Factors associated with failure of surface-modified implants up to four years of function

A 10-year Retrospective Clinical Study to Identify Risk Indicators for Peri-Implant Bone Loss and Implant Failure

AIM

To evaluate long-term survival and success of dental implants and evaluate indicators affecting the long-term outcome.

MATERIALS AND METHODS

Implant survival, success and crestal bone loss (BL) over time were evaluated. For covariates at patient level, Kaplan-Meier estimates of implant survival were compared between groups with the log-rank test. Observed mean bone loss (MBL) was plotted as a function of time. Cumulative frequencies of BL were plotted for different post-op times. Uni- and multivariate analysis was performed. Simple linear mixed and multiple linear mixed models for BL at 1, 5 and 10 years were fitted.

RESULTS

407 patients (221 women, 186 men; mean age 64.86 years (range 28-92, SD 10.11)), with 1482 implants, responded. Absolute implant survival was 94.74%; MBL was 0.81 mm (SD 1.58, range 0.00-17.00) after an average follow-up of 10.66 years (range 10-14, SD 0.87). Implant survival was influenced on implant level by smoking, implant width and early bone loss (EBL) > 0.5 mm; on patient level by a history of periodontitis. Indicators influencing MBL after the 1st year were abutment height, type of surgery and implant width, while after 5 and 10 years of function were abutment height, EBL > 0.5 mm and smoking.

CONCLUSION

Implant survival was significantly affected by a history of periodontitis on patient level and by smoking, implant width and EBL > 0.5 mm on implant level. Late bone loss was significantly affected by abutment height, EBL > 0.5 mm and smoking.

TRIAL REGISTRATION

B670201524796.

Impact of Implant Surface and Smoking on Peri-Implant Human Bone: What we Learned from The Last 20 Years?

The present review summarizes the findings from human histological studies conducted over the past 20 years at the University of Guarulhos, Brazil, examining the impact of various implant surface topographies and smoking on peri-implant bone response. Seven different implant surfaces were evaluated in 90 partially or completely edentulous individuals using a total of 123 micro-implants. Histometric parameters, including bone-implant contact (BIC%), bone area within the threads (BA%), and bone density (BD), were assessed after an 8-week healing period. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were also performed. Results showed that treated surfaces, regardless of the treatment type, consistently demonstrated better histometric outcomes compared to machined surfaces. Anodized surfaces and those subjected to airborne particle abrasion, followed by acid etching, exhibited higher BIC% values than machined surfaces in smoker patients. Smoking reduced BIC% around anodized implants. The presence of inflammatory cells was observed adjacent to the peri-implant soft tissue on some treated surfaces. In conclusion, implant surface topography significantly influences early bone response under unloaded conditions, with treated surfaces promoting better human bone tissue response than machined surfaces. However, smoking negatively impacts peri-implant bone healing, emphasizing the importance of smoking cessation for optimal osseointegration.

Dental Implants Inserted in Fresh Extraction Sockets versus Healed Sites: A Systematic Review and Meta-Analysis

The present review aimed to evaluate the difference of dental implant failure rates and marginal bone loss (MBL) between implants inserted in fresh extraction sockets or healed sites. Electronic search was undertaken in three databases, plus manual search of journals, including studies randomized or not. Meta-analyses were performed besides meta-regressions, in order to verify how the odds ratio (OR) and MBL were associated with follow-up time. The review included 163 publications. Altogether, there were 17,278 and 38,738 implants placed in fresh extraction sockets and healed sites, respectively. Pairwise meta-analyses showed that implants in sockets had a higher failure risk in comparison to healed sites: OR 1.349, all studies included; OR 2.070, only prospective non-RCTs; OR 2.487, only RCTs (all p < 0.001). The difference in implant failure between the groups was statistically significant in the maxilla (OR 1.616, p = 0.029), but not in the mandible (OR 2.192, p = 0.075). The MBL mean difference (MD) between the groups was -0.053 mm (p = 0.089). There was an estimated decrease of 0.003 in OR (p = 0.284) and an increase of 0.006 mm (p = 0.036) in the MBL MD between groups for every additional month of follow-up. In conclusion, implants placed in fresh extraction sockets present higher risk of failure than implants placed in healed sites.

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.

The Effect of Age of Titanium Dental Implants on Implant Survival and Marginal Bone Resorption: A 5-Year Retrospective Follow-Up Study

It has been demonstrated that the osteoconductivity, hydrophilicity, and biological capacity of titanium decreases over time, and this phenomenon was described as the biological aging of titanium. The aim of this study was to evaluate whether the age of sand-blasted and acid-etched (SLA) titanium dental implants (duration from the production date until the date of dental implant surgery) affects marginal bone resorption and implant survival. This nonrandom convenience-sample retrospective pilot study was carried out in 200 implants of 64 patients. Radiographic measurements were performed on intraoral periapical radiographs. Implants were divided into 2 age groups; group 1 = 0-3 months and group 2 = 36-41 months. A P value < .05 was considered statistically significant. Of the implants, 41% (n = 82) were between 0 and 3 months old, and 59% (n = 118) were between 36 and 41 months old. All (n = 200) of the implants survived and maintained their function. The mean mesial marginal resorption measurement was 0.60 ± 0.65 mm, and the mean distal marginal resorption was 0.77 ± 1.07 mm. There was no statistically significant difference between the amount of mesial and distal marginal bone resorption according to implant age (P > .05). In SLA surface titanium implants with adequate initial primary stability and a 3-month osseointegration period before loading, biological aging of titanium did not affect implant survival and marginal bone resorption.

The effectiveness of immediate implant placement for single tooth replacement compared to delayed implant placement: A systematic review and meta-analysis

AIM

To compare immediate implant placement (IIP) to delayed single implant placement (DIP, ≥3 months post-extraction) in terms of implant survival (primary outcome), surgical, clinical, aesthetic, radiographic and patient-reported outcomes (secondary outcomes).

MATERIALS AND METHODS

Two reviewers independently performed an electronic search in PubMed, Web of Science, EMBASE and Cochrane and a hand search to identify eligible studies up to May 2018. Only randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP to DIP with at least 1 year of follow-up were selected for a qualitative analysis and meta-analysis.

RESULTS

The search identified 3 RCTs and 5 NRSs out of 2,589 titles providing data on 473 single implants (IIP: 233, DIP: 240) that had been in function between 12 and 96 months. One RCT showed unclear risk of bias, whereas all other studies demonstrated high risk. Meta-analysis showed significantly lower implant survival for IIP (94.9%) as compared to DIP (98.9%) (RR 0.96, 95% CI [0.93; 0.99], p = 0.02). All were early implant failures. A subgroup meta-analysis demonstrated a trend towards lower implant survival for IIP when postoperative antibiotics had not been administered (RR: 0.93, 95% CI [0.86; 1.00], p = 0.07). This was not observed among studies including the administration of postoperative antibiotics (RR: 0.98, 95% CI [0.94; 1.02], p = 0.35). Meta-analyses showed similar probing depth (WMD 0.43 mm, 95% CI [-0.47; 1.33], p = 0.35) and aesthetic outcomes as assessed by the pink aesthetic score (standardized WMD -0.03, 95% CI [-0.46; 0.39], p = 0.88) for IIP and DIP. Data on marginal bone loss were conflicting and highly biased. Soft tissue recession was underreported and available data were highly biased. Patient-reported outcomes were underreported, yet both IIP and DIP seemed well tolerated.

CONCLUSION

Immediate implant placement demonstrated higher risk for early implant loss than DIP. There is a need for RCTs comparing IIP to DIP with CBCT analyses at different time points and data on midfacial recession with the preoperative status as baseline. In these studies, the need for hard and soft tissue grafting should also be evaluated.

An 11-Year Retrospective Research Study of the Predictive Factors of Peri-Implantitis and Implant Failure: Analytic-Multicentric Study of 1279 Implants in Peru

Aim

To analyze the risk factors by logistic regression and perform the analysis of the survival rate of osseointegrated dental implants placed in public and private institutions.

Methods

An analytic-multicentric study was carried out, where 1279 dental implants that were placed by specialists from January 2006 to October 2017 in public and private institutions (UPCH-SI, HCFAP, CMNAVAL, UPCH-SM, and UPSJB) were evaluated. The variables sex (X1), location (X2), hypertension (X3), antibiotic prophylaxis (X4), diabetes (X5), osteoporosis (X6), bisphosphonates (X7), history of periodontitis (X8), hypercholesterolemia (X9), bone quality (X10), bone quantity (X11), design (X12), smoker (X13), connection (X14), edentulism type (X15), staging (X16), 3D guided surgery (X17), load (X18), bone graft (X19), peri-implantitis (X20), mucositis (X21), and GBR (X22) were collected and analyzed by the Kaplan–Meier survival analysis. The logit analysis was performed among all the variables to choose the best statistical model that explains the true risk factors. The analysis was performed by multivariate logistic regression and the Kaplan–Meier test, at a level of statistical significance of p < 0.05.

Results

It was found that the failure rate of the 1279 implants evaluated was 17.98% corresponding to only 23 implants lost as they have good longevity over time. When establishing the best multivariate logistic regression model, it was found that the variables that remained stable in relation to their statistically significant value and more stable confidence intervals were age, osteoporosis, bisphosphonates, history of periodontitis, bone quality, bone graft, connection, number of implants, GBR (guided bone regeneration), and follow-up.

Conclusions

Dental implants placed by specialists in public and private institutions had a failure rate similar to that in studies previously published in other countries.

A comparison of implant complications and failures between the maxilla and the mandible

STATEMENT OF PROBLEM

Identifying factors that affect the clinical outcomes of implant therapy is important.

PURPOSE

The purpose of this retrospective study was to determine whether implant location was a factor affecting the complication and failure rates of single-tooth implant-supported restorations in a predoctoral setting.

MATERIAL AND METHODS

The charts of 431 patients treated with a surgically placed dental implant and restored with a single crown in the predoctoral clinic were analyzed. Data on implant location, type of complication (surgical or prosthetic), and type of failure were collected and analyzed according to implant location using the Fisher Exact Test and Mantel-Haenszel Exact Chi Square Test analysis (α=.05).

RESULTS

The charts revealed 158 complications (68 surgical and 90 prosthetic) in 110 patients, and 3.9% of the implants failed. No statistically significant difference was found between the number of surgical complications or prosthetic complications in the maxilla and the mandible (P=.469).

CONCLUSIONS

Jaw location (maxilla compared with mandible) of the implant had no statistically significant impact on the incidence of surgically or prosthetically related complications. No statistically significant difference was found in overall implant failures, surgical failures, and prosthetic failures between maxillary and mandibular implants.

[Criterion assessment system of the actual level of expertise of dental professionals practicing implant dentistry]

The aim of the study was to develop criterion assessment system of the actual level of expertise of dental professionals practicing Implant dentistry. The study comprised fifteen dental experts aged from 35 to 47 years with the average 15 years clinical experience. For evaluation of the clinical portfolio of the dentists we developed 10 reference points and to ensure unification of the assessment approach we organised consensus methodical conference for our expert group. Scores were applied by parity of reasoning with point-rating system applied in continuing education programs of Medical University. Assessment of 43 clinical portfolios with short term and long term results of implant supported restorations was performed. Treatment was provided with the use of Nobel Biocare implants and prosthodontic rehabilitation was achieved with the use of CAD/CAM 'Procera' technology. The study showed that dentists who practice implant dentistry from 1 to 7 years have good manual skills and clinical expertise sufficient for achieving positive treatment outcome. At the same time in general their actual diagnostic skills are not sufficient, they misapply additional diagnostic methods, do not perform risk analysis of potential clinical complications that leads to shifting responsibilities on the patients in case of complications emergence. Methods of Computer Assisted Design are widely popular during all stages of rehabilitation (diagnostic, surgical stent, final prosthesis framework). Actual level of expertise of dental professionals doesn't depend on sex distribution. Males and females who practice implant dentistry have similar levels of clinical expertise.

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.

Postoperative Infections After Dental Implant Placement: Prevalence, Clinical Features, and Treatment

PURPOSE

To determine the prevalence and describe the clinical features and treatment of patients with early infections after implant placement.

MATERIALS AND METHODS

A retrospective cohort study was performed. Postoperative infections were defined as the presence of purulent drainage and/or increasing pain and swelling in the operated area before prosthetic loading. Patient-based infection prevalences and 95% confidence intervals for implant were determined. Patients who healed, were followed up to determine implant survival and success rates.

RESULTS

Three hundred thirty-seven participants (1273 implants) were included. Twenty-two postoperative infections were recorded (6.5% of the patients and 1.7% of the implants). These complications were usually diagnosed within the first month, and in 17 cases (77.3%) surgical treatment was performed because of antibiotic therapy failure. Twelve implants (54.6%) in 12 patients (54.6%) failed before prosthetic loading. The survival and success rates of the infected loaded implants were 80% and 50%, respectively, with a mean follow-up of 42.9 months (SD of 10.2 months).

CONCLUSION

Four to 10% of patients receiving dental implants develop postoperative infections. This complication is important because applied treatments are usually ineffective and two-thirds of the infected implants fail, most before prosthetic loading.

Learning Curve of a Minimally Invasive Technique for Transcrestal Sinus Floor Elevation: A Split-Group Analysis in a Prospective Case Series With Multiple Clinicians

AIMS

To assess the learning curve of a minimally invasive procedure for maxillary sinus floor elevation with a transcrestal approach (tSFE) and evaluate the influence of clinician's experience in implant surgery on its outcomes.

MATERIALS AND METHODS

Patients were treated by clinicians with different levels of experience in implant surgery and inexperienced with respect to the investigated tSFE technique. The initial (n = 13) and final (n = 13) groups treated by the expert clinician were compared for tSFE outcomes. Additionally, the high, moderate, and low groups (n = 20 each) treated by the expert, moderately experienced, and low experienced clinician, respectively, were compared.

RESULTS

(1) No significant differences in clinical and radiographic outcomes were observed between initial and final groups; (2) high, moderate, and low groups showed substantial vertical augmentation in limited operation time with treatment outcomes being influenced by the level of experience in implant surgery.

CONCLUSIONS

The investigated technique allows for a substantial vertical augmentation at limited operation times when used by different clinicians. The extent of sinus lift (as radiographically assessed) seems to be influenced by the clinician's level of experience in implant dentistry.

Association between tumor necrosis factor-alpha G-308A polymorphism and dental peri-implant disease risk: A meta-analysis

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is a potent immune-inflammatory mediator involved in the regulation of bone resorption. The single nucleotide polymorphism G-308A in the TNF-α gene increases the level of this cytokine. This phenomenon is also related to several diseases. Although the association between TNF-α (G-308A) polymorphism and dental peri-implant disease has been investigated, results have remained controversial. Hence, we performed this meta-analysis to provide a comprehensive and systematic conclusion on this topic.

METHODS

We performed a systematic literature search in PubMed, Embase, ISI Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure until July 2015. A fixed-effect model was established to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). The calculated values were then used to assess the strength of the association between the TNF-α (G-308A) polymorphism and the dental peri-implant disease risk. The heterogeneity between included studies was evaluated with Cochran Q and I statistics. Interstudy publication bias was investigated with a funnel plot.

RESULTS

Six eligible studies were included in this meta-analysis. The pooled ORs did not reveal a significant relationship between the TNF-α (G-308A) polymorphism and the disease susceptibility. Subgroup analyses in terms of ethnicity and disease type yielded similar results.

CONCLUSION

Our meta-analysis revealed that TNF-α (G-308A) polymorphism was not significantly associated with the risk of dental peri-implant disease. However, further studies with large sample sizes should be performed to verify these results.

Effect of Bisphosphonate and Age on Implant Failure as Determined by Patient-Reported Outcomes

The aim of the current study was to elucidate whether there is an association between selected risk factors and implant failure, as determined by patient-reported outcomes. A trained clinician administered a formal survey questionnaire to 415 patients who had received a total of 963 implants through the University of Kentucky College of Dentistry's implant training program. The questionnaire was designed to obtain information about potential risk factors that may affect implant failure. Patients were also asked to rate their satisfaction with the appearance and function of the implant, their surgical experience, and the levels of pain and mobility associated with the implant(s). Both patient-level and implant-level data were analyzed in this study. Multiple logistic regression analysis at the patient level indicated that the following variables did not contribute to the success or failure of the implants: sex, smoking status, diabetes, osteoporosis, and use of bisphosphonates. When the statistical analyses controlled for these variables, the odds of patient-reported implant failure increased with the patient's age (by 15% every 5 years). The results of implant-level analyses adjusted for smoking status, diabetes, and osteoporosis showed that the patient's age (odds of failure increased by 12% every 5 years) and no use of bisphosphonates (odds ratio, 9.22; 95% confidence interval, 1.849, 45.975) were significantly associated with poor implant outcome. Our findings suggest a possible association between implant failure and the patient's age and use of bisphosphonates.

Dental implants inserted in fresh extraction sockets versus healed sites: a systematic review and meta-analysis

OBJECTIVES

To test the null hypothesis of no difference in the implant failure rates, postoperative infection and marginal bone loss for the insertion of dental implants in fresh extraction sockets compared to the insertion in healed sites, against the alternative hypothesis of a difference.

DATA

Main search terms used in combination: dental implant, oral implant, resh extraction socket, immediate placement, immediate insertion, immediate implant.

SOURCES

An electronic search was undertaken in July/2014, in PubMed, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching.

STUDY SELECTION

Eligibility criteria included clinical human studies, either randomized or not.

CONCLUSIONS

The search strategy resulted in 73 publications, with 8,241 implants inserted in sockets (330 failures, 4.00%), and 19,410 in healed sites (599 failures, 3.09%). It is suggested that the insertion of implants in fresh extraction sockets affects the failure rates (RR 1.58, 95% CI 1.27-1.95, P<0.0001). The difference was not statistically significant when studies evaluating implants inserted in maxillae or in mandibles were pooled, or when the studies using implants to rehabilitate patients with full-arch prostheses were pooled; however, it was significant for the studies that rehabilitated patients with implant-supported single crowns and for the controlled studies. There was no apparent significant effect on the occurrence of postoperative infection or on the magnitude of marginal bone loss. The results should be interpreted with caution due to the potential for biases and to the presence of uncontrolled confounding factors in the included studies, most of them not randomized.

CLINICAL SIGNIFICANCE

The question whether immediate implants are more at risk for failure than implants placed in mature bone has received increasing attention in the last years. As the philosophies of treatment alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

Dental implants placed by undergraduate students: clinical outcomes and patients'/students' perceptions

INTRODUCTION

Implant dentistry in undergraduate education is predominantly theoretical or prosthetics oriented. Clinical experience with implant surgery could provide students a better understanding of alternatives for tooth replacements. This study describes an implant dentistry programme for undergraduate students, which included surgical placement of implants. The study presents the clinical outcomes of the programme, patients' satisfaction and students' attitudes/perceptions. It reflects on barriers and problems encountered during implementation and provides suggestions for other institutions.

MATERIALS AND METHODS

Thirty-six students placed one implant each for a single tooth replacement after careful radiographic assessment and pre-surgical planning. One-stage surgery was performed under one-to-one supervision. Crowns were cemented on individual abutments 3-6 months later. Crestal bone loss was assessed radiographically immediately after surgery, at crown placement and after 1 year of loading. Questionnaires were used to investigate patients' perspectives and students' opinions towards the programme, as well as their perceived level of competence.

RESULTS

Thirty-six implants were placed in 27 patients; two (5.6%) failed prior to loading; mean bone loss from time of surgery to crown placement was 1.41 mm and remained unchanged thereafter, reflecting implant success. Overall, patients were satisfied and the majority would repeat the treatment by a student. The students thought it was a valuable experience, although they realised that additional education is necessary to perform implant surgery without supervision.

CONCLUSION

Implant placement by undergraduate students resulted in acceptable clinical outcome parameters, patient satisfaction and positive student perceptions. These findings support the further development of clinical implant education in undergraduate dental curricula.

Contemporary undergraduate implant dentistry education: a systematic review

INTRODUCTION

Consensus reports recommend that students upon graduation should possess a significant level of knowledge and competence in implant dentistry, including basic competences in diagnostics, treatment planning, restorative, straightforward surgical and maintenance procedures. In response, undergraduate curricula need to integrate implant dentistry. This narrative review explores educational programmes in terms of competences, related research and barriers or reflections, regarding implementation in undergraduate curricula.

MATERIALS AND METHODS

Publications (2008-2013) were searched systematically in WoS, PubMed and ERIC and screened independently by two authors in four stages: removal of duplicates, title screening, abstract screening and full-text reading. Inclusion criteria encompassed implant dentistry in undergraduate education.

RESULTS

Finally, 37 of 420 papers were included. Detailed information regarding programme content, number of participants, staff input, logistics/funding issues is scattered. Theoretical education is predominant, and pre-clinical/clinical training is offered minimally, often carried out in elective programmes. However, selected straightforward cases treated by undergraduates yield positive outcomes with low failure rates, few complications, high patient satisfaction and student appreciation. Barriers to implementing implant dentistry in the undergraduate curriculum include funding issues, limitations in time or staff availability/competence and lack of suitable patients. Overcoming these barriers is worthwhile as experience-based implant education affects future practice as well-informed students propose more restorative alternatives to their patients.

CONCLUSION

Although implant dentistry is increasingly integrated in undergraduate curricula, challenges remain in developing strategies to implement existing competence profiles and the extent of experience-based education. To support further advancement, universities should report comprehensively on their implant programmes to allow comparison and reproduction in other environments.

A multifactorial analysis to identify predictors of implant failure and peri-implant bone loss

OBJECTIVE

To identify risk factors for failure and bone loss of implants in a large study sample on the basis of multivariate analyses.

MATERIALS AND METHODS

Patient files of all patients referred for implant treatment from November 2004 to December 2007 were scrutinized, and information on implant- and patient-related factors was collected. The study sample in this retrospective cohort study consisted of both partially dentate and fully edentulous patients referred for various indications. The only inclusion criterion was a follow-up of at least 2 years. Implant survival and bone loss were assessed by an external investigator (SV) comparing digital periapical radiographs taken during recall visits with the postoperative ones. Univariate and multivariate tests were adopted to identify possible risk indicators for implant failure and peri-implant bone loss.

RESULTS

Twenty-one of 1,320 (1.6%) implants were lost in 19 of 376 (5.1%) patients (210 female, 166 male; mean age 56, range 17-82) after a mean follow-up of 32 months (range 24-62). Based on multivariate analysis, only smoking (p = .001) and recall compliance (p = .010) had a significant influence on implant failure, with smokers more prone to failure. The overall mean bone loss was 0.36 mm (SD 0.68, range 0.00-7.10). Smoking (p = .001) and jaw of treatment (p = .001) affected peri-implant bone loss. More peri-implant bone loss was observed in smokers and in the maxilla. A clear discrepancy was found between univariate and multivariate analysis with regard to identification of risk factors.

CONCLUSION

Multivariate analysis demonstrated that implant-related factors did not affect the clinical outcome, but smoking was identified as a predictor for implant failure. Predictors for peri-implant bone loss were smoking and jaw of treatment.

Smoking, radiotherapy, diabetes and osteoporosis as risk factors for dental implant failure: a meta-analysis

BACKGROUND

There are conflicting reports as to the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure. We undertook a meta-analysis to evaluate the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure.

METHODS

A comprehensive research on MEDLINE and EMBASE, up to January 2013, was conducted to identify potential studies. References of relevant studies were also searched. Screening, data extraction and quality assessment were conducted independently and in duplicate. A random-effects meta-analysis was used to pool estimates of relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

A total of 51 studies were identified in this meta-analysis, with more than 40,000 dental implants placed under risk-threatening conditions. The pooled RRs showed a direct association between smoking (n = 33; RR = 1.92; 95% CI, 1.67-2.21) and radiotherapy (n = 16; RR = 2.28; 95% CI, 1.49-3.51) and the risk of dental implant failure, whereas no inverse impact of diabetes (n = 5; RR = 0.90; 95% CI, 0.62-1.32) on the risk of dental implant failure was found. The influence of osteoporosis on the risk of dental implant failure was direct but not significant (n = 4; RR = 1.09; 95% CI, 0.79-1.52). The subgroup analysis indicated no influence of study design, geographical location, length of follow-up, sample size, or mean age of recruited patients.

CONCLUSIONS

Smoking and radiotherapy were associated with an increased risk of dental implant failure. The relationship between diabetes and osteoporosis and the risk of implant failure warrant further study.