Effectiveness of implant therapy analyzed in a Swedish population: early and late implant loss

Accuracy of dynamic navigation compared to static surgical guides and the freehand approach in implant placement: a prospective clinical study

BACKGROUND

Computer-guided implant surgery has improved the quality of implant treatment by facilitating the placement of implants in a more accurate manner. This study aimed to assess the accuracy of implant placement in a clinical setting using three techniques: dynamic navigation, static surgical guides, and freehand placement. We also investigated potential factors influencing accuracy to provide a comprehensive evaluation of each technique's advantages and disadvantages.

MATERIALS AND METHODS

Ninety-four implants in 65 patients were included in this prospective study. Patients were randomly assigned to one of three groups: dynamic navigation, static surgical guides, or freehand placement. Implants were placed using a prosthetically oriented digital implant planning approach, and postoperative CBCT scans were superimposed on preoperative plans to measure accuracy. Seven deviation values were calculated, including angular, platform, and apical deviations. Demographic and consistency analyses were performed, along with one-way ANOVA and post-hoc tests for deviation values.

RESULTS

The mean global platform, global apical, and angular deviations were 0.99 mm (SD 0.52), 1.14 mm (SD 0.56), and 3.66° (SD 1.64°) for the dynamic navigation group; 0.92 mm (SD 0.36), 1.06 mm (SD 0.47), and 2.52° (SD 1.18°) for the surgical guide group; and 1.36 mm (SD 0.62), 1.73 mm (SD 0.66), and 5.82° (SD 2.79°) for the freehand group. Both the dynamic navigation and surgical guide groups exhibited statistically significant differences in all values except depth deviations compared to the freehand group (p < 0.05), whereas only the angular deviation showed a significant difference between the dynamic navigation and surgical guide groups (p = 0.002).

CONCLUSION

Our findings highlight the superior accuracy and consistency of dynamic navigation and static surgical guides compared to freehand placement in implant surgery. Dynamic navigation offers precision and flexibility. However, it comes with cost and convenience considerations. Future research should focus on improving its practicality.

TRIAL REGISTRATION

This study was retrospectively registered at the Thai Clinical Trials Register-Medical Research Foundation of Thailand (MRF) with the TCTR identification number TCTR20230804001 on 04/08/2023. It was also conducted in accordance with the Declaration of Helsinki and approved by the institutional ethics committee at the Xian Jiaotong University Hospital of Stomatology, Xian, China (xjkqII[2021] No: 043). Written informed consent was obtained from all participants.

In-vitro biofilm removal from TiUnite® implant surface with an air polishing and two different plasma devices

BACKGROUND

We investigated the efficacy of two different cold atmospheric pressure jet plasma devices (CAP09 and CAPmed) and an air polishing device with glycine powder (AP) either applied as monotherapies or combined therapies (AP + CAP09; AP + CAPmed), in microbial biofilm removal from discs with anodised titanium surface.

METHODS

Discs covered with 7-day-old microbial biofilm were treated either with CAP09, CAPmed, AP, AP + CAP09 or AP + CAPmed and compared with negative and positive controls. Biofilm removal was assessed with flourescence and electron microscopy immediately after treatment and after 5 days of reincubation of the treated discs.

RESULTS

Treatment with CAP09 or CAPmed did not lead to an effective biofilm removal, whereas treatment with AP detached the complete biofilm, which however regrew to baseline magnitude after 5 days of reincubation. Both combination therapies (AP + CAP09 and AP + CAPmed) achieved a complete biofilm removal immediately after cleaning. However, biofilm regrew after 5 days on 50% of the discs treated with the combination therapy.

CONCLUSION

AP treatment alone can remove gross biofilm immediately from anodised titanium surfaces. However, it did not impede regrowth after 5 days, because microorganisms were probably hidden in holes and troughs, from which they could regrow, and which were inaccessible to AP. The combination of AP and plasma treatment probably removed or inactivated microorganisms also from these hard to access spots. These results were independent of the choice of plasma device.

Enhancement of in vitro antibacterial activity and bioactivity of iodine-loaded titanium by micro-scale regulation using mixed-acid treatment

Postoperative infection and subsequent device loss are serious complications in the use of titanium dental implants and plates for jawbone reconstruction. We have previously reported that NaOH-CaCl2 -thermal-ICl3 -treated titanium (NaCaThIo) has a nano-scale surface and exhibits antibacterial activity against Staphylococcus aureus. The present study examined the surface properties of mixed-acid treated and then iodine-treated titanium (MA-NaCaThIo), and evaluated oral antibacterial activity and cytotoxicity compared with the results obtained with NaCaThIo. MA-NaCaThIo formed a surface layer with a nano-scale network structure having microscale irregularities, and both the thickness of the surface layer (1.49 ± 0.16 μm) and the average surface roughness (0.35 ± 0.03 μm) were significantly higher than those of NaCaThIo. Furthermore, MA-NaCaThIo maintained high hydrophilicity with a contact angle of 7.5 ± 1.7° even after 4 weeks, as well as improved apatite formation, iodine ion release, and antibacterial activity against Prevotella intermedia compared to NaCaThIo. Cell culture test revealed that MA-NaCaThIo exhibited no cytotoxicity against MG-63 and Vero cells, while increased cell proliferation, ALP activity and mineralization of MG-63 compared to NaCaThIo. This treated titanium is expected to be useful for the development of next-generation titanium devices having both bone-bonding and antibacterial properties.

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.

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

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

Selection of Dental Implants and Restorations Among Dentists in the Kingdom of Saudi Arabia: A Cross-Sectional, Questionnaire-Based Survey

Background Dental implants play a crucial role in modern dentistry, offering a durable and aesthetic option for tooth replacement. Understanding the preferences and practices of dentists regarding implant selection and restoration can provide critical insights into current trends and potential areas for improvement. As such, the objective of this study was to discover characteristics determining the selection criteria and preferences for dental implants and restorations among Saudi Arabian dentists. Methodology A cross-sectional, questionnaire-based survey was conducted among Saudi Arabian dentists to assess their practices and preferences for dental implant selection and restoration. The survey explored variables, including age, gender, educational status, regional practice distribution, implant-related experience, loading protocols, and implant system preferences. Results A total of 742 dental professionals responded to our questionnaire. The study revealed that a significant majority of Saudi Arabian dentists had placed (78.7%) and restored (72.9%) implants. Most dentists (78.6%) had participated in implant treatment planning. However, consistent usage of implant planning software was relatively low (29.8%). Loading protocol preferences varied, with early loading favored for anterior teeth and immediate loading for posterior teeth and edentulous patients. The main deterrents to immediate loading were patient type (27.0%), lack of training (19.9%), additional surgeries (19.9%), and administrative restrictions (17.8%). Straumann was the most preferred implant system, with aesthetic outcomes considered the most important factor in system selection. Conclusions The study provides a comprehensive overview of dental implant practices among Saudi Arabian dentists. It highlights a strong emphasis on aesthetic outcomes, a diverse approach to loading protocols, and room for increased usage of implant planning software. The findings suggest potential areas for further training and support, particularly in the use of immediate loading and implant planning software.

Impact of keratinized mucosa on implant-health related parameters: A 10-year prospective re-analysis study

AIM

To investigate whether the lack of keratinized mucosa (KM) affects peri-implant health after 10 years of loading.

MATERIALS AND METHODS

Data from 74 patients with 148 implants from two randomized controlled studies comparing different implant systems were included and analyzed. Clinical parameters including bleeding on probing (BOP), probing depth (PD), plaque index, marginal bone loss (MBL), and KM width (KMW) at buccal sites were collected at baseline (time of the final prosthesis insertion), 5-year and 10 years postloading. Multivariable logistic and linear regression models by means of a generalized estimated equation (GEE) were used to evaluate the influence of buccal KM on peri-implant clinical parameters; BOP, MBL, PD, and adjusted for implant type (one-piece or two-piece) and compliance.

RESULTS

A total of 35 (24.8%) implants were healthy, 67 (47.5%) had mucositis and 39 (27.6%) were affected by peri-implantitis. In absence of buccal KM (KM = 0 mm), 75% of the implants exhibited mucositis, while in the presence of KM (KMW >0 mm) 41.2% exhibited mucositis. Regarding peri-implantitis, the corresponding percentages were 20% (KM = 0 mm) and 26.7% (KM >0 mm). Unadjusted logistic regression showed that the presence of buccal KM tended to reduce the odds of showing BOP at buccal sites (OR: 0.28 [95% CI, 0.07 to 1.09], p = 0.06). The adjusted logistic regression model revealed that having buccal KM (OR: 0.21 [95% CI, 0.05 to 0.85], p = 0.02) and using two-piece implants (OR: 0.34 [95% CI, 0.15 to 0.75], p = 0.008) significantly reduced the odds of showing BOP. Adjusted linear regression by means of GEE showed that KM and two-piece implants were associated with reduced MBL and MBL changes (p < 0.05).

CONCLUSION

The lack of buccal KM appears to be linked with peri-implant parameters such as BOP and MBL, but the association is weak. The design of one-piece implants may account for their increased odds of exhibiting BOP.

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

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

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

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

Etiology, pathogenesis and treatment of peri-implantitis: A European perspective

Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants. It is characterized by inflammation in the peri-implant mucosa and progressive loss of supporting bone. Over the last 30 years, peri-implantitis has become a major disease burden in dentistry. An understanding of the diagnosis, etiology and pathogenesis, epidemiology, and treatment of peri-implantitis must be a central component in undergraduate and postgraduate training programs in dentistry. In view of the strong role of European research in periodontology and implant dentistry, the focus of this review was to address peri-implantitis from a European perspective. One component of the work was to summarize new and reliable data on patients with dental implants to underpin the relevance of peri-implantitis from a population perspective. The nature of the peri-implantitis lesion was evaluated through results presented in preclinical models and evaluations of human biopsy material together with an appraisal of the microbiological characteristics. An overview of strategies and outcomes presented in clinical studies on nonsurgical and surgical treatment of peri-implantitis is discussed with a particular focus on end points of therapy and recommendations presented in the S3 level Clinical Practice Guideline for the prevention and treatment of peri-implant diseases.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: Ten-year results from a double-blind, randomised controlled split-mouth core-trial

The goal of this extension study was to compare the 10-year outcome of 3.3 mm diameter titanium-zirconium (TiZr) or grade IV titanium (Ti) implants in mandibular implant-overdentures.

MATERIALS AND METHODS

This study is the 10-year follow-up from a randomised, controlled, double-blind, split-mouth multicentre clinical trial. Patients with edentulous mandibles had received two implants in the interforaminal region (bone-level, diameter 3.3 mm, microrough surface), one of TiZr (test) and one of Ti (control). Implant survival and success, plaque and sulcus bleeding indices, probing pocket depth, gingival margin, clinical attachment level and radiographic crestal bone levels were evaluated.

RESULTS

Fifty of 91 patients with implants were available for the 10-year examination and 36 patients were valid for the intent-to-treat (ITT) analysis. The implant success rate was calculated as 94.6% and 91.9% for the TiZr implants and the Ti implants respectively. Four implants were lost (TiZr = 1; Ti = 3) in the entire study period. Kaplan-Meier survival analyses estimated 10- year implant survival rate for TiZr to 98.9% and Ti 95.8%.The mean of total and functional crestal bone loss was 1.49 mm (±1.37 mm) and 0.82 mm (±1.09 mm) in the TiZr group and 1.56 mm (±1.34 mm) and 0.85 mm (±1.16 mm) in the Ti group.

CONCLUSIONS

This split-mouth design RCT on mandibular implant-overdentures evidenced, bearing in mind its follow-up time-related reduced cohort size, high 10-year implant success- and survival rates. These results confirm TiZr as well-suited implant material for realising small-diameter implants. Registered on www.

CLINICALTRIALS

gov: NCT01878331.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The All-on-four concept for fixed full-arch rehabilitation of the edentulous maxilla and mandible: a longitudinal study in Japanese patients with 3-17-year follow-up and analysis of risk factors for survival rate

PURPOSE

Implant-supported immediately loaded fixed full-arch rehabilitation via All-on-four treatment yields good long-term results for both the maxilla and the mandible. However, the risk factors affecting long-term implant survival are unknown, and the long-term prognosis of All-on-four concept procedures in Japanese individuals has not been elucidated. We aimed to determine the cumulative implant survival rate after 3-17-year follow-up and identify the associated risk factors.

METHODS

We analysed 561 cases (307 maxillae, 254 mandibles) with 2364 implants (1324 maxillae, 1040 mandibles) that received All-on-four treatment. We investigated the cumulative implant- and patient-level survival rates and various risk factors for implant failure. Statistical analysis was performed using the log-rank test for differences in Kaplan-Meier curves, univariate analysis using the Chi-square test, and multivariate analysis for risk factors affecting the survival rate.

RESULTS

The cumulative survival rate was 94.4% by patient level and 97.4% by implant level for the maxilla, and 96.7% by patient level and 98.9% by implant for the mandible, with up to 17 years of follow-up. The maxillary survival rate at the implant level was significantly lower (p < 0.05). Furthermore, the maxillary survival rate within 24 months was significantly lower at the implant level (p < 0.01). Multivariate analysis revealed that the maxilla was the most significant risk factor (p < 0.01).

CONCLUSIONS

All-on-four treatment yielded high long-term survival rates in Japanese patients. However, the maxilla showed a significantly lower cumulative survival rate than the mandible, while early failure was significantly higher. Furthermore, the maxilla was a significant risk factor influencing the survival rate.

Effects of adjacent periodontitis on osseointegrated dental implants

PURPOSE

This study aimed to investigate whether new-onset periodontitis or apical periodontitis in the adjacent teeth affects osseointegrated dental implants in a beagle dog model.

METHODS

One control group and 2 experimental groups (periodontitis and apical periodontitis groups) were defined based on the presence of experimental periodontitis or apical periodontitis, with 1 beagle dog randomly assigned to each group. The mandibular second and fourth premolars on both sides of the 3 beagles were extracted. Eight weeks after extraction, 4 bone-level implant fixtures, 2 on both sides of each mandible, were placed in each beagle. Six weeks after implant surgery, healing abutments were connected. After sufficient osseointegration, plaque control was performed in the control group, while periodontitis and apical periodontitis were induced in the experimental groups. The beagles were euthanized for histological analyses 20 weeks after induction of experimental periodontitis. Statistical analyses were performed using the Kruskal-Wallis test with the Bonferroni correction to compare the 3 groups.

RESULTS

The implants in the control and apical periodontitis groups were well-maintained, while those in the periodontitis group showed clinical signs of inflammation with bone resorption. The bone-to-implant contact (BIC) and bone area values in the periodontitis group were lower than those in the other groups. The distance between the implant shoulder and the first BIC was significantly greater in the periodontitis group than in the control group (P<0.05).

CONCLUSIONS

The presence of periodontitis in adjacent teeth can pose a risk to dental implants, potentially resulting in peri-implantitis. However, this was not observed for apical periodontitis. Within the limitations of this study, periodontal care is necessary to reduce the impact of periodontitis in adjacent teeth on osseointegrated implants.

Long-Term Efficacy of Chlorhexidine Gel in Single-Crown Implant Rehabilitation: A Five-Year Follow-Up Study

Chlorhexidine digluconate (CHX) has shown the ability to significantly reduce inflammation and marginal bone loss (MBL) at the 1-year follow-up but limited data exist regarding its long-term efficacy in peri-implant stability. The objective was to compare the long-term effects (5 years of follow-up) of a placebo gel (16 patients in Group A) or a 0.20% CHX gel (15 patients in Group B) used at each previous surgical and prosthetic stage. Control visits were conducted in 2022, investigating the long-term effects by biological, radiological, and clinical evaluation. The data were statistically analyzed. The research achieved a 96.7% implant success rate over five years, but 41.9% of patients did not attend annual oral hygiene check-ups. The average MBL was 1.04 ± 0.39 mm, with no significant differences between the two groups. Notably, patients who attended regular periodontal check-ups experienced significantly less MBL than those who did not (p < 0.05). At five years, direct effects of CHX were absent, with both groups showing moderate bone loss. However, the results suggest that early disinfection could enhance both short- and long-term outcomes. In fact, patients with initial minor MBL due to use of CHX, preserve this advantage also after 5 years of follow-up. Additionally, the data underscore the importance of annual check-ups in early detection and management of biological complications.

A clinical retrospective study of implant as a risk factor for medication-related osteonecrosis of the jaw: surgery vs loading?

BACKGROUND

Risk factors for developing medication-related osteonecrosis of the jaw (MRONJ) include the general condition of the patient, smoking habit, poor oral hygiene, and the type, duration, and administration route of the drug, dentoalveolar surgery, such as implant placement. This study aimed to discuss whether implants may induce osteonecrosis in older patients receiving long-term medication and to analyze the radiological pattern of the bone necrosis.

METHODS

This study included 33 patients diagnosed with dental implant-associated medication-related osteonecrosis of the jaw. Data regarding the medical history, type of medication used, durations of administration, laboratory test results, onset of bone necrosis since implant placement, type of opposing teeth, and radiological pattern of the bone necrosis on cone-beam computed tomography were recorded in patients with and without implants.

RESULTS

The most commonly used drug was bisphosphonate, with an average duration of use of 61.37 (± 53.72) months. The laboratory results showed average serum C-terminal cross-linking telopeptide (CTX) level of 0.23 ng/mL, vitamin D, 23.42 ng/mL, and osteocalcin, 4.92 ng/mL. Osteonecrosis occurred after an average of 51.03 (± 39.75) months following implant placement. Radiological evaluation revealed obvious sequestration in the implant-absent group, and the formation of a unit sequestration with an implant fixture (en bloc) was observed in the implant-present group. The patients underwent surgical treatment of sequestrectomy and explantation.

CONCLUSION

Implant placement, especially loading, may be considered a potential risk factor for the development of osteonecrosis in patients undergoing antiresorptive treatment.

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

Purpose

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

Materials and methods

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

Results

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

Conclusions

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

Abnormal Decrease of Macrophage ALKBH5 Expression Causes Abnormal Polarization and Inhibits Osteoblast Differentiation

Peri-implant tissue inflammation is an inflammatory injury that occurs in the soft and hard tissues surrounding the implant and is the main cause of short- or long-term failure of implant prosthetic restorations, which is compounded by bone loss and bone destruction in the alveolar bone of diabetes patients with peri-implantitis. However, the mechanisms underlying the persistence of diabetic peri-implantitis, as well as the essential connections and key molecules that regulate its start and progression, remain unknown. In this study, we discovered that M1 macrophage polarization was abnormally enhanced in diabetic peri-implantitis and influenced the osteogenic differentiation of mesenchymal stem cells. RNA sequencing revealed that ALKBH5 expression was abnormally reduced in diabetic peri-implantitis. Further mechanism study showed that ALKBH5 and its mediated m6A can influence osteogenic differentiation, which in turn influences the persistence of diabetic peri-implantitis. Our findings present a new mechanism for the suppression of osteoblast development in diabetic peri-implantitis and a new treatment strategy to promote anabolism by inhibiting ALKBH5.

Osteoblastic and Bacterial Response of Hybrid Dental Implants

Bacterial infections in dental implants generate peri-implantitis disease that causes bone loss and the mobility of the dental implant. It is well known that specific ranges of roughness favor the proliferation of bacteria, and it is for this reason that new dental implants called hybrids have appeared. These implants have a smooth area in the coronal part and a rough surface in the apical part. The objective of this research is the physico-chemical characterization of the surface and the osteoblastic and microbiological behavior. One-hundred and eighty discs of titanium grade 3 with three different surfaces (smooth, smooth-rough, and completely rough) were studied. The roughness was determined by white light interferometry, and the wettability and surface energy by the sessile drop technique and the application of Owens and Wendt equations. Human osteoblast SaOS-2 was cultured to determine cell adhesion, proliferation, and differentiation. Microbiological studies were performed with two common bacterial strains in oral infection, E. faecalis and S. gordonii, at different times of culture. The roughness obtained for the smooth surface was Sa = 0.23 and for the rough surface it was 1.98 μm. The contact angles were more hydrophilic for the smooth surface (61.2°) than for the rough surface (76.1°). However, the surface energy was lower for the rough surface (22.70 mJ/m²) in both its dispersive and polar components than the smooth surface (41.77 mJ/m²). Cellular activity in adhesion, proliferation, and differentiation was much higher on rough surfaces than on smooth surfaces. After 6 h of incubation, the osteoblast number in rough surfaces was more than 32% higher in relation to the smooth surface. The cell area in smooth surfaces was higher than rough surfaces. The proliferation increased and the alkaline phosphatase presented a maximum after 14 days, with the mineral content of the cells being higher in rough surfaces. In addition, the rough surfaces showed greater bacterial proliferation at the times studied and in the two strains used. Hybrid implants sacrifice the good osteoblast behavior of the coronal part of the implant in order to obstruct bacterial adhesion. The following fact should be considered by clinicians: there is a possible loss of bone fixation when preventing peri-implantitis.

Evaluation of one-piece zirconia dental implants: An 8-year follow-up study

OBJECTIVES

Long-term studies of modern zirconia implants are still insufficient. This prospective 8-year follow-up study investigated one-piece zirconia implants.

MATERIALS AND METHODS

Patients who had received a one-piece zirconia dental implant (PURE ceramic implant, Institut Straumann GmbH, Basel, Switzerland) were included in this study. Next to the implant survival and success rates, the radiographic and clinical implant parameters were assessed.

RESULTS

The overall survival rate of 67 zirconia implants in 39 patients was 100%. The overall success rate was 89.6%. Around the immediate zirconia implants, the success rate was 94.7%, and around the delayed implants, 87.5%. The immediate implants showed a significantly higher bone crest compared to the delayed implants (p = 0.0120). According to the pink esthetic score, the immediate implants revealed more favorable esthetic results compared to the delayed implants after an 8-year follow-up (p = 0.0002).

CONCLUSIONS

After 8 years, the one-piece zirconia implants presented an 89.6% success rate. Regarding the timing of implantation, in individual cases, immediate implantation can have slight advantages over delayed implantation.

CLINICAL RELEVANCE

Immediate implants can also be considered for zirconia implants and should not be excluded on principle.

Corrosion Resistance and Titanium Ion Release of Hybrid Dental Implants

One of the strategies for the fight against peri-implantitis is the fabrication of titanium dental implants with the part close to the neck without roughness. It is well known that roughness favors osseointegration but hinders the formation of biofilm. Implants with this type of structure are called hybrid dental implants, which sacrifice better coronal osseointegration for a smooth surface that hinders bacterial colonization. In this contribution, we have studied the corrosion resistance and the release of titanium ions to the medium of smooth (L), hybrid (H), and rough (R) dental implants. All implants were identical in design. Roughness was determined with an optical interferometer and residual stresses were determined for each surface by X-ray diffraction using the Bragg-Bentano technique. Corrosion studies were carried out with a Voltalab PGZ301 potentiostat, using Hank's solution as an electrolyte at a temperature of 37 °C. Open-circuit potentials (Eocp), corrosion potential (Ecorr), and current density (icorr) were determined. Implant surfaces were observed by JEOL 5410 scanning electron microscopy. Finally, for each of the different dental implants, the release of ions into Hank's solution at 37 °C at 1, 7, 14, and 30 days of immersion was determined by ICP-MS. The results, as expected, show a higher roughness of R with respect to L and compressive residual stresses of -201.2 MPa and -20.2 MPa, respectively. These differences in residual stresses create a potential difference in the H implant corresponding to Eocp of -186.4 mV higher than for the L and R of -200.9 and -192.2 mV, respectively. The corrosion potentials and current intensity are also higher for the H implants (-223 mV and 0.069 μA/mm²) with respect to the L (-280 mV and 0.014 μA/mm² and R (-273 mV and 0.019 μA/mm²). Scanning electron microscopy revealed pitting in the interface zone of the H implants and no pitting in the L and R dental implants. The titanium ion release values to the medium are higher in the R implants due to their higher specific surface area compared to the H and L implants. The maximum values obtained are low, not exceeding 6 ppb in 30 days.

Influence of Smoking on Periodontal and Implant Therapy: A Narrative Review

BACKGROUND

smoking is considered the most modifiable risk factor for periodontal disease.

OBJECTIVE

the aim of this narrative review is to emphasize the effect of smoking on periodontal and implant therapy.

METHODS

The authors reviewed the literature reporting the clinical outcomes of smoking on periodontal surgical and nonsurgical treatment. The impact of smoking on implant therapy and sinus lifting procedures were also reviewed.

RESULTS

Periodontal and implant therapy outcomes are adversely affected by smoking. Smokers respond less favorably to periodontal therapy and periodontal flap procedures as compared to nonsmokers. Clinical outcomes for smokers are 50-75% worse than for nonsmokers. Studies reveal that smokers experience a significantly lower reduction in pocket depth compared to nonsmokers as well as less bone growth after treating infra-bony defects with guided tissue regeneration. The relative risk of implant failure is significantly higher in patients who smoke 20 cigarettes or more per day compared to nonsmokers. Additionally, smoking has also been shown to increase postoperative wound dehiscence and infection rates following sinus floor elevation. Longitudinal studies on smoke cessation have shown a reduction in bone loss and probing depths for periodontitis patients after cessation compared to those who smoke.

CONCLUSION

Smoking cessation can reduce probing depths and improve clinical attachment after nonsurgical periodontal therapy. There is insufficient evidence regarding the effect of smoking on peri-implantitis, as well as the loss of implants in the long-term.

Impact of salivary contamination during implant placement with different surface characteristics in native and augmented bone: An in vivo study in sheep calvaria model

OBJECTIVES

The aim of this study was to evaluate whether salivary contamination during placement of implants with different surface characteristics affects osseointegration in native and in augmented bone areas.

MATERIALS AND METHODS

Forty eight implants with machined surface (MS) and 48 implants with moderately rough surface (RS) were tested in the calvaria of 12 sheep. At the first surgery, 64 bony critical defects were randomly created and were subsequently augmented with two materials (autogenous or bovine bone). After 5 weeks of graft healing, 8 implants were placed per sheep, in native bone and in the centre of the augmented defects. Forty eight implants were soaked with saliva before placement (contaminated group [CG]), while 48 implants were not (non-contaminated group [NCG]). Five weeks after implant placement, bone-to-implant contact (BIC) and bone material area fraction occupancy (BMAFO) were calculated histomorphometrically.

RESULTS

Saliva contamination showed a significant negative effect (p = .000) on BIC, especially in augmented areas. RS showed significant positive effect on BIC, compared to MS (p = .000), while there were no significant differences for different bone conditions (p = .103). For BMAFO, the contamination showed a significantly negative affect (p = .000), while there were no significant differences for surface characteristics (p = .322) and for bone condition (p = .538).

CONCLUSION

Saliva contamination during dental implant placement has a negative effect on osseointegration in augmented areas. Moderately rough surface has a possible advantage in the aspect of initial bone to implant contact. However, it seems to be advisable to avoid saliva contamination especially for implants placed in augmented bone areas.

The use of autologous bone for augmentation procedures leads to low prevalence of peri-implantitis-a retrospective study over a 20-year period

The aim of this study was to compare the prevalence of peri-implantitis in implants inserted into pristine bone (control) to implants where autologous bone was used for grafting procedures (study). All patients who underwent implant surgery during a 20 years interval by one maxillofacial implant surgeon and received a prosthodontic rehabilitation afterwards were eligible for inclusion in the study. Periimplant bone resorption and periimplant disease were assessed. Of 421 patients 384 (91.2%) patients responded to a recall after having been treated over a 20-year period by one maxillofacial surgeon and several dentists. A total of 110 patients had 239 implants in pristine bone, and 274 patients had 607 implants placed in combination with autologous bone grafting procedures. Mean time in function was 74 months (range 15-236 months). In all, 342 implants (34.8%) were in function for longer than 7 years. A total of 64 implant sites (7.6%) in 39 patients (10.2%) showed signs of peri-implant mucositis. In addition, 17 implants (2.0%) in 14 patients (3.6%) revealed signs of peri-implantitis, of which five implants were in the control group (2.09%) whereas 12 implants were in the study group (1.98%), with no statistically significant difference (p = 0.8405). More than half of the patients with peri-implantitis had a history of periodontitis. Three implants were lost due to peri-implantitis and four implants failed for other reasons, resulting in an overall success rate of 99.2% in 846 implants. CONCLUSIONS: Within the limitations of the study it seems that the use of autologous bone still is a relevant option when performing augmentation procedures because of the low prevalence of peri-implantitis.

Common practices of dental implants maintenance among dental hygiene professionals in Israel and Germany

OBJECTIVE

The aim of this study was to assess the common practices of dental implant maintenance among dental hygiene professionals (DHP) in Israel (IL) and Germany (GE).

METHODS

An online questionnaire was developed by the Periodontology Departments of Tel Aviv (IL) and Frankfurt University (GE) to address demographics, training, prevention and treatment of peri-implant diseases. The questionnaire was distributed by DHP associations via social media.

RESULTS

The responses of 376 DHPs (IL: 169; GE: 207) were analysed. Most participants were female (IL: 168/99%; GE: 203/98%), had received education (IL: 179/97%; GE: 207/97%) and were working in their home countries (IL: 182/99%; GE: 211/99%). Peri-implant probing was not performed by 22% of DHPs in IL and 5% in GE. Of the DHPs who used probes, 49% used metal probes in IL, while 40% used plastic probes in GE (p < 0.001). A majority of DHPs performed peri-implant instrumentation (IL: 168/99%; GE: 190/92%). Most DHPs from IL did not use devices other than hand and/or sonic/ultrasonic instruments for peri-implant cleaning (IL: 130/77%; GE 5/2%); in GE, the use of airflow (IL: 31/18%; GE: 199/96%) is popular (p < 0.001).

CONCLUSIONS

Most DHPs in IL and GE perform peri-implant probing and debridement. However, there are some distinct differences between the two countries regarding the choice of instruments and treatment regimens.

Comparison of heat production and bone architecture changes in the implant site preparation with compressive osteotomes, osseodensification technique, piezoelectric devices, and standard drills: an ex vivo study on porcine ribs

This study aimed at investigating differences in heat generation and bone architecture following four different implant site preparation techniques: compressive osteotomes, conventional drills, osseodensification (OD mode with osseodensification drills), and piezoelectric systems. Porcine rib bones were used as a model for implant surgery. Thermocouples were employed to measure temperature changes, and micro-CT to assess the bone architecture. The primary stability and insertion torque values of the implants placed in the differently prepared sites were assessed. The temperature changes were higher with Piezo. The average primary stability using the ISQ scale was the greatest for drills (76.17 ± 0.90) and the lowest for osteotomes (71.50 ± 11.09). Insertion torque was significantly higher with the osseodensification method (71.67 ± 7.99 Ncm) in comparison to drills, osteotomes, and piezo. Osteotomes showed the highest bone to implant contact percentage (39.83 ± 3.14%) and average trabecular number (2.02 ± 0.21 per mm), while drills exhibited the lowest (30.73 ± 1.65%; 1.37 ± 0.34 per mm). Total implant site bone volume was the highest with osseodensification (37.26 ± 4.13mm³) and the lowest for osteotomes (33.84 ± 3.84mm³). Statistical analysis showed a high primary stability and decrease in temperature during implant site preparation with osseodensification technique. The results support the use of osseodensification technique for implant site preparation.

ISP good clinical practice recommendations for gum care

Oral health is vital for the general well-being, overall body health and the quality of life throughout our lifetime. Most of the oral diseases and conditions are largely related to the maintenance of oral hygiene, lacking that people suffer from diverse oral diseases at different times in their life. With greater life expectancy, the individuals have teeth involved with periodontal diseases that would not only require professional care but also home gum care for them to last a lifetime. Indian Society of Periodontology (ISP) has recognized the need for systematic documents to update everyday clinical practice of general dental practitioners and have provided evidence-based consensus documents, namely good clinical practice recommendations from time to time to raise the oral health-related awareness and standards of oral healthcare delivery across the country. The current set of clinical practice recommendations focused to "Gum Care for All", is aimed at emphasizing and enhancing the awareness regarding oral health promotion, maintenance, and disease prevention. Twenty-five subject matter experts from across the nation, prepared these recommendations after a thorough literature review and group discussions. The document has been prepared in three distinct sections, namely pretherapeutic, therapeutic, and post therapeutic, to provide guidance during the respective phases of patient management and may serve as a quick and concise reference to the readers. The guidelines shall provide the distinct definitions, signs and symptoms, treatment required; recall visit specifications for plausible clinical case situations, home care advice regarding maintenance of oral hygiene including information on brushing technique, care and change of brush, use of interdental aids, and mouthwashes, etc. The document should advocate and guide the combined efforts of general dentists, and the population at large toward an empowered, evidence based, integrated, and comprehensive oral health care, which shall enhance the healthful functioning and longevity of the dentition and general health of the individual.

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

OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Digital versus radiographic accuracy evaluation of guided implant surgery: an in vitro study

Background

Cone-beam computed tomography (CBCT) is the most widely used method for postsurgical evaluation of the accuracy of guided implant surgery. However, the disadvantages of CBCT include radiation exposure, artifacts caused by metal implants, and high cost. Few studies have introduced a digital registration method to replace CBCT for evaluating the accuracy of guided surgery. The purpose of this study was to compare digital registration to conventional CBCT in terms of the capacity to evaluate the implant positioning accuracy of guided surgery.

Materials and methods

This in vitro study included 40 acrylic resin models with posterior single mandibular tooth loss. Guided surgery software was used to determine the optimal implant position; 40 tooth-supported fully guided drilling templates were designed and milled accordingly. After the guided surgery, the accuracies of the surgical templates were evaluated by conventional CBCT and digital registration. For evaluation by conventional CBCT, postsurgical CBCT scans of the resin models were performed. The CBCT data were reconstructed and superimposed on the implant planning data. For digital registration, we constructed a virtual registration unit that consisted of an implant replica and a scan body. Next, we obtained postsurgical optical scans of resin models with the scan body. The postsurgical implant position was identified by superimposition of the registration unit and optical scan data. The implant planning data and postsurgical implant position data were superimposed; deviations were reported in terms of distance for implant entry/apex point and in terms of angle for the implant axis. Interclass correlation coefficients (ICCs) and Bland–Altman plots were used to analyze the agreement between the two evaluation methods.

Results

The ICCs between the two methods were 0.986, 0.993, and 0.968 for the entry point, apex point, and angle, respectively; all were significantly greater than 0.75 (p < 0.001). Bland–Altman plots showed that the 95% limits of agreement of the differences were − 0.144 to + 0.081 mm, − 0.135 to + 0.147 mm, and − 0.451° to + 0.729° for the entry point, apex point, and angle, respectively; all values were within the maximum tolerated difference.

Conclusion

Conventional CBCT and digital registration showed good agreement in terms of evaluating the accuracy of implant positioning using tooth-supported surgical templates.

Dental implants in dentate primary and secondary Sjögren's syndrome patients: A multicenter prospective cohort study

OBJECTIVES

To prospectively assess the clinical performance and patient-reported outcomes of dental implants in dentate patients with primary and secondary Sjögren's syndrome (pSS and sSS, respectively) compared to patients without SS.

MATERIALS AND METHODS

Thirty-seven implants were placed in 17 patients with pSS/sSS and 26 implants in 17 non-SS patients to replace missing (pre)molars. Clinical performance, marginal bone-level changes, patient satisfaction, and oral health-related quality of life (OHRQoL) were assessed at 1 (T1), 6 (T6), 12 (T12), and 18 (T18) months after placement of the superstructure. Marginal bone-level changes were measured on standardized dental radiographs. Clinical parameters included implant and crown survival, plaque, bleeding and gingival indices, and probing depth. Patient satisfaction and OHRQoL were assessed with validated questionnaires.

RESULTS

Implant survival at T18 was 100% in the patients with pSS/sSS and 96.2% in the non-SS group. Mean marginal bone loss at T18 did not differ between patients with pSS/sSS and non-SS patients, 1.10 ± 1.04 and 1.04 ± 0.75 mm, respectively (p = .87). Clinical performance was good with no differences between the groups for all outcome measures (p > .05). OHRQoL in patients with pSS/sSS had improved significantly after placement of implant supported crowns at all measuring moments compared to baseline (p < .05). Nevertheless, patient satisfaction and OHRQoL remained significantly higher for patients without SS at all measuring moments (p < .05).

CONCLUSION

Dental implants can be successfully applied in dentate patients with pSS/sSS and have a positive effect on OHRQoL.

Clinical outcomes of different implant types in mandibular bar-retained overdentures: a retrospective analysis with up to 20 years follow-up

PURPOSE

To determine the clinical and radiological outcomes of hybrid-design- (HD) and bone-level (BL) implants for bar-retained mandibular implant-overdentures (IODs).

METHODS

For this retrospective study, edentulous patients who had received maxillary complete dentures and mandibular bar-retained IODs were invited for a follow-up assessment. Implant survival, implant success and health of peri-implant tissues were assessed on an implant level-based analysis. Patient-based parameters served to identify risk factors for peri-implant bone loss, presence of peri-implantitis and success.

RESULTS

Eighty patients (median age 72.72 [67.03; 78.81] years, 46 females) with 180 implants (median follow-up 12.01 [10.82; 21.04] years) were assessed. There was no difference concerning the rate of implant failure (p = 0.26), or peri-implantitis (p = 0.97) between HD and BL implants. Solely in one study group, there was the presence of peri-implant pus. Implant success was higher in BL implants with one group being notably higher than the comparing groups (p = 0.045). For bone loss, a width of keratinized mucosa (KM) ≤ 1 mm (p = 0.0006) and the presence of xerostomia (p = 0.09) were identified as risk factors. Smoking (p = 0.013) and a higher body mass index (BMI) (p = 0.03) were a risk factor for peri-implantitis. As risk factors for reduced implant success, a small width of KM (p = 0.003) and the presence of xerostomia (p = 0.007) were identified.

CONCLUSIONS

For mandibular bar-retained IODs, both BL and HD implants are mostly successful. A minimum of 1 mm KM around implants and normal salivary flow are relevant factors for implant success and stable peri-implant bone levels. Smoking and a high BMI are potential risk factors for peri-implantitis.

The Effect of Microcosm Biofilm Decontamination on Surface Topography, Chemistry, and Biocompatibility Dynamics of Implant Titanium Surfaces

Since the inception of dental implants, a steadily increasing prevalence of peri-implantitis has been documented. Irrespective of the treatment protocol applied for the management of peri-implantitis, this biofilm-associated pathology, continues to be a clinical challenge yielding unpredictable and variable levels of resolution, and in some cases resulting in implant loss. This paper investigated the effect of microcosm biofilm in vitro decontamination on surface topography, wettability, chemistry, and biocompatibility, following decontamination protocols applied to previously infected implant titanium (Ti) surfaces, both micro-rough -Sandblasted, Large-grit, Acid-etched (SLA)-and smooth surfaces -Machined (M). Microcosm biofilms were grown on SLA and M Ti discs. These were treated with TiBrushes (TiB), combination of TiB and photodynamic therapy (PDT), combination of TiB and 0.2%CHX/1%NaClO, plus or minus Ultraviolet-C (UV-C) radiation. Surface topography was evaluated by Scanning Electron Microscopy (SEM) and Laser Surface Profilometry. Surface function was analysed through wettability analysis. Surface chemistry evaluation of the discs was performed under SEM/Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). Biocompatibility was tested with the cytocompatibility assay using human osteoblast-like osteosarcoma cell line (MG-63) cells. Elemental analysis of the discs disclosed chemical surface alterations resulting from the different treatment modalities. Titanium, carbon, oxygen, sodium, aluminium, silver, were identified by EDX as the main components of all the discs. Based on the data drawn from this study, we have shown that following the decontamination of Ti surfaces the biomaterial surface chemistry and topography was altered. The type of treatment and Ti surface had a significant effect on cytocompatibility (p = 0.0001). Although, no treatment modality hindered the titanium surface biocompatibility, parameters such as the use of chemical agents and micro-rough surfaces had a higher cytotoxic effect in MG-63 cells. The use of smooth surfaces, and photofunctionalisation of the TiO₂ layer had a beneficial effect on cytocompatibility following decontamination.

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

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

Development of a new preclinical model to study early implant loss: a validation study in the beagle dog

Objectives

To develop a new preclinical model to study early implant loss, where local infection conditions would impair the implant osseointegration.

Materials and methods

Forty-eight smooth, 2.9-mm diameter experimental implants were placed in the mandible of 8 beagle dogs (3 in each side). In half of the animals (test group, n = 24 implants), the implants received ligatures around the implant-abutment connection. In the other half, no ligatures were placed (control group, n = 24 implants). Four weeks later, implants were extracted in a flapless approach and standard 3.3-mm diameter SLActive implants were placed into the same osteotomy site without any further drilling. Eight weeks after the second implantation, animals were sacrificed and analyzed in terms of implant survival.

Results

After 8 weeks of healing, 4 implants were lost in the control group and 14 in the test group. This corresponded to a 17.4% of early implant loss in the control group and 58.3% in the test. Most of the early failures occurred within the first 5 weeks of healing.

Conclusions

Implants placed in a pre-contaminated site present higher early loss than those placed in a non-contaminated site. This study represents a valid and robust preclinical model to study mechanisms and reduction of early implant loss as new technologies become available.

Clinical relevance

Scientific rationale for the study: There is lack of animal models to study early implant loss. Thus, a proposal of a new model is presented. With the validation of this model, new technologies can be implemented to prevent early implant loss.

Bone morphogenetic protein-2 incorporated calcium phosphate graft promotes peri-implant bone defect healing in dogs: A pilot study

Objectives

The evaluation of three different drug delivery modes of bone morphogenetic protein‐2 (BMP‐2) in healing peri‐implant bone defects in beagle dogs. BMP‐2 was incorporated in or onto calcium phosphate (CaP) granules in various ways: (i) directly on the outer layer of granules CaP: as an adsorbed depot; (ii) during the entire precipitation process of CaP: an internally incorporated depot; or (iii) during the biomimetic coating precipitation of BMP‐2 on the surface of CaP granules: as a coating incorporated depot.

Material and Methods

After extraction of the lower molars and wound healing in 6 male beagle dogs, 36 implants were placed (n = 6 animal per group). Peri‐implant bone defects were induced. The following treatment groups were evaluated: no treatment; air abrasive surface cleaning (SC) using hydroxyapatite; SC and the subsequent filling of the defect with CaP without BMP‐2; SC plus the subsequent filling of the defect with CaP adsorbed BMP‐2; SC plus the subsequent filling of the defect with CaP internally incorporated BMP‐2; SC plus the subsequent filling of the defect with CaP coating incorporated BMP‐2. Histological and histomorphometric analyses were carried out to quantify and compare the changes in bone tissue surrounding the treated implants.

Results

In Group 1 with no treatment, four implants were lost. Group 5 with the SC and the subsequent filling of the defect with internally incorporated BMP‐2 biomimetically prepared CaP (BioCaP), whereby the BMP‐2 is incorporated in the entire volume of all BioCaP particles, showed overall the best results to regenerate bone around the implants.

Conclusion

This study concluded that the group treated with SC plus the subsequent filling of the defect with CaP BMP‐2 internally incorporated BMP‐2, whereby BMP‐2 has been incorporated in the entire volume of all CaP particles, showed overall the best results when aiming to regenerate bone around the implants.

Predicting the Risk of Dental Implant Loss Using Deep Learning

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Analysis of acute sinusitis-related early failed implant surface: a combined histological, electron microscopy, and X-ray spectroscopy approach

Background

Even though dental implants are a reliable choice for dental rehabilitation, implant failures due to various etiologies have been reported. Early implant failures account for 2 to 6% of installed implants and are reported to have a higher rate than late failures, regardless of loading time. We herein report three cases of acute sinusitis and early implant failure with implants that failed within 1 month after installation. The aim of this study was to evaluate the surface properties of early failed implants and peri-implant tissue to determine the early osseointegration pattern in acute sinusitis-related failed implants as well as the possible role of surface contamination in the failure of osseointegration.

Results

A combined histological, electron microscopy, and X-ray spectroscopy approach was used to characterize the surface of non-osseointegrated titanium implants and the surrounding biological tissues. Morphologic scanning electron microscopy revealed a heterogeneous surface and irregular osseointegration. The implant surface was covered mostly by carbon- and oxygen-rich organic matter. Energy-dispersive X-ray spectroscopy surface analysis of three implants showed the incorporation of some contaminants in both the upper and apical regions. Carbon, nitrogen, sodium, silicon, chlorine, sulfur, gold, and zirconium were detected on the surface of one or more failed implants. Fibrosis, lymphocytic, and macrophage infiltrates and a high activation of osteoclasts surrounding the bone graft particles were detected in the surrounding tissues.

Conclusions

The etiology and mechanism of early implant failure, especially in sinus-related cases, as well as the proper management interventions to minimize the rate of early implant failures, are of great concern. No matter how confident and accurate the surgeon’s operation, there may be unknown errors in the whole procedure that no one knows about. Rather than errors related to the implant surface, it is expected that there were invisible problems during the evaluation of the patient’s own unique sinus mucosal inflammation or the operator’s own procedure. Furthermore, well-designed researches are necessary to reveal the effect of material-related factors on acute sinus complication and early implant failure.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of decontamination efficacy of two electrolyte cleaning methods to diode laser, plasma, and air-abrasive devices

OBJECTIVE

To compare the in vitro decontamination efficacy of two electrolytic cleaning methods to diode laser, plasma, and air-abrasive devices.

MATERIAL AND METHODS

Sixty sandblasted large-grit acid-etched (SLA) implants were incubated with 2 ml of human saliva and Tryptic Soy Broth solution under continuous shaking for 14 days. Implants were then randomly assigned to one untreated control group (n = 10) and 5 different decontamination modalities: air-abrasive powder (n = 10), diode laser (n = 10), plasma cleaning (n = 10), and two electrolytic test protocols using either potassium iodide (KI) (n = 10) or sodium formate (CHNaO₂) (n = 10) solution. Implants were stained for dead and alive bacteria in two standardized measurement areas, observed at fluorescent microscope, and analyzed for color intensity.

RESULTS

All disinfecting treatment modalities significantly reduced the stained area compared to the untreated control group for both measurement areas (p < 0.001). Among test interventions, electrolytic KI and CHNaO₂ treatments were equally effective, and each one significantly reduced the stained area compared to any other treatment modality (p < 0.001). Efficacy of electrolytic protocols was not affected by the angulation of examined surfaces [surface angulation 0° vs. 60° (staining %): electrolytic cleaning-KI 0.03 ± 0.04 vs. 0.09 ± 0.10; electrolytic cleaning-CHNaO2 0.01 ± 0.01 vs. 0.06 ± 0.08; (p > 0.05)], while air abrasion [surface angulation 0° vs. 60° (staining %): 2.66 ± 0.83 vs. 42.12 ± 3.46 (p < 0.001)] and plasma cleaning [surface angulation 0° vs. 60° (staining %): 33.25 ± 3.01 vs. 39.16 ± 3.15 (p < 0.001)] were.

CONCLUSIONS

Within the limitations of the present in vitro study, electrolytic decontamination with KI and CHNaO₂ was significantly more effective in reducing bacterial stained surface of rough titanium implants than air-abrasive powder, diode laser, and plasma cleaning, regardless of the accessibility of the contaminated implant location.

CLINICAL RELEVANCE

Complete bacterial elimination (residual bacteria < 1%) was achieved only for the electrolytic cleaning approaches, irrespectively of the favorable or unfavorable access to implant surface.

Dental implant failure rates in patients with self-reported allergy to penicillin

BACKGROUND

In a number of previous studies, patients with reported penicillin allergies have been documented to experience higher rates of dental implant failure than those who had not reported this allergy. The authors of this study aimed to determine whether an increased risk of implant failure is associated with patient-reported penicillin allergy and which antibiotic was administered.

METHODS AND MATERIALS

A retrospective study was conducted through chart review of patients who received dental implants at the New York University College of Dentistry. Participants were eligible if they received one or more dental implants at the College and provided at least 1 year of follow-up data.

RESULTS

The overall implant failure rate was 12.9%. The failure rate in patients who reported no allergy to penicillin and took amoxicillin was 8.4%, while the failure rate in the allergy-reporting group was 17.1% (adjusted OR = 2.22, 95% CI = 1.44-3.44). The failure rate in allergy-reporting patients who took Clindamycin was also higher than in those who took amoxicillin (19.9%; adjusted OR = 2.9, 95% CI = 1.77-4.47) or any antibiotic other than amoxicillin (20.9%; adjusted OR = 2.77, 95% CI = 1.77-4.32).

CONCLUSIONS

Significant findings included a lower implant failure rate in patients taking amoxicillin than in patients taking other antibiotics. There was a significant increase in early implant failure in allergy reporting patients.

Design and Evaluation of Web-Based Dental Implant Registry (DIR) for Better Clinical Outcomes

Introduction

Identification of dental implant system in undocumented patients is a major challenge for dentists due to the vast variety of tools and technologies that are used in dental care. It also takes a long time to identify the type of connection or length and diameter of implant. To obtain accurate and timely information, it is necessary to have a Dental Implant Registry (DIR). In the present study, a DIR was designed, developed, and evaluated at the Dental Implant Research Center of Tehran University of Medical Sciences.

Materials and Methods

This is an applied, developmental, and cross-sectional study that was conducted between 2018 and 2020. In the present study, after determining the objectives of DIR system, its conceptual model was designed by EDraw Max 7.9 software. Then, the registry was developed in Visual Studio 2018 environment with the C# programming language and, finally, it was evaluated by Nielsen's ten principles of usability assessment.

Results

After creating the registry, its data entry search and report functions were tested. Also, in the exploratory evaluation, the highest number of problems related to the principles of system clarity and compatibility between the system and real world was identified.

Conclusion

The web-based DIR created in C# programming language has the ability to gather data, provide report with different access levels, and send text messages to patients for follow-up. This tool enables physicians to quickly identify the components of dental implant. The web-based DIR also provides support for health research, quality assessment, and dental performance assessment.

Etiology, occurrence, and consequences of implant loss

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

Characteristics of Particles and Debris Released after Implantoplasty: A Comparative Study

Titanium particles embedded on peri-implant tissues are associated with a variety of detrimental effects. Given that the characteristics of these detached fragments (size, concentration, etc.) dictate the potential cytotoxicity and biological repercussions exerted, it is of paramount importance to investigate the properties of these debris. This study compares the characteristics of particles released among different implant systems (Group A: Straumann, Group B: BioHorizons and Group C: Zimmer) during implantoplasty. A novel experimental system was utilized for measuring and collecting particles generated from implantoplasty. A scanning mobility particle sizer, aerodynamic particle sizer, nano micro-orifice uniform deposit impactor, and scanning electron microscope were used to collect and analyze the particles by size. The chemical composition of the particles was analyzed by highly sensitive microanalysis, microstructures by scanning electron microscope and the mechanical properties by nanoindentation equipment. Particles released by implantoplasty showed bimodal size distributions, with the majority of particles in the ultrafine size range (<100 nm) for all groups. Statistical analysis indicated a significant difference among all implant systems in terms of the particle number size distribution (p < 0.0001), with the highest concentration in Group B and lowest in Group C, in both fine and ultrafine modes. Significant differences among all groups (p < 0.0001) were also observed for the other two metrics, with the highest concentration of particle mass and surface area in Group B and lowest in Group C, in both fine and ultrafine modes. For coarse particles (>1 µm), no significant difference was detected among groups in terms of particle number or mass, but a significantly smaller surface area was found in Group A as compared to Group B (p = 0.02) and Group C (p = 0.005). The 1 first minute of procedures had a higher number concentration compared to the second and third minutes. SEM-EDS analysis showed different morphologies for various implant systems. These results can be explained by the differences in the chemical composition and microstructures of the different dental implants. Group B is softer than Groups A and C due to the laser treatment in the neck producing an increase of the grain size. The hardest implants were those of Group C due to the cold-strained titanium alloy, and consequently they displayed lower release than Groups A and B. Implantoplasty was associated with debris particle release, with the majority of particles at nanometric dimensions. BioHorizons implants released more particles compared to Straumann and Zimmer. Due to the widespread use of implantoplasty, it is of key importance to understand the characteristics of the generated debris. This is the first study to detect, quantify and analyze the debris/particles released from dental implants during implantoplasty including the full range of particle sizes, including both micro- and nano-scales.

Correlation between Peri-Implant Marginal Bone Loss Progression and Peri-Implant Sulcular Fluid Levels of Metalloproteinase-8

Objectives: The aim of this retrospective study was to analyze peri-implant marginal bone loss levels/rates and peri-implant sulcular fluid levels/rates of metalloproteinase-8 in three timeframes (6 months post-surgery—restoration delivery (T0)—and 6 (T6) and 24 (T24)-months post-loading) and to evaluate if there is a correlation between peri-implant sulcular fluid levels of metalloproteinase-8 and peri-implant marginal bone loss progression. Materials and Methods: Two cohorts of patients undergoing implant surgery between January 2017 and January 2019 were selected in this retrospective study. A total of 39 patients received 39 implants with a laser-microtextured collar surface, and 41 subjects received 41 implants with a machined/smooth surface. For each patient, periapical radiographs and a software package were used to measure marginal bone loss rates. Implant fluid samples were analyzed by an enzyme-linked immunosorbent assay (ELISA) test. The modified plaque index, probing depth, and bleeding on probing were also recorded. Results: High marginal bone rates at T24 were strongly associated with elevated rates between T0 and T6. The levels of metalloproteinase-8 were significantly more elevated around implants with marginal bone loss, in relation to implants without marginal bone loss. Marginal bone loss (MBL) rates at 24 months were associated with initial bone loss rates and initial levels of metalloproteinase-8. Conclusions: Peri-implant marginal bone loss progression is statistically correlated to peri-implant sulcular fluid levels of metalloproteinase-8. Moreover, the initial high levels of marginal bone loss and metalloproteinase-8 can be considered as indicators of the subsequent progression of peri-implant MBL: implants with increased marginal bone loss rates and metalloproteinase-8 levels at 6 months after loading are likely to achieve additional marginal bone loss values.

Efficiency of cold atmospheric plasma, cleaning powders and their combination for biofilm removal on two different titanium implant surfaces

Objectives

Biofilm removal is the decisive factor for the control of peri-implantitis. Cold atmospheric pressure plasma (CAP) can become an effective aid due to its ability to destroy and to inactivate bacterial biofilm residues. This study evaluated the cleaning efficiency of CAP, and air-polishing with glycine (APG) or erythritol (APE) containing powders alone or in combination with CAP (APG + CAP, APE + CAP) on sandblasted/acid etched, and anodised titanium implant surface.

Materials and methods

On respective titanium discs, a 7-day ex vivo human biofilm was grown. Afterwards, the samples were treated with CAP, APG, APE, APG + CAP, and APE + CAP. Sterile and untreated biofilm discs were used for verification. Directly after treatment and after 5 days of incubation in medium at 37 °C, samples were prepared for examination by fluorescence microscopy. The relative biofilm fluorescence was measured for quantitative analyses.

Results

Air-polishing with or without CAP removed biofilms effectively. The combination of air-polishing with CAP showed the best cleaning results compared to single treatments, even on day 5. Immediately after treatment, APE + CAP showed insignificant higher cleansing efficiency than APG + CAP.

Conclusions

CAP supports mechanical cleansing and disinfection to remove and inactivate microbial biofilm on implant surfaces significantly. Here, the type of the powder was not important. The highest cleansing results were obtained on sandblasted/etched surfaces.

Clinical relevance.

Microbial residuals impede wound healing and re-osseointegration after peri-implantitis treatment. Air-polishing treatment removes biofilms very effectively, but not completely. In combination with CAP, microbial free surfaces can be achieved. The tested treatment regime offers an advantage during treatment of peri-implantitis.

Clinicoradiographic evaluation of long-term efficacy and risk factors associated with dental implants used for full mouth rehabilitation

Background:

Despite various complications and failure factors, newer implants are designed that allow placement in sub-optimal conditions to allow the operator to place implants at sites with low bone quality. These newer designs also allow improved stability with higher survival rates in the short term.

Aims:

The present study was undertaken to evaluate long-term efficacy and risk factors associated with dental implant placement for full mouth rehabilitation.

Materials and Methods:

In 24 subjects, 438 implants were placed. The data collected were surgical and were retrospectively analyzed. The data collected included medical history, local, patient satisfaction, marginal bone loss, and systemic risk factors affecting implant survival. Outcome variables assessed were peri-implantitis, implant success, and survival at the follow-up visit. The data were expressed in terms of percentage and number, and the results were derived.

Results:

Peri-implantitis was seen in 31.05% (n = 136) of implants. 76.02% (n = 333) of implants were considered successful at recall. Concerning survival, compromised and satisfactory survival was shown by 10.04% (n = 44) and 2.96% (n = 13) of implants, respectively. 10.95% (n = 48) of implants were considered as failures.

Conclusion:

The present study concludes that good, long-term survival rates are associated with full mouth rehabilitation using dental implants.

Evaluation of failed implants and reimplantation at sites of previous dental implant failure: survival rates and risk factors

Purpose

The purpose of this study was to evaluate failed implants and reimplantation survival and to identify the relative risk factors for implant re-failure.

Methods

Ninety-one dental implants were extracted between 2006 and 2020 at the National Health Insurance Service Ilsan Hospital, including 56 implants in the maxilla and 35 implants in the mandible that were removed from 77 patients. Patient information (e.g., age, sex, and systemic diseases) and surgical information (e.g., the date of surgery and location of the implants and bone grafts) were recorded. If an implant prosthesis was used, prosthesis information was also recorded.

Results

In total, 91 first-time failed dental implants in 77 patients were analyzed. Of them, 69 implants in 61 patients received reimplantation after failure. Sixteen patients (22 implants) refused reimplantation or received reimplantation at a different site. Eight of the 69 reimplants failed again. The 1-year survival rate of the 69 reimplants was 89.4%. Age at reimplantation and smoking significantly increased the risk of reimplantation failure. However, a history of taking anti-thrombotic agents showed a statistically significant negative association with reimplantation failure. Of the failed implants, 66% showed early failure and 34% showed late failure of the initial implantation. All 8 re-failed implants showed early failure. Only 3 of these 8 failed reimplants were re-tried and the second reimplants all survived.

Conclusions

The total survival rate of implants, which included reimplants and second reimplants was 99.2%, although the survival rate of the initial implantations was 96.3%. Previous failure did not affect the success of the next trial. Reimplantation failure was more strongly affected by patient factors than by implant factors. Therefore, each patient’s specific factors need to be meticulously controlled to achieve successful reimplantation.

Health economic aspects of implant-supported restorative therapy

BACKGROUND

It is poorly understood how much additional dental care patients consume subsequent to implant therapy. The aim of the present study is to evaluate costs associated with implant-supported restorative therapy during the long-term follow-up.

MATERIAL AND METHODS

Costs associated with preventive measures and complication-related procedures over a mean follow-up period of 8.2 years were assessed in patient files of 514 Swedish subjects provided with implant-supported restorative therapy. The restorative therapy and each of the subsequent interventions were assigned a specific cost. Accumulated costs were calculated in three categories: (i) total cost including initial restorative therapy and complication-related interventions, (ii) cost of preventive measures alone, and (iii) cost of complication-related procedures alone. Potential differences by background variables were analyzed using growth curve models.

RESULTS

In the whole sample, costs during follow-up ranged from 878 € (95% CI 743; 1,014) for patients with single-tooth restoration(s) to 1,210 € (95% CI 1,091; 1,329) for subjects with full-jaw restoration(s). The majority of costs during follow-up originated from preventive measures (741 € 95% CI 716; 766). Among individuals receiving ≥1 intervention dealing with a complication (n = 253), complication-related costs amounted to 557 € (95% CI 480; 634). For patients with full-jaw restorations, the corresponding amount was 769 € (95% CI 622; 916). Procedures related to peri-implantitis and technical complications resulted in costs similar to each other. Implant loss generated greater costs than any other type of complication.

CONCLUSIONS

Costs related to implant-supported restorative therapy during follow-up were associated with the extent of initial therapy. The higher costs during follow-up noted in patients provided with full-jaw restorations were explained by complication-associated procedures. Implant loss was the most costly type of complication.