Risk Factors in Early Implant Failure: A Meta-Analysis

Dental Implant Survival Rates: Comprehensive Insights from a Large-Scale Electronic Dental Registry

BACKGROUND

This descriptive study aimed to assess the survival rates and outcomes of dental implants in one of the four national HMOs in Israel. Data are provided for the period from 1 January 2014 to 31 December 2022.

MATERIALS AND METHODS

This retrospective analysis utilized electronic medical records of patients who underwent dental implant placement during the specified period. Statistical analyses included chi-squared tests, Student's t-tests, and generalized estimating equation (GEE) analyses to identify potential risk factors associated with early and late implant failures.

RESULTS

A total of 158,824 dental implants were placed in 53,874 patients. The overall implant failure rate was 2.21%, while the early failure rate during the osseointegration phase-before prosthetic reconstruction-was 1.56%. Significant associations with implant failure were observed for male patients (2.53% failure rate), implants in the maxillary molar region (3%), and the central incisor region (3.37%), approximately double the failure rates seen in other implant sites (p < 0.001).

CONCLUSIONS

This extensive data analysis demonstrates a low overall failure rate for dental implants. The highest failure incidence occurred within the first year post-implantation, declining in subsequent years irrespective of rehabilitation status. Early failure risk factors differ based on various factors and should be carefully integrated into presurgical planning.

Risk factors for the failure of re-implanted dental implants: A 20-year retrospective study

BACKGROUND

Re-implantation of failed implants is common to maintain the original prosthetic plan; however, it may not always be ideal due to various factors. Few studies have thoroughly investigated the outcomes of re-implanted implants, while considering factors that can enhance their survival rates. Therefore, this study aimed to identify the risk factors that may contribute to the refailure of implants placed the second time by analyzing previously failed implants and evaluating their survival.

METHODS

Of 10,666 dental implants placed in 4063 patients at the Department of Periodontics of the Gangneung-Wonju National University Dental Hospital between December 1999 and March 2021, 259 failed implants in 170 patients were evaluated through clinical and radiographic records for patient-, surgical-, implant-, and prosthesis-related factors; survival analysis was conducted for implants that met the inclusion criteria.

RESULTS

Of the 259 failed implants, 80 second-time-placed implants met the inclusion criteria. Survival analysis showed that the 1-year survival rate of second-time-placed implants was 88.1%. Smoking (hazard ratio [HR] = 5.066, p = 0.081), implant surface (HR = 18.776, p < 0.01), and timing of reimplantation (HR = 0.086, p < 0.01) were identified as risk factors influencing the refailure of second-time-placed implants.

CONCLUSIONS

The survival rate of second-time-placed implants was lower than that of first-time-placed implants. The risk factors for second-time-placed implant failure were smoking, implant surface, and timing of reimplantation. To prevent further failure, previous failure factors should be analyzed and modifiable risk factors must be controlled before reimplantation.

Predictive Factors of Dental Implant Failure: A Retrospective Study Using Decision Tree Regression

INTRODUCTION

Dental implants are routinely used to replace missing teeth. Therefore, the primary aim of the present study was to assess the single-unit implant failure rate over a period of seven years from 2015 to 2021, with a minimum of two years post-implant follow-up. The secondary aim was to identify the risk factors associated with implant failure using machine learning decision tree regression and Kaplan-Meier survival analyses.

MATERIALS AND METHODS

An eight-year retrospective study was conducted using the clinical records of 224 patients who received single-unit dental implants between January 2014 and December 2021, where risk factors for early (EIF) and late implant failure (LIF) were identified. The patients' clinical case records and radiographs were used to assess implant failure.

RESULTS

Smoking and peri-implantitis were principal contributors to failure (p=0.001). Implant failure was more common in males, the maxillary jaw, and posterior teeth, although these factors were not significantly associated with implant failure (p>0.05). The duration of failure was 16.87±4.6 months for LIF, in contrast to 5.71±1.38 months in EIF. Bruxism and peri-implantitis were correlated with diminished survival duration, especially when compounded by additional risk factors such as diabetes mellitus. Isolated peri-implantitis yielded an average failure duration of approximately 13.4 months, whereas bruxism intensified the failure interval to approximately 13.8 months. Kaplan-Meier survival analysis revealed that among the identified causes of failure, peri-implantitis and smoking were the predominant factors, followed by bruxism, diabetes, and complications related to osseointegration.

CONCLUSION

Age, sex, type of surgical procedure, sinus lift, and grafting procedures were not significantly associated with dental implant failure, whereas bruxism, peri-implantitis, lack of osseointegration, smoking, and type 2 diabetes mellitus were significant predictors.

Treatment strategies for dental implant removal: A literature review

Dental implants have been widely used with success, but long-term usage sometimes leads to implant loss. The purpose of this review was to summarize the etiology of early and late failure requiring dental implant removal and the treatment strategies for the removal of failed implants and reimplantation. Early failures are often caused by patient-related factors, such as smoking, diabetes, radiotherapy, bone quality, and periodontitis of the remaining natural teeth. The most common cause of late failure is peri-implantitis, followed by implant fracture and implant malpositioning. Implants should be removed if they are mobile or if their superstructure cannot be maintained (e.g., implant fracture). For peri-implantitis, implant removal should be determined based on the patient's age and esthetic needs, the implant site, and the severity of bone loss. Many reports have been published on implant removal techniques. The reverse torque technique should always be the first choice because of its low invasiveness. The weighted survival rate for the replacement of failed implants is 86.3%, with a much lower survival rate after the second or subsequent implantations. Therefore, patient-specific problems, such as smoking habits and bruxism, should be checked before reimplantation and controlled to the greatest extent possible.

Innate immune regulation in dental implant osseointegration

PURPOSE

Dental implant osseointegration comprises two types of bone formation-contact and distance osteogenesis-which result in bone formation originating from the implant surface or bone edges, respectively. The physicochemical properties of the implant surface regulate initial contact osteogenesis by directly tuning the osteoprogenitor cells in the peri-implant environment. However, whether these implant surface properties can regulate osteoprogenitor cells distant from the implant remains unclear. Innate immune cells, including neutrophils and macrophages, govern bone metabolism, suggesting their involvement in osseointegration and distance osteogenesis. This narrative review discusses the role of innate immunity in osseointegration and the effects of implant surface properties on distant osteogenesis, focusing on innate immune regulation.

STUDY SELECTION

The role of innate immunity in bone formation and the effects of implant surface properties on innate immune function were reviewed based on clinical, animal, and in vitro studies.

RESULTS

Neutrophils and macrophages are responsible for bone formation during osseointegration, via inflammatory mediators. The microroughness and hydrophilic status of titanium implants have the potential to alleviate this inflammatory response of neutrophils, and induce an anti-inflammatory response in macrophages, to tune both contact and distance osteogenesis through the activation of osteoblasts. Thus, the surface micro-roughness and hydrophilicity of implants can regulate the function of distant osteoprogenitor cells through innate immune cells.

CONCLUSIONS

Surface modification of implants aimed at regulating innate immunity may be useful in promoting further osteogenesis and overcoming the limitations encountered in severe situations, such as early loading protocol application.

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.

Enhanced vascularization and osseointegration under osteoporotic conditions through functional peptide coating on implant surfaces

Patients with osteoporosis face challenges such as decreased bone density, a sparse trabecular structure, weakened osteogenic ability, and impaired angiogenesis, leading to poor osseointegration and implant failure. Surface modification of implants with biologically active molecules possessing various functions is an effective strategy to improve osseointegration. In this study, we constructed a simple multifunctional coating interface that significantly improves osseointegration. In brief, a multifunctional coating interface was constructed by coupling the Rgd adhesive peptide, Ogp osteogenic peptide, and Ang angiogenic peptide to Lys6 (k6), which self-assembled layer by layer with TA to form the (TA-Rgd@ogp@ang)n composite membrane. This study characterized the surface morphology and biomechanical properties of the coating under both gas and liquid phases and monitored the deposition process and reaction rate of the two peptides with TA using a quartz crystal microbalance. Moreover, (TA-Rgd@ogp@ang)n exhibited a triple synergistic effect on cell migration and adhesion, osteogenic differentiation, and angiogenesis. It also ameliorated the high ROS environment characteristic of osteoporosis pathology, promoted angiogenic bone defect regeneration in osteoporosis, thereby avoiding poor osseointegration. This work provides a new approach for the prevention of implant failure in pathological environments by constructing multifunctional coatings on implants, with tremendous potential applications in the fields of orthopedics and dentistry.

Implant-supported crowns with locking taper implant-abutment connection: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Implant-supported single crowns are more prone to screw loosening than splinted prostheses. Therefore, the locking taper system, which has a screwless abutment, may perform better when associated with this type of rehabilitation. However, systematic reviews on this system are lacking.

PURPOSE

The purpose of this systematic review was to evaluate the clinical performance and complications of single crowns retained by the locking taper system.

MATERIAL AND METHODS

This systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) under CRD42020189921. An electronic search was made in 5 databases and 3 other sources up to February 2021 to select prospective clinical studies evaluating the performance of single crowns retained by the locking taper system by using the outcomes implant survival, success rate, complications, marginal bone loss (MBL), and prosthesis success rate. Four meta-analyses grouped according to the follow-up intervals were performed. The risk of bias of the selected studies was evaluated by using the RoB 2 checklist for randomized controlled trials (RCTs) and Downs and Black for uncontrolled studies.

RESULTS

Twelve studies were included: 9 prospective cohort studies and 3 RCTs. A survival rate of 99% (98% to 99%) and a success rate of 97% (92% to 99%) after 5 years were found. Of the total, 2.6% biological and 2.9% prosthetic complications were described. The prosthesis success rate was 97% (96% to 98%) after 5 years. An average of -0.73 mm (-0.93 to -0.52) was found for the MBL after 5 years. The risk-of-bias assessment showed 2 RCTs with high risk and 1 RCT with low risk of bias. Among uncontrolled studies, 2 were classified as poor and 7 as fair.

CONCLUSIONS

Single crowns retained by locking taper implants can be safely indicated based on the high survival and success rates achieved in the long term, the maintenance of bone level stability over time, and the low incidence of complications.

Risk indicators associated with peri-implant diseases: a retrospective cross-sectional study of Colombian patients with 1 to 18 years of follow-up

PURPOSE

Peri-implant mucositis (PIM) and peri-implantitis (PI) are multicausal conditions with several risk factors contributing to their pathogenesis. In this study, we retrospectively investigated risk variables potentially associated with these peri-implant diseases (PIDs) over a follow-up period of 1 to 18 years.

METHODS

The study sample consisted of 379 implants placed in 155 patients. Single-visit clinical and radiographic evaluations were employed to determine the presence or absence of PIDs. Parameters related to the patient, site, surgery, implant, and prosthetic restoration were documented. The relationships between risk variables and the occurrence of PIDs were individually examined and adjusted for confounders using multivariate binary logistic regression models.

RESULTS

The prevalence rates of PIM and PI were 28.4% and 36.8% at the patient level and 33.5% and 24.5% at the implant level, respectively. Poor oral hygiene, active gingivitis/periodontitis, preoperative alveolar ridge deficiency, early or delayed implant placement, implant length of 11.0 mm or less, and poor restoration quality were strong and independent risk indicators for both PIDs. Furthermore, a follow-up period of more than 5 years and a loading time of more than 4 years were important indicators for PI. Simultaneously, age and smoking status acted as modifiers of the effect of mesiodistal (MD) and buccolingual (BL) widths of restoration on PI.

CONCLUSIONS

In this study population, oral hygiene, periodontal status, preoperative alveolar ridge status, implant placement protocol, implant length, and the quality of coronal restoration appear to be robust risk indicators for both PIM and PI. Additionally, the length of follow-up and functional loading time are robust indicators of PI. Furthermore, the potential modifying relationships of age and smoking status with the MD and BL widths of restoration may be crucial for the development of PI.

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.

Early Implant Failure: A Meta-Analysis of 7 Years of Experience

Background: The use of dental implant rehabilitation in the treatment of complete and partial edentulism has become an integral treatment today. This treatment is performed on healthy patients, but in some situations, also on those with associated general ailments. The presence of associated conditions increases the degree of difficulty of this type of treatment and tests the doctor's ability to manage the clinical case. The purpose of the study was to perform a meta-analysis of dental implants inserted over seven years and evaluate early implant failure in correspondence with age, sex, region of insertion, type of implant, and general state of health. Methods: A retrospective study was performed over 7 years of experience. For the study, 213 patients who fit the established inclusion criteria were selected. Patients were grouped taking into account age, sex, the type of implant used, and general associated conditions. The collected data were analyzed using IBM SPSS STATISTICS 25.0 for windows Results: There were no highlighted situations in which the rejection of the dental implant occurred 10 days postoperatively or later during the healing period. Conclusions: Our results confirm and strengthen the existing data in the specialized literature, especially those related to the loss of implants in patients with associated general diseases.

The cumulative survival rate of dental implants with micro-threads: a long-term retrospective study

PURPOSE

This study aimed to evaluate the long-term cumulative survival rate (CSR) of dental implants with micro-threads in the neck over a 10-year follow-up period and to examine the factors influencing the survival rate of dental implants.

METHODS

This retrospective study was based on radiographic and dental records. In total, 151 patients received 490 Oneplant® dental implants with an implant neck micro-thread design during 2006-2010 in the Department of Periodontology of Seoul National University Dental Hospital. Implant survival was evaluated using Kaplan-Meier analysis. Cox proportional hazard regression analysis was used to identify the factors influencing implant failure.

RESULTS

Ten out of 490 implants (2.04%) failed due to fixture fracture. The CSR of the implants was 97.9%, and no significant difference was observed in the CSR between external- and internal-implant types (98.2% and 97.6%, respectively, P=0.670). In Cox regression analysis, 2-stage surgery significantly increased the risk of implant failure (hazard ratio: 4.769, P=0.039). There were no significant differences in influencing factors, including sex, age, implant diameter, length, fixture type, location, surgical procedure, bone grafting, and restoration type.

CONCLUSIONS

Within the limitations of this retrospective study, the micro-thread design of the implant neck was found to be favorable for implant survival, with stable clinical outcomes.

Risk factors impacting the survival of implants replaced following failure: A retrospective study

AIM

This study aimed to investigate factors influencing the survival of replaced dental implants.

MATERIALS AND METHODS

Charts from 2005 to 2021 were reviewed. Replaced implants after removal for the first time were identified. Depending on their survival, the replaced group was divided into the surviving and second-removal groups. Risk factors affecting survival of replaced implants were evaluated considering clustering of multiple implants within patients.

RESULTS

The present study included 464 replaced implants of 370 patients, of which 429 and 35 implants were categorized into the surviving group and the second-removal group. The 5-year survival rate was 90.2 ± 0.18% in replaced implants at sites with a periodontitis history and 97.0 ± 0.15% at sites without a periodontitis history (p = 0.008). The 5-year survival rate was 89.1 ± 0.27% in replaced implants with guided bone regeneration (GBR) at first implant placement and 93.9 ± 0.14% at non-GBR (p = 0.032). The 5-year survival rate was 97.6 ± 0.13% in replaced implants with GBR and 90.3 ± 0.17% in replaced implants without GBR (p = 0.026). In the multivariable analysis adjusted for clinical variables, periodontitis history (adjusted hazard ratio [aHR] = 3.417; 95% confidence interval [CI] = 1.161-10.055), GBR at first implant placement (aHR = 2.152; 95% CI = 1.052-4.397) and non-GBR at primary implant replacement (aHR = 0.262; 95% CI = 0.088-0.778) were identified as independent risk factors for second implant removal.

CONCLUSIONS

Periodontitis history, GBR at first implant placement and non-GBR at primary implant replacement were identified as risk factors affecting the survival of replaced implants.

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.

Prosthetically guided oral implant surgery. A retrospective cohort study evaluating the 5-year surgical outcome

Purpose

This study primarily evaluated the 5-year implant survival and success rate of prosthetically guided inserted implants. The secondary aim was to evaluate the impact of clinical variables on the development of mucositis, peri-implant bone resorption, peri-implantitis, as well as early and late implant failure.

Materials and methods

An observational retrospective single-centre study was conducted on patients who were treated with dental implants in the department of oral and plastic maxillofacial surgery of the military hospital of Ulm University between 2008 and 2010. In all patients, computer-assisted 3D planning after wax-up of the prosthetic restoration and template-guided surgery with titanium implants were performed. Bone augmentation procedures were performed primarily if needed. Intraoperative and postoperative complications as well as technical and mechanical complications after prosthesis loading were evaluated. In a 5-year clinical and radiological follow-up, implant success and implant survival were assessed using descriptive statistics. A multivariable regression analysis evaluated the potential impact of augmentation procedures, wound healing complications, smoking, history of periodontitis, and preoperative API (approximal plaque index) and SBI (sulcus bleeding index) values on peri-implant mucositis, peri-implant bone resorption, peri-implantitis, as well as early and late implant failure.

Results

In this study, 466 implants in 283 patients were considered for inclusion, and sufficient data were obtained for analysis from 368 (78.9%) implants in 229 (80.9%) patients. An overall implant survival rate of 98.1% (n=361/368) at the 5-year follow-up was revealed. According to the success criteria of the study, the 5-year success rate was 97.04% (n=263/271). An early implant failure of 1.07% (n=5/466) was recorded. 48.2% of the implants were affected by peri-implant mucositis (n=122/253), while peri-implant bone resorption was detected in 21.7% of the radiologically examined implants (n=59/271). Fifteen cases of peri-implantitis (5.5%) were detected. Peri-implant bone resorption increased significantly after bone augmentation procedures (p=0.028). Wound healing complications after implantation significantly increased the prevalence of late implant failure in the maxilla (p<0.001). Peri-implant bone resorption and peri-implantitis were significantly more prevalent in smokers (p=0.022/p=0.043). Implants in patients with API>20% presented significantly higher rates of peri-implant mucositis (p=0.042). Wound healing complications after augmentation, history of periodontitis, and SBI>20% had no significant impact on the study parameters.

Conclusions

The study confirms the reliability of prosthetically guided implant surgery, showing a high implant survival and success rate in a 5-year follow-up. Intraoperative complications and technical or mechanical complications after prosthesis loading remain within acceptable clinical limits. The rate of peri-implant mucositis, peri-implant bone resorption, and peri-implantitis was within the current literature range. Optimizing periodontal health and reducing smoking would improve the outcome. Further studies need to clarify the clinical indications and investigate the long-term surgical outcome of this treatment concept.

Early Implant Bone Loss in the Preprosthetic Phase: A Retrospective Study

Initiation of the inflammatory response begins with the surgical placement of an implant that stimulates bone remodeling. The occurrence of crestal bone loss during submerged healing affects the prognosis of an implant. Hence, this study was conducted to estimate the early implant bone loss during the preprosthetic phase on bone level implants placed equicrestally. This retrospective observational study included evaluation of crestal bone loss around 271 two-piece implants placed in 149 patients from the archived postsurgical (P1) and preprosthetic (P2) digital orthopantomographic records using MicroDicom software. The outcome was categorized based on (1) sex (male or female), (2) time of implant placement (immediate [I] vs conventional [D]), (3) duration of healing period before loading (conventional [T1] vs delayed [T2]), (4) region of implant placement (maxilla [M1] vs mandible [M2]), and (5) site of implant placement (anterior [A] vs posterior [P]). To find the significant difference between the bivariate samples in the independent groups, an unpaired sample t test was used. The average marginal bone loss during the healing phase was 0.56 ± 0.573 mm in the mesial region and 0.44 ± 0.549 mm in the distal region of the implant, with a statistically significant difference (P < .01). There was no statistically significant difference in crestal bone level with the (1) sex of the patient (male or female), (2) type of implant placement (I or D), (3) time of implant loading (T1 or T2), (4) region of implant placement (M1 or M2), or (5) site of implant in the arch (A or P) (P > .05). An average of 0.50 mm crestal bone loss occurred in the peri-implant region during the preprosthetic phase. We found that the delayed placement of an implant and a delay in the healing period would further increase the early implant bone loss. The difference in the healing period did not alter the outcome of the study.

Avoiding implant-related complications in medically compromised patients with or without unhealthy lifestyle/Elevated oxidative stress

Increased human life expectancy broadens the alternatives for missing teeth and played a role in the widespread use of dental implants and related augmentation procedures for the aging population. Though, many of these patients may have one or more diseases. These systemic conditions may directly lead to surgical complications, compromise implant/bone healing, or influence long-term peri-implant health and its response to biologic nuisances. Offering patients credible expectations regarding intra- and postoperative complications and therapeutic prognosis is an ethical and legal obligation. Clear identification of potential types of adverse effects, complications, or errors is important for decision-making processes as they may be related to different local, systemic, and technical aspects. Therefore, the present review structures the underlying biological mechanisms, clinical evidence, and clinical recommendations for the most common systemic risk factors for implant-related complications.

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.

Assessing the Cleanliness of Dental Implants Using Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy Analysis-A SEM and EDS In Vitro Study

A wide variety of titanium (Ti) alloy dental implant systems are available and as a result, choosing the correct system has become a challenge. Cleanliness of the dental implant surface affects osseointegration but surface cleanliness may be jeopardized during manufacturing. The purpose of this study was to assess the cleanliness of three implant systems. Fifteen implants per system were examined with scanning electron microscopy to identify and count foreign particles. Particle chemical composition analysis was performed with energy-dispersive X-ray spectroscopy. Particles were categorized according to size and location. Particles on the outer and inner threads were quantitatively compared. A second scan was performed after exposing the implants to room air for 10 min. Carbon, among other elements, was found on the surface of all implant groups. Zimmer Biomet dental implants had higher particle numbers than other brands. Cortex and Keystone dental implants showed similar distribution patterns. The outer surface had higher particle numbers. Cortex dental implants were the cleanest. The change in particle numbers after exposure was not significant (p > 0.05). Conclusion: Most of the implants studied were contaminated. Particle distribution patterns vary with the manufacturer. The wider and outer areas of the implant have a higher probability of contamination.

Clinical and Radiological Evaluation of a Self-Condensing Bone Implant in One-Stage Sinus Augmentation: A 3-Year Follow-Up Retrospective Study

Stabilization of dental implants in the sinus region with a bone height below 4 mm gen-erally requires a two-stage sinus floor elevation surgery. To improve this aspect, the aim of this retrospective study was to demonstrate the feasibility of performing a one-stage maxillary sinus augmentation using an innovative self-condensing implant design, even in case of a bone height close to 2 mm. Clinical and radiological outcomes from 54 patients (26 females; 28 males; 69 total implants positioned) were analyzed 3 years post-surgery. The three-dimensional grafts change was evaluated by Cone-Beam Computed Tomography (CBCT) before surgery (T0), immediately after surgery (T1), and 1-year post-surgery (T2). The sinus floor levels measured at the medial (M-W), middle (MD-W), and lateral (L-W) walls reported: M-W of 1.9 ± 2.4 mm (T1) and 1.7 ± 2.6 mm (T2); MD-W of -0.1 ± 2.7 mm (T1) and 0.7 ± 2.4 mm (T2); L-W of 3.1 ± 3.0 mm (T1) and 3.1 ± 3.0 mm (T2); besides a bone crest height (C-F) of 4.6 ± 2.0 mm (T1) and 12.1 ± 1.4 mm (T2). Moreover, after 3 years only 1 implant was lost, and so an implant survival rate of 98.55% was recorded. In conclusion, these results suggest the efficacy of using this implant design for a one-stage sinus lift approach, not only in terms of increased implant survival rate and decreased marginal bone loss, but also for its potential applicability in case of reduced bone height.

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.

Implant-Supported Prosthesis Is a Viable Treatment Alternative for American Society of Anesthesiology Physical Status 3 Individuals—A Retrospective Cohort Study

Background: Within medicine, it is common to use risk prediction tools towards clinical decision making. One of the most widely accepted assessment tools is the American Society of Anesthesiologists Physical Status (ASA PS) classification. Oral and maxillofacial procedures performed in an ambulatory setting would be considered low risk for the procedure itself. However, little is known concerning the impact of ASA PS on surgical outcomes. The aim of the present research was to evaluate the effect of ASA PS classification on early implant failure (EIF). Methods: Retrospective cohort study based on dental records. All treatments were performed by experienced oral and maxillofacial surgeons and experienced prosthodontists. Inclusion criteria: ASA physical status 1,2,3, consecutive individuals. Variables included the following: age, gender, implant location, implant length, implant width, smoking, and early implant failure. Results: Univariate tests at the patient level showed no statistically difference between the different classifications of ASA PS (1,2,3). Multivariate model using logistic regression at individual level showed that two factors were found to be associated with an increased risk for EIF—augmented bone and implant brand. Conclusions: ASA PS 3 is not a contraindication for implant-supported prostheses. EIF in ASA PS 3 is not significantly different from ASA PS 1,2. In contrast, factors such as bone augmentation and implant brand might be significant risk factors for EIF, regardless of ASA PS.

The effect of triangular cross-section neck design on crestal bone stability in the anterior mandible: A randomized, controlled, split-mouth clinical trial

OBJECTIVES

This randomized controlled trial aimed to compare crestal bone loss (CBL) and buccal bone thickness (BBT) around triangular cross-section neck (TN) to round neck (RN) implants retaining mandibular overdentures one year after loading, using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

Twenty edentulous patients receiving 40 implants with similar diameters were randomly assigned to the RN and TN groups. Clinical buccal bone thickness (CBBT) around the implants was measured with a caliper at baseline. A resonance frequency analyzer was used to measure the implant stability quotient (ISQ) at the baseline and two months after insertion. Pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also recorded at postoperative months 2, 6, and 12. CBCT was used to evaluate proximal CBL and BBT at three levels (0, -2, and -4 mm) one year after loading.

RESULTS

No implant loss was observed during the follow-up period. No significant differences in CBBT, ISQ values, and scores for PPD, PI, and GI between the two groups were observed at any time (p > .05). BBT was also comparable one year after loading (p > .05). The mean ± SD proximal CBL one year after loading was 0.58 ± 0.36 mm for TN and 0.91 ± 0.59 mm for RN (p < .01).

CONCLUSIONS

This study found better crestal bone preservation in the implants with the novel neck design than conventional neck design in the anterior mandible after a follow-up of one year. However, it may not be clinically noticeable.

Cellular and Molecular Dynamics during Early Oral Osseointegration: A Comprehensive Characterization in the Lewis Rat

OBJECTIVE

There is a need to improve the predictability of osseointegration in implant dentistry. Current literature uses a variety of in vivo titanium (Ti) implantation models to investigate failure modes and test new materials and surfaces. However, these models produce a variety of results, making comparison across studies difficult. The purpose of this study is to validate an oral osseointegration in the Lewis rat to provide a reproducible baseline to track the inflammatory response and healing of Ti implants.

METHODS

Ti screws (0.76 mm Ø × 2 mm length) were implanted into the maxillary diastema of 52 adult male Lewis rats. Peri-implant tissues were evaluated 2, 7, 14, and 30 days after implantation (n = 13). Seven of the 13 samples underwent microtomographic analysis, histology, histomorphometry, and immunohistochemistry to track healing parameters. The remaining six samples underwent quantitative polymerase chain reaction (qPCR) to evaluate gene expression of inflammation and bone remodeling markers over time.

RESULTS

This model achieved a 78.5% success rate. Successful implants had a bone to implant contact (BIC)% of 68.86 ± 3.15 at 30 days on average. Histologically, healing was similar to other rodent models: hematoma and acute inflammation at 2 days, initial bone formation at 7, advanced bone formation and remodeling at 14, and bone maturation at 30. qPCR indicated the highest expression of bone remodeling and inflammatory markers 2-7 days, before slowly declining to nonsurgery control levels at 14-30 days.

CONCLUSION

This model combines cost-effectiveness and simplicity of a rodent model, while maximizing BIC, making it an excellent candidate for evaluation of new surfaces.

Systemic Antibiotic Prophylaxis to Reduce Early Implant Failure: A Systematic Review and Meta-Analysis

Systemic antibiotics are routinely prescribed in implant procedures, but the lack of consensus causes large differences between clinicians regarding antibiotic prophylaxis regimens. The objectives of this systematic review are to assess the need to prescribe antibiotics to prevent early implant failure and find the most appropriate antibiotic prophylaxis regimen. The electronic search was conducted in PubMed/MEDLINE, Scielo and Cochrane Central Trials Database for randomized clinical trials of at least 3 months of follow-up. Eleven studies were included in the qualitative analysis. Antibiotics were found to statistically significantly reduce early implant failures (RR = 0.30, 95% CI: 0.19-0.47, p < 0.00001; heterogeneity I2 = 0%, p = 0.54). No differences were seen between preoperative or both pre- and postoperative antibiotic regimens (RR = 0.57, 95% CI: 0.21-1.55, p = 0.27; heterogeneity I2 = 0%, p = 0.37). A single preoperative antibiotic prophylaxis dose was found to be enough to significantly reduce early implant failures compared to no antibiotic (RR = 0.34, 95% CI: 0.21-0.53, p < 0.00001; heterogeneity I2 = 0%, p = 0.61). In conclusion, in healthy patients a single antibiotic prophylaxis dose is indicated to prevent early implant failure.

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.

Prescription of Antibiotic Prophylaxis for Dental Implant Surgery in Healthy Patients: A Systematic Review of Survey-Based Studies

Background: Systemic antibiotic prophylaxis is frequently prescribed by dentists performing dental implant surgery to avoid premature implant failure and postoperative infections. The scientific literature suggests that a single preoperative dose suffices to reduce the risk of early dental implant failure in healthy patients. Material and Methods: A systematic review was made based on an electronic literature search in the PubMed-Medline, Embase, Web of Science, Scopus and Open Gray databases. The review addressed the question: "which antibiotic prophylaxis regimens are being used in dental implant surgery in healthy patients according to survey-based studies?" The identification, screening, eligibility and inclusion phases were conducted according to the PRISMA statement by two independent reviewers. The following data were collected: country, number of surveyed dentists, number of dentists who responded (n), response rate, routine prescription of antibiotic prophylactic treatment (yes, no, or conditioned prescription), prescription regimen (preoperative, perioperative or postoperative) and antibiotic choice (first and second choice). Cohen's kappa coefficient (k) evaluated the level of agreement between the two reviewers. The analysis of risk of bias was performed follow the Joanna Briggs Institute checklist for observational studies. A descriptive statistical analysis was performed to calculate total target sample, sample size and total mean. Results: A total of 159 articles were identified, of which 12 were included in the analysis. Two thousand and seventy-seven dentists from nine different countries on three continents were surveyed. The median response rate was low and disparate between studies. About three-quarters of the surveyed dentists claimed to routinely prescribe systemic antibiotic prophylaxis for dental implant surgery. The prescription regimen was perioperative, postoperative and preoperative, in decreasing order of frequency. The most frequent first choice drug was amoxicillin, with amoxicillin-clavulanic acid as second choice. Conclusions: A majority of dentists from different countries do not prescribe systemic antibiotic prophylaxis for dental implant surgery following the available scientific evidence and could be overprescribing. Efforts are needed by dental educators and professionals to reduce the gap between the use of antibiotic prophylaxis for dental implant surgery as supported by the scientific evidence and what is being done by clinicians in actual practice.

Does the systemic administration of L-arginine affect dental implant stability in nicotine consumer dogs?

Background

Nicotine can have detrimental effects on dental implant osseointegration. This study aimed to evaluate the influence of systemic l-arginine supplement on the osseointegration of dental implants in nicotine consumer dogs.

Methods

Twelve 1-year Labrador Retriever dogs had their right and left third and fourth mandibular premolars removed, and the sockets were left to heal for 6 months. Dogs were randomly divided into three groups (n = 16): group 1—0.2 mg/kg nicotine was injected twice daily; group 2—0.2 mg/kg nicotine was injected twice daily in addition to 200 mg/kg l-arginine capsules taken orally; and group 3—placebo. Forty-eight dental implants were inserted into the healed sockets of the dog’s mandible and were assessed by implant stability quotient (ISQ) using resonance frequency analysis (RFA) during 4 weeks and insertion and removal torque value analysis.

Results

No implant failure occurred during the study period. The change in torque value between insertion and removal was similar in the placebo and nicotine+arginine consumer dogs (p = 0.276), which shows a positive effect of arginine supplementation in nicotine consumers. There was a significant difference in torque value change between nicotine+arginine vs. nicotine consumers (p = 0.049) and placebo vs. nicotine (p = 0.003). After 4 weeks, the placebo had the most significant improvement in torque value (47.0 ± 16.9), followed by nicotine+arginine (25.1 ± 37.8), and the worst torque value was for the nicotine group (− 5.7 ± 24.0) pound per inch. The results show that except in the first week, there are significant differences in ISQ between the groups in different periods. ISQ in all of the groups has reduced at first but then increased over time. At the time of implant placement, insertion torque was significantly higher in the nicotine consumer group than the nicotine+arginine consumer group and placebo group (p = 0.020).

Conclusion

Arginine supplementation promotes bone healing and implant primary stability by improving dental implant osseointegration biomechanical characteristics.

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.

Biomechanical and histomorphometric analysis of endosteal implants placed by using the osseodensification technique in animal models: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Osseodensification, a counterclockwise drilling technique for the placement of endosseous implants is a popular clinical technique. However, the effect of the osseodensification technique on primary implant stability, bone-implant contact, and bone area frequency occupancy is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to investigate the biomechanical and histomorphometric outcomes of endosteal implants placed by using the osseodensification technique in animal models.

MATERIAL AND METHODS

An electronic search through Medline/PubMed, Lilacs, and Science Direct databases, and an additional manual search of the reference list of included articles was conducted by using specific keywords and Medical Subject Headings (MeSH) terms for articles in the English language and published up to April 31, 2020. Only animal studies comparing the biomechanical and histomorphometric outcomes of endosteal implants placed by using the osseodensification and conventional drilling protocol were included. The SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) tool was used to determine the risk of bias assessment, and the quality of included studies was assessed by using Animal Research: Reporting in Vivo Experiments (ARRIVE) guidelines.

RESULTS

Nine studies were included. The results of the meta-analysis showed that the pooled weighted mean difference of the insertion torque value for the primary implant stability of endosseous dental implants placed by using the osseodensification technique was 2.270 (95% confidence interval [CI]=1.147 to 3.393; P<.001), the weighted mean difference of the percentage of bone-implant contact at 3 weeks was 0.487 (95% CI=0.220 to 0.754; P=.114), the weighted mean difference of the percentage of bone-implant contact at 6 weeks was 0.565 (95% CI=0.219 to 0.911; P=.448), the weighted mean difference of the percentage of bone area frequency occupancy at 3 weeks was 0.679 (95% CI=0.265 to 1.093; P=.073), and the weighted mean difference of the percentage of bone area frequency occupancy at 6 weeks was 0.391 (95% CI=-0.204 to 0.986; P=.027).

CONCLUSIONS

Limited data from animal studies suggest that the primary implant stability, bone-implant contact, and bone area frequency occupancy significantly improved for the endosteal implants placed by using the osseodensification technique compared with conventional drilling protocol. However, additional laboratory and clinical studies are recommended to provide stronger evidence.

Clinical feasibility and benefits of a tapered, sand-blasted, and acid-etched surfaced tissue-level dental implant

BACKGROUND

It has been 50 years since Brånemark first introduced the concept of osseointegration. Since then, numerous ongoing research, developments, and optimization of implant properties have been conducted. Despite the high survival and success rates of dental implants, failures still occur in a small number of patients that are being rehabilitated by implants. The purpose of this study was to evaluate the survival and success rate of the Stella® implants that incorporate sand-blasted and acid-etched (S&E) surface treatment and tapered body design to confirm their clinical feasibility and benefits after placement.

METHODS

We reviewed 61 partially and fully edentulous patients who underwent a tapered, S&E surfaced tissue-level implant placement between May 2013 and February 2016 in the Department of Oral and Maxillofacial Surgery in the Seoul National University Dental Hospital. Patient characteristics and treatment results were collected, and records of dental implants were analyzed clinically and radiologically.

RESULTS

A total of 105 implant fixtures were placed in these patients. The mean age at the time of the surgery was 63.7 years with a range of 31 to 88 years. In total, 4.0-mm and 4.5-mm diameter implants were the most frequently used dental implants (40%, 49%) in this study. Implants 8.5 mm in length were predominantly used (60%). Seventy dental implants were placed in the mandible (70%), and only one dental implant was placed in the maxillary anterior region. At the end of the 5-year observation period, the success rate of the Stella® implants was 98.1%. Among the 105 implants placed, 2 were considered to be failures. Summarizing the clinical and radiographic results, the remaining 103 implants were considered successfully integrated.

CONCLUSION

The overall success rate was 98.1%. The tapered, S&E surfaced tissue-level implant system exhibited great performance in a variety of clinical situations including failed implant sites that enabled predictable and successful treatment outcomes. The effectives of a tapered design of tissue level, not a parallel design, are shown in this clinical report.

What Factors Are Associated With Implant Failure?

PURPOSE

Recognition of patient-specific risk factors should reduce implant failure. The purpose of this study was to identify risk factors associated with implant failure and to determine if these factors differ over time after implant placement.

METHODS

The investigators implemented a retrospective case-controlled study and enrolled a sample composed of patients who had 1 or more implants removed from December 1, 2007 to February 29, 2020. Risk factors were grouped into demographic, medical history, and treatment-related variables. The primary outcome variable was whether the patient's implant failed, with control patients including those without implant failure. The duration was recorded for follow-up from the time of implant placement to the last visit or implant removal. Backward variable selection was used to predict whether an implant failed within 1 year, 1 to 4 years, or after 4 years in 3 multivariable logistic regressions.

RESULTS

Of 224 patients in this cohort, 82 experienced an implant failure. The mean age was 58.6 ± 15.3 years, and 53.1% were females. Patients with osteoporosis had an increased risk of failure in each period. Alcohol use, smoking, depression, and penicillin allergy were all associated with an increased probability of failure within 1 or more of the periods considered.

CONCLUSIONS

This study has identified multiple discrete risk factors for implant failure and has demonstrated that these factors are associated with implant failure at different periods after placement.

Evaluation of maxillary sinus floor augmentation with the crestal approach and beta-tricalcium phosphate: a cone-beam computed tomography 3- to 9-year follow-up

Background

We performed maxillary sinus floor augmentation using the crestal approach and beta-tricalcium phosphate (β-TCP) and a long-term evaluation using cone-beam computed tomography (CBCT).

Methods

Twenty-three patients (30 implants) underwent sinus floor augmentation using the osteotome technique. Subjects underwent CBCT imaging before surgery, immediately after surgery, and at follow-up (≥ 3 years after surgery). We measured the changes in height of the augmented sinus floor (SL), the augmented bone above apex of the implant (BH), and the implant length that projected into the sinus (IL).

Results

The mean SL decreased from 6.54 ± 1.51 (immediately after surgery) to 3.11 ± 1.35 mm (follow-up). The mean BH decreased from 3.17 ± 0.97 to − 0.25 ± 1.19 mm; the maxillary sinus floor in many implants was near the apex at follow-up. The SL at follow-up showed a strong correlation with the IL (p = 0.0057).

Conclusions

Osteotome sinus floor elevation with beta-tricalcium phosphate was clinically effective. Cone-beam computed tomography analysis revealed that ≥ 3 years after surgery, the maxillary sinus floor was near the apex of the implant.

Risk Factors related to Late Failure of Dental Implant-A Systematic Review of Recent Studies

Resolving late failure of dental implant is difficult and costly; however, only few reviews have addressed the risk factors associated with late failure of dental implant. The aim of this literature review was to summarize the influences of different potential risk factors on the incidence of late dental implant failure. The protocol of this systematic review was prepared and implemented based on the PRISMA (Preferred reporting items for systematic reviews and meta-analyses) guideline. In December 2018, studies published within the previous 10 years on late dental implant failure were selected by fulfilling the eligibility criteria and the risk factors identified in qualified studies were extracted by using a predefined extraction template. Fourteen eligible studies were assessed. The common risk factors for late failure were divided into three groups according to whether they were related to (1) the patient history (radiation therapy, periodontitis, bruxism and early implant failure), (2) clinical parameters (posterior implant location and bone grade 4) or (3) decisions made by the clinician (low initial stability, more than one implant placed during surgery, inflammation at the surgical site during the first year or using an overdenture with conus-type connection). Clinicians should be cautions throughout the treatment process of dental implant-from the initial examination to the treatment planning, surgical operation and prosthesis selection-in order to minimize the risk of late failure of dental implant.

A 10 years retrospective study of assessment of prevalence and risk factors of dental implants failures

Aim:

The present study was conducted to determine the prevalence rate of dental implants failure and risk factors affecting dental implant outcome.

Materials and Methods:

The present retrospective study was conducted on 826 patients who received 1420 dental implants in both genders. Length of implant, diameter of implant, location of implant, and bone quality were recorded. Risk factors such as habit of smoking, history of diabetes, hypertension, etc., were recorded.

Results:

In 516 males, 832 dental implants and in 310 females, 588 dental implants were placed. Maximum dental implant failure was seen with length <10 mm (16%), with diameter <3.75 mm, and with type IV bone (20.6%). The difference found to be significant (P < 0.05). Maximum dental implant failures were seen with smoking (37%) followed by hypertension (20.8%), diabetes (20.3%), and CVDs (18.7%). Healthy patients had the lowest failure rate (4.37%).

Conclusion:

Dental implant failure was high in type IV bone, dental implant with <3.75 mm diameter, dental implant with length <10.0 mm, and among smokers.

UV-Photofunctionalization of Titanium Promotes Mechanical Anchorage in A Rat Osteoporosis Model

Effects of UV-photofunctionalization on bone-to-titanium integration under challenging systemic conditions remain unclear. We examined the behavior and response of osteoblasts from sham-operated and ovariectomized (OVX) rats on titanium surfaces with or without UV light pre-treatment and the strength of bone-implant integration. Osteoblasts from OVX rats showed significantly lower alkaline phosphatase, osteogenic gene expression, and mineralization activities than those from sham rats. Bone density variables in the spine were consistently lower in OVX rats. UV-treated titanium was superhydrophilic and the contact angle of ddH₂O was ≤5°. Titanium without UV treatment was hydrophobic with a contact angle of ≥80°. Initial attachment to titanium, proliferation, alkaline phosphatase activity, and gene expression were significantly increased on UV-treated titanium compared to that on control titanium in osteoblasts from sham and OVX rats. Osteoblastic functions compromised by OVX were elevated to levels equivalent to or higher than those of sham-operated osteoblasts following culture on UV-treated titanium. The strength of in vivo bone-implant integration for UV-treated titanium was 80% higher than that of control titanium in OVX rats and even higher than that of control implants in sham-operated rats. Thus, UV-photofunctionalization effectively enhanced bone-implant integration in OVX rats to overcome post-menopausal osteoporosis-like conditions.

Retrospective clinical analysis of risk factors associated with failed short implants

BACKGROUND

With advanced technology, short implants are more commonly used and have proven to have a relatively reliable curable efficacy. A consensus has not been reached regarding potential risk factors related to the loss of short implants.

PURPOSE

This large-sample retrospective study concentrated not only on patient characteristics and medical procedures but also on the features of implants in order to uncover the risk factors associated with short implants.

METHODS

Between 2014 and 2017, a total of 7001 implants were inserted at Nanjing Stomatological Hospital, Medical School of Nanjing University. Among the all, 1236 short implants were included after being evaluated according to the inclusion and exclusion criteria. In organizing the detailed information, seven variables including bone grafting procedure, age, gender, diameter of the implant, implant position, surface treatment, and definitive restorations were taken into consideration. The χ² test, Kaplan-Meier test, logistic regression, and multifactorial Cox regression analysis were employed to explore the risk factors.

RESULTS

The cumulative survival rate of short implants was 96.36%, slightly lower than that of the standard implants (98.16%, P < .001). Most of the short implants (84.44%) were lost at the early stage, mainly because of infection. Based on the results, male gender, implants treated by titanium anodizing and single-crown restoration increased the loss rate of short implants. Comparison of the short implants inserted into the maxillary and mandibular posterior area alone showed that the maxillary molar area was a risk factor for prognosis.

CONCLUSIONS

Male gender, TA surface treatment, and the presence of a single crown were associated with an increasing rate of short implants loss. Examination of the implant location focused on the posterior area revealed the maxillary posterior area to be a risk factor.

How old is old for implant therapy in terms of early implant losses?

OBJECTIVES

To assess, retrospectively, whether older age has an impact on implant osseointegration when compared with younger age.

METHODS

All patients ≥65 years old at implant installation, in an university setting over a time-period of 11.5 years, with complete anamnestic data and follow-up until prosthetic restoration were included, and any early implant loss (EIL; i.e. lack of osseointegration prior to or at the time-point of prosthetic restoration) was recorded. Further, one implant, from each of the elderly patients, was attempted matched to one implant in a younger patient (35 to <55 years old at implant installation) from the same clinic based on (a) gender, (b) implant region, (c) smoking status and (d) bone grafting prior to/simultaneously with implant installation. The potential impact of various local and systemic factors on EIL in the entire elderly population, and in the matched elderly and younger patient group was statistically assessed.

RESULTS

Four hundred forty-four patients ≥65 years old (range 65.1-91.3; 56.8% female) receiving 1,517 implants were identified; 10 patients had one EIL each (implant/patient level: 0.66/2.25%). Splitting this patient cohort additionally into four age groups [65-69.9 (n = 213), 70-74.9 (n = 111), 75-79.9 (n = 80) and ≥80 (n = 40)], EIL was on the implant level 0.41, 0.83, 0.34 and 2.26%, respectively, (p = .102) and on the patient level 1.41, 2.70, 1.25 and 7.50%, respectively, (p = .104); multilevel analysis showed weak evidence of association of increasing age with higher EIL rate (p = .090). Matching was possible in 347 cases, and 5 (1.44%) and 9 (2.59%) EIL in the elderly and younger patients, respectively, were observed (p = .280). EIL could not be associated with any systemic condition or medication intake.

CONCLUSIONS

Elderly patients ≥65 years old presented a similarly low EIL rate as younger patients 35 to <55 years old, while patients ≥80 years old may have a slight tendency for a higher EIL rate. Hence, ageing does not seem to compromise osseointegration, and if at all, then only slightly and at a later stage of life.

Descriptive retrospective study analyzing relevant factors related to dental implant failure

Background

The objective of this retrospective descriptive study was to analyze the characteristics of incident reports provided by dentists while using a specific brand of dental implants.

Material and Methods

The study was carried out in collaboration with Oxtein Iberia S.L.®, with the company providing access to the incident database in order to evaluate the characteristics of incidents from January 2014 to December 2017 (a total of 917 over four years). The data sheet recorded different variables during each of the stages of implant treatment, from initial implant placement to subsequent prosthetic rehabilitation. These variables included age, sex, systemic pathologies, smoking habits, bone quality, implant type, prosthesis type, and type of load applied, among others. SPSS Statistics was used to perform statistical analysis of the qualitative variables (univariate logistic regressions, χ2 test, Haberman's adjusted standardized residuals).

Results

The total study sample consisted of 44,415 implants shipped from Oxtein® warehouses on the dates indicated, of which 917 implants (2.1%) were flagged due to reports of lack of primary stability, failed osseointegration, or implant failure within one year of placement. When analyzing incident reports, it was observed that 61.6% of incidents occurred in male patients, compared to 38.4% in female patients. The average age of patients in the reported cases was 56.12 ± 12.15 years. A statistically significant correlation was discovered between incidents of implant failure and tobacco use, diabetes, heart disease, poor oral hygiene, previous infection, poor bone quality, and bruxism (p < 0.05). A (statistically significant) higher rate of incidents was also observed in tapered, internal connection, Grade IV titanium, narrow, and short implants.

Conclusions

Analysis of these implants reveals a higher rate of complication in short, tapered, internal connection and narrow-diameter implants. These data can help and encourage clinicians to use the utmost surgical precautions when placing these implants.

Key words:Pharmacovigilance, Dental implant, Dental implant failure.

Early implant failure: a retrospective analysis of contributing factors

Purpose

The aim of this retrospective study was to determine the prevalence of early implant failure using a single implant system and to identify the factors contributing to early implant failure.

Methods

Patients who received implant treatment with a single implant system (Luna^®, Shinhung, Seoul, Korea) at Dankook University Dental Hospital from 2015 to 2017 were enrolled. The following data were collected for analysis: sex and age of the patient, seniority of the surgeon, diameter and length of the implant, position in the dental arch, access approach for sinus-floor elevation, and type of guided bone regeneration (GBR) procedure. The effect of each predictor was evaluated using the crude hazard ratio and the adjusted hazard ratio (aHR) in univariate and multivariate Cox regression analyses, respectively.

Results

This study analyzed 1,031 implants in 409 patients, who comprised 169 females and 240 males with a median age of 54 years (interquartile range [IQR], 47–61 years) and were followed up for a median of 7.2 months (IQR, 5.6–9.9 months) after implant placement. Thirty-five implants were removed prior to final prosthesis delivery, and the cumulative survival rate in the early phase at the implant level was 95.6%. Multivariate regression analysis revealed that seniority of the surgeon (residents: aHR=2.86; 95% confidence interval [CI], 1.37–5.94) and the jaw in which the implant was placed (mandible: aHR=2.31; 95% CI, 1.12–4.76) exerted statistically significant effects on early implant failure after adjusting for sex, age, dimensions of the implant, and type of GBR procedure (preoperative and/or simultaneous) (P<0.05).

Conclusions

Prospective studies are warranted to further elucidate the factors contributing to early implant failure. In the meantime, surgeons should receive appropriate training and carefully select the bone bed in order to minimize the risk of early implant failure.

Factors affecting the early failure of implants placed in a dental practice with a specialization in implantology - a retrospective study

Background

To evaluate early failure and possible risk factors for failure of dental implants placed under practice-based conditions.

Methods

To clarify the research question, anonymized data from 106 patients with 186 dental implants were analyzed. The presence of sucessful healing (yes/no) at the time of incorporation of the final prosthesis was assessed. Mixed models were compiled for each target variable to enable estimation of the effects of patient-related and implant-related conditions on the risk of early implant failure.

Results

Nine out of 186 implants (4.8%) placed in 106 participants failed before incorporation of the final prosthesis. The use of shorter implants (< 10 mm) and the need for augmentation procedures were associated with a greater risk of early implant failure. For shorter implants, the risk was 5.8 times greater than that for longer implants (p = 0.0230). Use of augmentation procedures increased the risk by a factor of 5.5 (p = 0.0174).

Conclusions

Implants placed in the dental practice with a specialization in implantology heal successfully. The use of augmentation procedures and of implants shorter than 10 mm seems to be associated with a greater risk of early implant failure.

Influence of length, diameter and position of the implant in its fracture incidence: A Systematic Review

Background. Implant fractures can cause difficult problems for patients and dentists. This systematic review aimed to determine the influence of some implant parameters on the occurrence of their fracture and to determine the incidence of fractures reported in recent years.

Methods. A search was conducted in Pubmed database, from which 12 studies published in the last 12 years were selected.

Results. This review reported a 2% incidence of implant fracture. Most implants had been in function between 3 and 4 years until fracture. The studies did not provide necessary information to establish a relationship between the different parameters of implants and the incidence of fractures.

Conclusion. Thus, the indication of type, diameter and length of an implant and the bone quality in the region receiving it should be studied and accurately examined for each individual case in order to avoid future failures.

The Effect of Ultraviolet Photofunctionalization on a Titanium Dental Implant with Machined Surface: An In Vitro and In Vivo Study

Ultraviolet (UV) photofunctionalization has been suggested as an effective method to enhance the osseointegration of titanium surface. In this study, machined surface treated with UV light (M + UV) was compared to sandblasted, large-grit, acid-etched (SLA) surface through in vitro and in vivo studies. Groups of titanium specimens were defined as machined (M), SLA, and M + UV for the disc type, and M + UV and SLA for the implant. The discs and implants were assessed using scanning electron microscopy, confocal laser scanning microscopy, electron spectroscopy for chemical analysis, and the contact angle. Additionally, we evaluated the cell attachment, proliferation assay, and real-time polymerase chain reaction for the MC3T3-E1 cells. In a rabbit tibia model, the implants were examined to evaluate the bone-to-implant contact ratio and the bone area. In the M + UV group, we observed the lower amount of carbon, a 0°-degree contact angle, and enhanced osteogenic cell activities (p < 0.05). The histomorphometric analysis showed that a higher bone-to-implant contact ratio was found in the M + UV implant at 10 days (p < 0.05). In conclusion, the UV photofunctionalization of a Ti dental implant with M surface attained earlier osseointegration than SLA.

Effect of dental implant surface roughness in patients with a history of periodontal disease: a systematic review and meta-analysis

BACKGROUND

To review the literature on the effect of dental implant surface roughness in patients with a history of periodontal disease. The present review addresses the following focus question: Is there a difference for implant survival, mean marginal bone loss, and the incidence of bleeding on probing in periodontally compromised patients receiving a machined dental implant or rough surface dental implant?

METHODS

Electronic and manual literature searches were conducted on PubMed/MEDLINE and the Cochrane Library on studies published until May 2018 to collect information about the effect of machined, moderately rough, and rough dental implant surfaces in patients with a history of periodontal disease. The outcome variables implant survival, mean marginal bone level, and the incidence of peri-implantitis and bleeding on probing were evaluated. Meta-analysis was performed to obtain an accurate estimation of the overall, cumulative results.

RESULTS

Out of 2411 articles, six studies were included in this systematic review. The meta-analysis of the implant survival and implant mean marginal bone loss revealed a risk ratio of 2.92 (CI 95% 0.45, 18.86) for implant failure and a total mean difference of - 0.09 (CI 95% - 0.31, 0.14) for implant mean marginal bone loss measured in a total group of 215 implants, both not statistically significant.

CONCLUSIONS

Due to lack of long-term data (> 5 years), the heterogeneity and variability in study designs and lack of reporting on confounding factors, definitive conclusions on differences in implant survival, and mean marginal bone loss between machined and moderate rough implants in periodontally compromised patients cannot be drawn. Future well-designed long-term randomized controlled trials are necessary to reveal that machined surfaces are superior to moderately rough and rough surfaces in patients with a history of periodontal disease.

The role of bacterial biofilm and mechanical forces in modulating dental implant failures

Currently many assume that bacteria are the primary etiological factor associated with failure of titanium dental implants. However, emerging data indicates a possible role for mechanical forces in implant failure. This study is based on the hypothesis that the synergistic effect of mechanical forces and bacterial biofilm can lead to surface damage resulting in in vivo release of metallic particles. The primary aim of the study was to develop a dynamic fatigue test method for dental implants immersed in wet environments such as; (i) 0.01 M phosphate buffer saline (PBS); (ii) lactic acid (pH = 5); (iii) bacterial polyculture. Four dental implants each were subjected to fatigue loading from 45 N to 450 N at 4 Hz for 2 million cycles while immersed in (i) PBS (negative control); (ii) bacterial culture (test); and (iii) lactic acid (positive control). Post-testing, optical microscopy, x-ray photoelectron spectroscopy, and electrochemical corrosion tests were performed to evaluate the surface morphology, chemistry, and potential, respectively, of titanium implants. Post-testing, surface discoloration was evident in all three groups. However, the surface damage was further established in XPS analyses of test specimens, which showed that the interplay of bacterial biofilm and mechanical forces resulted in thinning of the TiO₂. Lower corrosion potential (Ecorr) of the test specimens compared to positive and negative controls also illustrated damage to the oxide layer. However, other electrochemical parameters such as linear polarization resistance (LPR) and corrosion rate (CR) were comparable among the groups indicating the corrosion resistance post-testing. The synergistic effect of cyclic occlusal loading and bacteria biofilm could negatively affect the surface of titanium dental implants.

Monte Carlo simulation of reasons for early failure of implants: effects of two risk factors

We have estimated the joint effects of two important risk factors on early failure of implants and then ranked all quoted risks by importance. We made a systematic search of published papers listed in PubMed, Web of Knowledge, Scopus, and Cochrane Central up to March 2018, and identified a total of 437 records. Eight studies met the inclusion criteria, in which seven significant risk factors for early failure were selected and used to build a conceptual simulation model. Selected risk factors were: "male sex", "smoking", "quality of bone", "short implants", "wide implants", "adjacent teeth", and "periodontitis". Based on these risk factors, all two-factor combinations that accounted for a total of 21 areas of greatest risk were created. We made a Monte Carlo simulation with 10 000 iterations and a sensitivity analysis to evaluate the estimates of these risks and to identify those that had the most influence on the model of early failure. The outcomes of the Monte Carlo simulation model showed that the SRS values of the combinations of these risks had different ranges of effects and probabilities of the early risk of failure. As a result, the most sensitive areas of greatest risk were "smoking and periodontitis", the second "short implants and periodontitis", and the third "smoking and short implants". The least sensitive combination of risks for early failure was "wide implants and male sex". This is to our knowledge the first study that has illustrated the contributions of various combinations of risk factors to early failure of implants. "Smoking and periodontitis" was thought to be associated with the greatest risk of early failure.

Association Between Early Implant Failure and Prosthodontic Characteristics

PURPOSE

To identify associations between early implant failure and prosthodontic characteristics that could be used to guide subsequent continuous quality improvement efforts of patient care.

MATERIALS AND METHODS

An implant-level analysis was performed in which data were abstracted from a prospective clinical database of all adult patients treated with implants and followed up from January 2000 through December 2014 at the Department of Dental Specialties at Mayo Clinic in Rochester, Minnesota. These data were used to determine time to implant failure. Associations between prosthodontic characteristics and early implant failure were evaluated with Cox proportional hazards regression models and summarized with hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Among 8762 implants in 2787 patients, 395 (4.5%) failed within the first year of placement at a mean (SD) of 127 (97) days (range, 2-364 days). Univariable analysis showed no associations between early implant failure and use of a cover screw, prosthesis, or definitive or provisional prosthesis at implant placement. Three of 25 single crowns failed, and use of a single crown was significantly associated with early implant failure (HR, 3.94; 95% CI, 1.08-14.35; P = 0.04). This study identified no significant associations between prosthodontic characteristics identified after implant placement and early implant failure.

CONCLUSIONS

Use of a prosthesis at implant placement, use of a definitive or provisional prosthesis, and early mechanical complications were not associated with increased risk of early implant failure. Quality improvement efforts should focus on aspects of decision making that aim to decrease surgical complications.