Immediate Restoration of Single-Piece Zirconia Implants: A Prospective Case Series—Long-Term Results after 11 Years of Clinical Function

Objectives: The aim of this prospective case series was to evaluate single-piece zirconia implants restored with lithium disilicate CAD/CAM crowns through a long-term follow-up. Methods: In this trial, 20 one-piece zirconia implants were placed in 20 patients. Implants were restored (i) immediately with lithium disilicate CAD/CAM provisionals, and (ii) permanently four months after surgery. Patients were followed for 11 years. Clinical parameters and radiological measurements of the zirconia implants were assessed. For the statistical analysis, paired t-test was applied. Results: Four implants were counted as implant failure due to the loss of implant stability, resulting in a Kaplan–Meier survival rate of 80% up to 11 years. The mean bleeding on probing values were 19.1% (SD ± 13.1) and 18.2% (SD ± 17.6) 96 and 11 years after implant placement, respectively. The plaque index revealed a significant decrease over time (p < 0.001) with a value between 25.9% (SD ± 5.7) and 12.6% (SD ± 10.0) at baseline and 11-years follow-up respectively. The marginal bone level revealed a significant decrease 4, 8, and 11 years after implant insertion (p = 0.001, p = 0.019, and p = 0.027, respectively). Conclusions: Immediately loaded zirconia single-piece implants showed a suitable success rate in clinical and radiographic outcomes.     

Endosseous Dental Implant Materials and Clinical Outcomes of Different Alloys: A Systematic Review

In recent years, implantology has made significant progress, as it has now become a safe and predictable practice. The development of new geometries, primary and secondary, of new surfaces and alloys, has made this possible. The purpose of this review is to analyze the different alloys present on the market, such as that in zirconia, and evaluate their clinical differences with those most commonly used, such as those in grade IV titanium. The review, conducted on major scientific databases such as Scopus, PubMed, Web of Science and MDPI yielded a startling number of 305 results. After the application of the filters and the evaluation of the results in the review, only 10 Randomized Clinical Trials (RCTs) were included. Multiple outcomes were considered, such as Marginal Bone Level (MBL), Bleeding on Probing (BoP), Survival Rate, Success Rate and parameters related to aesthetic and prosthetic factors. There are currently no statistically significant differences between the use of zirconia implants and titanium implants, neither for fixed prosthetic restorations nor for overdenture restorations. Only the cases reported complain about the rigidity and, therefore, the possibility of fracture of the zirconium. Certainly the continuous improvement in these materials will ensure that they could be used safely while maintaining their high aesthetic performance.     

Clinical and Radiographic Outcomes of Zirconia Dental Implants—A Clinical Case Series Study

The purpose of this clinical series was to evaluate the clinical and radiographic outcomes of 20 zirconia dental implants, with a minimum follow-up of two years. Patients with at least one zirconia dental implant were included, with a mean follow-up of 34.05 months. The patient complaints such as pain and foreign body sensation, as well as clinical parameters including peri-implant infections with suppuration, implant mobility, gingival index (GI), modified plaque index (mPI), modified sulcus bleeding index (mBI), probing depth (PD) and radiological distance between the implant shoulder to the closest mesial and distal bone-to-implant contact (BIC), were assessed. All zirconia implants were successfully integrated without any pain or foreign body sensation. No mobility was detected in any of the 20 implants. Clinical examination revealed a mean PD of 2.56 mm and a radiological mean distance between the implant shoulder and the initial site of visible bone-to-implant contact (BIC) of 1.44 mm. In addition, GI, mPI and mBI indicated minimal to no inflammation. Results obtained from this series suggest that one-piece zirconia dental implants achieve good clinical and radiographic outcomes over a mean follow-up of 34 months and may be deemed a good option in patients with favorable bone conditions.     

Titanium Allergy Caused by Dental Implants: A Systematic Literature Review and Case Report

(1) Background: Hypersensitivity reactions to metals may arise in predisposed patients chronically exposed to metallic materials, including dental implants made of titanium alloys. The purpose of this article was to systematically review titanium allergy manifestations in patients treated with dental implants and report a clinical case; (2) Methods: A systematic electronic search was performed for articles published in the English language until July 2021. The following eligibility criteria were adopted: (1) Population: individuals undergoing titanium and/or titanium alloy implant-supported rehabilitations; (2) Exposure: peri-implant soft tissue reactions attributable to implant insertion; (3) Outcome: evidence of titanium allergy, diagnostic methods, and forms of resolution; (3) Results: The included studies, in summary, presented evidence that titanium should not be considered an inert material, being able to trigger allergic reactions, and may be responsible for implant failure. A 55-year-old male patient received 3 implants in the posterior region of the left mandible and presented an epulis-like lesion developed from the peri-implant mucosa. The immunohistochemical analysis of the biopsy specimen confirmed the initial diagnosis of allergic reaction to titanium; (4) Conclusions: Although the evidence is weak, and titanium allergy has a low incidence, hypersensitivity reactions should not be underestimated. A rapid and conclusive diagnosis is mandatory to prevent further complications.     

Cardiovascular and Renal Outcomes of Incretin-based Therapies: A Review of Recent Clinical Trials

Background To report the cardiovascular and renal effects of incretin-based therapies.Methods The studies of clinical trials on incretin-based therapy published in medical journals from the years 2010 to 2017 were comprehensively searched using MEDLINE and EMBASE with no language restriction. The studies were reviewed and the cardiovascular and renal risks reported were recorded.Results Incretin-based therapeutics represent novel and promising anti-diabetes drugs, the direct cardiovascular actions which may translate into demonstrable clinical benefits on cardiovascular outcomes. Furthermore, incretin-based therapies do not adversely affect renal function.     

Scientific Trends in Clinical Research on Zirconia Dental Implants: A Bibliometric Review

Background: The clinical use of zirconia implants has been shown to increase steadily due to their biological, aesthetic, and physical properties; therefore, this bibliometric study aimed to review the clinical research and co-authors in the field of zirconia dental implant rehabilitation. Methods: We searched Scopus and Web of Science databases using a comprehensive search strategy to 5 October 2020, and independently paired reviewers who screened studies, and collected data with inclusion criteria restricted to clinical research only (either prospective or retrospective). Data on article title, co-authors, number of citations received, journal details, publication year, country and institution involved, funding, study design, marginal bone loss, survival rate, failure, follow-up, and the author’s bibliometric data were collected and evaluated. Results: A total of 29 clinical studies were published between 2008 and 2020 as 41.4% were prospective cohort studies and 48.3% originated from Germany. Most of the included studies had been published in Clinical Oral Implant Research (n = 12), and the most productive institution was the Medical Center of University of Freiburg. The author with the largest number of clinical studies on zirconia implants was Kohal R.J. (n = 10), followed by Spies B.C. (n = 8). Conclusions: This study revealed that zirconia implants have been more prominent in the last ten years, which is a valuable option for oral rehabilitation with marginal bone loss and survival rate comparable to titanium dental implants.     

Prospect of Metal Ceramic (Titanium-Wollastonite) Composite as Permanent Bone Implants: A Narrative Review

This literature review discusses the influence of titanium ceramic composites as a biomaterial towards the fabrication of implants for orthopedic applications. The concept of applying metal-ceramic composites enable many novel combinations in the design and fabrication of complex materials which enhances functionality to improve cell and tissue matrix interactions particularly in the formation of bone. Specific focus is placed on its plethora of materials selected from the metals and ceramic group and identifying the optimal combination that matches them. The prospect of wollastonite as the ceramic counterpart is also highlighted. In this review, we have highlighted the different fabrication methods for such metal-ceramic materials as well as the role that these hybrids play in an in vitro and in vivo environment. Its economic potential as a bone implant material is also discussed.     

Surface Structure of Zirconia Implants: An Integrative Review Comparing Clinical Results with Preclinical and In Vitro Data

Background: The purpose of this review was to analyze and correlate the findings for zirconia implants in clinical, preclinical and in vitro cell studies in relation to surface structure. Methods: Electronic searches were conducted to identify clinical, preclinical and in vitro cell studies on zirconia implant surfaces. The primary outcomes were mean bone loss (MBL) for clinical studies, bone-to-implant contact (BIC) and removal torque (RT) for preclinical studies and cell spreading, cell proliferation and gene expression for cell studies. The secondary outcomes included comparisons of data found for those surfaces that were investigated in all three study types. Results: From 986 screened titles, 40 studies were included for data extraction. In clinical studies, only micro-structured surfaces were investigated. The lowest MBL was reported for sandblasted and subsequently etched surfaces, followed by a sinter and slurry treatment and sandblasted surfaces. For BIC, no clear preference of one surface structure was observable, while RT was slightly higher for micro-structured than smooth surfaces. All cell studies showed that cell spreading and cytoskeletal formation were enhanced on smooth compared with micro-structured surfaces. Conclusions: No correlation was observed for the effect of surface structure of zirconia implants within the results of clinical, preclinical and in vitro cell studies, underlining the need for standardized procedures for human, animal and in vitro studies.     

Monitoring Artificial Pancreas Trials Through Agent-based Technologies: A Case Report

The increase in the availability and reliability of network connections lets envision systems supporting a continuous remote monitoring of clinical parameters useful either for overseeing chronic diseases or for following clinical trials involving outpatients. We report here the results achieved by a telemedicine infrastructure that has been linked to an artificial pancreas platform and used during a trial of the AP@home project, funded by the European Union. The telemedicine infrastructure is based on a multiagent paradigm and is able to deliver to the clinic any information concerning the patient status and the operation of the artificial pancreas. A web application has also been developed, so that the clinic staff and the researchers involved in the design of the blood glucose control algorithms are able to follow the ongoing experiments. Albeit the duration of the experiments in the trial discussed in the article was limited to only 2 days, the system proved to be successful for monitoring patients, in particular overnight when the patients are sleeping. Based on that outcome we can conclude that the infrastructure is suitable for the purpose of accomplishing an intelligent monitoring of an artificial pancreas either during longer trials or whenever that system will be used as a routine treatment.     

Short Implants versus Longer Implants with Sinus Floor Elevation: A Systemic Review and Meta-Analysis of Randomized Controlled Trials with a Post-Loading Follow-Up Duration of 5 Years

This study compared the outcome of fixed prostheses supported by short implants (<8 mm) and longer implants (≥8 mm) with an elevated sinus floor after 5 years of follow-up. The literature searches were performed electronically and manually in PubMed, EMBASE, and Web of Science databases to identify relevant articles published from 1 January 2013 to 31 January 2020. We selected eligible studies using inclusion criteria and assessed their quality. From 1688 identified studies, five randomized controlled trials were included. Between the short implant group and the control group, the implant failure-related pooled risk ratio (RR) was 3.64 (p = 0.07). The RR for technical complications was 2.61 (p = 0.0002), favoring longer implants. Marginal peri-implant bone loss after 1 and 5 years of function showed statistically significant less bone loss at short implants (1 year: mean difference = 0.21 mm; p < 0.00001; 5 years: mean difference = 0.26 mm; p = 0.02). The implant failure and the biological failure of both groups were similar after 5 years of follow-up. Short implants could be an alternative to long implants with an elevated sinus floor for atrophic maxillae in aging populations. Studies with larger trials and longer periods of follow-up (10 years) remain essential.     

Short versus Longer Implants in Sites without the Need for Bone Augmentation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objectives: The present systematic review and meta-analysis aims to analyse the clinical performance of short compared to longer implants inserted in sites without the need for bone augmentation. Methods: The protocol of the present PRISMA-driven meta-analysis was registered on PROSPERO (CRD42021264781). Electronic and manual searches were performed up to January 2022. All Randomized Controlled Trials (RCTs) comparing short (≤6 mm) to longer (≥8.5 mm) implants placed in non-atrophic and non-augmented sites were included. The quality of the included studies was assessed using the Cochrane risk of bias tool for randomized clinical trials (RoB 2) and the quality of evidence was determined with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. A meta-analysis was performed on implant survival rate, marginal bone level change (MBLc), and technical and biological complications at the available follow-up time points. The power of the meta-analytic findings was determined by trial sequential analysis (TSA). Results: From 1485 initial records, 13 articles were finally included. No significant difference was found in the survival rate between short and long implant at any follow-up (moderate quality of evidence). Significantly more bone loss for long implants at 1 and 5 years from implant placement and more technical complications with short implants at 10 years were found. No other significant inter-group differences in terms of MBLc and biological complications were detected. Conclusions: Moderate evidence exists suggesting that short implants perform as well as longer ones in the rehabilitation of edentulous sites without the need for bone augmentation. Further long-term, well-designed RCTs, however, are still needed to provide specific evidence-based clinical recommendations for an extended use of short implants in non-atrophic sites.     

The Surface Conditions and Composition of Titanium Alloys in Implantology: A Comparative Study of Dental Implants of Different Brands

The success of titanium dental implants depends on their osseointegration into the bone, which is determined by the composition and surface properties of the implant in close contact with the bone. There is a wide variety of implants on the market. Is it possible to identify the implant with the best composition and surface topography for optimal osseointegration? To this aim, 13 brands of dental implants from nine distinct manufacturers have been selected and their composition and surface topography determined. The obtained results show differences between these implants, in this case, the Ssk averages of the three measurements performed on each implant were positive, or 0.4 (0.1–0.8), indicating that the roughness of all implants analyzed was primarily textured and not flat. Like Sa, we found the highest Sdr for implants subjected only to sandblasting. In addition, only the ALS-active^® implant had a modified microstructure on its surface. However, analysis of the NANOTITE implant surface revealed a 1.40% presence of calcium which we consider too low to have an effect on bone formation around the implant. As a result, we have also highlighted the lack of a recognized independent standard for dental implant surface conditions and the lack of independent quality control vis-à-vis manufacturers. Of all the surface types studied, none proved more satisfactory than another.     

Properties and Clinical Application of Three Types of Dental Glass-Ceramics and Ceramics for CAD-CAM Technologies

The main properties (mechanical, thermal and chemical) and clinical application for dental restoration are demonstrated for three types of glass-ceramics and sintered polycrystalline ceramic produced by Ivoclar Vivadent AG. Two types of glass-ceramics are derived from the leucite-type and the lithium disilicate-type. The third type of dental materials represents a ZrO₂ ceramic. CAD/CAM technology is a procedure to manufacture dental ceramic restoration. Leucite-type glass-ceramics demonstrate high translucency, preferable optical/mechanical properties and an application as dental inlays, onlays and crowns. Based on an improvement of the mechanical parameters, specially the strength and toughness, the lithium disilicate glass-ceramics are used as crowns; applying a procedure to machine an intermediate product and producing the final glass-ceramic by an additional heat treatment. Small dental bridges of lithium disilicate glass-ceramic were fabricated using a molding technology. ZrO₂ ceramics show high toughness and strength and were veneered with fluoroapatite glass-ceramic. Machining is possible with a porous intermediate product.     

All-Ceramic Single Crown Restauration of Zirconia Oral Implants and Its Influence on Fracture Resistance: An Investigation in the Artificial Mouth

The aim of the current investigation was to evaluate the fracture resistance of one-piece zirconia oral implants with and without all-ceramic incisor crowns after long-term thermomechanical cycling. A total of 48 implants were evaluated. The groups with crowns (C, 24 samples) and without crowns (N, 24 samples) were subdivided according to the loading protocol, resulting in three groups of 8 samples each: Group “0” was not exposed to cyclic loading, whereas groups “5” and “10” were loaded with 5 and 10 million chewing cycles, respectively. This resulted in 6 different groups: C0/N0, C5/N5 and C10/N10. Subsequently, all 48 implants were statically loaded to fracture and bending moments were calculated. All implants survived the artificial aging. For the static loading the following average bending moments were calculated: C0: 326 Ncm; C5: 339 Ncm; C10: 369 Ncm; N0: 339 Ncm; N5: 398 Ncm and N10: 355 Ncm. To a certain extent, thermomechanical cycling resulted in an increase of fracture resistance which did not prove to be statistically significant. Regarding its fracture resistance, the evaluated ceramic implant system made of Y-TZP seems to be able to resist physiological chewing forces long-term. Restauration with all-ceramic single crowns showed no negative influence on fracture resistance.