Long‐Term Evaluation of ANKYLOS ® Dental Implants, Part I : 20‐Year Life Table Analysis of a Longitudinal Study of More Than 12,500 Implants

Risk factors associated with early implant failure: A retrospective review

PURPOSE

The purpose of this study was to investigate the association between possible risk factors and early implant failure.

PATIENTS AND METHODS

This retrospective cohort study included consecutive patients receiving dental implant treatment in a four-year timeframe. Patient-related variables (age, sex, smoking, and systemic disease), local factors (area, reason for tooth extraction, and bone quality), surgical variables (bone augmentation, time of implant placement, staging, and antibiotic prophylaxis), and implant-related factors (brand, length, and diameter) were analyzed. Bivariate analyses and multivariate logistic regression model were used to determine the variables associated with early implant failure.

RESULTS

The study group comprised 1323 implants in 738 patients with a mean of 1.8 implants/patient of which, 53 failed in 52 patients in the early stage (before final prosthetic loading). According to the multivariate model, smoking (Odds Ratio=1.836, P=0.031), posterior maxillary region (OR=2.958, P=0.006), implantation in place of teeth extracted due to periodontal problems (OR=2.531, P=0.004), bone type IV (OR=2.881, P=0.008), implant in previously augmented site (OR=2.239, P=0.014), and immediate provisional prosthesis (OR=3.418, P=0.019) were associated with a significantly higher risk of early implant failure. Narrow implants showed a significantly higher risk of early failure in bivariate analyses (P=0.012). However, the effect was no longer significant in the multivariate model (OR=2.322, P=0.068).

CONCLUSION

Early implant failure would be more expected in smokers, posterior maxilla, history of periodontal problems, type IV bone, augmented bone, and immediately loaded cases.

Guided tooth autotransplantation of a palatally impacted maxillary canine into the site of a failed maxillary canine implant

The aim of this report is to demonstrate the guided tooth autotransplantation of a palatally impacted maxillary canine into the site of a failed maxillary canine dental implant. A 47-year-old woman visited a dental clinic complaining of loose dental implant in the left maxillary canine site, tooth #11, as well as pain and swelling of the gum around the implant. The clinical examination revealed a mobile implant along with swollen soft tissues with bleeding on probing. A periapical radiograph demonstrated peri-implant marginal bone loss. Cone beam computed tomography sections revealed that tooth #11 was impacted palatally. The implant was removed and replaced with the impacted canine via guided autotransplantation and posterior orthodontic alignment. The patient was recalled at 1, 3, 6, 9, 12, 24 and 48 months after the procedure. During this period, the patient was symptom-free and radiographic examination at 2 years revealed no periapical pathosis or root resorption.

Evaluation of Survival Rates of Dental Implants and the Risk Factors: A Retrospective Follow-Up Study

Introduction The current research sets out to assess implant early survival rates and identify relevant parameters. Methods The research spanned the years 2021 and 2022 and included all individuals who had dental implants. Various criteria, such as age, sex, maxilla/mandible, implant location, immediate implant, implant diameter, implant length, and others, were used to determine the implant survival rate in the research. A multiple logistic regression model was used to show the risk variables for early survival rates of implants, and components with p < 0.05 were further included after the Chi-square test was employed to filter them. Results The current research included 128 patients who had a single implant procedure, including 70 males and 58 females. The early survival rate was 91.40%, and 117 implants were retained after implantation. Risk variables that were shown to be associated with early survival rates were patients aged 30-60 years (OR: 2.542), immediate implant placement (OR: 3.742), and implant length less than 10 mm (OR: 3.972). Conclusions Age, tooth location, implant length, and immediate implantation were risk variables that contributed to our subjects' above 91% early survival rate of implants.

Evaluation of a platform-switched Morse taper connection for all-on-four or six treatment in edentulous or terminal dentition treatment: A retrospective study with 1-8 years of follow-up

BACKGROUND

The survival rate, marginal bone loss and soft tissue health of the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients has not been reported in the clinical research.

PURPOSE

This retrospective study aimed to evaluate the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients after 1-8 years of follow-up.

MATERIALS AND METHODS

A retrospective study was conducted based on the medical records of 33 patients who received all-on-four or six treatments from April 2014 to May 2020. Four radiographic examinations [immediate postoperative (T0), definitive restorations (T1), 1-3 years after prosthetic restorations (T2), and more than 3 years after prosthetic restorations (T3)] were obtained to evaluate vertical bone height (VBH). We also calculated the survival rate and examined the condition of soft tissue with this implant system in edentulous or terminal dentition patients. Three-level linear model analyses were used to explore potential risk factors for VBH changes on the mesial and distal sides. The generalized linear model was used to analyze the influencing factors of BOP and plaque.

RESULTS

A total of 218 implants were included in this study. The cumulative survival rate of the implants was 97.25% before the definitive prosthesis, 96.33% within 3 years of follow-up and 95.32% after more than 3 years of follow-up. The mean ± standard deviation (SD) bone losses of the VBH were 0.27 ± 0.05 mm (T1-T3) on the mesial side and 0.49 ± 0.06 mm (T1-T3) on the distal side. During 1-8 years of follow-up, the height and angle of the abutment (p < 0.001), the mandible implant site (p < 0.001), the length of the implant (p = 0.014 < 0.05) and age (p = 0.029 < 0.05) showed statistically significant effects on vertical mesial bone height (VMBH) and vertical distal bone height (VDBH). The risk of BOP among participants who brushed three times a day was lower than those who brushed less than three times. The plaque risk of short abutment height was higher than the long abutment.

CONCLUSION

The current study showed that the Ankylos implants with the balanced base abutments in all-on-four or six implants treatment is a viable and predictable option with a high survival rate and low marginal bone loss in edentulous or terminal dentition patients. VBH around the implants was strongly associated with the mandible implant site, abutment height and angle, the length of the implant and age. Moreover, teeth-brushing times and abutment height significantly affect soft tissue health.

Single geometry abutment for narrow and extra-narrow implant systems: Survival and failure modes

The use of identical prosthetic components for all implant diameters could reduce the production costs by companies and the complexity of component selection for the clinician and his team. However, it would imply in reduction of thickness of the cervical walls of tapered internal connection implants, which could compromise the reliability of narrow and extra-narrow implants. Therefore, this study aims to evaluate the probability of survival and failure modes of extra-narrow implant systems with the same internal diameter as standard-diameter implants using the same prosthetic components. It was used eigth different implant system configurations, including narrow (Ø 3.3 mm) (N) extra-narrow (Ø 2.9 mm) (EN) and extra-narrow-scalloped (Ø 2.9 mm) (ENS) implants, both with cementable abutments (Ce) or titanium bases (Tib) and one-piece implants (Ø 2.5 mm and Ø 3.0 mm) (OP) (Medens, Itu, SP, Brazil), comprising the following groups: OP 3.0; OP 2.5; N Ce; N Tib; EN Ce, EN Tib, ENS-Ce and ENS-Tib. The implants were embedded using polymethylmethacrylate acrylic resin in a 15 mm matrix. Standardized maxillary central incisor crowns were virtually designed and milled to fit on the different studied abutments and cemented using a dual self-adhesive resin cement. The specimens were submitted to SSALT (Step Stress Accelerated Life Testing) at 15 Hz in water until failure or suspension of the test, until a maximum load of 500 N. Fractographic analysis of the failed specimens were realized in scanning electron microscopy. All implant systems demonstrated high probability of survival (90-100%) for missions at 50 and 100 N and values of characteristic strength superior to 139 N. Failure modes were restricted to the abutment in all the implant configurations tested. Therefore, the use extra-narrow implants with standardized prosthetic components for different implant diameters is a viable option for the replacement of anterior teeth.

Impact of Implant Diameter on the Early Survival Rate of Dental Implants in the Saudi Population: A One-Year Retrospective Study

Introduction The use of dental implants provides a revolutionary solution to the problem of missing teeth in the oral cavity. The aim of this study was to assess the early implant survival rate in relation to implant diameter and site of placement. Methods The data were collected from 186 patients treated between January 2019 and June 2021. All the implants were evaluated and restored after three months of implant placement. The early implant survival was calculated for different implant diameters with the odds ratio (OR). Results A total of 373 implants were placed. Implants were placed in the following areas: upper posterior area (UPA), n = 123, upper anterior area (UAA), n = 49, lower posterior area (LPA), n = 184, and lower anterior area (LAA), n = 17. Implants of the following diameters were placed: 3.5 mm (n = 129), 4.3 mm (n = 166), and 5 mm (n = 78). The overall early survival rate was 97.32% after three months of placement. The highest early survival rate was at LAA (100%) and the lowest early survival rate was at UAA (95.9%). The implants 5 mm in diameter had the highest early survival rate (98.72%), while the implants 3.5 mm in diameter had the lowest early survival rate (94.57%). The ORs of the early implant survival were 4.7 [95% confidence interval (CI): 0.96-23.05)] and 4.42 (95% CI: 0.53-36.61) for the 4.3 mm and 5 mm implants, respectively, with no statistical significance. Conclusions The implants placed in the oral cavity had acceptable survival rates regardless of implant diameter or site of placement.

The lack of keratinized mucosa as a risk factor for peri-implantitis: a systematic review and meta-analysis

This study aimed to investigate the effect of the lack of keratinized mucosa on the risk of peri-implantitis, while also accounting for possible confounding factors. A literature search was conducted in PubMed and Scopus, including human studies that assessed the presence and width of keratinized mucosa in relation to the occurrence of peri-implantitis. Twenty-two articles were included, and 16 cross-sectional studies we meta-analyzed. The prevalence of peri-implantitis was 6.68-62.3% on patient-level and 4.5-58.1% on implant-level. The overall analysis indicated that the lack of keratinized mucosa was associated with a higher prevalence of peri-implantitis (OR = 2.78, 95% CI 2.07-3.74, p < 0.00001). Similar results were shown when subgroup analyses were performed, including studies with a similar case definition of peri-implantitis (Marginal Bone Loss, MBL ≥ 2 mm) (OR = 1.96, 95% CI 1.41-2.73, p < 0.0001), fixed prostheses only (OR = 2.82, 95% CI 1.85-4.28, p < 0.00001), patients under regular implant maintenance (OR = 2.08, 95% CI 1.41-3.08, p = 0.0002), and studies adjusting for other variables (OR = 3.68, 95% CI 2.32-5.82, p = 0.007). Thus, the lack of keratinized mucosa is a risk factor that increases the prevalence of peri-implantitis and should be accounted for when placing dental implants.

Prevention of peri-implant disease in edentulous patients with fixed implant rehabilitations

OBJECTIVES

To provide an overview about the current approaches to prevent peri-implant diseases in edentulous patients with complete-arch implant-supported prostheses, and to review the clinical applications of the latest digital technologies for implant prosthodontics.

METHODS

A review of the guidelines to prevent peri-implant diseases in patient's receiving complete-arch implant-supported prostheses including facially driven treatment planning procedures using either conventional or digital methods, computer-aided implant planning procedures, and prosthodontic design variables including the optimal number and distribution of dental implants, implant to abutment connection type, implant or abutment level design, screw- or cement-retained alternatives, prostheses contours, and material selection is provided. Furthermore, an outline of the current therapeutic management approaches to address peri-implant diseases is reviewed.

CONCLUSIONS

Clinicians should understand and know different planning and design-related variables that can affect biological and mechanical complication rates of complete-arch implant-supported prostheses. Maintenance protocols are fundamental for minimizing biological and mechanical complications.

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

BACKGROUND

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Implications of considering peri-implant bone loss a disease, a narrative review

BACKGROUND

Peri-implantitis has been suggested to cause significant increasing proportions of implant failure with increasing time.

PURPOSE

To assess whether implant failure rates in long term studies are matching the supposed high prevalence of peri-implantitis.

MATERIAL AND METHODS

This paper is written as a narrative review of the long-term clinical investigations available in the literature.

RESULTS

Some implant systems have seen unacceptable marginal bone loss figures with time coupled to increased implant failure rates, resulting in the withdrawal of these systems. The reasons for such mishap are generally unknown, with the exception of one system failure that was found to be due to improper clinical handling. Modern, moderately rough implant systems have functioned excellently over 10-15 years of follow up with minor problems with marginal bone loss and implant failure rates within a few per cent. Machined implants have functioned adequately over 20-30 years of follow up. Implant failures occur predominantly during the first few years after implant placement. No significant increase of implant failures has been observed thereafter over 20-30 years of follow up. Over the years of our new millennium, scientific and technical advances have allowed the discovery of numerous molecular pathways and cellular interactions between the skeletal and immune system promoting the development of the interdisciplinary field called osteoimmunology. Nowadays, this knowledge has not only allowed the emergence of new etiologic paradigms for bone disease but also a new dynamic approach on the concept of osseointegration and MBL around oral implants, re-evaluating our older disease oriented outlook. This facilitates at the same time the emergence of translational applications with immunological perspectives, scientific approaches based on omics sciences, and the beginning of an era of personalized dental implant therapy to improve the prognosis of oral implant treatment.

CONCLUSIONS

Oral implant systems have been found to function with very good clinical outcome over follow-up times of 20-30 years. Registered implant failures have occurred predominantly during the first few years after implantation, and there has been no significant increase in late failures due to peri-implantitis.

Long-Term Results after Placing Dental Implants in Patients with Papillon-Lefèvre Syndrome: Results 2.5-20 Years after Implant Insertion

Aim: A retrospective evaluation of patients with Papillon-Lefèvre syndrome (PLS) treated with dental implants to identify factors that may influence treatment outcomes. Methods: All PLS patients with dental implants currently registered at the Department of Periodontology, Goethe-University Frankfurt (20–38 years; mean: 29.6 years), were recruited. Five patients from three families (two pairs of siblings) with a total of 48 dental implants (inserted in different dental institutions) were included with a follow-up time of 2.5–20 years (mean: 10.4 years). Results: Implant failure occurred in three patients (at least 15 implants). Nearly all patients demonstrated peri-implantitis in more or less advanced stages; 60% of patients demonstrated bone loss ≥50% around the implants. Two patients did not follow any supportive therapy. Conclusions: Implants in PLS patients who did not follow any maintenance programme had a high risk of peri-implantitis and implant loss.

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.

A retrospective study of 12,538 internal conical connection implants: focused on the long-term integrity of implant-abutment complexes

OBJECTIVES

To evaluate the long-term integrity of implant-abutment complexes in implant systems with two internal conical angles.

MATERIAL AND METHODS

12,538 bone-level implants of two systems placed between January 2012 and December 2018 were retrospectively analyzed. Cumulative abutment/implant fracture rates in systems with larger (LA, 7.5°) and smaller (SA, 5.7°) internal conical angles were estimated using Kaplan-Meier analysis and compared between groups. The association between implant systems and jammed abutment retrievability was evaluated by multivariable generalized estimating equation logistic regression modelling.

RESULTS

For LA, the 8-year cumulative incident rate was 0.10% (95% confidence interval (CI): 0-0.24%) for implant fracture and 0.26% (95% CI: 0.11%-0.41%) for abutment fracture, demonstrating a significant difference in gender (p = 0.03), implant diameter (p = 0.01), jaw (p = 0.006) and antagonist tooth (p < 0.001). For SA, the 8-year cumulative incident rate was 0.38% (95% CI: 0-0.79%) for implant fracture and 2.62% (95% CI: 0.05%-5.13%) for abutment fracture, which was influenced by implant diameter (p < 0.001) and site (p = 0.03). The cumulative implant/abutment fracture rate was lower for LA implants, particularly for LA implant-supported single crowns (SCs) (p < 0.05). The abutment-retrieval success rate was 92.8% for LA, and 57.1% for SA (p = 0.055).

CONCLUSION

LA implants exhibited a lower incidence of fracture in abutment-implant complexes and a relatively higher retrievability success rate for jammed abutments.

Peri-implant bone-level changes in the second decade of loading with regard to the implant-abutment connection: a retrospective study on implants under systematic aftercare

BACKGROUND

This retrospective study investigates the change in the peri-implant bone level (PBL) during the 2nd decade of intraoral function in patients complying with a 'supportive implant therapy' (SIT) program. The results were statistically analyzed with respect to the implant abutment connection used.

METHODS

In a private practice, only patients with 20-year SIT compliance were identified. Of these, all patients with 10- and 20-year radiographs available were selected. Therefore, no control group was possible and implant losses had to be excluded. Two experienced researchers assessed the peri-implant bone levels. As three different abutment connection concepts (bone-level butt-joint, bone-level conical and tissue-level conical) and two different implant surfaces (machined vs. roughened) were involved, statistical analyses were performed to detect potential differences.

RESULTS

Ninety-three implants from 36 patients with 20-year SIT compliance and available radiographs were included in the study. At study baseline (10 years intraoral), a mean bone loss of - 1.7 mm (median - 1.2; standard deviation [sd] 1.4, range: 0 to - 7.2) was recorded. After 20 years, we found a mean bone loss of - 2.5 mm (median - 2.3, sd 1.79, range: - 0.5 to + 7.4). Furthermore, we found a mean bone loss of 0.8 mm in intraoral function from year 10 to year 20 (mean: 0.08 mm per year); this change was independent of the abutment connection type.

CONCLUSIONS

During the 2nd decade of function, peri-implant bone loss in patients with SIT compliance might be small in value and should not be expected in all implants.

The survival rates and risk factors of implants in the early stage: a retrospective study

Background

Few large-sample studies in China have focused on the early survival of dental implants. The present study aimed to report the early survival rates of implants and determine the related influencing factors.

Methods

All patients receiving dental implants at our institution between 2006 and 2017 were included. The endpoint of the study was early survival rates of implants, according to gender, age, maxilla/mandible, dental position, bone augmentation, bone augmentation category, immediate implant, submerged implant category, implant diameter, implant length, implant torque, and other related factors. Initially, SPSS22.0 was used for statistical analysis. The Chi-square test was used to screen all factors, and those with p < 0.05 were further introduced into a multiple logistic regression model to illustrate the risk factors for early survival rates of implants.

Results

In this study, we included 1078 cases (601 males and 477 females) with 2053 implants. After implantation, 1974 implants were retained, and the early survival rate was 96.15%. Patients aged 30–60 years (OR  2.392), with Class I bone quality (OR  3.689), bone augmentation (OR  1.742), immediate implantation (OR  3.509), and implant length < 10 mm (OR  2.972), were said to possess risk factors conducive to early survival rates.

Conclusions

The early survival rate of implants in our cohort exceeded 96%, with risk factors including age, tooth position, bone quality, implant length, bone augmentation surgery, and immediate implantation. When the above factors coexist, implant placement should be treated carefully.

A four-year prospective study of self-assembling nano-modified dental implants in patients with type 2 diabetes mellitus

Background/purpose

Dental implantation has become an efficient and important method of replacing lost teeth. However, the success rate of dental-implant treatment in diabetics is higher than patients without diabetes. The aim of this study was to prospectively evaluate long-term marginal bone loss (MBL) and the stability of a self-assembling nano-modified implant in patients with type 2 diabetes mellitus compared with a conventional implant.

Materials and methods

Twenty-five patients with type 2 diabetes were recruited for this study. Through a random selection process, one site in each patient received a conventional implant and the other site received a nano-modified implant. The implant stability quotient was measured using resonance frequency analysis (RFA), and MBL was measured using panoramic radiography from uncovering to four-year follow-up.

Results

No significant difference in implant stability quotient was found between the two groups (P > 0.05), except for the time at implant insertion (P < 0.05). MBL in the nano-modified implant group exhibited a decreasing change compared with the conventional implant group, between the uncovering and the loading stage (P < 0.05), while there was no significant difference in other stages (P > 0.05).

Conclusion

There was potentially increased implant stability and diminished MBL around the self-assembling nano-modified implant in the uncovering-loading stage of early osseointegration in patients with type 2 diabetes.

Evaluation of the relationship between Periotest values, marginal bone loss, and stability of single dental implants: A 3-year prospective study

STATEMENT OF PROBLEM

Although the Periotest has been shown to provide reliable information about initial implant stability, whether Periotest values (PTVs) can be correlated with the stability of implants in function for several years is unclear.

PURPOSE

The purpose of this prospective clinical study was to investigate implant stability by using PTVs, as well as changes in stability and peri-implant marginal bone levels (as measured by radiographs) over a 3-year follow-up period. The exploratory hypothesis was that there is a significant correlation between PTVs and bone loss around the implant and that PTVs can provide predictive information about marginal bone-level changes and implant stability over time.

MATERIAL AND METHODS

The study population included patients who needed single-tooth replacement with restoration of cemented fixed partial dentures. Clinical data, PTVs, and periapical radiographs were collected at the time points of implant placement, 3 to 6 months after insertion, and 1 year, 2 years, and 3 years after the final definitive prosthetic restoration. Pearson correlation coefficient tests were performed to estimate the correlation between the PTVs received at the first follow-up time point and the subsequent PTVs received during the follow-up period (up to 3 years after the restoration). The Pearson test was applied, as well as the t test and repeated-measures ANOVA, to evaluate PTVs and bone loss changes over time. The Pearson test was also applied to estimate the correlation between the bone loss values measured at the first follow-up visit and the subsequent bone loss values at the annual follow-up time points (up to and including 3 years after the restoration).

RESULTS

A total of 43 implants were inserted in 34 patients (26 men and 8 women); the average patient age was 52.8 years. A significant reduction in implant stability was detected between implant insertion and the 3- to 6-month follow-up time point, which was then followed by a significant increase in stability at the 1-year follow-up time point and then stabilized during the 2- and 3-year follow-up time points (P<.014). Furthermore, a significant correlation was found between PTVs at the 1-year follow-up and the PTVs at all measured follow-up time points (P<.05). A positive correlation was obtained with high-strength correlation coefficient R (R>0.7) at all follow-up time points. Bone loss changes during the follow-up time points were significantly different and correlated with PTVs (P<.001).

CONCLUSIONS

The Periotest is a reliable device for assessing implant stability and providing predictive information about marginal bone level changes around an implant.

Incidence and prevalence of peri-implantitis and peri-implant mucositis 17 to 23 (18.9) years postimplant placement

PURPOSE

To evaluate the prevalence of peri-implantitis (PI) and peri-implant mucositis (PM) in a long-term follow-up with comparison among different PI and PM definitions, and to report on the incidence of PI.

MATERIALS AND METHODS

In a retrospective clinical study five different PI and PM definitions were applied onto a population with 274 implants 17 to 23 years postimplant placement. Recommendations by the Eighth European Workshop on Periodontology (EWOP) were used as base reference. Clinical and radiological measurements were considered. Risk factors were evaluated in a regression analysis.

RESULTS

After an average observation period of 18.9 years, 40.1% of the implants were diagnosed with PM and 15.0% with PI (Eighth EWOP). PI incidence reached 7.9% on implant level and 13.2% on patient level. Implants diagnosed with PI and progressive bone loss displayed exceptionally vertical bone defect configuration (BDC). Diabetes mellitus, smoking, regular maintenance, or a former periodontal infection did not show significant influence on the prevalence of peri-implant diseases. Patients with bruxism displayed significantly less PM and PI.

CONCLUSIONS

Vertical BDC seems to correspond with active PI, wherefore we estimate such a defining factor of importance. Diagnosis of PM and evaluation of probing pocket depths might be only of descriptive interest as they could lead to false-positive results.

Use of osseointegrated implants in the intermaxillary suture in a patient with microstomia: Case report with a 2-year follow-up

AIM

To report the rehabilitation of a female patient, 40 years old, with a microstomia.

CASE REPORT

The Z-plasty surgery was performed in the region of the labial commissure to increase the mouth opening. In the mandible, two implants were installed in the interforaminal region and an overdenture with bar/clip attachment system was made. The maxilla was atrophic, with the presence of two bone sites in the intermaxillary suture region: the first one anterior to the incisive foramen and the second one in the middle of the hard palate. Two implants were placed without a graft in those sites. The conventional maxillary denture was converted into an overdenture with ball attachments system.

CONCLUSION

Based on the presented case, with a 2-year follow-up, it can be concluded the validity of the use of the techniques of surgeries to increase the mouth opening, implants in intermaxillary suture and overdentures as rehabilitation therapy for patients with microstomia.

Knowledge and perception about dental implants among undergraduate dental students

Introduction

Awareness about dental implants is increasing among dental patients, which demands a higher level of competence for dental students. So, the objective of this study was to assess the knowledge and perception of undergraduate dental students about dental implants.

Materials and methods

This cross-sectional questionnaire-based survey was conducted after taking ethical clearance and approval from the Institutional Review Committee of B.P. Koirala Institute of Health Sciences and informed consent from each dental college of Nepal. The sample included all those students who were present at the time of survey. Data collection were carried out during the academic schedules of the colleges, supervised, and monitored by the investigators themselves. Collected data were coded, entered in Microsoft excel 2013 and descriptive analysis was carried out.

Results

A majority of the total (54.6%) and 59.2% of 5^th year respondents perceived to be moderately well-informed about dental implants. The main advantage of dental implants was thought to be longevity by 53.1% of total and 48.4% of 5^th year students; only 27.6% of the total and 42.2% of 5^th year students said the main advantage of dental implants is they are more conservative than other tooth-replacement modalities. Highest percentage of the total respondents (31.9%) said most important factor for implant success to be implant type and material, whereas 59.8% of 5^th year students said case selection. Those who felt dental implants require additional oral hygiene maintenance and care by the patient and dentist were 58.4% of total and 75.1% of 5^th year students. Over two-thirds (67.5%) of total thought that economic feasibility will limit use of dental implants in Nepal. The difficulty encountered to place implants was perceived to be average by 56.8% of total and 58.1% of 5^th year. There were differences in the perception and knowledge at different academic levels, but not as expected.

Conclusions

It could not be concluded that knowledge about dental implants increased with increase in academic level. Even at the late-clinical year a majority of students gave unsatisfactory responses.

Morse taper implant macrodesign, loading protocol and site of installation – retrospective study of 5,601 implants

Abstract Introduction The long-term implant-supported prosthetic rehabilitation monitoring is extremely important in evaluating parameters that could interfere in the success of the treatment. Objective To evaluate the influence of macrodesign (shape of the body and apex), length and diameter, insertion torque, site of installation as well as the loading protocol, on long-term survival rates. Material and method The data obtained was from the medical records of rehabilitated patients who had had at least one Morse taper implant surgery done at ILAPEO School between 2006 -2012. Incomplete medical records, from which it would have been impossible to extract all data essential to complete the study, were excluded. Result A total of 1,142 patient’s medical records comprised the sample; documenting the progress of 5,601 implants, done in both jaws and mandibles. The final survival rate was 98.31%, over an average time of 37.54 months. The type of implant most used was cylindrical (70.33%). The mean installation torque most evidenced in the study was between 41 and 50 Ncm. A logistical regression analysis showed that none of the following variables, site of installation, body and apex shape designs and length, had any significant statistical influence on implant loss. Torque increase and diameter influenced implant loss while immediate loading favored implant maintenance. Conclusion It can be concluded that Morse taper implants present a long-term survival rate that can be lowered by excessive torque, as well as by the diameter of the implant.

Implant survival and patient satisfaction in completely edentulous patients with immediate placement of implants: a retrospective study

Background

This study evaluated full-arch rehabilitation of patients with immediately placed implants in terms of the cumulative implant survival rate, risk factors for implant failure, and patient satisfaction.

Methods

Time-to-event data of 52 completely edentulous jaws (370 implants) were collected using retrospective clinical chart review for the time period from 2008 to 2014. A conventional two stage approach for surgery was adopted to immediately placed implants in the maxilla, and immediate placement and immediate loading protocols for the mandible were followed. The study calculated the 7-year cumulative survival rates (CSR), and a Bayesian hierarchical Cox proportional hazard model was used to measure the effect of covariates. Patient satisfaction on chewing ability, esthetic appearance, and overall satisfaction was also measured with a face-to-face interview survey.

Results

Of the total 370 implants, 194 were immediate placement. Two delayed loading maxillary implants failed within the first year, and another one failed in the second year of loading. Two failures were recorded in the first year and one in seven years for the immediate loading mandibular implants. The 1-, 5-, and 7-year CSR of the 370 implants were 0.989 (0.979, 1.000), 0.986 (0.975, 0.998), and 0.978 (0.957, 0.999), respectively. Only the length of the implant affected implant failure (p < 0.05); other patient characteristics, systemic diseases, implant diameter, immediate loading, and immediate placement, did not have an effect on implant failure rates. Patients reported a high degree of satisfaction regardless of their age group or length of the observation period.

Conclusions

Immediately placed implant had CSR as high as delayed placed implants, and 7-year CSRs of immediate loading were not significantly different from delayed loading. The procedure also had a high degree of chewing ability, esthetic appearance, and overall satisfaction. The study results suggested that the clinical procedures applied in this study to completely edentulous patients were acceptable rehabilitation procedures.

A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth edentulous area: 3-year follow-up

BACKGROUND

Traditionally, dental implants have been made from titanium or titanium alloys. Alternatively, zirconia-based ceramic implants have been developed with similar characteristics of functional strength and osseointegration. Ceramic implants offer advantages in certain settings, e.g. in patients who object to metal dental implants. The aim of this study was to investigate the mid-term (36 months) clinical performance of a ceramic monotype implant in single-tooth edentulous area.

METHODS

This was a prospective, open-label, single-arm study in patients requiring implant rehabilitation in single-tooth edentulous area. Ceramic implants (PURE Ceramic Implant, Institut Straumann AG, Basel, Switzerland) with a diameter of 4.1 mm were placed following standard procedure and loaded with provisional and final prostheses after 3 and 6 months, respectively. Implant survival rate and implant success rate were evaluated and crestal bone levels were measured by analysing standardized radiographs during implant surgery and at 6, 12, 24 and 36 months.

RESULTS

Forty-four patients received a study implant, of whom one patient withdrew consent after 3 months. With one implant lost during the first 6 months after surgery, the implant survival rate was 97.7% at 6 months. No further implants were lost over the following 30 months, and 3 patients were lost to follow-up during this time frame. This led to a survival rate of 97.5% at 36 months. Six months after implant surgery 93.0% of the implants were considered "successful", increasing to 97.6% at 12 months and remaining at this level at 24 months (95.1%) and 36 months (97.5%). Bone loss was most pronounced in the first half-year after implant surgery (0.88 ± 0.86 mm). By contrast, between 12 and 36 months the mean bone level remained stable (minimal gain of 0.06 [± 0.60] mm). Hence, the overall bone loss from implant surgery to 36 months was 0.97 (± 0.88) mm.

CONCLUSIONS

In the follow-up period ceramic implants can achieve favourable clinical outcomes on a par with titanium implants. For instance, these implants can be recommended for patients who object to metal dental implants. However, longer term studies with different edentulous morphology need to confirm the present data.

TRIAL REGISTRATION

Registered on www.clinicaltrials.gov : NCT02163395 .

Retrospective evaluation of the survival rate of single tooth prostheses supported in external hexagonal implants: mean follow-up of 9 years

Abstract Introduction The use of osseointegrated dental implants for the rehabilitation of patients has revolutionized dentistry. Objective To retrospectively evaluate the survival rate and the frequency of complications with external hexagon platform supporting single crowns. Material and method Dental forms of 110 patients who received 143 implants at the Ilapeo College (2004-2015) were used. The variables were: age, gender, systemic involvement at the time of surgery, region, implant design, type of surface, fixation system, pillar type and prosthesis material. The outcome variables were the incidence of complications in the implant or prosthesis and time in use. The mean follow-up period was 9 years. Result 32.8% had some systemic disease. Ninety-six implants (67.1%) were installed in the maxilla and 47 (32.9%) in the mandible, 87 (60.8%) were in the posterior region and 56 (39.2%) in the anterior region, while 40 (28%) were placed in regions that had received bone reconstruction. The majority (97.2%) of the implants presented surface treatment, 42% had a cylindrical design and 58% were tapered. The majority of the prosthetic components (89.6%) used were UCLAs and most of the prostheses were fused-to-metal (79.7%). The rate of prosthetic complications was 19.58% and three implants had been lost (97.9% survival rate). There was no statistical difference between the variables analyzed for both the occurrence of prosthetic complications and for the loss of the implant. Conclusion Implants with external hexagon connection were an effective and predictable option to support crowns and had high survival rates.

Long-term survival of teeth in the posterior region after apical surgery

Oftentimes the discussion of long-term success rates and treatment modalities becomes a central issue in consultations with patients. The aim of this study was to retrospectively evaluate survival rates of teeth after apicoectomy in an established private practice for Oral and Maxillofacial Surgery in Kiel, Germany. All teeth treated with apicoectomy between 2001 and 2006 were included. Treatment success was previously defined as preservation of the tooth. Putative influence factors on success as kind and quality of endodontic treatment, additional intraoperative endodontic filling, inflammatory status, tooth mobility, and pre- and postoperative X-rays were further evaluated. A total of 149 teeth could be included. The mean observation period was 6.3 (SD: 4.4) years. In all, 48.3% of these teeth could be retained after a 10-year period. Teeth that received an additional retrograde root canal filling during surgery resulted in a significantly higher success rate (p = 0.0237) compared to those with orthograde root canal fillings or without additional endodontic treatment. The quality of endodontic treatment had no impact (p = 0.125). Our results suggest that apical surgery is a reliable procedure to treat and ensure the survival of symptomatic teeth in the posterior region for several years. A significant improvement was further determined for a retrograde filling.

Randomized controlled trial comparing immediate loading with conventional loading using cone-anchored implant-supported screw-retained removable prostheses: A 2-year follow-up clinical trial

STATEMENT OF PROBLEM

Implant-based prosthetic solutions can be time consuming. If implants can be loaded immediately, treatment time can be reduced.

PURPOSE

The purpose of this prospective randomized controlled trial was to monitor the survival rate of Ankylos implants, comparing conventional with immediate loading by using abutments with the SynCone concept for screw-retained removable prostheses in the edentulous maxilla.

MATERIAL AND METHODS

A total of 90 implants were placed in 15 study participants. The participants were randomly assigned to the immediate or conventional loading treatment group. Radiographic and clinical parameters were recorded at the time of permanent prosthesis installment and at 1- and 2-year follow-up examinations, and participants' satisfaction was measured by using questionnaires before and after prosthesis installation. A linear mixed model was used to measure differences.

RESULTS

One implant in the conventional group was lost during abutment placement; hence, 89 implants could be followed for 2 years. Approximately 90% of these implants showed no bone loss or even bone gain at 1 and 2 years follow-up. Mean values for the immediate group were, respectively, 0.09 ±0.35 mm and 0.13 ±0.38 mm and 0.01 ±0.41 mm and -0.06 ±0.32 mm for the conventional method. No significant differences (P=.053) were found in bone level alterations between the groups. For all participants, the mean number of surfaces (4 per implant) with bleeding on probing (BoP) and plaque were 0.76 ±0.81 and 0.16 ±0.42 at 1 year follow-up and 0.44 ±0.66 and 0.02 ±0.15, respectively, at the second-year follow-up. The mean pocket probing depths were 2.05 ±0.54 mm at 1 year and 2.18 ±0.64 mm at 2 years. For both groups, a significant rise in satisfaction and quality of life was observed (P≤.001) at 1 and 2 years compared with pretreatment.

CONCLUSIONS

Ankylos implants placed in the edentulous maxilla, immediately or conventionally loaded by a detachable prosthesis, showed favorable bone-level preservation after 2 years of follow-up. No significant differences could be found between the immediate and conventional groups. A significant increase in quality of life was observed for both loading modes.

The micromechanical behavior of implant-abutment connections under a dynamic load protocol

BACKGROUND

The implant-abutment connection (IAC) is known to be a key factor for the long-term stability of peri-implant tissue.

PURPOSE

The aim of the present in vitro study was to detect and measure the mechanical behavior of different IACs by X-ray imaging.

MATERIALS AND METHODS

A total of 20 different implant systems with various implant dimensions and IACs (13 conical-, 6 flat-, and 1 gable-like IAC) have been tested using a chewing device simulating dynamic and static loading up to 200 N. Micromovements have been recorded with a high-resolution, high-speed X-ray camera, and gap length and gap width between implant and abutment have been calculated. Furthermore, X-ray video sequences have been recorded to investigate the sealing capacity of different IACs.

RESULTS

Out of the 20 implant systems, eight implant systems with a conical IAC showed no measurable gaps under static and dynamic loading (200 N). By contrast, all investigated implant systems with a flat IAC showed measurable gaps under dynamic and static loading. X-ray video sequences revealed that a representative conical IAC had sufficient sealing capacity.

CONCLUSION

Within the limits of the present in vitro study, X-ray imaging showed reduced formation of microgaps and consecutive micromovements in implants with conical IAC compared to flat IACs.

An up to 17-year follow-up retrospective analysis of a minimally invasive, flapless approach: 18 945 implants in 7783 patients

BACKGROUND

This study investigates gender, age, jaw, implant position, loading protocol (immediate vs delayed), smoking, and type of surgery (punch vs flap) as influential factors of implant survival in a large patient collective.

PURPOSE

To evaluate the survival rates of implants in patients using a mucoperiosteal punch for flapless implantation in the majority of cases in order to evaluate its medical efficacy and safety.

MATERIALS AND METHODS

Between 1994 and 2015 all patients with complete data treated at the Wienerberg Dental Clinic, Vienna, Austria, were included and statistically analyzed in Cox proportional hazard (PH) models. As patients with multiple implants were included, a clustering term was added to the Cox PH model to respect pooled failures in patients.

RESULTS

Of the initial 24 282 ANKYLOS/Dentsply implants placed in 8137 patients a total of 7783 patients with 18 945 implants were finally included. The mean follow-up was 2.8 ± 3.2 up to 17.9 years. Cumulative survival rates (CSRs) after 1, 3, 5, and 10 years were 98.5%, 97.7%, 96.7%, and 93.0%, respectively. Of these, 17 517 (92.5%) implants were placed minimally invasive via a flapless approach by use of the ATP-Punch with comparable survival rates as observed for flap surgery. The Cox PH models proved smoking (hazard ratio [HR] = 2.2) and implant position as significant factors of implant survival. In the maxilla, canines and third molars were identified as low risk sites in comparison to the most frequently implanted first premolar site. In the mandible, the central incisor and second premolar were identified as high-risk sites, the canine as low risk site in comparison to the most frequently placed first molar site.

CONCLUSION

The analyzed data concludes the safety and medical efficacy of the ATP-Punch. The CSRs using this flapless technique are comparable to the classic surgical flap approach.

Optimization of the Conical Angle Design in Conical Implant–Abutment Connections: A Pilot Study Based on the Finite Element Method

Conical implant–abutment connections are popular for their excellent connection stability, which is attributable to frictional resistance in the connection. However, conical angles, the inherent design parameter of conical connections, exert opposing effects on 2 influencing factors of the connection stability: frictional resistance and abutment rigidity. This pilot study employed an optimization approach through the finite element method to obtain an optimal conical angle for the highest connection stability in an Ankylos-based conical connection system. A nonlinear 3-dimensional finite element parametric model was developed according to the geometry of the Ankylos system (conical half angle = 5.7°) by using the ANSYS 11.0 software. Optimization algorithms were conducted to obtain the optimal conical half angle and achieve the minimal value of maximum von Mises stress in the abutment, which represents the highest connection stability. The optimal conical half angle obtained was 10.1°. Compared with the original design (5.7°), the optimal design demonstrated an increased rigidity of abutment (36.4%) and implant (25.5%), a decreased microgap at the implant–abutment interface (62.3%), a decreased contact pressure (37.9%) with a more uniform stress distribution in the connection, and a decreased stress in the cortical bone (4.5%). In conclusion, the methodology of design optimization to determine the optimal conical angle of the Ankylos-based system is feasible. Because of the heterogeneity of different systems, more studies should be conducted to define the optimal conical angle in various conical connection designs.

Osseointegration of standard and mini dental implants: a histomorphometric comparison

Background

Mini dental implants (MDIs) are becoming increasingly popular for rehabilitation of edentulous patients because of their several advantages. However, there is a lack of evidence on the osseointegration potential of the MDIs. The objective of the study was to histomorphometrically evaluate and compare bone apposition on the surface of MDIs and standard implants in a rabbit model.

Methods

Nine New Zealand white rabbits were used for the study to meet statistical criteria for adequate power. Total 18 3M^™ESPE^™ MDIs and 18 standard implants (Ankylos^® Friadent, Dentsply) were inserted randomly into the tibia of rabbits (four implants per rabbit); animals were sacrificed after a 6-week healing period. The specimens were retrieved en bloc and preserved in 10% formaldehyde solution. Specimens were prepared for embedding in a light cure acrylic resin (Technovit 9100). The most central sagittal histological sections (30–40 μm thick) were obtained using a Leica SP 1600 saw microtome. After staining, the Leica DM2000 microscope was used, the images were captured using Olympus DP72 camera and associated software. Bone implant contact (BIC) was measured using Infinity Analyze software.

Results

All implants were osseointegrated. Histologic measures show mineralized bone matrix in intimate contact with the implant surface in both groups. The median BIC was 58.5 % (IQR 8.0) in the MDI group and 57.0 % (IQR 5.5) in the control group (P > 0.05; Mann-Whitney test). There were no statistical differences in osseointegration at 6 weeks between MDIs and standard implants in rabbit tibias.

Conclusions

Based on these results, it is concluded that osseointegration of MDIs is similar to that of standard implants.

Histologic Evaluation of Wound Healing After Ridge Preservation With Cortical, Cancellous, and Combined Cortico-Cancellous Freeze-Dried Bone Allograft: A Randomized Controlled Clinical Trial

BACKGROUND

Cortical and cancellous mineralized freeze-dried bone allografts (FDBA) are available for use in alveolar ridge preservation after tooth extraction. There are currently no data regarding use of a combination 50%/50% cortico-cancellous FDBA compared with a 100% cortical or 100% cancellous FDBA in ridge preservation. The primary objective of this study is to dimensionally and histologically evaluate healing after ridge preservation in non-molar sites using 50%/50% cortico-cancellous FDBA versus 100% cortical and 100% cancellous FDBA.

METHODS

Sixty-six patients requiring extraction of a non-molar tooth were enrolled and randomized into three groups to receive ridge preservation with the following: 1) 100% cortical FDBA; 2) 100% cancellous FDBA; or 3) 50%/50% cortico-cancellous FDBA. After 18 to 20 weeks of healing, a biopsy was harvested, and an implant was placed. The alveolar ridge was measured pre- and postoperatively to evaluate change in ridge height and width. Percentages of vital bone, residual graft, and connective tissue (CT)/other were determined via histomorphometric analysis.

RESULTS

Histomorphometric analysis revealed no significant differences among groups regarding percentage of vital bone or CT/other. The 100% cortical FDBA group had significantly greater residual graft material (P = 0.04). Dimensional analysis revealed no significant between-group differences in any parameter measured.

CONCLUSION

To the best knowledge of the authors, this study offers the first histologic evidence demonstrating no significant difference in vital bone formation or dimensional changes among 50%/50% cortico-cancellous FDBA, 100% cortical FDBA, and 100% cancellous FDBA when used in ridge preservation of non-molar tooth sites.

Retrospective analysis of 10,000 implants from insertion up to 20 years-analysis of implantations using augmentative procedures

BACKGROUND

A sufficient amount of bone is essential to ensure long-term stability of dental implants. To support the bone regeneration process, different techniques and materials are available. It has been questioned whether these techniques and materials may compromise implant survival compared to pristine bone. To properly answer this question, long-term stability up to 20.2 years after insertion of implants placed in augmented or non-augmented sites was retrospectively analysed.

METHODS

Retrospective analysis included 10,158 implants from 3095 patients in three private practices who underwent implant therapy with or without bone augmentation procedures. Different graft materials and membranes were used for augmentation. If necessary, the graft was stabilised using a titanium mesh. Implant survival was evaluated analysing explantation rates and Kaplan-Meier survival curves in augmented or non-augmented sites. In additional subgroup analyses, augmentation procedures, graft materials and membranes were compared applying descriptive statistics.

RESULTS

The observation period varied from the day of implantation up to 20.2 years after implant insertion. The overall implant survival was 95.5% (augmented sites 96.33%; native sites 94.27%). Comparison of Kaplan-Meier survival curves revealed significantly better survival of implants in augmented sites (p = 0.0025). When comparing different augmentation procedures, the best results were found for bone condensing followed by lateral augmentation. Graft materials were used in 58.2%, membranes in 36.6% of all implant sites. The most often used graft materials were a deproteinized bovine bone mineral (53.0%) and autogenous bone particles (32.5%). Both provided the best results and showed a significantly better implant survival compared to no graft material using the Kaplan-Meier method (p = 0.0104 and p < 0.0001). A native collagen membrane was used most often (74.0% of the membrane sites) and provided the best results regarding implant survival in the log-rank test.

CONCLUSIONS

The retrospective analysis shows that implants inserted in augmented or native bone demonstrate similar implant survival under the conditions of private practice compared to prospective studies. To establish a broad base of support, further well-designed clinical trials are necessary.

Long-Term Effect of Surface Roughness and Patients' Factors on Crestal Bone Loss at Dental Implants. A Systematic Review and Meta-Analysis

Publications from 2011 to 2015 were selected to evaluate effect of implant surface roughness on long-term bone loss as surrogate for peri-implantitis risk. 87 out of 2,566 papers reported the mean bone loss after at least 5 years of function. Estimation of the proportion of implants with bone loss above 1, 2, and 3 mm as well as analysis the effect of implant surface roughness, smoking, and history of periodontitis was performed. By means of the provided statistical information of bone loss (mean and standard deviation) the prevalence of implants with bone loss ranging from 1 to 3 mm was estimated. The bone loss was used as a surrogate parameter for "peri-implantitis" given the fact that "peri-implantitis" prevalence was not reported in most studies or when reported, the diagnostic criteria were unclear or of dubious quality. The outcome of this review suggests that peri-implant bone loss around minimally rough implant systems was statistically significant less in comparison to the moderately rough and rough implant systems. No statistically significant difference was observed between moderately rough and rough implant systems. The studies that compared implants with comparable design and different surface roughness, showed less average peri-implant bone loss around the less rough surfaces in the meta-analysis. However, due to the heterogeneity of the papers and the multifactorial cause for bone loss, the impact of surface roughness alone seems rather limited and of minimal clinical importance. Irrespective of surface topography or implant brand, the average weighted implant survival rate was 97.3% after 5 years or more of loading. If considering 3 mm bone loss after at least 5 years to represent the presence of "peri-implantitis," less than 5% of the implants were affected. The meta-analysis indicated that periodontal history and smoking habits yielded more bone loss.

A randomized, 12-month controlled trial to evaluate non-inferiority of early compared to conventional loading of modSLA implants in single tooth gaps

Background

The aim of the study was to evaluate whether early loading of implants with a chemically modified sandblasted, large-grit, acid-etched (SLA) (SLActive®) surface was non-inferior to conventional loading in terms of change in crestal bone level.

Methods

This was a randomized, controlled, multicenter study. Patients requiring single-tooth rehabilitation in the posterior maxilla or mandible received implants and were randomized to receive a provisional restoration in occlusal load after 25 ± 3 days (early loading) or after 13 ± 1 weeks (conventional loading). The primary endpoint was change in crestal bone level between implant placement (baseline) and 6 months. Secondary endpoints included change in crestal bone level between baseline and 12 months, implant survival and success rates, and patient satisfaction.

Results

Of the 84 patients enrolled, 78 received implants and were randomized onto the early loading (41 patients) and conventional loading (37 patients) groups. The mean change in crestal bone level between baseline and 6 months was 0.56 ± 0.58 and 0.51 ± 0.62 mm for early and conventional loading, respectively; at 12 months, the mean change was 0.76 ± 0.60 and 0.73 ± 0.77 mm, respectively. Implant survival and success at 12 months were 100 % for both groups. Patient satisfaction was similar between the groups, except that more patients in the early loading group were satisfied or highly satisfied with the time taken for fitting.

Conclusion

The study demonstrated that early implant loading was non-inferior to conventional implant loading in terms of crestal bone level change in a Japanese patient population in short follow-up period and single tooth gaps in molar regions.

Morse taper dental implants and platform switching: The new paradigm in oral implantology

The aim of this study was to conduct a literature review on the potential benefits with the use of Morse taper dental implant connections associated with small diameter platform switching abutments. A Medline bibliographical search (from 1961 to 2014) was carried out. The following search items were explored: “Bone loss and platform switching,” “bone loss and implant-abutment joint,” “bone resorption and platform switching,” “bone resorption and implant-abutment joint,” “Morse taper and platform switching.” “Morse taper and implant-abutment joint,” Morse taper and bone resorption,” “crestal bone remodeling and implant-abutment joint,” “crestal bone remodeling and platform switching.” The selection criteria used for the article were: meta-analysis; randomized controlled trials; prospective cohort studies; as well as reviews written in English, Portuguese, or Spanish languages. Within the 287 studies identified, 81 relevant and recent studies were selected. Results indicated a reduced occurrence of peri-implantitis and bone loss at the abutment/implant level associated with Morse taper implants and a reduced-diameter platform switching abutment. Extrapolation of data from previous studies indicates that Morse taper connections associated with platform switching have shown less inflammation and possible bone loss with the peri-implant soft tissues. However, more long-term studies are needed to confirm these trends.

The influence of professional competence on the inter- and intra-individual esthetic evaluation of implant-supported crowns in the anterior maxilla

OBJECTIVES

Evaluation of the influence of professional competence on esthetic predictability of implant-supported crowns in the anterior maxilla and identification of objective factors allowing predictable planning for esthetic results.

MATERIALS AND METHODS

Sixty patients with 82 implants in the esthetic zone were included in this study. Width of keratinized mucosa, biotype, recessions, and papilla index according to Jemt as well as radiological bone loss were assessed. Study casts and photographs were obtained. Each patient as well as people with different level of expertise (laypersons, students and dentists) rated the esthetic satisfaction after final restoration on a scale (1-10). Correlations between esthetic assessments and previously documented clinical parameters were tested.

RESULTS

The study failed to show a significant relationship between the raters' level of dental expertise and their subjective esthetic evaluation. However, patients rated themselves much more favorable than the three evaluator groups did. A comparison of the clinical parameters with the esthetic evaluation revealed significantly more favorable ratings by the lay group in the presence of a wide attached gingiva (P = 0.021) than by the other groups and by the laypersons (P = 0.002), the dentists (P = 0.003), and students (P = 0.009) in the absence of recessions. The ratio of the implant crown length to the length of the contralateral crown had a negative effect on ratings for all three groups ([laypersons P < 0.001], [students P < 0.001] and [dentists P = 0.001]). The papilla index of the mesial papilla correlated significantly with laypersons' ratings (P = 0.036).

CONCLUSION

Earlier investigations are confirmed. Width of keratinized mucosa is a risk factor for esthetic predictability of implant-supported crowns in the anterior maxilla in laypersons' ratings. Furthermore, there is an association between the discrepancy of lengths of implant-supported single crowns to their contralateral natural teeth and esthetic satisfaction for all expertise levels.

Long-term cumulative survival and mechanical complications of single-tooth Ankylos Implants: focus on the abutment neck fractures

PURPOSE

To evaluate the cumulative survival rate (CSR) and mechanical complications of single-tooth Ankylos® implants.

MATERIALS AND METHODS

This was a retrospective clinical study that analyzed 450 single Ankylos® implants installed in 275 patients between December 2005 and December 2012. The main outcomes were survival results CSR and implant failure) and mechanical complications (screw loosening, fracture, and cumulative fracture rate [CFR]). The main outcomes were analyzed according to age, sex, implant length or diameter, bone graft, arch, and position.

RESULTS

The 8-year CSR was 96.9%. Thirteen (2.9%) implants failed because of early osseointegration failure in 3, marginal bone loss in 6, and abutment fracture in 4. Screw loosening occurred in 10 implants (2.2%), and 10 abutment fractures occurred. All abutment fractures were located in the neck, and concurrent screw fractures were observed. The CSR and rate of screw loosening did not differ significantly according to factors. The CFR was higher in middle-aged patients (5.3% vs 0.0% in younger and older patients); for teeth in a molar position (5.8% vs 0.0% for premolar or 1.1% for anterior position); and for larger-diameter implants (4.5% for 4.5 mm and 6.7% for 5.5 mm diameter vs 0.5% for 3.5 mm diameter) (all P<.05).

CONCLUSION

The Ankylos® implant is suitable for single-tooth restoration in Koreans. However, relatively frequent abutment fractures (2.2%) were observed and some fractures resulted in implant failures. Middle-aged patients, the molar position, and a large implant diameter were associated with a high incidence of abutment fracture.

Analysis of factors associated with maintenance discontinuation in implant patients

Maintenance following implant treatment is essential to ensure long-term stability. Accordingly, the objective of this study was to investigate the factors leading patients to discontinue maintenance following implant treatment. Among the 729 patients that underwent implantation at the Department of Oral Implantology, Osaka Dental University Hospital from January 2008 to December 2012, 41 patients were excluded from the study. Exclusion criteria comprised patients without a superstructure attachment, those who only underwent maxillary sinus floor augmentation procedures and those who discontinued visiting the hospital prior to superstructure attachment. Treatment was discontinued in 181 patients. The rate of discontinuation was 26.6 %. The odds ratio (OR) in the adjustment model was 1.552 (95 % CI 1.078–2.236) in males when compared with females. When compared with those who were 30–64 years old, the OR was 5.818 (95 % CI 3.017–11.220) in those 29 years old or younger and 1.561 (95 % CI 1.021–2.386) in those 65 years old or older. Moreover, when compared with those with a O’Leary’s Plaque Control Record of all teeth and superstructures (PCR) level of 20 % or less following superstructure attachment, the OR was 2.113 (95 % CI 1.471–3.035) in those with a PCR level of 20 % or more following superstructure attachment. It is highly important to decrease maintenance discontinuation, especially in patients aged 29 years old or younger with a PCR level of 20 % or more following superstructure attachment. Moreover, a support system must be developed to enable patients with difficulties visiting the hospital to continue their maintenance program.