Working with Zirconia Implants Requires a Different Approach

The use of ceramic implants has been on the rise in recent years. More and more dental clinicians add this option in their therapy concepts. Also, more and more implant companies add this kind implants to their product portfolio. As mean reason, the growing demand from patients for metal-free restorations can be identified. However, applying zirconia implants is surely not identical to the manipulation of titanium implants. Therefore, it is of utmost importance that practitioners are well informed and decently trained before starting to use these implants. This article gives an overview on the main differences between the 2 types of implants.

Outcomes of Revision of Interposition Implant Trapeziometacarpal Arthroplasty

Background Implant arthroplasties for trapeziometacarpal osteoarthritis are often associated with high complication and revision surgery rates. There are no previous studies reporting revision outcomes of failed interposition implant arthroplasty. Methods A patient register search was done for all implant arthroplasties performed for trapeziometacarpal osteoarthritis during a 10-year period in a single hand surgical unit. Altogether, 32 patients had primary interposition implant arthroplasty (Artelon 22, Pyrosphere 6, Ortosphere 2, and Pyrodisk 2), and 19 of these patients had revision surgery with 23 revision procedures performed. In all, 15 of the revised 19 patients were reexamined clinically (Connolly-Rath score, Quick Disabilities of the Arm Shoulder and Hand, patient evaluation measure, the visual analog score for pain, thumb range of motion and strength measurements) and radiographically. Results The indication for revision surgery was pain alone or implant dislocation accompanied by pain in all cases. Thirteen of the revised 15 patients reported functional deficit and pain after revision. There was no statistically significant difference in the revision outcomes between patients operated on primarily with the Artelon implant versus pyrocarbon/ceramic implants. Compared to previous studies on revision surgery and primary trapeziometacarpal arthroplasty, our results showed slightly higher pain and poorer functional scores. Conclusions Interposition implant arthroplasty may yield high revision rates. The results after revision surgery may be worse than previously described, and there may also be a tendency for worse results than those of primary arthroplasty. Interposition implant arthroplasty should always be thoroughly contemplated.

A Novel Zirconia-Based Composite Presents an Aging Resistant Material for Narrow-Diameter Ceramic Implants

A novel ceria-stabilized zirconia-alumina-aluminate composite (Ce-TZP-comp) that is not prone to aging presents a potential alternative to yttrium-stabilized zirconia for ceramic oral implants. The objective of this study was to evaluate the long-term stability of a one-piece narrow-diameter implant made of Ce-TZP-comp. Implant prototypes with a narrow (3.4 mm) and regular (4.0 mm) diameter were embedded according to ISO 14801, and subgroups (n = 8) were subsequently exposed to dynamic loading (107 cycles, 98N) and/or hydrothermal treatment (aging, 85 °C). Loading/aging was only applied as a combined protocol for the 4.0 mm diameter implants. One subgroup of each diameter remained untreated. One sample was cross-sectioned from each subgroup and evaluated with a scanning electron microscope for phase-transformation of the lattice. Finally, the remaining samples were loaded to fracture. A multivariate linear regression model was applied for statistical analyses (significance at p < 0.05). All samples withstood the different loading/aging protocols and no transformation propagation was observed. The narrow diameter implants showed the lowest fracture load after combined loading/aging (628 ± 56 N; p < 0.01), whereas all other subgroups exhibited no significantly reduced fracture resistance (between 762 ± 62 and 806 ± 73 N; p > 0.05). Therefore, fracture load values of Ce-TZP-comp implants suggest a reliable intraoral clinical application in the anterior jaw regions.

Early and medium-term results of total joint arthroplasty of first carpo-metacarpal joint

Introduction. Reviews dedicated to surgical treatment of the first carpo-metacarpal joint repeatedly state that the evaluation of arthroplasty results is difficult. This is due to the small clinical study groups and the lack of description of all types of outcomes. The aim of the study is to analyze obtained early and midterm results of ceramic CMC-arthroplasty. The endoprosthesis are represented with unbound proximal and distal components made of ceramic material. The interaction of the head and cup is represented with no intersecting forces that impede on the multi-axial movement. The surgical technique of CMC-1 joint arthroplasty prescribes the installation of components by the press-fit fixation. There is a brief emphasis on the features of the joint and contributing factors for the development of risarthrosis. Early results are described. Cases of unsatisfactory outcomes are described separately. Materials and methods. The study group included patients from 33 to 72 years. The total number of observers was 28 people. We performed revision endoprosthetics in 2 cases (7%), which were associated with aseptic instability of the proximal component according to the osteoporosis. It obvious that endoprosthetics is the only method of orthopedic care that allows maintain mobility and achieve stability of the destroyed CMC joint. Evaluation of the results was carried out by clinical and instrumental methods. Results. It cannot be denied that the CMC arthroplasty is the only method of orthopedic care that allows to preserve mobility and achieve stability of the broken joint. Conclusion. Arthroplasty of the carpo-metacarpal joint with ceramic implants is a promising method of orthopedic care, that allows to restore the function of the hand.

Clinical Longevity of Zirconia Implants with the Focus on Biomechanical and Biological Outcome

Purpose of Review The goal of the present review is to update the reader on the scientific background of zirconia ceramic implants. Clinical investigations using zirconia ceramic implants over the last couple of years have brought up some new developments and questions. Can we be confident in placing zirconia ceramic implants given the recently published data? Is there a difference in the application of one- and two-piece implants? Recent Findings Systematic reviews on preclinical investigations of zirconia implants revealed that one-piece zirconia implants (> 4 mm) are sufficiently stable for clinical use. The same is true for some clinically available two-piece implant systems. Osseointegration and soft tissue integration are, according to the reviews, similar between titanium and zirconia implants with similar surface topographies. Regarding the clinical outcome, a meta-review exists evaluating systematic reviews. The findings of the systematic reviews and the meta-review are that there are good short-term clinical results for one-piece zirconia implants. However, the data for two-piece implants is not robust. Summary In certain applications (single tooth restorations and small bridges), the results of zirconia implants are comparable with titanium implants in short-term studies. Some mid-term investigations support the short-term results. However, according to the current scientific data available, zirconia implants cannot yet be considered an alternative to titanium implants because there are many areas where there is a lack of clinical studies on zirconia implants. Currently, they are an addendum to the titanium implant armamentarium for situations where they are useful (patient request, known hypersensitivity to titanium, or questions of esthetics when titanium might appear inappropriate for a certain situation/condition), but long-term studies are needed. Without a doubt, there is a need for two-piece zirconia implants, but limited research exists to support their clinical use at the moment.

Design and Fabrication of Complex-Shaped Ceramic Bone Implants via 3D Printing Based on Laser Stereolithography

3D printing allows the fabrication of ceramic implants, making a personalized approach to patients’ treatment a reality. In this work, we have tested the applicability of the Function Representation (FRep) method for geometric simulation of implants with complex cellular microstructure. For this study, we have built several parametric 3D models of 4 mm diameter cylindrical bone implant specimens of four different types of cellular structure. The 9.5 mm long implants are designed to fill hole defects in the trabecular bone. Specimens of designed ceramic implants were fabricated at a Ceramaker 900 stereolithographic 3D printer, using a commercial 3D Mix alumina (Al2O3) ceramic paste. Then, a single-axis compression test was performed on fabricated specimens. According to the test results, the maximum load for tested specimens constituted from 93.0 to 817.5 N, depending on the size of the unit cell and the thickness of the ribs. This demonstrates the possibility of fabricating implants for a wide range of loads, making the choice of the right structure for each patient much easier.

In situ bone regeneration of large cranial defects using synthetic ceramic implants with a tailored composition and design

The repair of large cranial defects with bone is a major clinical challenge that necessitates novel materials and engineering solutions. Three-dimensionally (3D) printed bioceramic (BioCer) implants consisting of additively manufactured titanium frames enveloped with CaP BioCer or titanium control implants with similar designs were implanted in the ovine skull and at s.c. sites and retrieved after 12 and 3 mo, respectively. Samples were collected for morphological, ultrastructural, and compositional analyses using histology, electron microscopy, and Raman spectroscopy. Here, we show that BioCer implants provide osteoinductive and microarchitectural cues that promote in situ bone regeneration at locations distant from existing host bone, whereas bone regeneration with inert titanium implants was confined to ingrowth from the defect boundaries. The BioCer implant promoted bone regeneration at nonosseous sites, and bone bonding to the implant was demonstrated at the ultrastructural level. BioCer transformed to carbonated apatite in vivo, and the regenerated bone displayed a molecular composition indistinguishable from that of native bone. Proof-of-principle that this approach may represent a shift from mere reconstruction to in situ regeneration was provided by a retrieved human specimen, showing that the BioCer was transformed into well-vascularized osteonal bone, with a morphology, ultrastructure, and composition similar to those of native human skull bone.