Do zirconia dental implants present better clinical results than titanium dental implants? A systematic review and meta-analysis

A randomized clinical trial on zirconia versus titanium implants in maxillary single tooth replacement

OBJECTIVES

This RCT aimed to compare zirconia and titanium dental implants in the maxillary premolar region. The comparison was based on marginal bone level (MBL) changes, clinical parameters, aesthetic outcomes, and patient related outcome measures (PROMs) 1 year after prosthetic loading.

MATERIALS AND METHODS

Fifty patients were randomly assigned to receive either a zirconia (ZrO2, n = 25) implant or a titanium (Ti, n = 25) bone-level implant. Implants were provided with a lithium disilicate crown 3 months after placement. Follow-up was at 1 month and after 1 year. The primary outcome pertained to changes in MBL. Reported secondary outcomes consisted of implant survival, peri-implant tissue health, aesthetics, and PROMs.

RESULTS

Mean MBL change after 1 year was 0.01 mm (SD = 0.45; min = 0.72, max = 0.86) for ZrO2 and -0.09 mm (SD = 0.34; min = 0.53, max = -1.06) for Ti (p = .439). Scores for the other clinical outcome parameters and PROMs were generally favorable, with no significant differences. However, significant differences were found for the aesthetic outcomes regarding two criteria: (a) level of facial mucosa (p = .022), in favor of Ti, and (b) root convexity/soft tissue color and texture (p = .005) in favor of ZrO2.

CONCLUSION AND CLINICAL IMPLICATIONS

The ZrO2 and Ti implant types used in this study, replacing a single missing maxillary premolar, show a comparable outcome in terms of MBL change after 1 year. Clinical and aesthetic parameters, as well as PROMs, are favorable and similar between both implant types after 1 year of prosthetic loading. These short-term study results suggest that both are suitable for clinical use.

Biomechanical Fatigue Behavior of a Dental Implant Due to Chewing Forces: A Finite Element Analysis

The use of titanium as a biomaterial for the treatment of dental implants has been successful and has become the most viable and common option. However, in the last three decades, new alternatives have emerged, such as polymers that could replace metallic materials. The aim of this research work is to demonstrate the structural effects caused by the fatigue phenomenon and the comparison with polymeric materials that may be biomechanically viable by reducing the stress shielding effect at the bone-implant interface. A numerical simulation was performed using the finite element method. Variables such as Young's modulus, Poisson's coefficient, density, yield strength, ultimate strength, and the S-N curve were included. Prior to the simulation, a representative digital model of both a dental implant and the bone was developed. A maximum load of 550 N was applied, and the analysis was considered linear, homogeneous, and isotropic. The results obtained allowed us to observe the mechanical behavior of the dental implant by means of displacements and von Mises forces. They also show the critical areas where the implant tends to fail due to fatigue. Finally, this type of non-destructive analysis proves to be versatile, avoids experimentation on people and/or animals, and reduces costs, and the iteration is unlimited in evaluating various structural parameters (geometry, materials, properties, etc.).

One-piece versus two-piece ceramic dental implants

In this narrative review, a structured comparison between one-piece and two-piece zirconia dental implants is highlighted. Ceramic dental implants have long ceased to be hype; on the contrary, they can offer a significant addition to the daily dental implant practice. Not only do their favourable aesthetics play a significant role, but their ability to work completely metal-free is of added value, particularly for patients with a proven allergy for Grade 5 titanium. Furthermore, the fact that peri-implantitis seems to appear only incidentally is an important supporting argument for their use as well. Whereas the original design of zirconia implants was formerly always of a one-piece/one-phase structure (the monobloc design), nowadays, two-piece/two-phase designs (the so-called hybrid concept) are also widely utilised to restore missing teeth. Both concepts have advantages and disadvantages, scientifically as well as clinically.For this paper, relevant articles from the recent scientific literature were selected from PubMed. The aim was to identify and summarise what has previously been published on one-piece versus two-piece ceramic implants. This article will compare the benefits and drawbacks of one-piece versus two-piece ceramic implants based on clinical- (design, different sizes, surgical protocol, prosthetics), scientific- (loading and eventual complications) and patient-related (costs and long-time perspectives) criteria.

Biomedical Applications of Titanium Alloys: A Comprehensive Review

Titanium alloys have emerged as the most successful metallic material to ever be applied in the field of biomedical engineering. This comprehensive review covers the history of titanium in medicine, the properties of titanium and its alloys, the production technologies used to produce biomedical implants, and the most common uses for titanium and its alloys, ranging from orthopedic implants to dental prosthetics and cardiovascular devices. At the core of this success lies the combination of machinability, mechanical strength, biocompatibility, and corrosion resistance. This unique combination of useful traits has positioned titanium alloys as an indispensable material for biomedical engineering applications, enabling safer, more durable, and more efficient treatments for patients affected by various kinds of pathologies. This review takes an in-depth journey into the inherent properties that define titanium alloys and which of them are advantageous for biomedical use. It explores their production techniques and the fabrication methodologies that are utilized to machine them into their final shape. The biomedical applications of titanium alloys are then categorized and described in detail, focusing on which specific advantages titanium alloys are present when compared to other materials. This review not only captures the current state of the art, but also explores the future possibilities and limitations of titanium alloys applied in the biomedical field.

Vacuum Ultraviolet (VUV) Light Photofunctionalization to Induce Human Oral Fibroblast Transmigration on Zirconia

Soft tissue adhesion and sealing around dental and maxillofacial implants, related prosthetic components, and crowns are a clinical imperative to prevent adverse outcomes of periodontitis and periimplantitis. Zirconia is often used to fabricate implant components and crowns. Here, we hypothesized that UV treatment of zirconia would induce unique behaviors in fibroblasts that favor the establishment of a soft tissue seal. Human oral fibroblasts were cultured on zirconia specimens to confluency before placing a second zirconia specimen (either untreated or treated with one minute of 172 nm vacuum UV (VUV) light) next to the first specimen separated by a gap of 150 µm. After seven days of culture, fibroblasts only transmigrated onto VUV-treated zirconia, forming a 2.36 mm volume zone and 5.30 mm leading edge. Cells migrating on VUV-treated zirconia were enlarged, with robust formation of multidirectional cytoplastic projections, even on day seven. Fibroblasts were also cultured on horizontally placed and 45° and 60° tilted zirconia specimens, with the latter configurations compromising initial attachment and proliferation. However, VUV treatment of zirconia mitigated the negative impact of tilting, with higher tilt angles increasing the difference in cellular behavior between control and VUV-treated specimens. Fibroblast size, perimeter, and diameter on day seven were greater than on day one exclusively on VUV-treated zirconia. VUV treatment reduced surface elemental carbon and induced superhydrophilicity, confirming the removal of the hydrocarbon pellicle. Similar effects of VUV treatment were observed on glazed zirconia specimens with silica surfaces. One-minute VUV photofunctionalization of zirconia and silica therefore promotes human oral fibroblast attachment and proliferation, especially under challenging culture conditions, and induces specimen-to-specimen transmigration and sustainable photofunctionalization for at least seven days.

Optimized Gingiva Cell Behavior on Dental Zirconia as a Result of Atmospheric Argon Plasma Activation

Several physico-chemical modifications have been developed to improve cell contact with prosthetic oral implant surfaces. The activation with non-thermal plasmas was one option. Previous studies found that gingiva fibroblasts on laser-microstructured ceramics were hindered in their migration into cavities. However, after argon (Ar) plasma activation, the cells concentrated in and around the niches. The change in surface properties of zirconia and, subsequently, the effect on cell behavior is unclear. In this study, polished zirconia discs were activated by atmospheric pressure Ar plasma using the kINPen^®09 jet for 1 min. Surfaces were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and water contact angle. In vitro studies with human gingival fibroblasts (HGF-1) focused on spreading, actin cytoskeleton organization, and calcium ion signaling within 24 h. After Ar plasma activation, surfaces were more hydrophilic. XPS revealed decreased carbon and increased oxygen, zirconia, and yttrium content after Ar plasma. The Ar plasma activation boosted the spreading (2 h), and HGF-1 cells formed strong actin filaments with pronounced lamellipodia. Interestingly, the cells' calcium ion signaling was also promoted. Therefore, argon plasma activation of zirconia seems to be a valuable tool to bioactivate the surface for optimal surface occupation by cells and active cell signaling.