Marginal bone loss around dental implants: comparison between matched groups of bruxer and non-bruxer patients: A retrospective case-control study

The Effect of Patient-associated Factors on Long-term Survival of Dental Implants

Dental implant therapy has developed over the past half century to have documented successful outcomes in most patients who receive treatment. The long-term survival of dental implants depends upon a variety of factors including patient, surgeon, restorative dentist, and materials-related factors. The impact of patient-associated factors may impact significantly on the success of dental implants including diabetes mellitus, medications, smoking, parafunctional habits, oral hygiene, head and neck radiation, and the use of bisphosphonates, antiangiogenic, and antiresorptive medications.

Diagnostic methods/parameters to monitor peri-implant conditions

The diagnostic accuracy of clinical parameters, including visual inspection and probing to monitor peri-implant conditions, has been regarded with skepticism. Scientific evidence pointed out that primary diagnostic tools (chairside) seem to be highly specific, while their sensitivity is lower compared with their use in monitoring periodontal stability. Nonetheless, given the association between pocket depth at teeth and implant sites and the aerobic/anaerobic nature of the microbiome, it seems plausible for pocket probing depth to be indicative of disease progression or tissue stability. In addition, understanding the inflammatory nature of peri-implant diseases, it seems reasonable to advocate that bleeding, erythema, ulceration, and suppuration might be reliable indicators of pathology. Nevertheless, single spots of bleeding on probing may not reflect peri-implant disease, since implants are prone to exhibit bleeding related to probing force. On the other side, bleeding in smokers lacks sensitivity owing to the decreased angiogenic activity. Hence, the use of dichotomous scales on bleeding in the general population, in contrast to indices that feature profuseness and time after probing, might lead to false positive diagnoses. The definitive distinction between peri-implant mucositis and peri-implantitis, though, relies upon the radiographic evidence of progressive bone loss that can be assessed by means of two- and three-dimensional methods. Accordingly, the objective of this review is to evaluate the existing clinical and radiographic parameters/methods to monitor peri-implant conditions.

New Radiological Corticalization Index as an Indicator of Implant Success Rate Depending on Prosthetic Restoration-5 Years of Follow-Up

The new Radiological Corticalization Index (CI) is an indicator that describes bone remodeling near the dental implant's neck at the pixel level and is not visible to the naked eye. The aim of this research was to evaluate the correlation between the CI and bone remodeling using only radiographic (RTG) images. RTG samples were divided into groups depending on prosthetic restoration; the implant neck area around dental implants was examined, and texture features of the RTG images were analyzed. The study also investigated the type of prosthetic restoration and its influence as a factor on bone structure. The statistical analysis included evaluating feature distribution, comparing means (t-test) or medians (W-test), and performing a regression analysis and one-way analysis of variance or the Kruskal-Wallis test, as no normal distribution or between-group variance was indicated for the significant differences in the investigated groups. Differences or relationships were considered statistically significant at p < 0.05. The research revealed correlations between single crowns, overdenture restoration, bridge restoration, platform switching, prosthetic fracture, CI, and also marginal bone loss where p was lower than 0.05. However, the corticalization phenomenon itself has not yet been fully explored. The findings suggest that, depending on the type of prosthetic restoration, the corticalization index may correlate with marginal bone loss or not. Further research is necessary, as the index is suspected to not be homogeneous.

Addition of recombinant human bone morphogenic protein-2 to the graft materials improves the clinical outcomes of implants placed in grafted maxillary sinus

Background/purpose

The long-term outcomes of implants placed in grafted sinuses using recombinant human bone morphogenetic protein-2 (rhBMP-2) are unclear. This study aimed to compare 3- and 5-year implant survival rates and marginal bone loss (MBL) during functional loading.

Materials and methods

In this retrospective study, we analyzed 63 implants inserted after maxillary sinus floor augmentation (MSFA) in 45 patients between January 2016 and April 2019. The outcome variables were: 1) 3- and 5-year cumulative survival rates of the implants and 2) MBL after functional loading. Other assessed variables included patient demographic information, preoperative residual bone height (RBH), surgical site, implant length and diameter, graft material, healing period before loading, prosthetic type, and opposing dentition.

Results

The cumulative 3- and 5-year survival rates of the implants were 100% in the rhBMP-2 group and 95.5% and 86.4% in the non-rhBMP-2 group, respectively. The average 3- and 5-year MBL were 1.14 ± 0.67 mm, 1.30 ± 0.74 mm in the rhBMP-2 group and 1.68 ± 0.90 mm, 2.27 ± 1.29 mm in the non-rhBMP-2 group, respectively. Significant differences were observed between 3 and 5 years between the two groups.

Conclusion

Addition of the rhBMP-2 to the graft materials positively affects implant placement in the grafted maxillary sinus in terms of implant survival and MBL when preoperative RBH is unfavorable.

Hypertension and Dental Implants: A Systematic Review and Meta-Analysis

PURPOSE

The aim of the present systematic review was to investigate the influence of hypertension on the dental implant failure rate.

METHODS

An electronic search was undertaken in four databases, plus a manual search of journals. The I2 statistic was used to check heterogeneity and the inverse-variance method was used for the meta-analysis. The estimate of relative effect for dichotomous outcome was expressed as an odds ratio (OR).

RESULTS

The review included 24 publications. There were 4874 implants (257 failures) placed in hypertensive patients and 16,192 implants (809 failures) placed in normotensive patients. A pairwise meta-analysis showed that implants in hypertensive patients did not have a higher risk of failure than implants placed in normotensive patients (OR 1.100, p = 0.671). The log OR of implant failure between hypertensive and normotensive patients did not significantly change with the follow-up time (p = 0.824).

CONCLUSIONS

This review suggests that implants in hypertensive patients do not present higher odds of failure in comparison to normotensive patients. However, further research on this topic, with the use of more rigorous criteria to diagnose patients as being hypertensive, as well as clearer information about the pharmacological management of the condition in the patients, is recommended.

Bruxism and dental implants: A systematic review and meta-analysis

BACKGROUND

Overload from bruxism may affect survival of dental implants.

OBJECTIVES

To evaluate implant failure and marginal bone loss (MBL) in patients presenting with probable bruxism compared to non-bruxers. The study was registered in PROSPERO (CRD42021238397).

METHODS

An electronic search September 2022 in PubMed/Medline, Web of Science and Science Direct was combined with a hand search. Two independent reviewers carried out abstract screening, full-text assessment, quality assessment (National Institutes of Health tool) and data extraction. Only studies that provided information on self-report and clinical examination needed for the diagnosis of at least 'probable' bruxism were included. A pairwise random-effect meta-analysis was carried out.

RESULTS

In total 1338 studies were identified, and after screening and full-text assessment 27 studies that presented data on 2105 implants in probable bruxers and 10 264 implants in non-bruxers were included, with 138 and 352 implant failures in respective groups. the meta-analysis showed that implants placed in probable bruxers had a higher risk of failure than in non-bruxers (OR 2.189; 95% CI 1.337, 3.583, p = .002). A meta-regression showed that follow-up time did not affect this OR. Eighteen studies provided general data on MBL but did not report results separated between bruxers and non-bruxers. Therefore, an analysis of MBL was not possible.

CONCLUSION

The results of the present systematic review show that implants placed in probable bruxers present a significantly higher risk of failure than implants placed in non-bruxers. This should be considered in treatment planning and management of implant patients.

Difference in marginal bone loss around implants between short implant-supported partial fixed prostheses with and without cantilever: a retrospective clinical study

PURPOSE

To investigate the influence of cantilever prosthetic arm on the marginal bone loss (MBL) over time around dental implants supporting short fixed partial dentures (FPDs), in a record-based retrospective study.

METHODS

All cases of 3-unit implant-supported FPDs, supported by 2-3 implants, from the database of cases treated at one specialist clinic were considered for inclusion. Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built.

RESULTS

One-hundred-thirty-nine patients (64 men, 75 women) with 164 3-unit implant-supported FPDs (333 implants supporting non-cantilevered FPDs, 94 supporting cantilevered FPDs) were included in the study. The patients were followed up clinically and radiographically for a mean of 154.1 ± 78.0 (min-max, 37.3-364.6) and 132.9 ± 77.3 months (min-max, 36.8-329.9), respectively. The total number of marginal bone level double measurements (mesial and distal sides of each implant) was 2909. FPDs with cantilever presented an estimated greater MBL over time compared to FPDs without cantilever. Bruxism, sex (women), implant (modified) surface, and (poor) bone quality were also associated with higher MBL over time.

CONCLUSIONS

The use of a cantilever extension is suggested to negatively affect the bone marginal level over time around implants supporting 3-unit FPDs. Due to the small difference of the estimated MBL over long periods of follow-up between the groups, it is a matter of debate if the observed negative effect may be of clinical significance.

Risk Factors Associated with Failure and Technical Complications of Implant-Supported Single Crowns: A Retrospective Study

Background and Objectives: Implant-supported single crowns have become a routine approach for the replacement of missing single teeth, being considered as one of the most common ways of rehabilitation when adjacent teeth are healthy. The present retrospective study aimed to investigate the risk factors possibly associated with failure and technical complications of implant-supported single crowns and their supporting implants. Materials and Methods: Patients treated at one faculty (2009-2019) were considered for inclusion. Complications investigated included ceramic fracture/chipping, crown loss of retention/mobility, crown failure/fracture, loosening/loss/fracture of prosthetic screw, and implant failure/fracture. Any condition/situation that led to the removal/replacement of crowns (implant failure not included) was considered prosthesis failure. Univariate/multivariate Cox regression models were used to evaluate the associations between clinical covariates and failure. Results: 278 patients (358 crowns) were included. Mean ± SD follow-up was 56.5 ± 29.7 months. Seven implants (after a mean of 76.5 ± 43.7 months) and twenty crowns (21.3 ± 23.5 months) failed. The cumulative survival rate (CSR) for crowns was 93.5% after 5, remaining at 92.2% between 6 and 11 years. The most common reasons for crown failure were porcelain large fracture (n = 6), crown repeatedly loose (n = 6), and porcelain chipping (n = 5). Men and probable bruxism were identified in the Cox regression model as being associated with crown failure. The most common observed technical complications were mobility of the crown and chipping of the ceramic material, with the latter being observed even in crowns manufactured of monolithic zirconia. Cases with at least one technical complication (not considering loss of screw hole sealing) were more common among probable bruxers than in non-bruxers (p = 0.002). Cases of ceramic chipping were more common among bruxers than in non-bruxers (p = 0.014, log-rank test). Conclusions: Probable bruxism and patient's sex (men) were factors associated with a higher risk of failure of implant-supported single crowns.

Assessment of Various Risk Factors for Biological and Mechanical/Technical Complications in Fixed Implant Prosthetic Therapy: A Retrospective Study

The goals of this research were to determine the influence of several factors on implants' biological and technical complications in posterior fixed implant prosthetic therapy.

MATERIALS AND METHODS

The study group consisted of 67 edentulous patients (mean age: 63.88 ± 11.709 yrs; 20 males, 47 females) with implant prosthetic therapy for posterior edentulism. A total of 76 implant-supported fixed partial dentures (IP-FPDs) and 178 implants were assessed using clinical and paraclinical assessments. Risk factors for biological complications (peri-implantitis) and technical complications were determined by using the Pearson Chi-squared test and multivariate analysis.

RESULTS

The implant success (the absence of biological and mechanical/technical complications) was 66.30%. The prevalence of biological complications was 13.5%. The prevalence of technical complications was 28.70%. Variables that were associated with a higher risk of peri-implantitis were poor oral hygiene and bruxism. In univariate analysis, poor oral hygiene increased the risk of peri-implantitis 5.778 times and bruxism 5.875 times. Variables that were associated with a higher risk of mechanical/technical complications were age group > 60 yrs, smoking, history of periodontal disease, and bruxism. In univariate analysis, the risk of technical complications increased 4.14 times for patients in the age group > 60 years (vs. age group 40-60 years) and 20.5 times for patients with bruxism. Bruxism and smoking were significant predictors of mechanical/technical complications in the multivariate model.

CONCLUSIONS

In univariate models, patients with poor oral hygiene and bruxism have an increased risk of peri-implantitis. In multivariate models, we did not identify significant predictors of peri-implantitis. Age group > 60 yrs, smoking, history of periodontal disease, bone grafting, and bruxism are risk factors for the increase in the mechanical/technical complication rate. In the multivariate model, smoking and bruxism are significant predictors of the mechanical/technical complications.

Marginal bone loss around dental implants: comparison between diabetic and non-diabetic patients-a retrospective clinical study

OBJECTIVES

The aim of the present retrospective study was to compare the marginal bone loss (MBL) around dental implants in a group of diabetic patients in relation to a matched group of non-diabetic patients.

MATERIALS AND METHODS

The present dental record-based retrospective study included patients selected from individuals treated with dental implants at one specialist clinic in Malmö, Sweden. Patients were excluded if they had history of periodontitis and/or were treated for periodontal disease. The study group included 710 implants installed in 180 patients (mean age 60.3±13.0 years), 349 implants in 90 diabetic (21 T1DM and 69 T2DM patients), and 361 implants in 90 non-diabetic patients.

RESULTS

The results suggested that jaw (greater MBL in the maxilla), diabetes (greater MBL for diabetic patients, and worse for T1DM patients), bruxism (greater MBL for bruxers), and smoking (greater MBL for smokers and former smokers) had a statistically significant influence on MBL over time.

CONCLUSIONS

Patients with diabetes have an estimated greater MBL over time compared to non-diabetic patients. The difference was greater in patients with diabetes type 1 compared to patients with diabetes type 2. Bruxism, smoking, and implant location (maxilla) were also associated with a higher loss of marginal bone around implants over time.

CLINICAL RELEVANCE

Awareness of the possible influence of diabetes on the long-term outcomes of dental implant treatment is important, in order to be able to minimize the possibility of a high MBL with time, which can eventually lead to the loss of the implant.

Influence of Crown-Implant Ratio and Implant Inclination on Marginal Bone Loss around Dental Implants Supporting Single Crowns in the Posterior Region: A Retrospective Clinical Study

The aim of this present record-based retrospective study was to investigate the influence of the crown-implant ratio (CIR) and implant inclination in relation to the occlusal plane on the marginal bone loss (MBL) around dental implants supporting single crowns in the posterior region of the jaws. All the cases of implant-supported single crowns in the premolar and molar regions were initially considered for inclusion. Only implants not lost, with baseline radiographs taken within 12 months after implant placement and with a minimum of 36 months of radiological follow-up, were considered for the analysis of MBL. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built. After the exclusion of 49 cases, a total of 316 implant-supported single crowns in 234 patients were included. The results from the statistical models suggested that implant inclination and anatomical- and clinical CIR (the main related factors investigated in the study) were not statistically significantly related to MBL over time. Age (older people), tooth region (premolar), and bruxism (bruxers) had a statistically significant influence on MBL over time.

Frequency of Smoking and Marginal Bone Loss around Dental Implants: A Retrospective Matched-Control Study

This dental record-based retrospective study aimed to compare the marginal bone loss (MBL) around dental implants in a group of smokers in relation to a matched group of non-smokers, with a special focus on five different frequencies of daily smoking (non-smokers, and frequency of 1-5, 6-10, 11-15, and 20 cig./day). Only implants with a minimum of 36 months of radiological follow-up were considered. Univariate linear regression models were used to compare MBL over time between 12 clinical covariates, after which a linear mixed-effects model was built. After matching of the patients, the study included 340 implants in 104 smokers, and 337 implants in 100 non-smokers. The results suggested that smoking degree (greater MBL for higher degrees of smoking), bruxism (greater MBL for bruxers), jaw (greater MBL in maxilla), prosthesis fixation (greater MBL for screw-retained prosthesis), and implant diameter (greater MBL for 3.75-4.10 mm) had a significant influence on MBL over time. There appears to be a positive correlation between the degree of smoking and the degree of MBL, meaning, the higher the degree of smoking, the greater the MBL. However, the difference is not apparent for different degrees of smoking when this is high, namely above 10 cigarettes per day.