CATEGORY 100 AUSTRALASIAN DENTIST LABS Ask our Expert: Ian Feigen on material selection When it comes to dental restorations, choosing the right material is crucial for achieving best-practice durability, aesthetics, and patient satisfaction. Ian Feigen, Technical Services Director at Avant Dental, addresses the most common questions he encounters in daily dental lab practice, and shares his expert insights and practical advice to help dentists choose the restoration materials that will achieve the best possible patient outcomes. What factors should be considered when deciding between zirconia, lithium disilicate, and hybrid ceramics? Zirconia is typically preferred for its strength and versatility, particularly in posterior restorations. Improved translucency in modern zirconia has also enhanced its aesthetic appeal for anterior restorations. Lithium disilicate is also often chosen for anterior crowns due to its excellent translucency and ability to closely mimic the appearance of natural teeth and bondability. Hybrid ceramics are generally suitable for partial restorations where some flexibility is beneficial. But keep in mind that each material has specific preparation requirements, which should also guide the choice. Q&A column The importance of material selection with Ian Feigen A new column where technicians respond to a common question: i.e zirconia or metal crown/PFM What are the pros and cons of zirconia crowns compared to traditional metal crowns? Zirconia crowns are durable and resistant to fractures, which typically makes them suitable for anterior and posterior applications. However, zirconia can be challenging to adjust once in place and may increase the risk of abrasion on opposing teeth. Traditional metal crowns are known for their strength and longevity but may be less aesthetic and potentially unsuitable for anterior restorations due to their metallic appearance. Metal margins may also become visible over time, which may impact the overall look. is suitable for anterior teeth with adequate structure, and where aesthetics is a priority. Hybrid ceramics can be considered for teeth requiring partial restorations. How do different materials impact the overall cost of treatment for the patient? Zirconia and lithium disilicate tend to be more expensive than traditional materials like PFM or acrylic resins due to their advanced properties and aesthetic benefits. However, they typically offer better durability and fewer long-term maintenance costs, potentially making them more cost-effective in the long run. Acrylic resins may be more affordable but may require frequent repairs or replacements, which can add to long-term costs. What are the unique preparation considerations for each material? Zirconia typically requires minimal tooth reduction due to its strength, but adequate space for material thickness is essential. Rounded shoulder or chamfer preparations are common for zirconia and ensure optimal fit. Lithium disilicate may require more reduction to achieve adequate material thickness for strength and aesthetics. The bonding and cementation process for lithium disilicate restorations can also be technique sensitive. Hybrid ceramics usually also require minimal reduction but must be resin-bonded to enamel for optimal performance. What are the common pitfalls in choosing the wrong material for crown or bridge restorations? Choosing lithium disilicate for posterior teeth subject to heavy forces may increase the risk of chipping, and hybrid ceramics may not provide sufficient durability for high-stress areas. Proper assessment of the tooth’s condition, functional requirements, and aesthetic goals is essential to selecting the material that will achieve the best patient outcome. u Ian Feigen How does the strength of zirconia compare to lithium disilicate or PFM? Zirconia is perhaps the strongest material available for dental restorations. Lithium disilicate provides a balance between strength and aesthetics, however, it may be more prone to chipping under stress than zirconia. PFM combines the strength of a metal substructure with the aesthetics of porcelain but often requires significant tooth reduction and may have aesthetic limitations due to the metal substructure and the weakness of the layering ceramic. What role does the patient’s tooth condition play in material choice? For teeth with significant cracks or minimal remaining structure, zirconia is often the best choice due to its strength and minimal reduction requirements. Lithium disilicate
RkJQdWJsaXNoZXIy MTc3NDk3Mw==