Porcelain Fused to High Noble Metal Crown from Istar Dental Lab

Porcelain Fused to High Noble Metal (PFM-HN) crowns are a basic and long-lasting option in dental repair work. These crowns mix the strength and body-friendliness of a high-noble metal base with the good looks of a porcelain layer. Their main job is to fix damaged teeth with a good mix of toughness, a tight fit at the edges, and nice looks, especially for back teeth or in difficult situations.

The great results you get from Porcelain Fused to High Noble Metal (PFM-HN) crowns come from the advanced science of their high-noble metal bases. These metal mixes are carefully made to give the best strength, great protection against wear, and excellent safety for the body inside the mouth.

Why Choose Our High Noble Metal PFM Crown?

Choosing the right crown is important for making patients happy. Our high noble metal PFM crown has many good points.

Amazing Strength: The strength-related features of high-noble alloys are very important for making sure PFM-HN crowns stay strong and last a long time:

• Yield Strength: These alloys usually have a yield strength between 250–500 MPa, giving great protection against being bent out of shape by chewing and biting.
• Ultimate Tensile Strength (UTS): The UTS is usually between 400–700 MPa, which shows they can handle a lot of pulling force before breaking.
• Modulus of Elasticity: With a modulus of elasticity of 80–110 GPa, high-noble alloys are stiff enough to hold up the porcelain layer, though they are more flexible than base metal alloys.
• Vickers Hardness: High-noble alloys usually have a Vickers Hardness (HV) of 150–250. Gold-platinum-palladium alloys are on the softer side, and gold-palladium-silver alloys are a bit harder.
• How the Tiny Structure Helps: The tiny inner structure is very important. Structures with small grains, made by quick cooling or by adding things that make the grains smaller, make it much stronger and lower the chance of the porcelain cracking.

Very Safe for Patients: The biocompatibility of high-noble alloys is a big plus:

• Allergic Reactions: They have the lowest rates ever recorded of allergic reactions, happening in less than 0.1% of cases. Rare cases of palladium or silver allergy have been seen, but these are very rare.
• Gum Discoloration: Gold-based alloys hardly ever stain the gums. While alloys with silver might cause a slight color change that can go away in people with thin gums, this is usually not a big problem.
• Swelling Response: Studies of tissue show very little swelling next to the edges of the high-noble alloy, which shows the gums accept it very well.

Looks Great: Our crowns are great for cosmetic dental work. We work on getting a perfect color match using a shade guide like the Vita Shade Guide. The crown will look partly see-through, just like a natural tooth. This helps it fit in with other teeth for a beautiful smile. A skilled dental technician from our team makes each one by hand.

Lasts a Long Time: Patients want a solution that will last. Our crowns have a very long life. With good brushing and flossing, they can last for many years. This makes them a smart choice for a permanent crown.

The Istar Dental Lab Difference: Our Process

We use a careful process to make every porcelain fused to high noble metal crown. Our goal is a perfect fit every time.

Case Arrival: You send us a mold of the patient’s prepared tooth. We also take digital files from systems like CEREC (Chairside Economical Restoration of Esthetic Ceramics).

Digital Design: We use CAD/CAM dentistry. This computer technology helps us design a perfect crown. We carefully check the design to make sure the edge fits the tooth perfectly.

Making the Core: We create the metal core, also called a coping (dental). High-noble alloys, according to the rules from top dental groups, must have at least 60% noble metals by weight, with at least 40% being gold. Common mixes we use in our lab are:

• Gold-Platinum-Palladium Alloys: These are usually made of 85–88% gold, 7–10% platinum, and 3–5% palladium. Small amounts of things like indium, iridium, or ruthenium are often added to make the grains smaller and help form a stable oxide layer needed for the porcelain to stick.
• Gold-Palladium-Silver Alloys: These mixes usually have 50–60% gold, 25–35% palladium, and 10–15% silver, with small amounts of zinc, indium, or tin added to help the porcelain stick and to control the metal’s melting temperature.

The way we make it has a big effect on the final result:

• Casting Quality: Our lab uses modern casting methods to reduce tiny holes and make it as strong as possible, which is better than the old way of casting with a flame.
• Heat Treatment: Heat treatments after casting, usually done at 700–900°C, are very important for getting rid of hidden stress, making the tiny inner structure even, and making the bond with the porcelain as strong as possible.
• Microstructural Control: Careful cooling and using grain refiners make sure the tiny structure has small grains, which improves both its strength and its ability to resist wear.

Adding the Porcelain: Our experts put on the porcelain in layers. First, a non-see-through layer hides the metal. Then, we add body porcelain and incisal porcelain to make it look natural.

Final Firing: The crown goes into a special oven. We use an exact heating plan for the porcelain. A final glaze firing gives the crown a smooth, shiny finish and stops the porcelain from becoming cloudy or weak.

Tips for Clinical Success

For the best results that last a long time, PFM-HN crowns really depend on careful tooth shaping and exact cementing steps. Our lab works closely with dentists to make sure these important steps are done in the best way.

Tooth Preparation: Removing enough of the tooth is necessary to make room for both the metal base and the porcelain layer, making sure there is enough material for strength and good looks.

• Occlusal Reduction: Usually, removing 1.5–2.0 mm from the chewing surface is suggested. This provides enough space for both metal and porcelain to avoid weak spots that could break.
• Axial Reduction: Removing an even 1.2–1.5 mm from the sides is suggested, with a taper of 6–10°. This special shape helps the crown stay in place and resist forces, lowering the chance of it coming loose.
• Incisal Reduction: For front PFM-HN crowns, especially in areas where looks are important, removing 2.0 mm from the biting edge is usually needed to make sure the porcelain is thick enough to look natural and not break.

Dental Cementation: Choosing the right cement is important for the crown to stay on and have a strong bond. You can use many types of dental glue:

• Resin-based cement or Resin Cement
• Glass ionomer cement
• Zinc phosphate cement
• Polycarboxylate Cement
• Resin-Modified Glass Ionomer (RMGI) Cement

Working with Istar Dental Lab

We are here to help your dental office. We know about common PFM crown problems like porcelain chipping and work hard to stop them from happening. We help you explain the cost of PFM crowns and dental insurance to patients.

We also offer services for taking off old crowns and putting on new ones. Whether the patient has a tooth that has had a root canal or needs a dental bridge, we can help. The specialists on your team, like the Prosthodontist, Endodontist, Periodontist, Oral Surgeon, and Hygienist, will appreciate our work. We also make other kinds of dental repairs like the porcelain veneer, inlay, and onlay.

Work with Istar Dental Lab for your porcelain fused to high noble metal crown needs. We promise great work to help you make healthy, beautiful smiles.