparisons of the research variables regarding cumulative survival rate mostly yielded insignificant results. The mean mesial and distal MBLs were 1.85±2.31 mm and 1.59±2.03 mm, respectively. Factors influencing these values included age, diabetes mellitus (DM), jaw location, implant diameter, bone augmentation surgery, and prosthetic unit.

CONCLUSIONS

This study found that the implant survival rates at SNUDH fell within the acceptable published criteria. The patients' sex, age, DM status, implant location, implant design, implant size, surgical type, bone augmentation, and prosthetic unit had no discernible influence on long-term implant survival. Sandblasted, large-grit, acid-etched implants might offer advantages in terms of implant longevity and consistent clinical outcomes.

A Study of the Associated Risk Factors for Early Failure and the Effect of Photofunctionalisation in Full-Arch Immediate Loading Treatment Based on the All-on-Four Concept

Early implant failure occurring within 1 year after implantation has been attributed to various factors. Particularly, early failure can lead to challenges in maintaining a full-arch prosthetic device, necessitating prompt intervention, including reoperation. This study aimed to retrospectively examine implant- and patient-related factors and the effects of photofunctionalisation associated with early failure in patients who underwent treatment using the all-on-four concept in both the maxilla and mandible. We conducted this retrospective study comprising 561 patients with 2364 implants who underwent implant-supported immediate loading with fixed full-arch rehabilitation using the all-on-four concept. We aimed to assess the survival rate within 1 year after implantation and determine the risk factors influencing early failure. The 1-year survival rates after implantation were 97.1% (patient level) and 98.9% (implant level) for the maxilla and 98.5% (patient level) and 99.6% (implant level) for the mandible. There was a significant difference in the implant-level survival rates between the maxilla and mandible, with a lower rate in the maxilla (p = 0.043). The risk factors associated with early implant failure according to the all-on-four concept included the maxilla (implant level) and smoking (patient level). We could not find a significant effect of photofunctionalisation on early failure (p = 0.25) following this treatment protocol.

Risk Factors for Early Implant Failure and Selection of Bone Grafting Materials for Various Bone Augmentation Procedures: A Narrative Review

Implant therapy is now an established treatment with high long-term success and survival rates. However, early implant failure, which occurs within one year of superstructure placement, occurs at a higher rate than late failure, which is represented by peri-implantitis caused by bacterial infection. Furthermore, various risk factors for early failure have been reported, including patient-related factors, such as systemic diseases, smoking, and bone quality and quantity, as well as surgery-related factors, such as surgeons' skill, osteogenesis technique, and selection of graft material, and implant-related factors, such as initial implant fixation and implant length diameter. Due to the wide variety of relevant factors reported, it is difficult to identify the cause of the problem. The purpose of this review is to discuss the risk factors associated with various types of bone augmentation which have a close causal relationship with early implant failure, and to determine the optimal bone grafting material for bone augmentation procedures to avoid early implant failure.

Is Vitamin D Deficiency a Risk Factor for Osseointegration of Dental Implants - A Prospective Study

Introduction

Early dental implant failure (EDIF) can occur even when optimal materials are used, surgical protocols are strictly followed and the quantity and quality of bone at the recipient site are sufficient. The existence of specific patient-related risk factors require an investigation into the regulatory mechanisms controlling bone metabolism, bone remodelling and bone turnover as well as serum Vitamin D. The implant stability quotient is used as a prognostic indicator for possible implant failure. The aim of the study is to investigate the relationship between serum Vitamin D levels and EDIF.

Materials and Methods

A total of 143 implant placement sites were identified in 53 patients enrolled in this study. All patients had the assessments of serum Vitamin D levels side by side with assessments of primary and secondary implant stability at proposed implant sites at the time of implant placement and after 12 weeks using a resonance frequency analysis device.

Results

Ten early failures (7%) were recorded. There was no correlation between gender, age, smoking, hyperglycaemia or an increased incidence of early failures. Statistical analysis reported two early failures (4.5%) in patients with serum levels of Vitamin D >30 ng/mL, two early failures (2.3%) in patients with levels between 10 and 30 ng/mL and six early failures (46.2%) in patients with levels <10 ng/mL.

Discussion

The role of Vitamin D as a risk factor for early implant failure should be considered in patients with Vitamin D deficiency. The incidence of early implant failures was higher in patients with low serum levels of Vitamin D. Patients with low serum Vitamin D levels had a greater rate of early implant failure.

Clinical and patient-centered outcomes following rehabilitation of atrophic edentulous maxilla using six implants placed simultaneously with bilateral maxillary sinus augmentation: A retrospective case series

OBJECTIVES

To evaluate treatment success, patient satisfaction, and oral health-related quality of life (OHRQoL) after rehabilitation of atrophic edentulous maxilla (AEM) with six implants placed simultaneously with bilateral maxillary sinus floor augmentation (MSFA).

MATERIALS AND METHODS

The selected patients were fully edentulous with atrophic maxillary posterior residual ridges and rehabilitated with six implants placed simultaneously with bilateral MSFA and immediate All-on-4 provisional fixed prosthesis (PFP). After 7-12 months of implant surgery, all patients have received an All-on-6 definitive fixed prosthesis (DFP). After at least one year of function with DFP, clinical and radiographic examinations were performed. Patient satisfaction was assessed through a visual analog scale (VAS). The OHRQoL before treatment (T0), during provisional (T1), and after definitive prosthesis (T2) was evaluated using OHI-14.

RESULTS

20 maxillary edentulous patients were rehabilitated with 120 implants, 20 immediate All-on-4 PFP, and 20 All-on-6 DFP. Of those, 12 patients have passed at least a year follow-up after DFP insertion and were eligible to be included in the assessment of treatment success. After a mean of 20 (12-36) months follow-up, the implant and prosthesis survival rates were 100%. The success rate at the implant level was 98.6%. The mean marginal bone loss (MBL) was 0.09 ± 0.06 mm. No prosthetic or postoperative complications, and the mean general satisfaction was (91.75 ± 7.06). There was a significant improvement in all OHIP-14 domains during the final All-on-6 prosthesis (T2) (P < 0.01).

CONCLUSIONS

Rehabilitation of atrophic edentulous maxilla using six implants with simultaneous bilateral MSFA and immediate All-on-4 PFP is a successful treatment approach associated with minimal postoperative complications and significant improvement in OHRQoL.

Survival analysis of implants placed simultaneously with lateral sinus floor elevation in severely atrophic maxilla: A 3- to 12-year retrospective cohort study

OBJECTIVES

To retrospectively evaluate whether implants placed simultaneously with lateral sinus floor elevation (LSFE) in severely atrophic maxilla (residual bone height [RBH] ≤3 mm) could achieve long-term survival and comprehensively analyze the factors influencing their survival rates.

MATERIALS AND METHODS

A total of 123 patients receiving LSFE and simultaneous implant placement from 2010 to 2019 and their 123 implants in sites with RBH ≤3 mm were included in this study. Basic characteristics of patients and implants were collected from the medical record system and cone-beam computed tomography (CBCT) images. Kaplan-Meier survival curves were applied to estimate cumulative survival rates (CSRs) and Cox proportional hazards regression models were used to detect factors influencing implant survival.

RESULTS

The 6-year and 12-year CSR of implants placed in sites with RBH ≤3 mm were 95.7% (95% confidence interval [CI]: 92.1%-99.5%) and 76.6% (95% CI: 58.1%-100%), respectively. Eight patients presented late implant failure. Univariate and multivariate Cox regression analyses demonstrated that RBH ≤2 mm (hazard ratio [HR]: 20.63, p = 0.000) and smoking habit (HR: 6.055, p = 0.024) were significantly associated with long-term implant survival. Specifically, the 10-year CSR of implants in sites with RBH ≤2 mm (53.3%, 95% CI: 27.5%-100%) was dramatically lower than those in sites with RBH >2 mm (92.9%, 95% CI: 81.7%-100%, p = 0.000).

CONCLUSIONS

Implants placed simultaneously with LSFE in sites with RBH ≤3 mm can achieve long-term survival. However, caution is required especially for implantation in sites with RBH ≤2 mm. Besides, the smoking habit is also considered a risk factor jeopardizing long-term implant survival.

Retrospective analysis of 50,333 implants on implant failure and associated patient-related factors

PURPOSE

The aim of this investigation was to retrospectively evaluate the long-term implant loss rates and to identify associations between implant failure and patient-related factors in a sample of patients who had consecutively received implant therapy in ten dental universities in the United States using a large database.

METHODS

Dental records of adult patients who had attended the dental clinics of the universities contributing data to the BigMouth network between 2011 and 2022 seeking dental therapy were evaluated. Information regarding patients' characteristics including age, gender, ethnicity, race, tobacco use and systemic medical conditions were extracted from patients' files.

RESULTS

A total of 20,842 patients who received 50,333 dental implants over a 12-year period (2011-2022) were included. The mean age of the cohort was 57.50±14.27 years which consisted of 51.8% females, 91.1% non-Hispanic, 66.3% white individuals and 8% tobacco users. In the univariate analysis, ethnicity, race and marijuana use were significantly associated with implant treatment outcome. Race and ethnicity were significantly associated with implant loss in the multivariate analysis. The implant failure rate was estimated to be 2.7% at the patient level and 1.4% at the implant level.

CONCLUSION

Within the limitations of this retrospective study that utilized records of 50,333 dental implants placed in ten institutions contributing data to the BigMouth network, the implant failure rate was estimated to be 2.7% at patient level and 1.4% at implant level. Ethnicity and race were significantly associated with implant failure, while none of the examined systemic conditions were associated with implant loss.

Analyzing the Causes and Frequency of Early Dental Implant Failure among Iranians: An Epidemiological Study

Aim

The rate of early dental implant failure (DIF) has increased in recent years, though the risk factors associated with this primary failure remain unclear. This study aimed to determine the rate of early implant failure and identify contributing factors. It was conducted from March 2018 to 2020 in Mashhad, Iran.

Method

This observational study examined the records of 983 implants from the Implant Department of Mashhad Dental School. Variables considered included age, gender, systemic diseases, smoking habits, implant type and size, and surgery-related factors. Data were analyzed using Chi-square, Mann-Whitney U, and Fisher exact tests in SPSS V22, with a p-value of 0.05 or less considered statistically significant.

Result

Of the 983 implants, 42 (4.3%) experienced early failure. The study population consisted of 555 (56.5%) females and 428 (43.5%) males, with an average age of 49.34 ± 13.67 years. A significant correlation was found between surgical complications (e.g., fracture of implant fixtures and inferior alveolar nerve exposure) and implant loading time (Yes or No) with early DIF (p=0.05 and p < 0.01, respectively). However, no significant correlation was observed between early failure and factors such as age, gender, smoking habits, systemic diseases, implant dimensions, or manufacturer.

Conclusion

Surgical complications and loading time may be the most critical factors contributing to early implant failure. Therefore, we suggest dentists pay attention to the mentioned factors in the surgical protocols and their relationship. Further prospective studies on risk factors that could affect early implant failure are needed.

COVID-19 as a factor associated with early dental implant failures: A retrospective analysis

OBJECTIVES

To analyze the effect of COVID-19 on early implant failures and identify potential risk factors for early implant failure, concerning patient- and implant-related factors.

MATERIALS AND METHODS

This retrospective study is based on 1228 patients who received 4841 implants between March 11, 2020, and April 01, 2022, at Erciyes University Faculty of Dentistry. COVID-19, age and gender of patients, smoking, diabetes, irradiation, chemotherapy, osteoporosis, the implant system, location, and characteristics of implants were recorded. At the implant level, univariate and multivariate generalized estimating equation (GEE) logistic regression was used to examine the effect of explanatory variables on early implant failure.

RESULTS

The early implant failure rate was 3.1% at the implant level and 10.4% at the patient level. Smokers showed a significantly higher incidence of early implant failures compared to nonsmokers. (odds ratio (OR; 95% CI): 2.140 (1.438-3.184); p < 0.001). Short implants (≤8 mm) had a higher risk of early implant failure than long implants (≥12 mm) (OR (95% CI): 2.089 (1.290-3.382); p = 0.003).

CONCLUSIONS

COVID-19 had no significant effect on early implant failure. Smoking and short implants were associated with a higher risk for early implant failures.

Radiographic evaluation of the tenting screw technique in horizontal alveolar bone augmentation: A retrospective study

OBJECTIVES

To radiographically analyze the effects of tenting screw technique (TS) and onlay bone grafts (OG) in horizontal bone augmentation.

MATERIALS AND METHODS

Patients receiving horizontal bone augmentation by TS or OG were selected. The clinical outcomes and cone beam computed tomography (CBCT) data were documented pre-grafting, immediately post-grafting, before and after implantation. The survival rates, clinical complications, alveolar bone width, and volumetric bone augmentation were evaluated and statistically analyzed.

RESULTS

A total of 25 patients and 41 implants were involved in this study, with no grafting failures observed in either the TS group (n = 20) or the onlay group (n = 21). Volumetric bone resorption rate in the TS group (21.34%) was significantly lower than that of the OG group (29.38%). In addition, significant horizontal bone gain was achieved in both groups (TS: 6.15 ± 2.12 mm; OG: 4.86 ± 1.40 mm) during the recovery period, with higher gain in the TS group. No apparent statistical difference in terms of volumetric bone gain was observed between the TS (748.53 mm³ , 607.47 mm³ ) and OG group (811.77 mm³ , 508.49 mm³ ) immediately post-grafting or after the recovery period.

CONCLUSION

Both TS and OG achieved satisfactory bone augmentation effects, yet TS resulted in more bone augmentation and better stability than OG, with a reduced use of autogenous bone. Overall, the tenting screw technique can serve as an effective alternative to autogenous bone grafts.

Drilling- and withdrawing-related thermal effects of implant site preparation for ceramic and stainless steel twist drills in standardized bovine bone

INTRODUCTION

Excessive surgical trauma is believed to be among the most important causes for early implant losses. As thermal injury to the bone is not only dependent on the amount of generated heat but also on the tissue exposure time, and the greatest temperature increase was found within the withdrawing period, the entire osteotomy procedure with the parameters contributing to thermal damage is of particular clinical relevance. The aim of this study was to investigate the thermal performance of metal-based and ceramic implant drills regarding the temperature exposure time during the whole osteotomy process.

MATERIALS AND METHODS

This investigation consisted of 240 individual preparations in total, comprising two different drilling depths (10 and 16 mm), two irrigation methods (external and without irrigation), two implant drill materials (stainless steel and zirconia), and three consecutive drill diameters per material (2.0/2.2, 2.8, and 3.5 mm) with 10 identical repetitions. Real-time multichannel temperature measurement was conducted during automated drilling procedures in standardized bovine bone specimens.

RESULTS

The maximum temperature changes were highly associated with the time period of passive drill withdrawing (p ≤ 0.05), irrespective of drill material, drilling depth, or drill diameter. Statistically significant differences in temperature generation between stainless steel and ceramic drills were observed in irrigated testing sites at both drilling depths with smaller drill diameters (2.0/2.2 and 2.8 mm, p ≤ 0.05).

CONCLUSION

Results of this in vitro study could demonstrate a strong association between the highest temperature increase and the passive withdrawing time period in both investigated drill materials. Considering these findings and the resulting thermal bone damage due to the whole surgical procedure, high overall temperatures in combination with a prolonged heat exposure time may impact the future osseointegration process.

Masseter muscle cross-sectional area and late implant failure: A case-control study

INTRODUCTION

Occlusal overload is considered to be one of the causes of late implant failure. However, it is unclear whether the magnitude of the patient's occlusal force is a risk factor for late implant failure.

PURPOSE

This case-control study aimed to clarify the association between the cross-sectional area (CSA) of the masseter muscle and late implant failure.

METHODS

This case-control study was limited to implant-supported fixed prostheses. We compared cases with at least one late implant failure (n = 25 patients) to controls (n = 82 patients) without implant failure. Patients were matched by age, sex, year of surgery, jaw and tooth type, and bone graft. Log-rank and Cox proportional hazard regression analyses were used to identify possible risk factors for late implant failure.

RESULTS

The incidence of late implant failure was significantly associated with masseter muscle CSA ≥504.5 mm² (hazard ratio: 4.43; 95% CI: 1.82-10.79; p < 0.01).

CONCLUSION

Higher masseter muscle CSA increases the risk of late implant failure.

Implant failure and associated risk factors of transcrestal sinus floor elevation: A retrospective study

OBJECTIVES

This retrospective study aimed to evaluate early and late implant loss rates after transcrestal sinus floor elevation (TSFE) and to identify the risk factors related to these failures.

MATERIAL AND METHODS

All patients treated with TSFE and simultaneous implant placement during October 2015 to March 2019 were evaluated for inclusion. A total of 802 patients with 976 implants met the inclusion criteria. Clinical and radiographic information was collected from medical records and image software. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify potential risk factors associated with early and late implant loss after TSFE.

RESULTS

The 3-year cumulative implant survival rate was 96.9% (95% CI 95.8%-98.0%). Twelve implants in 12 patients were lost before or at the abutment connection, while 24 implants in 24 patients were lost after functional loading. The Cox frailty regression analyses indicated that two factors were correlated with early implant loss: TSFE with grafting materials, and operators with less clinical experience. As for late implant loss, RBH ≤6 mm, male sex, and certain implant brands were associated with a significantly increased failure rate.

CONCLUSIONS

Transcrestal sinus floor elevation with simultaneous implant placement is a predictable treatment option in the atrophic maxilla. The presence of grafting materials and the lack of clinical experience of the surgeon were possibly associated with early implant loss, while low RBH, male sex, and certain implant brands tended to increase late implant loss.

Dental implant failure and factors associated with treatment outcome: A retrospective study

PURPOSE

The purpose of the present study was to retrospectively 1) investigate the association between implant-, patient- and bone-related parameters with the risk of implant failure; 2) analyze the survival rates of dental implants placed in a university clinical setting.

METHODS

Data were retrieved from patient charts from the University of Minnesota School of Dentistry to identify patients older than 18 years of age who received dental implant treatment by faculty, residents or students in the university dental clinics. Implant-, patient- and bone-related parameters such as implant system, length, diameter, jaw, region, installation protocol, gender, smoking, medical history, history of periodontal disease, self-reported oral parafunctions, type of bone, and operator were manually retrieved and analyzed.

RESULTS

Five hundred and fifty-three implants were randomly selected from a total of 4,424. Of these 553 implants, 440 (79.6%) were associated with a >10 mm length, 371 (67.1%) with a >4 mm diameter and 431 (77.9%) had replaced a single tooth. Submerged healing mode was followed in 363 (65.6%) of the implants with the mean healing time being 3.2 months. History of periodontal disease was identified in 294 (53.2%) of these cases. A total of 17 implants failed after a mean time of 6.29 ± 6.75 months, resulting in an overall survival rate of 96.9%. Based on a univariate analysis, implant system, operator, time between extraction and implant surgery, time between bone grafting and implant placement, tobacco use as well as clenching and grinding were considered potential implant failure predictors and were further included in the multivariate logistic regression analysis. Tobacco use (p < 0.001) was significantly associated with implant failure.

CONCLUSION

Within the limitations of this retrospective randomly selected university-treated sample tobacco use increased the risk for implant failure. Failure occurred in 17 implants representing a 3.1% failure rate.

Influence of Serum Vitamin D Levels on Survival Rate and Marginal Bone Loss in Dental Implants: A Systematic Review

This systematic literature review set out to investigate the relationship between serum vitamin D levels and dental implants in terms of survival rates, marginal bone loss, and associated complications. The review was conducted according to PRISMA guidelines, performing an electronic search in four databases (Pubmed, Web of Science, Cochrane, and Scopus), complemented by a manual search up to April 2022. Four articles were selected for analysis. The Newcastle-Ottawa Quality Assessment Scale tool was used to assess the quality of evidence of cohort studies, and the Cochrane bias assessment tool was used to assess the quality of evidence of randomized clinical trials. The study included 1089 patients restored with 1984 dental implants, with follow-up periods ranging from 20-240 months. Cases presenting lower serum vitamin D levels obtained slightly worse results in terms of marginal bone loss. Longer follow-up periods are needed in order to determine whether serum vitamin D levels affect implant survival rates and osseointegration over time.

Survival Rates and Factors Affecting the Outcome Following Immediate and Delayed Implant Placement: A Retrospective Study

Background: Immediate implant placement into extraction sockets has become a widely acceptable treatment option to decrease treatment time and enhance esthetics. The objectives of this study were to assess and compare the survival rates of immediate and delayed implant treatment as well as to investigate the effect of patient- and site-related variables on the treatment outcome in a large-scale population-based study. Methods: Dental records of patients who received implant therapy were retrieved from the electronic records of the University of Minnesota School of Dentistry. Demographic characteristics, dental insurance status, socioeconomic status as well as medical history and tobacco use were recorded. The treatment outcome was included as a binary variable (survival/failure). Time to failure (date of procedure to date of visit with failure) was compared between immediate and delayed implant treatment in Cox regression models. Kaplan−Meier plots for the survival of both treatment modalities were created. Patient-sites without failure were censored at the last follow-up visit. Results: A total of 4519 records of implants were included. The sample mean age was 60.27 years and included 50.7% males and 12.9% tobacco users. High socioeconomic status was characterized for 82.3% of the included population and 63.0% of them were self-payers. Immediate implants were significantly more frequently placed in the maxillary arch (p < 0.001) than in the mandible. Tobacco users received more often a delayed rather than an immediate implant placement (p = 0.001). The survival rate analysis revealed there were no significant differences between immediate and delayed implant placements (p = 0.48). The mean follow-up time was 32.27 months during which 1.5% immediate and 1.1% delayed implants were removed. The estimated mean survival time for immediate implants was 68.90 months, while delayed implants placed in healed sockets showed a mean survival time of 75.11 months. A statistically significant association was found between gender (p = 0.03) and osteoporosis (p = 0.001) with treatment outcome. Conclusions: The placement of immediate implants achieved similarly high survival rates when compared to delayed implants placed in healed sites. Males and osteoporotic individuals showed significantly higher implant failure than females and non-osteoporotic patients. This study demonstrated that both immediate and delayed implant placements are sound options with predictable treatment outcome.

Predicting the Risk of Dental Implant Loss Using Deep Learning

AIM

To investigate the feasibility of predicting dental implant loss risk with deep learning (DL) based on preoperative cone-beam computed tomography.

MATERIALS AND METHODS

Six hundred and three patients who underwent implant surgery (279 high-risk patients who did and 324 low-risk patients who did not experience implant loss within 5 years) from January 2012 to January 2020 were enrolled. Three models, a logistic regression clinical model (CM) based on clinical features, a DL model based on radiography features, and an integrated model (IM) developed by combining CM with DL, were developed to predict the 5-year implant loss risk. The area under the receiver operating characteristic curve (AUC) was used to evaluate the model performance. Time to implant loss was considered for both groups, and Kaplan-Meier curves were created and compared by the log-rank test.

RESULTS

The IM exhibited the best performance in predicting implant loss risk [AUC = 0.90, 95% confidence interval (CI) 0.84-0.95], followed by the DL model (AUC = 0.87, 95% CI 0.80-0.92) and the CM (AUC = 0.72, 95% CI 0.63-0.79).

CONCLUSION

Our study offers preliminary evidence that both the DL model and IM performed well in predicting implant fate within 5 years and thus may greatly facilitate implant practitioners in assessing preoperative risks.

Analysis of implant loss risk factors after simultaneous guided bone regeneration: A retrospective study of 5404 dental implants

PURPOSE

The purpose was to analyze the risk factors for implant loss after simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

Patients who underwent implant placement with simultaneous GBR between January 2011 and December 2018 were screened for this study. The cumulative survival rate (CSR) was calculated using the life table method. Log-rank test and Kaplan-Meier survival estimates were used to identify potential risk factors for implant loss. The association between the investigated variables and implant loss was determined using hazard ratios (HRs) obtained from a multivariate Cox regression analysis.

RESULTS

A total of 3973 patients with 5404 implants were included in this study. The CSRs of the implants at 1, 5, and 10 years were 99.6%, 98.9%, and 98.7%, respectively. Male patient (HR = 2.94, 95% CI: 1.41-6.14), periodontitis (HR = 4.26, 95% CI: 2.05-9.86), tissue-level implants (HR = 3.02, 95% CI: 1.30-6.98), narrow implants (HR = 2.71, 95% CI: 1.12-6.57), and implant length ≤10 mm (HR = 2.91, 95% CI: 1.41-6.02) significantly increased the risk of implant loss (p < 0.05). The risk of implant loss was significantly higher in the maxillary posterior region (HR = 2.26, 95% CI: 1.04-4.90) than in the maxillary anterior region (p < 0.05). Compared to Straumann, Nobel (HR = 4.07, 95% CI: 1.75-9.44) and other implant systems (HR = 14.23, 95% CI: 4.32-46.85) showed a significantly higher risk of implant loss (p < 0.05).

CONCLUSION

Male patient, periodontitis, maxillary posterior region, Nobel implant system, other implant systems, tissue-level implants, narrow implants, and implant length ≤10 mm were considered risk factors for implant loss after simultaneous GBR.

Implant failure rate and the prevalence of associated risk factors: a 6-year retrospective observational survey

Introduction: The purpose of this monocentric retrospective observational investigation is to evaluate the implant failure rate observed in an oral surgery department and analyze the risk factors associated with them. Preventative measures will be suggested to reduce the incidence of implant failure. Material and method: All implants removed between 2014 and 2020 were analyzed. The main criterion assessed was the overall failure rate over 6 years of activity;the secondary criteria were the risk factors associated with implant failure. Results: 12 out of 376 implants placed between 2014 and 2019 in 11 patients (mean age: 55.5 ±11.5 years);sex ratio M/F=5/6) were removed, for an overall failure rate of 3.11%. The majority, 83% (10/12) of the lost implants, were in the maxilla, while only 17% (2/12) were placed in the mandible. The main risk factors identified were: a III−IV bone type density (75%, 9/12), pre-implant sinus lift surgery (42%, 5/12) smoking (8.3%, 1/12), surgical site infection (8.3%, 1/12) and rheumatoid arthritis (8.3%, 1/12). Conclusion: The failure rate observed in this oral surgery unit is consistent with the other international studies, confirming the compliance with good clinical practices of the healthcare team. Pre-implant bone surgery is the major risk factor to consider before implant surgery.

Free-Hand versus Surgical Guide Implant Placement

One of the most key areas of dentistry is dental implant surgery. The use of digital equipment and software in dentistry has developed considerably in recent years compared to other fields of medicine. Since examining the advantages and disadvantages of each approach, along with case studies, can help physicians make informed decisions, this review study aims to raise the awareness of dentists to make easier decisions about using guided or free-hand surgery. When planning for a dental implant, one of the most challenging questions that doctors face is which method to use (guided surgery or free-hand). Choosing the right method, such as other clinical considerations, will depend on the individual circumstances of each patient and the preference of the treating physician. Free-hand surgery is a cost-effective method in which the flap is reflected, and, according to the doctor's diagnostic information, an implant is placed, which in many cases is a useful method. Guided surgery has the highest level of accuracy and control, in which osteotomy is designed and printed through a digital surgery guide, and depending on the complexity of the case and the patient's anatomy, it has a higher level of value than free surgery. The surgical guide helps the surgeon make the implant surgery more accurate, safer, simpler, at a lower cost, and in less time. In fact, there are patterns that convey information about the position of the tooth to the dentist before the implant is placed.

Etiology, occurrence, and consequences of implant loss

Implant therapy aims at providing the patient with a functional and esthetically pleasing rehabilitation in a long‐term perspective. The loss of an implant constitutes a major complication, which may have an impact on the treatment plan and/or jeopardize the longevity of the restoration. Implant loss may occur during the phase of osseointegration (early) or at a later time when the previously achieved osseointegration is lost (late). The present work evaluates the evidence on the occurrence of both events and discusses etiology, risk factors, and consequences.

The Relationship Between Low Serum Vitamin D Level and Early Dental Implant Failure: A Systematic Review

The variety in shape and type of dental implants in the present time is considered one of the most successful evolutions in dentistry. This facilitates dental treatment options to restore patient function and appearance. However, numerous significant factors influence the predictability of survival or the success rates of dental implants, some of which, such as vitamin D levels, have not been included in many studies. The main purpose of this systematic review was to investigate whether there is a relationship between low serum levels of vitamin D and early dental implant failures (EDIFs). Our literature search involved international databases including PubMed, Directory of Open Access Journals (DOAJ), and Web of Science. Initially, according to our search criteria, 1200 studies were found. After excluding duplicates, incomplete studies, and studies not meeting our inclusion criteria, only six human studies were included in this research and analyzed. Finally, upon meticulous analysis of included studies, this systematic review revealed inconsistent results in articles with respect to the association between vitamin D deficiency and implant failures. Large-scale studies, especially clinically relevant studies, on this subject is recommended.

Correlations between implant success rate and personality types in the older people: A preliminary case control study

Background/ purpose

Older patients inevitably have a higher need for implant treatment, it is unknown how mental changes or psychological aspects affect the outcome of implant treatment. This study evaluated the success rate of implants and the influence of personality traits in the older people. The goal was to provide evidence for predictable implant treatment while taking into account the unique psychological changes of elders.

Materials and methods

Participants were patients who were able to independently visit our hospital between March 2004 and May 2021. Inclusion criteria were patients aged 65 years or older at the time of implant placement with regular follow-up for at least 1 year. The implant success rate was calculated by counting peri-implantitis and implant loss as failures. Multivariate analysis was used to examine the effect of patient personality characteristics on the success rate.

Results

Fifty-six implants were included in 23 patients (12 men, 11 women), with a mean age of 68.5 years (65–76) and mean maintenance duration of 9 years and 2 months. The cumulative survival rate was 87% at the patient level (94.6% at the implant level). Statistically significant differences were found for adaptive traits (odds ratio [OR] = 0.04) and non-adaptive traits (OR = 6.38); however, no significant differences were found for the other independent variables.

Conclusion

The overall implant success rate was 69.6% at the patient level (82.1% at the implant level). The personality traits in older people had a significant effect on the implant failure rate.

Systematic review on the association between genetic polymorphisms and dental implant-related biological complications

OBJECTIVES

The aim of this systematic review was to evaluate the association between specific genetic polymorphisms and dental implant-related biological complications in patients having a follow-up period of at least 12-months post-loading.

MATERIAL AND METHODS

A sensitive search strategy was developed to identify implant-related genetic-association studies. This was performed by searching five databases. A three-stage screening (titles, abstract, full text) was carried out in duplicate and independently by two reviewers. Assessment was carried out according to the suggested scale for quality assessment of periodontal genetic-association studies and adapted to genetic analyses of implant-related studies leading to an overall final score 0-20 based on the summation of positive answers.

RESULTS

The initial search resulted in 1838 articles. Sixty-seven full-text articles were assessed for eligibility and four studies met the defined inclusion criteria. IL-6 G174C, TNF-α -308, IL-1A-889 and IL-1B+3954 and CD14-159 C/T polymorphisms were evaluated. The quality assessment scores ranged from 6 to 11 positive answers from out of a maximum score of 20. The great heterogeneity among the studies did not allow a meta-analysis.

CONCLUSIONS

The published evidence on genetic predisposition and implant biologic complications is limited. The small number of identified studies evaluating the association between genetic polymorphisms and peri-implant disease presented methodological and reporting inadequacies. Thus, the potential link between genetic polymorphisms and biological complications should be further investigated and clarified through well-designed clinical studies on adequately powered and appropriately included study populations.

Logistic Regression Analysis of the Factors Involved in the Failure of Osseointegration and Survival of Dental Implants with an Internal Connection and Machined Collar: A 6-Year Retrospective Cohort Study

Background

Although the long-term success rate of dental implants is currently close to 95%, it is necessary to provide more evidence on the factors related to the failure of osseointegration and survival.

Purpose

To establish the risk factors associated with the failure of osseointegration and survival of dental implants with an internal connection and machined collar and to establish a predictive statistical model.

Materials and Methods

An analytical, retrospective, and observational clinical study of a sample of 297 implants with a follow-up of up to 76 months. Independent variables related to the implant, patient, and surgical and rehabilitative procedures were identified. The dependent variables were failure of osseointegration and failure of implant survival after prosthetic loading. A survival analysis was carried out by applying the Kaplan-Meier model (significance for p < 0.05). The log-rank test and the Cox regression analysis were applied to the factors that presented differences. Finally, the regression logit function was used to determine whether it is possible to predict the risk of implant failure according to the analyzed variables with the data obtained in this study.

Results

The percentages of osseointegration and survival were 97.6 and 97.2%, respectively. For osseointegration, there were significant differences according to gender (p = 0.048), and the risk of nonosseointegration was 85% lower in women. Regarding survival, the Cox analysis converged on only two factors, which were smoking and treatment with anticoagulant drugs. The risk of loss was multiplied by 18.3 for patients smoking more than 10 cigarettes per day and by 28.2 for patients treated with anticoagulants.

Conclusions

The indicated risk factors should be considered, but the analysis of the results is not sufficient to create a predictive model.

Failure rates associated with guided versus non-guided dental implant placement: a systematic review and meta-analysis

Objective

The purpose of the systematic review and meta-analysis was to evaluate implant failure rates and their association with guided and free-hand implant placement techniques.

Materials and methods

A literature search was conducted across PubMed, Medline via Ovid, Cochrane database, and Google Scholar. The search was completed in September 2020. Series of meta-analyses were conducted to compare implant failure rates with guided and free-hand techniques.

Results

A total of 3387 articles were identified from the electronic search. After applying the inclusion criteria, eight articles were selected for qualitative assessment and four for quantitative synthesis (meta-analysis). The included studies had a risk ratio of 0.29 (95% CI: 0.15, 0.58), P < 0.001 for the use of guided implant placement. Implant failure rates were affected by the different placement techniques indicated by the test for overall effect (Z = 3.53, P = 0.0004). The incidence of implant failure in guided surgery versus free-hand surgery was found to be 2.25% and 6.42%, respectively.

Conclusion

Both guided and free-hand implant placement techniques resulted in a high implant survival rate. However, implant failure rates were almost three times higher in the free-hand implant placement category. A guided implant placement approach is recommended for a successful outcome.

Osseointegrated implant survival, success and prosthodontic outcomes in composite free flaps: A 10-year retrospective cohort study

OBJECTIVES

To evaluate implant survival, success and prosthodontic outcomes in a variety of composite free flaps.

MATERIAL AND METHODS

A retrospective analysis of patient records was used for data collection of implants placed into flaps. Free flap donor sites included fibula, iliac crest, scapula, medial femoral condyle and radial forearm. Kaplan-Meier survival curves were used to estimate survival. Cox regression was used to assess variables affecting survival, and binary logistic regression was utilised to determine effect of variables on prosthodontic outcomes.

RESULTS

There were 150 implants placed into 45 fibula, 98 implants into 29 iliac crest, 62 implants into 22 scapula, 6 implants into 3 medial femoral condyle and 2 implants in radial forearm composite free flaps. There was no difference in survival or success between or within the various flaps. Active smoking, increasing age, male gender and radiotherapy were associated with implant failure. Of patients completing prosthodontic rehabilitation, 93% were successful. There was no difference in likelihood of failure between different flap types. Fixed implant-supported dentures were associated with poor oral hygiene compared with removable designs (OR2.9, 95%CI 1.1-7.8, p = .03).

CONCLUSIONS

There is adequate survival and success of implants in common flaps. Caution is required when planning implants in patients exposed to radiotherapy and smokers. Ability to maintain adequate oral hygiene is an important prosthetic design consideration.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

The survival rates and risk factors of implants in the early stage: a retrospective study

Background

Few large-sample studies in China have focused on the early survival of dental implants. The present study aimed to report the early survival rates of implants and determine the related influencing factors.

Methods

All patients receiving dental implants at our institution between 2006 and 2017 were included. The endpoint of the study was early survival rates of implants, according to gender, age, maxilla/mandible, dental position, bone augmentation, bone augmentation category, immediate implant, submerged implant category, implant diameter, implant length, implant torque, and other related factors. Initially, SPSS22.0 was used for statistical analysis. The Chi-square test was used to screen all factors, and those with p < 0.05 were further introduced into a multiple logistic regression model to illustrate the risk factors for early survival rates of implants.

Results

In this study, we included 1078 cases (601 males and 477 females) with 2053 implants. After implantation, 1974 implants were retained, and the early survival rate was 96.15%. Patients aged 30–60 years (OR  2.392), with Class I bone quality (OR  3.689), bone augmentation (OR  1.742), immediate implantation (OR  3.509), and implant length < 10 mm (OR  2.972), were said to possess risk factors conducive to early survival rates.

Conclusions

The early survival rate of implants in our cohort exceeded 96%, with risk factors including age, tooth position, bone quality, implant length, bone augmentation surgery, and immediate implantation. When the above factors coexist, implant placement should be treated carefully.

The Possible Role of Vitamin D Deficiency in Early Implant Failure

Background. Dental implants are one of the most successful treatments for restoring tooth function and beauty. Identifying the causes of dental implant failure is useful and vital. This review was aimed at studying the possible role of vitamin D in early implant failure. Method and Material. This review was designed based on the PRISMA guideline. Data was collected using keywords including implant, vitamin D, deficiency, failure, dental, OR tooth in international databases including PubMed, Scopus, Web of Science, Cochrane, and Embase, until 2020. Based on the inclusion and exclusion criteria, data were extracted and gathered in a checklist. Results. Finally, twelve studies were selected from five different countries. In 6 studies (2 animal studies and four human studies), there was no significant relationship between vitamin D deficiency and dental implant failure. In the other six studies (1 animal study and five human studies), there was a significant relationship in this regard. Conclusion. It is difficult to conclude the association between vitamin D and implant failure based on the literature’s researches. However, vitamin D appears to play an essential role in implant success through its effects on immune system modulation.

Implant failure and associated risk indicators: A retrospective study

OBJECTIVES

To evaluate early and late implant loss rates in a sample of patients who had received implant therapy in a university setting as well as patient- and implant-related variables for implant failure.

MATERIAL AND METHODS

This is a retrospective analysis in a cohort of patients who were treated with implant-supported restorative therapy during the period 2001-2012. Patients were randomly selected from an electronic database and scheduled for an appointment to record subject and implant characteristics. The primary study outcome was implant loss (i.e., early and late implant failure).

RESULTS

A total of 190 patients and 710 implants were included. The mean time in function was 8.2 (SD 2.4) years. Four implants (0.6%) failed in four patients (2.1%) prior to connection of the restoration within a mean period of 1.5 (SD 1.3) months after surgical procedure. Moreover, 17 subjects (8.9%) exhibited late implant failure, representing 26 implants (3.7%), after a mean follow-up of 5 years (SD 2.2) from prosthesis connection. The final multivariable model indicated three factors related to late implant failure: subjects <55 years (OR = 3.62; 95% CI 1.46-10.22; p = .002), smokers/former smokers (OR = 6.25; 95% CI 1.70-17.52; p = .005), and implants with no access to interproximal hygiene (OR = 7.25; 95% CI 2.20-28.25; p < .001).

CONCLUSIONS

The rate for early and late implant failure in a sample of 190 patients who had received implant therapy in a university setting was 2.1% and 8.9%, respectively, at subject level. Subjects <55 years and smokers/former smokers as well as implants with inadequate access to interproximal hygiene were significantly associated with late implant failure.

The risk factors of early implant failure: A retrospective study of 6113 implants

BACKGROUND

The risk factors of early implant failure were controversial among previous studies, especially for implants in different sites.

PURPOSE

To analyze the rate and risk factors of early implant failure occurring before the placement of final prosthesis.

MATERIALS AND METHODS

A retrospective study was conducted based on electrical medical records of patients who received dental implant placement from 2015 to 2019. Generalized estimation equation analyses were used to explore potential risk factors influencing early implant failure.

RESULTS

Overall, 6113 implants in 3785 patients were included. The rate of early implant failure was 1.6% at patient level and 1.2% at implant level. The early implant failure was significantly associated with implants in the posterior maxilla, with specific surface modifications and in previously augmented sites (p < 0.05). Risk factors for maxillary implants included surface modification and bone augmentation procedures (p < 0.01), whereas risk factors for mandibular implants included gender and bone augmentation procedures (p < 0.05). For implants placed in previously augmented sites, implants placed in the anterior mandible had a higher risk of early failure (p < 0.05).

CONCLUSIONS

The risk factors for early implant failures varied among different sites; hence, they should be comprehensively considered in presurgical treatment plan.

The Relationship Between Serum Level of Vitamin D3 and Osseointegration Around the Dental Implant

At present, dental implants are used more than before, and their high success rate is attributed to sufficient osseointegration, which depends on prosthetic-, implant-, and patient-related factors. The quality and quantity of bone and the host response are the main patient-related factors. Vitamin D3 affects bone metabolism by stimulating both osteoclasts and osteoblasts. This study aimed to review the human studies on the efficacy of vitamin D3 for dental implant osseointegration. Search of the literature yielded only 4 studies on human models, of which 2 showed the optimal efficacy of vitamin D3 for dental implant osseointegration, whereas the remaining 2 did not report any positive effect. However, this finding may be related to the small sample size of the vitamin D3-deficient group, which can compromise statistical analyses. In conclusion, vitamin D3 seems to be effective for dental implant osseointegration, although further research is required on human models.

Survival rate and potential risk indicators of implant loss in non-smokers and systemically healthy periodontitis patients: An up to 9-year retrospective study

BACKGROUND

An increasing number of patients with chronic periodontitis (CP) have received implant restoration. However, very few studies have evaluated the probable risk indicators of implant loss in patients with CP.

OBJECTIVE

The aim of this study is to evaluate implant long-term survival rates in patients with CP. The results are analyzed to discern potential risk indicators of implant loss.

METHODS

A total of 1549 implants were inserted in 827 non-smokers and systemically healthy CP patients between March 2011 and March 2019. Clinical variables (age; sex; implant location; implant diameter; implant length; implant type; bone quality; bone graft, periodontal disease status, and insertion torque) were recorded. Kaplan-Meier survival curves illustrated the cumulative survival rate. The relationship between variables and implant loss was discerned by univariate analysis. Further multivariate Cox proportional hazard regression analysis was carried out for the variables with P < 0.2.

RESULTS

The cumulative survival rates were 98.8% after 3 months, 97.9% after 6 months, 97.7% after 1 year, and 97.4% after 2 to 9 years. After adjusting possible confounders, the multivariable Cox regression model revealed statistically significant influences of implant location, history of bone graft, and insertion torque on implant loss. Implants with history of bone graft were more likely to loss. Implants inserted in the anterior area had a higher implant loss risk; insertion torque of <15 Newton-centimeter (Ncm) showed a relatively high risk of being lost.

CONCLUSIONS

The study represented public hospital insight into long-term implant results of patients with CP. Under the premise of strict periodontal control, patients with the history of CP exhibited relatively high implant survival rate. Anterior implant location, history of bone graft, and insertion torque <15 Ncm are associated with a lower implant survival rate and could be considered at a higher risk of implant failure in patients with CP.

Tantalum Particles Induced Cytotoxic and Inflammatory Effects in Human Monocytes

The aim of this study is to evaluate the biological safety of tantalum (Ta) particles and to further explore the effects of Ta particles on human monocyte toxicity and inflammatory cytokine expression. Human monocyte leukemia (THP-1) cells were cultured with Ta and hydroxyapatite (HA) particles. Cell counting kit-8 method was used to evaluate the cytotoxicity of Ta and HA particles. The apoptosis effects were evaluated by flow cytometry, and the protein expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA. The protein levels of inflammation-related signaling pathways including nuclear factor-kappa B (NF-κB) and extracellular regulated kinase (ERK) were detected by western blotting. The cytotoxicity test showed that the toxicity level of Ta in vitro was grade l, which is within the clinically acceptable range. Compared with the HA control, Ta had no significant effect on THP-1 cell apoptosis, IL-6, and TNF-α release. The phosphorylated levels of NF-κB and ERK at 3 h in the Ta group were lower than those in the HA and control groups (P < 0.001 both). These results reveal Ta particles behave good biosafety properties and provide some new insights for the future clinical use of Ta.

Evaluation of the Association of Early Implant Failure With Local, Environmental, and Systemic Factors: A Retrospective Study

PURPOSE

This study aimed to assess the association of early implant failure (EIF) with demographic, local, environmental, and systemic factors.

METHODS

Clinical charts of 594 individuals with 2,537 dental implants were assessed. EIF was characterized by implant loss before and up to the abutment connection. Logistic regression analysis was used to verify the association between EIF and local, environmental, and systemic factors at the individual and implant levels. The chosen level of significance was 5%.

RESULTS

EIF occurred in 144 implants (5.68%) and in 97 individuals (16.3%). At the individual level, smoking habits (odds ratio [OR] = 2.54; 95% confidence interval [CI] = 1.00 to 6.47; P = .05), absence of postoperative antibiotic therapy (OR = 2.73; CI = 1.22 to 6.13; P = .02), and bone augmentation (OR = 1.83; CI = 1.17 to 2.85; P = .01) were significantly associated with EIF. At the implant level, smoking habits (OR = 2.90; CI = 1.60 to 5.26, P < .001), absence of postoperative antibiotic therapy (OR = 2.77; CI = 1.36 to 5.63, P = .005), postoperative complications (OR = 28.35; CI = 6.79 to 118.45, P < .001), implant length ≤8.5 mm (OR = 1.79; CI = 1.07 to 2.99; P = .03), and diameter <3.75 mm (OR = 1.65; CI = 1.08 to 2.52, P = .02) were associated with EIF. Age, sex, alcohol abuse, diabetes, hypertension, and long-term medication use were not associated with EIF at both individual and implant levels (P ≥ .12).

CONCLUSIONS

Smoking habits, absence of antibiotic therapy, bone augmentation, postoperative complications, implant diameter <3.75 mm, and implant length ≤8.5 mm were associated with EIF. Clinicians should be aware of these associations that should be controlled for when feasible. Future cohort studies are required to confirm the risk factors.

Efficacy of preoperative antibiotics in prevention of dental implant failure: a Meta-analysis of randomized controlled trials

BACKGROUND

Dental implants are commonly used for replacement of missing teeth. Despite the published data highlighting the high success rate of dental implants, failures do occur. Some of these failures are believed to be a result of bacterial contamination at the site of implant insertion. Various antibiotic regimens have already been suggested to prevent failure due to infection.

OBJECTIVE

This meta-analysis aims to examine the efficacy of preoperative antibiotics in prevention of dental implant failure secondary to infections.

METHODOLOGY

An exhaustive search was conducted on electronic database including PubMed Medline, Google Scholar, Scopus, and Cochrane on July 15, 2019. All the randomized controlled trials (RCT) comparing preoperative antibiotics with no antibiotics/placebo in dental implants were included in the study. The primary outcome for assessment was implant failure. A random effect meta-analysis was conducted for risk ratios of dichotomous data.

RESULTS

A total 8544 abstracts were screened following which 16 full text articles were reviewed and 5 RCTs were included in the analysis. Meta-analysis results indicated that the preoperative antibiotics resulted in statistically significantly lower number of implant failures.

CONCLUSION

Preoperative antibiotics effectively reduce the implant failure rate. However, it is recommended to conduct large-scale RCT to determine the efficacy of preoperative antibiotics in dental implants.

Potential risk factors for early and late dental implant failure: a retrospective clinical study on 9080 implants

Background

The aim of this study was to analyze potential risk factors for early and late dental implant failure (DIF) in a clinical cohort trial.

In a private practice, 9080 implants were inserted during a period of 10 years. In case of DIF, data were classified into early and late DIF and compared to each other in regard of gender, age, site of implantation, implant geometry, and patients’ systemic diseases.

Results

Three hundred fifty-one implants failed within the observation period (survival rate: 96.13%). Early DIF occurred in 293 implants (83.48%) compared to late DIF in 58 implants (16.52%). Significant earlier DIF was seen in the mandible (OR = 3.729, p < 0.001)—especially in the posterior area—and in younger patients (p = 0.017), whereas an increased likelihood of late DIF was associated with maxillary implants (OR = 3.729, p < 0.001) and older patients.

Conclusions

Early DIF is about twice as common as late DIF. Main risk factors for early DIF are implant location in the (posterior) mandible as well as younger age. On contrary, late DIF is rather associated with older patients, cancellous bone quality, and longer implants.

Factors associated with discontinuation and resumption of implant maintenance therapy

Discontinuation of implant maintenance is the main risk factor for implant failure. The purpose of this study was to identify factors associated with previous discontinuation and resumption of maintenance among implant patients. A questionnaire survey was sent to 171 patients receiving implant maintenance at a university hospital; 169 patients responded. To assess the effect of job status, 26 patients (15.4%) with a history of maintenance discontinuation were classified as employed and nonemployed. The main reasons for previously discontinuing maintenance were work issues (in employed respondents) and dissatisfaction with treatment skill or chairside manner (in nonemployed respondents). The main reasons for resuming maintenance were those related to dental treatment (in employed respondents) and awareness of the importance of maintenance (in nonemployed respondents). There were significant differences in relation to job status in the reasons reported for discontinuing and resuming maintenance (both P < 0.05). The present findings suggest that oral health professionals should consider these factors when assisting patients in reducing the risk of implant failure.

The impact of the alveolar bone sites on early implant failure: a systematic review with meta-analysis

Dental implants are the first option for replacement of missing teeth. Failure usually involves additional cost and procedures. As a result, the physician should limit the risk factors associated with implant failures. Implant site is one of many factors that can influence the success or failure of dental implants. The association between early implant failure (EIF) and implant site has yet to be documented. This review aims to estimate the impact of insertion site on the percentage of EIFs. An electronic and manual search of studies that reported early failure of dental implants based on collection site. A total of 21 studies were included in the review and examined for the association between EIF and alveolar site. Subgroup analysis, including a comparison between implants inserted in four alveolar ridge regions of both jaws was performed. The early failure rate was higher for maxillary implants (3.14%) compared to mandibular implants (1.96%). Applying a random effect, risk ratio (RR), and confidence interval (CI) of 95% revealed higher failure in the maxilla compared to the mandible (RR 1.41; 95% CI [1.19, 1.67]; P<0.0001; I²=58%). The anterior maxilla is more critical for early implant loss than other alveolar bone sites. Implants in the anterior mandible exhibited the best success rate compared of the sites.