By Hilarie Galloway, DMD
BruxZir is a brand of zirconia used in dental restorations. Zirconia, a ceramic material, is known for being one of the strongest tooth-colored options available. BruxZir solid zirconia offers various types, including BruxZir Full-Strength Zirconia and BruxZir Esthetic Zirconia, each tailored for specific BruxZir restorations.
Zirconia is an excellent choice for clinicians aiming to create restorations that require exceptional toughness. BruxZir zirconia offers a balanced option, providing both high durability and superior esthetics for denture dentists seeking the best of both worlds.
Advantages of BruxZir Zirconia
Discover the benefits of BruxZir Esthetic restorations and the advantages of dental zirconia.
Fracture Resistance
Zirconia’s mechanical properties make it ideal for posterior dental restorations, allowing for a reduced core thickness while maintaining strength. The material’s ability to retain a tetragonal structure at room temperature—achieved by adding stabilizing oxides like Y2O3—prevents catastrophic failure caused by phase transformation. Zirconia’s toughness is enhanced by the compressive stresses that arrest crack propagation, although processes like grinding and sandblasting can weaken the material and increase its susceptibility to aging, particularly in the presence of water.
In dental applications, zirconia-based frameworks exhibit mechanical strength up to three times higher than other all-ceramic materials, effectively withstanding posterior occlusal forces. However, porcelain cracking remains a concern, especially when compared to metal-ceramic prostheses. The interface between zirconia and porcelain can lead to issues like chipping, although recent advances in bioceramics, such as zirconia magnesia composites, show promise in mitigating these challenges.
Shear Bond Strength and Aging
Zirconia-ceramic restorations exhibit bond strength comparable to metal-ceramic alternatives. However, the bond mechanisms between zirconia and ceramic are less understood, with micromechanical interactions playing a role. Aging processes, including exposure to oral fluids, can lead to stress corrosion, slow crack growth, and eventual failure.
Despite this, studies show that zirconia systems maintain their bond strength over time, with little effect from thermocycling or artificial aging. Differences in bond strength and failure modes between zirconia-layered and zirconia-pressed ceramics highlight the need for careful consideration of material properties and aging effects in dental restorations.
Color and Esthetics
Zirconia frameworks offer a better esthetic alternative than metal frameworks but can appear too white and opaque. Manufacturers address this by introducing colored zirconia frameworks or using techniques like pigment addition and liner application to improve color matching. The ability to control the core shade allows for minimal veneering, especially in areas with limited space, enhancing the esthetic outcome.
Despite advances, achieving perfect color matching remains a challenge, though overpressed ceramics and layering techniques offer potential solutions. Zirconia restorations also require minimum occlusal reduction, better maintaining the natural tooth structure.
Manufacturing Zirconia
CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) materials used in dental restorations typically come in the form of fully or partially sintered blocks and discs. The state of these blocks and discs plays a crucial role in the fabrication process, influencing the precision, efficiency, and overall outcome of the dental restorations.
Zirconia dental prosthetics are typically fabricated using CAD/CAM technology through two main methods, each with its benefits and challenges.
Method 1: Milling from Fully Sintered Zirconia Blocks
This method involves milling dental restorations from zirconia blocks that have already been fully sintered. The advantage is that it eliminates concerns about shrinkage, ensuring the final prosthetic matches the design dimensions. However, the hardness of fully sintered zirconia can cause significant wear on milling burs, potentially leading to flaws that could compromise the restoration’s mechanical properties.
Method 2: Milling from Partially Sintered Zirconia Blocks
In this method, the prosthesis is milled from partially sintered blocks, which are larger to account for shrinkage during the final sintering process. This approach is more cost-effective and less taxing on milling tools, as the material is easier to work with before final sintering.
Milling and Sintering Process
After milling, the zirconia framework undergoes a final sintering phase, shrinking by about 25%. This contraction is crucial for achieving the correct dimensions, and many zirconia blocks come with barcodes to assist the CAD/CAM system in precise milling.
Adjusting and Veneering the Sintered Zirconia Framework
Once sintered, the zirconia may need further adjustments before applying ceramic veneers. These layers enhance the esthetics, closely resembling natural teeth.
Finalizing the Restoration
The final steps include applying glaze and stain to the ceramic layers, producing a restoration that meets both functional and esthetic standards, with a lifelike vitality. Though time-consuming, the CAD/CAM process ensures precise and high-quality zirconia restorations.
Dental Applications of Zirconia
A denturist with the right dental education and experience with denture and implant restorations can create durable, stunning restorations.
Zirconia-Based Dental Posts
The demand for more esthetic dental posts, especially under all-ceramic restorations, has led to the development of zirconia-based materials. Metal posts can cause esthetic issues, such as a gray discoloration of ceramic crowns and surrounding gingiva, and may lead to complications like corrosion, metallic taste, and oral pain.
To address these issues, zirconia posts have been developed. These posts, which can be smooth, tapered, or parallel, offer high strength and biocompatibility. While they are advantageous in terms of esthetics and light transmission, they also present challenges such as poor resin-bonding capabilities and lower retention compared to metal posts.
Zirconia-Based Crowns and Bridges
Zirconia frameworks are used for BruxZir zirconia crowns and bridges due to their high flexural strength and favorable clinical results. Studies have shown that zirconia-based prostheses offer good survival rates, though minor issues like porcelain chipping have been reported. BruxZir crowns are generally long lasting and lifelike.
Zirconia-Based Implant Abutments
Zirconia ceramics have also been extended to implant-supported restorations due to their toughness, biocompatibility, and tooth-matched color. While zirconia abutments have shown high success rates and good tissue compatibility, concerns remain about long-term stability and the potential for veneering porcelain fractures.
Premier Zirconia Restorations With Stomadent
When you partner with Stomadent Dental Lab, you can trust that our technicians leverage the latest advancements in dental technology to craft top-quality zirconia dental products. Whether you need same-day denture repairs, relines, or the in-house design and vacuum casting of metal frameworks, crowns, bridges, or partial dentures, we are your comprehensive dental lab solution.
Our mission is to support you in meeting your patients’ needs for both comfort and quality with exceptional dental products. Reach out today to get started.
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