Implant survival and complications. The Third EAO consensus conference 2012

Outcomes of Dental Implants in Routine Clinical Practice: A Retrospective Multicenter Study

Purpose: This study evaluated the clinical and radiographic outcomes of subjects rehabilitated with dental implants placed in daily practice. Materials and Methods: This retrospective multicentric case series study involved 339 patients (168 males, 171 females, mean age 54.0 ± 14.7 (standard deviation) years, range 28-81 years) treated in five private clinics, who received 651 implants between January 2019 and January 2023. The main outcomes were marginal bone loss (MBL) and implant survival rate. The effect of variables such as soft tissue status, crestal/subcrestal implant placement, immediate/delayed implantation, bone grafting/no graft, screwed, or cemented prosthesis were analyzed. Results: The implant survival rate was 99.9%, with only one implant failure observed in a 71-year-old female with subcrestal placement. Implants immediately placed in post-extraction sites had significantly greater MBL compared to delayed placements (p=0.0002). Subcrestally positioned implants showed significantly less MBL than crestal implants (p < 0.0001), while grafted and non-grafted sites showed similar results, and cemented prostheses demonstrated lower MBL compared to screwed prostheses (p < 0.0001). The prevalence of peri-implant mucositis was only 3.6% on implant basis. No intra-operative complications nor adverse events in the follow-up period were reported. Conclusion: Following current guidelines for implant therapy, consisting of proper diagnosis and personalised treatment plan and maintenance, and adhering to implant system manufacturer's recommendations, it is possible to achieve satisfactory clinical and radiographic outcomes in routine practice.

The Relationship Between Peri-Implant Marginal Bone Loss and Resonance Frequency Analysis

Resonance frequency analysis (RFA) has been used as a diagnostic method to measure implant stability at all stages of healing. In addition to evaluating the status of the peri-implant marginal bone, it can also indicate the most appropriate time to load the implant. This in vitro study aimed to evaluate the efficacy of RFA as a diagnostic method for the detection of peri-implant marginal bone loss (MBL). Forty bone-level Klockner Vega implants were placed in a polyurethane block with elastic properties similar to those of the maxillary bone. The insertion torque and primary implant stability at the time of placement were measured using an RFA device. A circumferential peri-implant defect was created by removing the cortical bone portion in each implant using a trephine. The stability values were measured again using RFA. The stability values measured using RFA were lower after the creation of the circumferential peri-implant defect, indicating a statistically significant decrease in implant stability. The results of the study tend to show a relationship between peri-implant marginal bone loss and modifications in implant stability measured by RFA.

Impact of Implant Mesiodistal Distance on Peri-Implant Bone Loss: A Cross-Sectional Retrospective Study

PURPOSE

The purpose of this study was to verify the effect of our previously proposed mesiodistal distance for multiple posterior implants on preserving peri-implant bone, and to provide a measurable criterion for predicting implant prognosis.

METHODS

One hundred and two patients with dental implants placed in the posterior free-end edentulous arches were recruited in this cross-sectional study. Calibrated X-rays (peri-apical [PA] or bite-wing x-ray) were collected to measure the mesiodistal space as well as the corresponding bone resorption of implants after prosthesis placement. Implants were assigned to the test/control group according to whether their mesiodistal distance following our proposed algorithm. After adjusting covariates, logistic multivariate regression analyses were performed to examine the relationship between inter-implant distance and marginal bone loss (MBL) during each follow-up interval. The effect of smoking habits was also analyzed.

RESULTS

Every observation period exhibited great significance between experimental and control group on peri-implant bone level (p = 0.006, 0.005, 0.001, 0.025, 0.001, correspondingly) and the difference had a tendency to grow as time went by except 4-year (MD = -0.19, -0.39, -0.43, -0.30, -1.26, correspondingly). While no significant difference was observed between smokers and nonsmokers in the same group (p > 0.05).

CONCLUSION

The mesiodistal algorithm of 4-4.6 mm (implant to adjacent canine tooth), 7-7.4 mm, 8-8.5 mm, and 9-9.5 mm was proved to be effective for maintaining peri-implant bone level. It was also observed in our study that the impact of inter-implant distance outweighed that of smoking. This study provided clinicians predictable prognostic outcomes for implants and reference for deciding treatment plans.

Restorative option for hemisected root canal treated mandibular molar: two case reports

The success of hemisection is based on meticulous case selection, considering the quality and quantity of bone surrounding the remaining roots. Additionally, a well-devised prosthetic plan is crucial to direct forces along the preserved roots, and ongoing maintenance is imperative for long-term success. This case report aims to present two different restorative designs for the pontic on the edentulous space after the hemisection of a molar tooth. The treatment approach included initial root canal treatment, followed by periodontal intervention involving hemisection. The hemisected tooth was restored through a fixed partial denture, utilizing premolar, or molar as abutments. Hemisection is an excellent option for retaining the molar tooth in the mouth. The restorative option might be chosen between original molar anatomy or transformation into premolars. This must be in accordance with the patient's wishes as well.

Effectiveness of Implant Therapy in Patients With and Without a History of Periodontitis: A Systematic Review With Meta-Analysis of Prospective Cohort Studies

AIM

This systematic review investigates the effectiveness of implant therapy in patients with and without a history of periodontitis in terms of implant loss, peri-implant marginal bone loss (MBL), and occurrence of peri-implant diseases.

METHODS

The protocol of the present meta-analysis was registered on PROSPERO (CRD42021264980). An electronic search was conducted up to April 2024. All prospective cohort studies reporting implant loss, MBL, and occurrence of peri-implant diseases in both patients with a history of periodontitis (HP) and patients with no history of periodontitis (NHP) after at least 36-month follow-up were included. The risk of bias was evaluated using the Newcastle-Ottawa Scale and the quality of the evidence was also assessed. A meta-analysis was performed on the selected outcomes at the available follow-up time points. Subgroup analyses were conducted based on follow-up time, rate of progression and severity of periodontitis, and implant surface characteristics. Publication bias was evaluated using the Funnel plot and Egger's test.

RESULTS

From 13 761 initial records, 14 studies (17 articles) were finally included. Eight studies had a low risk of bias level, and six had a medium risk of bias level. Meta-analysis showed that HP patients had a significantly greater risk for implant loss (HR: 1.75; 95% CI: 1.28-2.40; p = 0.0005; I2 = 0%), MBL (MD: 0.41 mm; 95% CI 0.19, 0.63; p = 0.0002; I2 = 54%), and peri-implantitis (3.24; 95% CI: 1.58-6.64; p = 0.001; I2 = 57%) compared to NHP, whereas no significant intergroup difference for peri-implant mucositis was found. Subgroup analyses revealed a particularly greater risk for implant loss for HP patients over a ≥ 10-year follow-up (HR: 2.02; 95% CI: 1.06-3.85; p = 0.03; I2 = 0%) and for patients with a history of grade C (formerly aggressive) periodontitis (HR: 6.16; 95% CI: 2.53-15.01; p < 0.0001; I2 = 0%). A greater risk for implant loss for stages III-IV (severe) periodontitis, and implants with rough surfaces was also found.

CONCLUSIONS

Within the limits of heterogeneous case definitions and methods of assessment, a history of periodontitis has been proved to significantly increase the risk for implant loss, particularly at long follow-up (≥ 10 years) and in case of rapidly progressive forms (grade C), and for MBL and peri-implantitis.

Single missing molar with wide mesiodistal length restored using a single or double implant-supported crown: A self-controlled case report and 3D finite element analysis

PURPOSE

Based on a self-controlled case, this study evaluated the finite element analysis (FEA) results of a single missing molar with wide mesiodistal length (MDL) restored by a single or double implant-supported crown.

METHODS

A case of a missing bilateral mandibular first molar with wide MDL was restored using a single or double implant-supported crown. The implant survival and peri-implant bone were compared. FEA was conducted in coordination with the case using eight models with different MDLs (12, 13, 14, and 15 mm). Von Mises stress was calculated in the FEA to evaluate the biomechanical responses of the implants under increasing vertical and lateral loading, including the stress values of the implant, abutment, screw, crown, and cortical bone.

RESULTS

The restorations on the left and right sides supported by double implants have been used for 6 and 12 years, respectively, and so far have shown excellent osseointegration radiographically.The von Mises stress calculated in the FEA showed that when the MDL was >14 mm, both the bone and prosthetic components bore more stress in the single implant-supported strategy. The strength was 188.62-201.37 MPa and 201.85-215.9 MPa when the MDL was 14 mm and 15 mm, respectively, which significantly exceeded the allowable yield stress (180 MPa).

CONCLUSIONS

Compared with the single implant-supported crown, the double implant-supported crown reduced peri-implant bone stress and produced a more appropriate stress transfer model at the implant-bone interface when the MDL of the single missing molar was ≥14 mm.

Clinical Performance of 170 Frictional Morse Taper Implants: 2 Years Follow-Up

This study evaluated the clinical survival rates of 170 Morse taper implants through clinical and mechanical parameters in different therapeutic approaches such as single crowns, fixed partial prostheses, and fixed full-arch prostheses. Patients referred to the Center on Education and Research on Dental Implants from May 2017 to July 2018 with the indication for dental implant therapy, aged >18 years, without periodontal disease, recent evidence of inflammatory activity or other oral disorders, current pregnancy, uncontrolled diabetes mellitus or heavy smoking habit were included in this study. After 12 weeks of healing since the implants were placed in the mandible and after 16 weeks following implants placed in the maxilla, patients returned to the Center for prosthetic rehabilitation. After implant therapy, all patients underwent periodical, clinical, and prosthetic examinations every 6 months. Prosthetic restorations involved 109 fixed reconstructions in function. Few prosthetic complications were reported (6.55%). Twenty implants were rehabilitated with cemented prostheses; from those, 1 crown suffered a loss in retention/decementation. Of the 148 implants rehabilitated with screwed-retained prostheses, 6.76% suffered prosthetic screw loosening. The cumulative implant survival rate was 98.2%. When peri-implant tissue health was evaluated, the keratinized mucosa band appeared related to peri-implant tissue stability. Thus, Morse taper implants represented a successful procedure for implant rehabilitation, with a high cumulative implant survival rate, low prevalence of biological and prosthetic complications, and good stability of peri-implant tissues over the assessed period.

An introduction to dental implants

The use of implants to replace missing teeth is now commonplace and practised by clinicians worldwide in both general and specialist practice. There is an abundance of evidence on the general success of implant treatment. As well as reviewing the history of dental implants, this narrative review will discuss the merits and successful placement of tissue-level verses bone-level implants. Furthermore, the article will evaluate the concept and benefits of platform switching for implant treatment. Finally, with the increased placement of implants, this narrative paper will review how different titanium surfaces impact on the risk of peri-implantitis.

Maintenance of peri-implant health in general dental practice

The long-term maintenance or restoration of peri-implant tissues' health depends on the strategic implementation of preventive measures and interventions. These measures should be initiated before implant placement and continued throughout a patient's lifetime, as part of a tailored and comprehensive supportive peri-implant care (SPIC) programme. Central to the clinical efforts of maintaining and rehabilitating peri-implant tissues are several key factors, including the ongoing assessment and frequent monitoring of tissue health and stability, proactive oral health promotion, the control of risk factors and indicators and the provision of professional plaque biofilm removal. It is of paramount importance to underline that SPIC should not limit its scope exclusively to patients already in a state of peri-implant health; in fact, it is imperative that it should extend its protective effect to individuals who have been previously diagnosed and treated for peri-implant diseases, focusing on preventing its recurrence and progression, thereby avoiding further complications, such as implant loss.This narrative review presents an overview of the current literature on the maintenance of peri-implant tissues' health and the steps of SPIC providing insights into the critical factors to be considered when managing dental implant patients in the general dental practice.

Awareness of peri-implantitis among general dental practitioners in the UK: a questionnaire study

Introduction Dental implants are a predictable prosthetic option for replacement of missing teeth with good survival rates. Peri-implant diseases are the main reason for implant failure by causing bone loss around the implant leading to implant loss. General dental practitioners see patients with dental implants routinely and therefore, awareness of risk factors for peri-implant disease and early diagnosis is essential for appropriate management. The aim of this study is to assess the awareness of general dental practitioners in diagnosing peri-implantitis, with a view to identify any potential training needs.Design, setting, materials and methods A quantitative study method was designed using an online questionnaire sent to closed social media groups in the UK. The significance level was taken as p <0.05. The chi-squared tests and Kruskal-Wallis tests were used with IBM SPSS software. Descriptive statistical analysis of data was also done.Results and conclusion A total of 224 responses were received. The results show that there is lack of awareness of diagnostic criteria of peri-implantitis among general dental practitioners. However, majority of practitioners are aware of the legal implications of failing to diagnose this condition. There is a perceived need for more undergraduate training in diagnosing peri-implant diseases.

Load bearing capacity of 3-unit screw-retained implant-supported fixed dental prostheses with a mesial and distal cantilever on a single implant: A comparative in vitro study

OBJECTIVES

To assess the mechanical durability of monolithic zirconia implant-supported fixed dental prostheses (iFDP) design on one implant, with a distal and a mesial extension cantilever bonded to a titanium base compared to established designs on two implants.

MATERIALS AND METHODS

Roxolid Tissue level (TL), and tissue level x (TLX) implants were used to manufacture screw-retained 3-unit iFDPs (n = 60, n = 10 per group), with following configurations (X: Cantilever; I: Implant, T: Test group, C: Control group): T1: X-I-X (TL); T2: X-I-X (TLX); T3: I-I-X (TL); T4: I-I-X (TLX); C1: I-X-I (TL); C2: I-X-I (TLX). The iFDPs were thermomechanically aged and subsequently loaded until fracture using a universal testing machine. The failure load at first crack (Finitial) and at catastrophic fracture (Fmax) were measured and statistical evaluation was performed using two-way ANOVA and Tukey's post-hoc tests.

RESULTS

The mean values ranged between 190 ± 73 and 510 ± 459 N for Finitial groups, and between 468 ± 76 and 1579 ± 249 N for Fmax, respectively. Regarding Finitial, neither the implant type, nor the iFDP configuration significantly influenced measured failure loads (all p > 0.05). The choice of implant type did not show any significant effect (p > 0.05), while reconstruction design significantly affected Fmax data (I-I-Xa < X-I-Xb < I-X-Ic) (p < 0.05). The mesial and distal extension groups (X-I-X) showed fractures only at the cantilever extension site, while the distal extension group (I-I-X) showed one abutment and one connector fracture at the implant/reconstruction interface.

CONCLUSION

Results suggest that iFDPs with I-X-I design can be recommended regardless of tested implant type followed by the mesial and distal extension design on one implant abutment (X-I-X).

Evaluation of safety and efficacy of locally developed dental implants: A noninferiority randomized controlled trial

STATEMENT OF PROBLEM

Various dental implants are available in India, but imported devices are expensive; an affordable locally produced dental implant system would be beneficial.

PURPOSE

The purpose of this noninferiority randomized controlled trial was to compare the safety and efficacy of a locally developed dental implant system to those of an established imported dental implant system with similar microsurface characteristics.

MATERIAL AND METHODS

A total of 136 participants with 201 partially edentulous sites, aged 18 to 65 years, were enrolled in the trial, with 134 sites receiving test implants and 67 sites control implants (n ratio, 2:1). The implants received a delayed submerged healing protocol and were loaded 3 to 6 months after surgery. Maximum insertion torque (IT) was recorded during the implant surgery, and the implant stability quotient (ISQ) was evaluated on the day of surgery and at the second-stage procedure. The mean crestal bone loss (MCBL) was measured on periapical radiographs at prosthetic placement (baseline) and at 6 months and 12 months after loading. The primary measure of outcome was the implant survival rate, and the secondary measure of evaluation was the intergroup difference in MCBL at baseline, 6 months, and 12 months.

RESULTS

A total of 127 test and 61 control implant sites were available for follow-up 1 year after prosthesis placement. At the end of 12 months, the test and control implant groups demonstrated a survival rate of 97% and 100%, respectively. The MCBL difference was significant between the 2 groups at baseline (P<.05). However, at 6 and 12 months, the difference between the test and control groups was not significantly different (P>.05).

CONCLUSIONS

The survival rate of the test group fell within the previously assumed 10% noninferiority margin. Therefore, the null hypothesis was accepted for the trial, and the locally developed implants were noninferior to the imported implants at a sample allocation ratio of 2:1.

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.

GL13K-modified titanium regulates osteogenic differentiation via the NF-κB pathway

The osteoimmune response plays a crucial regulatory role in the osseointegration of dental implants. Previous studies found the antimicrobial peptide coating (GL13K) could activate the immunomodulatory potential of macrophages (Raw 264.7) and promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). To further investigate the mechanism of interaction between immunomodulation and differentiation, a co-culture model of the representative cells (Raw 264.7 and BMSCs) was constructed to mimic the immune microenvironment. In this system, GL13K coating of titanium implant effectively inhibited the polarization of the inflammatory M1 type and promoted the polarization of the anti-inflammatory M2 type. Furthermore, the inhibited NF-κB signaling pathway and Mip-2 gene expression were found and validated by bioinformatics analysis and virus-induced gene silencing, which significantly affected the tissue repair process. It can be concluded that the GL13K coating had the potential to establish a localized immune microenvironment conducive to osteogenic differentiation through cellular interactions. Subsequent investigations would be dedicated to a thorough examination of the osseointegration effects of GL13K coating.

Advancements in artificial intelligence algorithms for dental implant identification: A systematic review with meta-analysis

STATEMENT OF PROBLEM

The evidence regarding the application of artificial intelligence (AI) in identifying dental implant systems is currently inconclusive. The available studies present varying results and methodologies, making it difficult to draw definitive conclusions.

PURPOSE

The purpose of this systematic review with meta-analysis was to comprehensively analyze and evaluate articles that investigate the application of AI in identifying and classifying dental implant systems.

MATERIAL AND METHODS

An electronic systematic review was conducted across 3 databases: MEDLINE/PubMed, Cochrane, and Scopus. Additionally, a manual search was performed. The inclusion criteria consisted of peer-reviewed studies investigating the accuracy of AI-based diagnostic tools on dental radiographs for identifying and classifying dental implant systems and comparing the results with those obtained by expert judges using manual techniques-the search strategy encompassed articles published until September 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess the quality of included articles.

RESULTS

Twenty-two eligible articles were included in this review. These articles described the use of AI in detecting dental implants through conventional radiographs. The pooled data showed that dental implant identification had an overall accuracy of 92.56% (range 90.49% to 94.63%). Eleven studies showed a low risk of bias, 6 demonstrated some concern risk, and 5 showed a high risk of bias.

CONCLUSIONS

AI models using panoramic and periapical radiographs can accurately identify and categorize dental implant systems. However, additional well-conducted research is recommended to identify the most common implant systems.

Survival and success of zirconia compared with titanium implants: a systematic review and meta-analysis

OBJECTIVE

This systematic review assessed the available evidence on the survival and success rate of zirconia and titanium implants. As secondary outcomes, aesthetic, radiographic and clinical parameters, as well as biological and mechanical complications, were considered.

MATERIALS AND METHODS

A systematic search was performed up to March 2022 to identify CCTs/RCTs comparing zirconia and titanium implants with a minimum of 12 months of follow-up. Meta-analysis was performed when ≥ 2 articles with similar characteristics were retrieved.

RESULTS

Four published articles with two RCTs (2 different patient populations) with 100 zirconia and 99 titanium implants that were followed up over 12-80 months were selected out of the 6040 articles. A non-statistically significant difference between zirconia and titanium implant survival at 12 months was suggested (P = 0.0938). The success rates were 57.5-93.3% and 57.1-100% for zirconia and titanium implants, respectively. The pink aesthetic score (PES) was higher for zirconia (10.33 ± 2.06 to 11.38 ± 0.92) compared to titanium implants (8.14 ± 3.58 to 11.56 ± 1.0).

CONCLUSION

Based on the 2 RCTs retrieved in the literature, similar survival rates were reported for zirconia and titanium implants in the short term (12 months of follow-up). Future RCTs are warranted to evaluate the long-term outcomes of zirconia implants.

CLINICAL RELEVANCE

Zirconia implants may be the procedure of choice, particularly in the aesthetic zone, since they show a similar survival and success rate as titanium implants on a short-term follow-up.

TRIAL REGISTRATION

Systematic review registration number-CRD42021288704 (PROSPERO).

Deep learning and clustering approaches for dental implant size classification based on periapical radiographs

This study investigated two artificial intelligence (AI) methods for automatically classifying dental implant diameter and length based on periapical radiographs. The first method, deep learning (DL), involved utilizing the pre-trained VGG16 model and adjusting the fine-tuning degree to analyze image data obtained from periapical radiographs. The second method, clustering analysis, was accomplished by analyzing the implant-specific feature vector derived from three key points coordinates of the dental implant using the k-means++ algorithm and adjusting the weight of the feature vector. DL and clustering model classified dental implant size into nine groups. The performance metrics of AI models were accuracy, sensitivity, specificity, F1-score, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC-ROC). The final DL model yielded performances above 0.994, 0.950, 0.994, 0.974, 0.952, 0.994, and 0.975, respectively, and the final clustering model yielded performances above 0.983, 0.900, 0.988, 0.923, 0.909, 0.988, and 0.947, respectively. When comparing the AI model before tuning and the final AI model, statistically significant performance improvements were observed in six out of nine groups for DL models and four out of nine groups for clustering models based on AUC-ROC. Two AI models showed reliable classification performances. For clinical applications, AI models require validation on various multicenter data.

Comparison of external, internal flat-to-flat, and conical implant abutment connections for implant-supported prostheses: A systematic review and network meta-analysis of randomized clinical trials

STATEMENT OF PROBLEM

The implant abutment connection interface has been considered one of the major factors affecting the outcome of implant therapy. However, drawbacks of traditional meta-analyses are the inability to compare more than 2 treatments at a time, which complicates the decision-making process for dental clinicians, and the lack of a network meta-analysis.

PURPOSE

The purpose of this network meta-analysis was to assess whether the implant abutment connection influences the outcome of implant-supported prostheses.

MATERIAL AND METHODS

An electronic search was undertaken to identify all randomized clinical trials comparing the effect of at least 2 different implant abutment connection designs published from 2009 up to May 2020. Outcome variables were implant survival rate, peri-implant marginal bone loss, and biologic and prosthetic complication rates at 12 months after prosthetic loading. Relevant information was extracted, and quality and risk of bias assessed. Pairwise meta-analyses and network meta-analyses based on a multivariate random-effects meta-regression were performed to assess the comparisons (α=.05 for all analyses).

RESULTS

For peri-implant marginal bone loss and prosthetic complications, conical interfaces were determined to be the most effective, with significant differences when compared with external hexagonal connections (P=.011 and P=.038, respectively). No significant differences were found among the implant abutment connections in terms of survival and biologic complications (P>.05 in all direct, indirect, and mixed comparisons).

CONCLUSIONS

After 1 year of loading, conical connections showed lower marginal bone loss and fewer prosthetic complications than external hexagonal connections. However, the implant abutment connection design had no influence on the implant survival and biologic complication rates.

In vitro fatigue and fracture testing of temporary materials from different manufacturing processes in implant-supported anterior crowns

OBJECTIVES

The aim of this study was to investigate the in vitro fatigue and fracture force of temporary implant-supported anterior crowns made of different materials with different abutment total occlusal convergence (TOC), with/without a screw channel, and with different types of fabrication.

MATERIALS AND METHODS

One hundred ninety-two implant-supported crowns were manufactured (4° or 8° TOC; with/without screw channel) form 6 materials (n = 8; 2 × additive, 3 × subtractive, 1 × automix; reference). Crowns were temporarily cemented, screw channels were closed (polytetrafluoroethylene, resin composite), and crowns were stored in water (37 °C; 10 days) before thermal cycling and mechanical loading (TCML). Fracture force was determined.

STATISTICS

Kolmogorov-Smirnov, ANOVA; Bonferroni; Kaplan-Meier; log-rank; α = 0.05.

RESULTS

Failure during TCML varied between 0 failures and total failure. Mean survival was between 1.8 × 105 and 4.8 × 105 cycles. The highest impact on survival presented the material (η2 = 0.072, p < .001). Fracture forces varied between 265.7 and 628.6 N. The highest impact on force was found for the material (η2 = 0.084, p < .001).

CONCLUSION

Additively and subtractively manufactured crowns provided similar or higher survival rates and fracture forces compared to automix crowns. The choice of material is decisive for the survival and fracture force. The fabrication is not crucial. A smaller TOC led to higher fracture force. Manually inserted screw channels had negative effects on fatigue testing.

CLINICAL RELEVANCE

The highest stability has been shown for crowns with a low TOC, which are manufactured additively and subtractively. In automix-fabricated crowns, manually inserted screw channels have negative effects.

Evaluation of the Photoactivation Effect of 3% Hydrogen Peroxide in the Disinfection of Dental Implants: In Vitro Study

Photoactivation of 3% hydrogen peroxide with a 445 nm diode laser represents a relatively new, insufficiently researched antimicrobial method in the treatment of peri-implantitis. The purpose of this work is to evaluate the effect of photoactivation of 3% hydrogen peroxide with a 445 nm diode laser, and to compare the obtained results with 0.2% chlorhexidine treatment and 3% hydrogen peroxide treatment without photoactivation, in vitro, on the surface of dental implants contaminated with S. aureus and C. albicans biofilms. Previously, 80 infected titanium implants with S. aureus and C. albicans cultures were divided into four groups: G1-negative control (no treatment), G2-positive control (0.2% chlorhexidine), G3 (3% hydrogen peroxide), and G4 (photoactivated 3% hydrogen peroxide). The number of viable microbes in each sample was determined by the colony forming unit (CFU) count. The results were statistically processed and analyzed, showing a statistically significant difference across all groups compared to the negative control (G1), and the absence of a statistically significant difference between groups G1-G3. The new antimicrobial treatment, according to the results, could be worthy of further analysis and research.

Automated deep learning for classification of dental implant radiographs using a large multi-center dataset

This study aimed to evaluate the accuracy of automated deep learning (DL) algorithm for identifying and classifying various types of dental implant systems (DIS) using a large-scale multicenter dataset. Dental implant radiographs of pos-implant surgery were collected from five college dental hospitals and 10 private dental clinics, and validated by the National Information Society Agency and the Korean Academy of Oral and Maxillofacial Implantology. The dataset contained a total of 156,965 panoramic and periapical radiographic images and comprised 10 manufacturers and 27 different types of DIS. The accuracy, precision, recall, F1 score, and confusion matrix were calculated to evaluate the classification performance of the automated DL algorithm. The performance metrics of the automated DL based on accuracy, precision, recall, and F1 score for 116,756 panoramic and 40,209 periapical radiographic images were 88.53%, 85.70%, 82.30%, and 84.00%, respectively. Using only panoramic images, the DL algorithm achieved 87.89% accuracy, 85.20% precision, 81.10% recall, and 83.10% F1 score, whereas the corresponding values using only periapical images achieved 86.87% accuracy, 84.40% precision, 81.70% recall, and 83.00% F1 score, respectively. Within the study limitations, automated DL shows a reliable classification accuracy based on large-scale and comprehensive datasets. Moreover, we observed no statistically significant difference in accuracy performance between the panoramic and periapical images. The clinical feasibility of the automated DL algorithm requires further confirmation using additional clinical datasets.

The Incidence of Retrograde Peri-Implantitis in a Single University Dental Hospital Training Center: A Retrospective Analysis

Background and objective: Retrograde peri-implantitis (RPI) is a periapical radiolucent lesion developed around the implant apex. This study aimed to investigate the Incidence of RPI in a single university dental hospital training center. Materials and Methods: All records of patients who received single Implants between 2016-2020 were screened. For cases that met inclusion criteria, clinical and radiographic data were analyzed. Results: A total of 215 were included and categorized as follows, Category A: implants were placed next to endodontically treated teeth (n = 58, 27%); category B, implants placed at the sites with previous endodontic involvement within 6 months of tooth extraction (n = 25, 11.6%); Category AB: implants placed at sites that fulfill the criteria of groups A and B (n = 18, 8.4%); and Category C: Implants that were placed next to vital teeth and at a site with no previous endodontic treatment or a site that was allowed to heal for more than six (n = 114, 53%). Categories A, B and AB served as the endodontically involved (EI) group, while category C served as non- endodontically involved (NEI) group. Only two sites (0.9%) were confirmed as RPI, both from group A (3.4%). Comparing all groups studied showed no statistically significant difference in RPI incidence. Conclusions: The incidence of RPI is low; however, endodontically treated teeth with periapical lesions (PALs) next to an implant site could contribute to RPI.

Use of bioinformatic strategies as a predictive tool in implant-supported oral rehabilitation: A scoping review

STATEMENT OF PROBLEM

The use of bioinformatic strategies is growing in dental implant protocols. The current expansion of Omics sciences and artificial intelligence (AI) algorithms in implant dentistry applications have not been documented and analyzed as a predictive tool for the success of dental implants.

PURPOSE

The purpose of this scoping review was to analyze how artificial intelligence algorithms and Omics technologies are being applied in the field of oral implantology as a predictive tool for dental implant success.

MATERIAL AND METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist was followed. A search strategy was created at PubMed and Web of Science to answer the question "How is bioinformatics being applied in the area of oral implantology as a predictive tool for implant success?"

RESULTS

Thirteen articles were included in this review. Only 3 applied bioinformatic models combining AI algorithms and Omics technologies. These studies highlighted 2 key points for the creation of precision medicine: deep population phenotyping and the integration of Omics sciences in clinical protocols. Most of the studies identified applied AI only in the identification and classification of implant systems, quantification of peri-implant bone loss, and 3-dimensional bone analysis, planning implant placement.

CONCLUSIONS

The conventional criteria currently used as a technique for the diagnosis and monitoring of dental implants are insufficient and have low accuracy. Models that apply AI algorithms combined with precision methodologies-biomarkers-are extremely useful in the creation of precision medicine, allowing medical dentists to forecast the success of the implant. Tools that integrate the different types of data, including imaging, molecular, risk factor, and implant characteristics, are needed to make a more accurate and personalized prediction of implant success.

The efficacy of bone reconstructive therapies in the management of peri-implantitis. A systematic review and meta-analysis

AIM

To evaluate the efficacy of bone reconstructive procedures for the reduction of probing pocket depth (PPD), bleeding on probing (BOP), and suppuration in peri-implantitis-related bone defects at ≥12-month follow-up.

MATERIALS AND METHODS

Three databases were searched for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared bone reconstructive therapies to access flap surgery (AFS) (Focused Question-FQ 1), and RCTs, CCTs, and prospective case series that assessed the efficacy of reconstructive therapies (FQ 2). Meta-analysis was performed for FQ1 when more than three studies were identified, while for FQ2 a network was drawn based on RCTs with common treatment arms.

RESULTS

Seven RCTs were identified for FQ1 while five RCTs and six prospective case series for FQ2. There was no significant difference in PPD change between AFS and reconstructive surgery (-0.387; p = .325) at 12 months. Furthermore, no clear differences in terms of PPD and BOP changes resulted from the different reconstructive therapies included in the network. Only a small percentage of treated cases with any modality achieved peri-implantitis resolution, as defined by different composite outcomes.

CONCLUSIONS

Reconstructive surgery does not offer significant improvements in peri-implant clinical parameters as compared to AFS at 12 months. It was not possible to establish a hierarchy of efficacy among the different biomaterials employed for reconstructive surgery.

Does Bruxism Affect Marginal Bone Level around Single Tooth Implants in the Posterior Mandible?

Background

Parafunctional forces are a potential risk factor for implant-related complications. This study aimed to evaluate the possible relationship of bruxism with implant-related complications and marginal bone loss (MBL).

Methods

In this prospective cohort study, patients were divided into two groups with and without bruxism, and received single-tooth implants in the posterior mandible. Patients in the bruxer group were requested to use a customized fabricated night guard. Bone quality was also assessed based on CBCT scans. The MBL, crown detachment, and porcelain fracture were evaluated, and clinical assessments were made at the 12-month follow-up.

Results

Seventy patients were studied in two groups (n = 35 in each group). None of the implants in any of the two groups showed pain, sensitivity, suppuration, exudation, clinically detectable mobility, or peri-implant radiolucency. No significant difference was observed between the two groups in the mean MBL at the 12-month follow-up (p =  0.60). Regarding bone quality, there was no significant difference in the mean MBL among different types of bone qualities (p = 0.66). There were no significant differences regarding crown detachment and porcelain fracture between the two groups either (p =  0.32 and p =  0.30, respectively).

Conclusion

According to the results of this study, dental implant treatment according to the suggested protocol in bruxers yielded promising outcomes.

What is the prevalence of peri-implantitis? A systematic review and meta-analysis

Background

Peri-implantitis is a usual finding but estimates of its prevalence fluctuate very much. This may be due to the wide variety of disease definitions. This systematic review aims to estimate the overall prevalence of peri-implantitis and the effect of different study designs, function times and use of probing depth on prevalence rate.

Methods

Following electronic and manual searches of the literature published from January 2005 to December 2021, data were extracted from the studies fitting the study criteria. Fifty-seven articles were included in this study.

Results

Prevalence of peri-implantitis was 19.53% (95% CI 12.87–26.19) at the patient-level, and 12.53% (95% CI 11.67–13.39) at the implant-level and it remains highly variable even following restriction to the clinical case definition. The use of probing depth like diagnostic criteria affected the prevalence data.

Conclusion

The results indicate that it remains essential the identification of the diagnostic markers for more accurate disease classification.

Abutment mechanical complications of a Morse taper connection implant system: A 1- to 9-year retrospective study

BACKGROUND

The fracture of a Morse tapered abutment connection in an osseointegrated implant is one of the most serious mechanical complications, and it is extremely hard to deal with this complication in clinical practice.

PURPOSE

The aim of this study was to explore the cumulative mechanical complications focus on abutment of a platform switching Morse taper connection implant system after loading, and to perform a retrospective, approximately 1- to 9-year follow-up study to identify the predisposing factors.

MATERIALS AND METHODS

A total of 495 patients with 945 fitted implants were enrolled in this study with a follow-up from January 2012 to January 2020. The data of mechanical complications of the abutment, including abutment fracture (AF) and abutment screw loosening (ASL), and possible causative factors were extracted and evaluated statistically.

RESULTS

A total of 25 out of 945 (2.65%) cumulative abutment mechanical complications occurred. AF was the most common complication (n = 13, 1.38%), followed by ASL (n = 12, 1.27%). For AF, gender, type of prosthesis, abutment design, and implant diameter were identified as the causative factors. AF was mostly observed in the single crown of males in molar areas, while ASL was more likely to occur on an angled abutment than on a non-angled abutment. Moreover, the abutment with the positioning index (/X) had a higher incidence of fracture than the abutment without the positioning index (C/).

CONCLUSIONS

This study shows that the Morse taper connection is a safe abutment connection. AF occurs more frequently within single crowns in molar area of males, especially with the positioning index (/X), while ASL is more likely to occur in an angled abutment.

Electrical Potentiometry with Intraoral Applications

Dental implants currently in use are mainly made of titanium or titanium alloys. As these metallic elements are immersed in an electrolytic medium, galvanic currents are produced between them or with other metals present in the mouth. These bimetallic currents have three potentially harmful effects on the patient: micro-discharges, corrosion, and finally, the dispersion of metal ions or their oxides, all of which have been extensively demonstrated in vitro. In this original work, a system for measuring the potentials generated in vivo is developed. Specifically, it is an electrogalvanic measurements system coupled with a periodontal probe that allows measurement of the potentials in the peri-implant sulcus. This device was tested and verified in vitro to guarantee its applicability in vivo. As a conclusion, this system is able to detect galvanic currents in vitro and it can be considered capable of being employed in vivo, so to assess the effects they may cause on dental implants.

The accuracy of probing, ultrasound and cone-beam CT scans for determining the buccal bone plate dimensions around oral implants - A systematic review

OBJECTIVE

The objective of this review was to assess the accuracy of available means of determining the BBT (buccal bone thickness) and/or BBL (buccal bone level). This was translated into the following research question: What is the accuracy of the available means of visualizing the BBP (buccal bone plate) to establish the BBT and/or the BBL, when compared to control measurements? As control measurements histomorphometric measurements, direct measurements and cone-beam computed tomography (CBCT) measurements in the absence of metal are accepted.

BACKGROUND DATA

METHODS: The literary search was performed by searching the databases of MEDLINE, Embase, and Web of Science, up to July 13, 2021. Types of studies included were clinical, in vitro and animal trials, specifically looking into the bone level and/or bone thickness of the buccal bone plate at oral implants. Reference lists were hand searched for relevant articles. Two reviewers performed the data extraction and analysis. Only studies using reliable control measurements to evaluate the accuracy of the tested means of visualizing BBT and/or BBL were included for analysis. The QUADAS-2 tool was used to perform bias analysis on the relevant studies. Extracted data was tabulated to show the differences between test and control measurements for BBT and BBL. For in vitro studies on CBCT measurements of BBT meta-analysis could be performed.

RESULTS

A total of 1176 papers were identified in the search. Twenty-two articles were used for data extraction and qualitative analysis. Of these studies nine were animal studies, 9 were in vitro studies and four were human studies. Six animal studies and three human studies provided data on probing. CBCT and sonography as techniques for visualizing the buccal bone plate. Probing at implant sites seems to provide data that correlates with a consistent distance from the BBP. Meta-analysis for probing studies could not be performed due to heterogeneity in the setups of these studies. Eleven studies on CBCT were eligible for inclusion. Of these three were animal studies, the remaining 8 studies were all in vitro studies. Meta-analysis was performed on the accuracy of CBCT for in vitro studies, finding a significant underestimation of the BBT when compared to control measurements by a mean difference of -0.15 mm with 95%CI [-0.26,-0.03]. Three studies were identified on measurement of BBT and/or BBL by sonography. This included one human study and two in vitro studies. The identified studies show a low error when determining the buccal bone level or thickness using sonography. All included studies possess a high risk of bias according to risk of bias analysis, mostly due to selection of the patient.

CONCLUSION

A strong limitation of this systematic review is the inclusion of different studies with heterogeneous designs. Within the limits of this analysis it cannot be concluded that probing is an accurate way of visualizing the BBP. CBCT cannot yet be recommended as a standard diagnostic tool for follow-up of the BBP at oral implants. The application of sonography as a diagnostic tool to visualize the BBP needs further scientific validation.

Interproximal contact loss at implant sites: a retrospective clinical study with a 10-year follow-up

AIM

To assess the frequency and quantity of interproximal contact loss (ICL) between implant restorations and adjacent teeth after at least 10 years of follow-up (FU).

METHODS

Thirty-nine patients (median age 57.3 years) with 80 implants were re-examined at least 10 years after insertion of final restorations (single-crowns or fixed dental prostheses (FDPs)). Baseline (insertion of the restorations) and FU examinations encompassed: stone casts were scanned and superimposed for metric assessment of tooth movements, radiographs and clinical measurements. Outcome measures at implant sites were: the extent of tooth movement and the frequency of interproximal contact loss [ICL], peri-implant marginal bone levels [MBLs], and clinical measurements (plaque control record [PCR], bleeding on probing [BOP] and probing depth [PD]). Data were analyzed statistically with generalized regression modelling with robust standard errors to account for within-patient clustering at 5%.

RESULTS

ICL for at least one contact point after 10 years was observed in 50% of all implants (with open interproximal spaces up to 1.64 mm). Mesial contact points were significantly more prone to ICL than distal ones (relative risk [RR]=1.79; 95% confidence interval [CI]=1.07-2.99; p=0.03). The type of restoration had a significant effect on ICL, with FDPs of 2 implants being significantly more prone to mesial ICL than single crowns (RR=1.52; 95% CI=1.02-2.25; p=0.04). ICL was also associated with a significant increase in PD (+0.46 mm (95% CI=0.04-0.88 mm; P=0.03)) compared to implant sites without ICL. BOP, MBLs and PCR were not significantly influenced by ICL.

CONCLUSION

ICL was a common finding in 50% of the implant sites and was significantly associated with an increase in PD.

Influence of Different Incision Designs on Flap Extension: A Cadaveric Animal Model

It is well known that wound dehiscence is one of the most frequent complications in guided bone regeneration. The main cause of this complication may be a lack of tension-free and primary wound closure. The aim of this study was to evaluate and compare the effect of periosteal releasing incisions (PRI) on the extension of 3 different flap designs: envelope, triangular, and trapezoidal. Twelve pig mandibles were used to quantify extension of the flap designs. The mandibles were equally and randomly distributed into the 3 flap groups. Each mandible was divided into 2 sides: 1 was subjected to a PRI and the other not. The flap was pulled with a force of 1.08 N, and the extension was recorded. The subgroups without PRI showed an average extension of 5.14 mm with no statistically significant differences among them (P = .165). The PRI provided an average extension of 7.37 mm with statistically significant differences among the subgroups (P < .001). The releasing incisions significantly increased flap extension in each flap design. The increase in extension of the trapezoidal flap with PRI was significantly greater than in the other subgroups. In cases where primary closure is required, surgeons should consider performing trapezoidal flaps with PRI in order to reduce tension.

Implants Survival Rate in Regenerated Sites with Innovative Graft Biomaterials: 1 Year Follow-Up

In thirteen different dental clinics in Singapore, Spain, Czech Republic and Italy, 504 patients were selected, and 483 dental implants were placed in maxillary sites after alveolar socket preservation (ASP) procedures with an autologous demineralized tooth extracted as graft material from an innovative Tooth Transformer device was obtained. All procedures used were reported in n°638 Ethical Committee surgical protocol of University of Chieti and approved. After 4 months, at dental implant placing, bone biopsies were performed to evaluate the histologic outcomes, and 12 months after implant loading, global implant survival rate, failure percentage and peri-implant bone loss were detected. After ASP, only 27 post-operative complications were observed and after 4 months, bone biopsy histomorphometric analysis showed a high percentage of bone volume (BV) 43.58 (±12.09), and vital new bone (NB) 32.38 (±17.15) with an absence of inflammation or necrosis areas. Twelve months after loading, only 10 dental implants failed (2.3%), with a 98.2% overall implant survival rate, nine cases showed mucositis (1.8%) and eight showed peri-implantitis (1.6%). At mesial sites, 0.43 mm (±0.83) of bone loss around the implants was detected and 0.23 mm (±0.38) at the distal sites with an average value of 0.37 mm (±0.68) (p > 0.568). Several studies with a longer follow-up will be necessary to confirm the preliminary data observed. However, clinical results seem to suggest that the post-extraction socket preservation procedure using innovative demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone able to support dental implant rehabilitation of maxilla edentulous sites.

Implant complications in bruxism patients

Bruxism is defined as a parafunctional activity during sleep or while awake that includes locking and grinding of teeth and clenching. It generates excessive occlusal force that may lead to implant failure. Therefore, diagnosis of bruxism and providing specific protocols such as occlusal splint and/or injection of botulinum toxin before implant installation are important to prevent increases the risk of implant failure in bruxism patients.

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.

Variation in dental occlusal schemes two years after placement of single-implant posterior crowns. A preliminary study

Some authors have recommended that implant-supported single crowns should only contact during heavy clenching. However, a lack of occlusal contact with moderate clenching may cause supra-eruption of antagonist natural teeth. The main objective of this study was to assess changes in the occlusal contacts of posterior implant-supported single crowns with natural antagonist teeth two years after placement. The occlusal schemes of 14 patients who received 16 implant-supported single crowns in molar and premolar regions were assessed in this prospective study. Just after crown placement, at 6 months and after 2 years a silicone maxillomandibular relationship and T-scan records were obtained during the intercuspal position with light and heavy clenching, determined using near half of the maximum force and maximum force respectively. Occlusal contacts were assessed quantitatively and qualitatively in the implant-supported single crowns, contralateral tooth and adjacent tooth; the latter two were used as controls. After six months and two years, no significant variations were observed in any region of the occlusal scheme in any assessments, including silicone record or T-Scan, using light or heavy clenching, and qualitative or quantitative occlusal contact assessment. In this preliminary study, the occlusal scheme did not vary at the intercuspal position two years after placing posterior implant-supported single crowns.

Interproximal open contacts between implant restorations and adjacent natural teeth as a risk-indicator for peri-implant disease-A cross-sectional study

OBJECTIVES

The primary aim of this study was to investigate the relationship between interproximal open contacts and peri-implant disease. The secondary aim was to assess patient-reported outcome measures in relation to contact status.

MATERIALS AND METHODS

A cross-sectional study was performed on 61 patients with 142 implants adjacent to at least one natural tooth. Patients underwent a clinical examination to assess contact status and width, plaque index (PI), gingival index (GI), periodontal probing depths (PPD), and bleeding on probing (BoP). Radiographic marginal bone level was measured in vertical bitewings taken within one year. A diagnosis was given to each implant. Last, subjects completed a brief questionnaire. Rao-scott chi-squared tests and generalized estimating equations (GEE) models were used to compare outcomes between groups.

RESULTS

Seventy-seven (54.2%) implants were found to have ≥1 interproximal open contact. Sixty-five (45.8%) implants had closed contacts only. Implants with interproximal open contacts were significantly associated with peri-implant mucositis and peri-implantitis (p = .003) and increased prevalence of peri-implant disease (adjusted PR = 1.57; 95% CI: 1.09-2.27, p = .015). Open contact status was also associated with higher PPD (p = .045), PI scores (p = .036), and GI scores (p = .021). Open contact prevalence was 75.4% on the patient-level and 54.2% on the implant-level, involving the mesial surface of the implant restorations 68.5% of the time (p < .001).

CONCLUSION

Interproximal open contacts between implant restorations and adjacent natural teeth are a risk indicator for peri-implant disease. Adequate contact between implant restorations and natural teeth may contribute to the health of peri-implant tissues.

Exploring the relationship among dental caries, nutritional habits, and peri-implantitis

BACKGROUND

A study was made of the prevalence, co-occurrence and association among caries, nutritional habits, and peri-implant disease, with an analysis of the influence of other patient and implant factors upon peri-implant disease.

METHODS

The included subjects underwent a clinical examination and were asked to complete a questionnaire. Demographic data and potential lifestyle/behavioral variables were collected. Clinical and radiographic assessment allowed calculation of the decayed, missing and filled teeth (DMFT) index and peri-implant diagnosis. Uni- and multivariate multinomial logistic regression analyses were applied to identify predictors of peri-implant disease.

RESULTS

A total of 169 patients with 311 implants were studied. At patient level, 92.2% of the subjects presented at least one carious lesion, whereas 22.5% and 56.2% were diagnosed with peri-implantitis and mucositis, respectively. Those patients with more than two caries had a higher risk of mucositis (OR = 3.33). Statistically significant associations for peri-implantitis included full mouth periodontal indexes, sugar-rich diets, keratinized mucosa width, number of missing teeth and interproximal untreated caries or fillings adjacent to implants.

CONCLUSION

High caries risk profiles and mucositis/peri-implantitis tended to accumulate within subjects. A sugar-enriched diet and untreated caries or fillings adjacent to implant sites may be further considered as risk indicators of peri-implantitis.

A clinical and radiographic study of implants placed in autogenous bone grafts covered by either a platelet-rich fibrin membrane or deproteinised bovine bone mineral and a collagen membrane: a pilot randomised controlled clinical trial with a 2-year follow-up

Purpose

To compare the survival and clinical performance of implants placed in sites previously augmented with autogenous bone grafts covered by either a platelet-rich fibrin (PRF) membrane (PRF group) or a standard procedure (gold standard) involving coverage of the autogenous bone graft with deproteinised bovine bone mineral and a resorbable collagen membrane (control group).

Methods

A total of 27 partially edentulous patients (test n = 14, control n = 13) with indication for staged lateral bone block augmentation and dental implant placement were included. Twenty-four months after crown placement (range: 14–32 months), patients were recalled for a final clinical and radiographic follow-up. Outcome measures were implant survival, implant crown survival, clinical parameters of the implant, peri-implant marginal bone level, marginal bone level of adjacent tooth surfaces, biological and technical complications and patient-related outcome measures.

Results

Two implants were lost in the control group (85% survival rate); none were lost in the PRF group (100% survival rate). None of the 26 initially placed implant crowns were lost, but one implant and therefore one implant crown were lost after 20 months. Consequently, the definitive implant crown survival was 92% (95% confidence interval (CI): 73–110%) in the control group and 100% in the PRF group. No statistical difference in implant survival rate (p = 0.13) or implant crown survival was seen between the groups (p = 0.28). The mean marginal bone level at the follow-up was 0.26 mm (95% CI: 0.01–0.50 mm) in the PRF group and 0.68 mm (95% CI: 0.41–0.96 mm) in the control group. The difference between the groups was − 0.43 mm (95% CI: − 0.80 to − 0.05 mm, p = 0.03), which was statistically significant (p = 0.03). Both groups demonstrated similar healthy peri-implant soft tissue values at the final follow-up.

Conclusion

Although the current study is based on a small sample of participants, the findings suggest that the methodology of the PRF and the control group approach can both be used for bone augmentation with a similar outcome. A significant, but clinically irrelevant, higher peri-implant marginal bone level was registered in the PRF group than in the control group. Patients in both groups were highly satisfied with the treatment.

Trial registration

ClinicalTrials.gov Identifier: NCT04350749. Registered 17 April 2020. Retrospectively registered.

Association between diabetes and dental implant complications: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to explore the possible association between diabetes mellitus and dental implant complications.

MATERIAL AND METHODS

A systematic literature review was conducted to answer the following PICO (Participants, Intervention, Comparison, and Outcome) question: Is there association between diabetes mellitus and dental implant complications? Two independent searchers performed a literature search of the PubMed/MEDLINE, Web of Science, Cochrane Library and EMBASE databases for studies published until February 2020, focussing on studies including continuous outcomes, marginal bone loss (primary outcome), probing depth, and bleeding upon probing (secondary outcomes).

RESULTS AND CONCLUSIONS

A final total of 10 published studies were included in this systematic review. There were statistically significant differences between the groups with regard to marginal bone loss (p < .00001), probing depth (p < .00001) and bleeding around dental implants (p < .00001), and subjects without diabetes had lower complication rates. Additionally, in the subgroup analysis performed with loading time and HbA1c levels, a more evident association was found in immediate loading for probing depth. Moreover, the analysis results of bleeding around dental implants suggested that as HbA1c level increases, the bleeding of the tissues surrounding the implant will also increase. With regard to dental implant complications, there were statistically significant differences favouring patients without diabetes mellitus.

Risk factors for abutment and implant fracture after loading

PURPOSE

Implant component fractures are one of the most serious complications in implant treatment. With a better understanding of the risk factors for fracture in the preoperative, surgery, superstructure, and post-loading phases of implant treatment, low-risk treatment could reduce implant component fractures, leading to a better prognosis. The aim of this study was to clarify the risk factors for abutment and implant fractures that occur after loading, and to perform a retrospective, approximately 10-year follow-up study to explore the risk factors in each treatment phase.

METHODS

Subjects were fitted with an implant prosthesis between January 2008 and December 2009. In total, 1,126 Ankylos implants in 430 patients were included for analysis. Binary logistic regression analysis was performed to extract factors related to non-fracture and fracture of the abutment or implant as a dependent variable.

RESULTS

Gender (OR = 3.466, 95% CI 1.296-9.268, P = 0.013), gonial angle (OR = 3.420, 95% CI 1.308-8.945, P = 0.012), and splinting status of the superstructure (OR = 4.456, 95% CI 1.861-10.669, P = 0.001) were identified as significant risk factors.

CONCLUSION

The risk of fracture is increased in males, especially those with a mandibular angle of less than 120° on panoramic radiographs, and those with a non-splinted superstructure.

Role of New Hydrophilic Surfaces on Early Success Rate and Implant Stability: 1-Year Post-loading Results of a Multicenter, Split-Mouth, Randomized Controlled Trial

OBJECTIVE

 To compare early implant failure and implant stability of one-stage Hiossen ET III implants with its new hydrophilic (NH) surface, compared with Hiossen ET III implants with the sandblasted and acid-etched (SA) surface at 1-year follow-up.

MATERIALS AND METHODS

 This study was designed as a split-mouth, multicenter randomized controlled trial aimed to compare SA surface implants (SA group) and NH surface, (NH group). Outcomes were implant and prosthetic survival rates, complications, the insertion torque at implant placement, and implant stability quotient (ISQ) values.

RESULTS

 Twenty-nine patients (mean age 59.9 ± 11.3 years) were treated and followed up to 1 year after loading. No patient dropped out. Fifty-eight implants (29 SA group and 29 NH group) were placed. No implants or prostheses failed and no complications were experienced during follow-up. The mean insertion torque was 40.5 ± 3.23 (38.17-41.83) Ncm in the SA group and 40.48 ± 3.49 (38.02-41.98) Ncm in the NH group (p = 0.981). There was a statistically significant difference at the second week (T2) with higher values in the NH group (p = 0.041). Similar results were found in the maxilla (p = 0.045), but not in the mandible (p = 0.362). A positive correlation was found between initial insertion torque and ISQ with higher value in the NH group (0.73 vs. 0.66).

CONCLUSIONS

 NH implants are a viable alternative to SA surface, as they seem to avoid the ISQ drop during the bone remodeling phase.

Vertical and Horizontal Augmentation of Deficient Maxilla and Mandible for Implant Placement

Ridge augmentation for implant procedures has been shown to be highly successful. There are several techniques available to the dentist, but they require some degree of surgical expertise and experience. No particular technique has been shown to be superior. This article presents the indications, techniques, and complications of the various procedures for alveolar ridge augmentation. This information will educate the general dental practitioner of the techniques available and provide information on the surgical procedures that could be used to discuss with patients when they are being referred to a specialist.

Anterior Esthetic Rehabilitation of an Alveolar Cleft Using Novel Minimally Invasive Prosthodontic Techniques: A Case Report

Missing lateral incisors are the most frequent dental disorder associated with cleft alveolus. When orthodontic closure of the edentulous space is not possible, more aggressive prosthodontic treatments are required. Contemporary resin-bonded fixed dental prostheses (RBFDPs) represent a promising, time-efficient alternative treatment with fewer biological complications. This clinical report proposes a modified approach to the esthetic rehabilitation of a patient with a complete unilateral cleft lip and palate on the left side and an incomplete cleft lip and alveolar cleft on the right side. Digital diagnostics, treatment planning, and clinical procedures involved in the fabrication of facially bonded RBFDPs are presented. This modified technique enables the concurrent replacement of lateral incisors and correction of the malformed central incisors as well as increasing the retention of the restorations.

Is the Fixed Mandibular 3-Implant Retained Prosthesis Safe and Predicable for Full-Arch Mandibular Prostheses? A Systematic Review

PURPOSE

To evaluate implant and prosthetic survival rates of full-arch rehabilitations retained by three implants in patients with edentulous mandibles.

MATERIALS AND METHODS

This systematic review was developed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The focused question was: Are fixed mandibular 3-implant retained prostheses safe and predicable for full-arch mandibular prostheses? The Medline/PubMed and Cochrane Library databases were used to conduct the systematic search for clinical trials on fixed mandibular 3-implant retained prostheses published between 1999 and 2020. Only English-language studies that presented information on implant and prosthetic survival were included.

RESULTS

A total of 302 studies were identified, of which 13 addressed the inclusion criteria. Additionally, 574 participants were included in these studies. As reported, 73 (4.57%) of 1596 implants failed, with a survival rate of 95.43%. In addition, the mean survival rate of the presented prostheses was 89.66%. The mean marginal bone loss was 1.09 mm.

CONCLUSION

Within the limitations of the present review, implant and prosthetic survival rates of fixed mandibular 3-implant retained prostheses were similar to those of full-arch mandibular prostheses retained by four or more implants. Further research exploring the topic is necessary.

Effectiveness and surface changes of different decontamination protocols at smooth and minimally rough titanium surfaces

BACKGROUND

The objective of this study is to evaluate titanium decontamination after different protocols while assessing changes in surface roughness, chemical composition, and wettability.

METHODS

Ninety-six smooth (S) and 96 minimally rough (R) titanium microimplants were used. Pristine microimplants were reserved for negative control (S-nC/R-nC, n = 9), while the remaining microimplants were incubated in Escherichia coli culture. Non-decontaminated microimplants were used as positive control (S-pC/R-pC, n = 3). The other microimplants were divided into seven different decontamination protocols (12 S/R per group): 24% EDTA, 2% chlorhexidine (CHL), gauze soaked in 2% chlorhexidine (GCHL), gauze soaked in ultrapure water (GMQ), scaling (SC), titanium brush (TiB), and implantoplasty (IP). Contaminated areas were assessed by scanning electron microscope images, chemical composition by energy dispersive X-ray spectroscopy, wettability by meniscus technique, and roughness by an optical profiler.

RESULTS

Higher residual bacteria were observed in R-pC compared with S-pC (P <0.0001). When comparing S and R with their respective pC groups, the best results were obtained with GCHL, SC, TiB, and IP, with no difference between these protocols (P >0.05). Changes in surface roughness were observed after all treatments, with S/R-IP presenting the smoother and a less hydrophilic surface (P <0.05). Apart from IP protocol, all the other groups presented a more hydrophilic surface in R than in S microimplants (P <0.003). All decontamination protocols resulted in a lower percentage of superficial Ti when compared with S/R-nC (P <0.002).

CONCLUSIONS

All decontamination protocols resulted in changes in roughness, wettability, and chemical composition, but GCHL, SC, TiB, an IP presented the best decontamination outcomes.

Implants with a Laser-microgrooved Collar Placed in Grafted Posterior Maxillary Extraction Sockets and in Crestally Grafted Sinuses: a 5-Year Multicentre Retrospective Study

Objectives

The aim of this retrospective multicentre cohort study was to compare clinical outcomes, soft tissues conditions and differences in marginal bone loss between implants with a laser-microgrooved collar placed in posterior maxillary extraction sockets grafted by 4 to 5 months, and in posterior maxillary pristine bone (spontaneously healed posterior maxillary extraction sockets) by means of osteotome-mediated sinus floor elevation, over a period of 5 years after functional loading.

Material and Methods

Patients of Group 1 underwent extractions with sockets preservation using porcine-derived bone, covered with collagen membrane. Group 2 underwent extractions without socket preservation. Patients of Group 1 received implants in grafted sites, and Group 2 received implants in spontaneously healed bone using a maxillary sinus lift with crestal approach.

Results

Over the observation period, the overall clinical success rate in Group 1 and Group 2 was 98% and 100%, respectively, with no differences between the procedures and implants used. Cumulative radiographic marginal bone loss ranged from 0.03 to 0.39 mm after 60 months of functional loading. There were no statistically significant differences in marginal bone loss between short and standard-length implants placed in grafted extraction sockets and in pristine bone.

Conclusions

Short and standard implants with a laser-microgrooved collar, placed in posterior maxillary extraction sockets grafted by 4 to 5 months, and in posterior maxillary pristine bone (spontaneously healed posterior maxillary extraction sockets) by means of osteotome-mediated sinus floor elevation, exhibited no statistical difference in success rate, clinical parameters and marginal bone loss.

In vitro performance and fracture resistance of interim conventional or CAD-CAM implant-supported screw- or cement-retained anterior fixed partial dentures

STATEMENT OF PROBLEM

Interim restorations represent an essential clinical treatment step; however, limited information is available concerning the performance of computer-aided design and computer-aided manufacturing (CAD-CAM) interim materials.

PURPOSE

The purpose of this in vitro study was to evaluate the performance and fracture load of resin anterior implant-supported interim fixed partial dentures (IFPDs).

MATERIAL AND METHODS

Identical anterior resin IFPDs (maxillary central incisor to canine; n=16 per material) were milled from polymethylmethacrylate (PMMA) or di-methacrylate (DMA) systems with different filler content. The IFPD groups were split to simulate a chairside (cemented implant-supported prosthesis) or laboratory procedure (screw-retained implant-supported prosthesis). A cartridge DMA material served as a control. After interim cementation, combined thermocycling and mechanical loading (TCML) was performed on all restorations to approximate a maximum of 2.5 years of clinical function. Behavior during TCML and fracture force was determined, and failures were analyzed. The data were statistically investigated (Kolmogorov-Smirnov test, 1-way-ANOVA; post hoc Bonferroni, Kaplan-Meier survival, α=.05).

RESULTS

Drop out during TCML varied between no failures and complete failure during loading. For most systems, failure occurred between 120 000 and 600 000 mechanical loading cycles. For IFPDs without a screw channel fracture, values varied between 644 ±263 N and 987 ±101 N. Those with a screw channel fracture failed between 493 ±89 N and 951 ±248 N. Individual IFPDs had significantly higher mean fracture loads (P<.002), but the mean fracture values between IFPDs with and without a screw channel were not significantly different (P>.137). Failures were characterized by fracture of the connector (n=53) followed by mixed failures (n=22) or fractures at the abutment (n=21).

CONCLUSIONS

These interim materials are sufficiently fracture resistant for the fabrication of implant-supported anterior IFPDs and are expected to survive between 6 months and 2 years before failure. The stability of IFPDs depended on the type of material but not on the restoration design (with or without a screw channel).

In vitro performance and fracture resistance of pressed or CAD/CAM milled ceramic implant-supported screw-retained or cemented anterior FDPs

PURPOSE

This study investigated the in-vitro performance of anterior implant-supported fixed dental prostheses (FDP). The effect of ceramics, fabrication, finalization and the presence of a screw-channel wa s investigated.

METHODS

Identical anterior ceramic FDPs (tooth 11-13; n=80) were milled (Lithiumdisilicate (LiSiCAD, emaxCAD, Ivoclar-Vivadent), Lithiumaluminiumsilicate (LiAlSi, experimental material) or pressed (Lithiumdisilicate (LiSiPress, emaxPress, Ivoclar-Vivadent), Lithiumsilicate (ZLS, CeltraPress, Dentsply Sirona). FDP-groups (n=8 per material and group) simulated a cemented or screw-retained approach. After cementation or screwing on titanium abutments, thermal cycling and mechanical loading (TCML) was performed on all restorations to mimic 5-year clinical performance. Performance and fracture force were determined and failures were analyzed.

STATISTICS

(Kolmogorov-Smirnov-test, one-way-ANOVA; post-hoc-Bonferroni, multivariate-regression, α=0.05).

RESULTS

All FDPs survived TCML without aging, cracks, fractures or chipping. For FDPs without screw channel fracture values varied between with 839.8±112.3N (LiAlSi glazed) and 1485.9±232.6N (LiSiCAD). With screw channel, fracture results varied between 701.4±220.1N (LiALSi glazed) and 1516.3±253.7N (LiSipress). The type of material had a significant influence on the fracture results (LiSi>ZLS>LiAlSi; p≤0.012). Fabrication and finalization had no influence on the results. A screw channel did not significantly (p≥0.135) reduce the fracture force of the FDPs. Type of failure was mostly characterized by a fracture of the connector (LiSi, LiAlSi) or the abutment (ZLS, LiAlSi).

CONCLUSIONS

FDPs survived TCML without failures indicating that the in vitro performance was not influenced by the tested parameters. Composition of ceramic material has significant influence on the fracture resistance of implant supported LiSi based FDPs. Screw channel, fabrication or finalization did not weaken the FDPs.

Fracture resistance after implantoplasty in three implant-abutment connection designs

Background

To assess the effect of implantoplasty and implant-abutment design on the fracture resistance and macroscopic morphology of narrow-diameter (3.5 mm) dental implants.

Material and Methods

Screw-shaped titanium dental implants (n = 48) were studied in vitro. Three groups (n = 16) were established, based on implant-abutment connection type: external hexagon, internal hexagon and conical. Eight implants from each group were subjected to an implantoplasty procedure; the remaining 8 implants served as controls. Implant wall thickness was recorded. All samples were subjected to a static strength test.

Results

The mean wall thickness reductions varied between 106.46 and 153.75 µm. The mean fracture strengths for the control and test groups were, respectively, 1211.90±89.95 N and 873.11±92.37 N in the external hexagon implants; 918.41±97.19 N and 661.29±58.03 N in the internal hexagon implants; and 1058.67±114.05 N and 747.32±90.05 N in the conical connection implants. Implant wall thickness and fracture resistance (P < 0.001) showed a positive correlation. Fracture strength was influenced by both implantoplasty (P < 0.001) and connection type (P < 0.001).

Conclusions

Implantoplasty in diameter-reduced implants decreases implant wall thickness and fracture resistance, and varies depending on the implant-abutment connection. Internal hexagon and conical connection implants seem to be more prone to fracture after implantoplasty.

Key words:Dental implants, narrow diameter, implant connection, peri-implantitis, implantoplasty, fracture strength.