A dental crown is a small, cap-like restoration, which covers a cracked or damaged tooth. It gives complete support to a badly broken or misshapen tooth, and replaces a missing tooth permanently to ensure that you have a beautiful smile. Now, when we talk about dental crowns material, there are quite a few, often confusing you what to pick and what not to.
Though your dentist is the right person to guide you (based on the condition of the teeth) which material is the best to go with, it is good to be aware of what works and what doesn’t.
So, let’s get started.
Most common dental crowns materials
Dental crowns can be made from different types of materials, based on their purpose. Say, for instance, if the purpose is to enhance the appearance of a smile, then a suitable material like ceramic or porcelain will be used to make the bridge or crown look more natural in your mouth.
Besides this, strength is yet another crucial feature for a dental crown. Frequently, the material chosen will have both:
The most commonly used dental crowns materials are:
• Metal alloys
But deciding what material to use depends completely on your tooth’s situation, which can be best advised only by a lab technician or a dental professional, who knows what works most effectively for your tooth.
Did you know?
Throughout history, different types of materials have been used for tooth replacements. You will be fascinated to read the fact that the ancient Egyptians used pieces of bone and animal teeth as primitive replacement materials.
According to archaeological evidence, the ancient Chinese used bamboo pegs to replace a lost tooth. The reason for early implants was as much as what it is today – to restore a beautiful smile. But rather being built from titanium, it was fabricated using other materials. (Source)
Dental implants aren’t new either. The practice dates back to 600 AD when ancient Egyptians used ivory, precious metals, and other’s human teeth for the implants. (Source)
Dental crown materials: A quick comparison
When we talk about restorative materials for teeth, dentistry, today, offers more options. Enhancements in beauty, durability, and strength of materials such as zirconium & porcelain have made cosmetic restorations so lifelike and natural that even the “most excellent” materials couldn’t accomplish it 10 to 20 years back.
However, it is vital to note that not every patient or tooth is best served with a complete porcelain restoration. Chances are that materials like gold may be an ideal option for you.
Considering this, let’s understand the benefits and drawbacks of the most commonly used materials for crown restorations.
1. Gold crowns
Gold has been one of the oldest and most commonly used crown materials in the dentistry world. Gold is highly durable and features the least reactivity of all the metals in your mouth.
Moreover, it is very gentle on the contrasting teeth and is particularly ideal for patients who grind or clench habitually. Even in its thin state, gold remains strong, allowing for a conventional crown preparation as well as the preservation of a healthier tooth structure.
The best part about using a gold crown is that it works wonderfully with glass ionomer cement, which is less sensitive than full-porcelain crowns.
Certainly, from a beauty perspective, most patients wouldn’t prefer a gold crown to restore their front tooth. Though the gold crown is one of the least reactive metals in dental restorations, some might be still sensitive to it.
Note: Pure gold is very soft to use it in your mouth. Therefore, gold is always mixed with other metals for added strength.
An excellent gold restoration is a high-noble alloy, which means that 60% of the dental crown is made of gold and other 40% is a mixture of valuable metals like palladium, silver, and platinum.
Though non-precious metal restorations are less expensive, patients are more likely to be sensitive to these materials that they might even develop a severe allergy. This, in turn, requires either immediate replacement or removal.
Another disadvantage of a gold restoration is that it conducts hot & cold temperatures quickly. Due to this, patients often experience sensitivity to cold or hot food in the initial weeks of crown placement. Though the sensitivity subsides after a few weeks, patients who are extremely sensitive should go for other options.
Gold crowns are best-suited for:
• Back teeth, where the cosmetic concern is lower
• Patients with grinding habits
Gold crowns might not suit for:
• Front teeth
• Patients with metal sensitivities or allergies
• Patients who are extremely sensitive to cold and hot temperatures
• Gentle on the opposing teeth
• Highly durable, even if it is thin
• Long lasting
• Cementation procedure is less-sensitive
• Conducts cold and hot temperatures quickly. This causes sensitivity in the initial weeks of replacement.
• Some patients may react to it if they are sensitive to gold metal. So, it is important to perform a test before using it.
• It appears different from the rest of the teeth.
• It tends to wear away after a few years if it is placed opposite to a fully-porcelain crown.
• It tends to wear away after a few years if the person grinds heavily.
• It can leave some micro-gaps, especially at the margins, making it highly vulnerable to decay.
2. All-ceramic crowns
An all-ceramic dental crown is more of innovation in the world of cosmetic dentistry. In many ways, an all-ceramic crown is a step ahead from a porcelain crown that is fused to metal.
The main reason a dentist might suggest you to go with an all-ceramic crown is for its aesthetics. It matches ideally with other teeth – be it appearance or color. This feature makes it hard for anyone to notice if an impaired tooth has been hidden.
When porcelain fused to metal is used for crowns, a receding gum line may show some dark metal. However, this doesn’t happen with an all-ceramic crown because it doesn’t display such lines.
An all-ceramic crown is best-suited for:
• Patients who are sensitive to metal or are prone to metal allergies
• Patients who suffer from receding gums
An all-ceramic crown might not suit for:
• Patients looking for a durable crown. Also, they may wear off the opposing teeth.
• Do not contain any metal
• Great for people who have a metal hypersensitivity
• Appearance is natural, as it matches the teeth perfectly
• Tissue friendly
• Less durable when compared to other materials
• More likely to break or crack if not handled carefully
• Expensive and the repair is not possible
3. Full porcelain crowns
For decades, restorations with full porcelain have been considered natural and lifelike. They are beautiful and great for an impressive cosmetic result. Since porcelain doesn’t conduct cold and heat, sensitivity to cold or hot foods isn’t much. Though this is a good factor to weigh, it still may not be the ideal choice for each tooth in your mouth.
Keep in mind that porcelain has a unique amalgamation of being both weak and strong at the same time. Porcelain is hard than your tooth enamel, and this makes it more vulnerable to damage to the opposite teeth, especially in patients who grind habitually. Moreover, porcelain can be stiff and may cause fractures easily if it is thin.
To prevent fractures from thinness, full-porcelain crowns should be thicker than gold restorations. This calls for a healthier tooth structure and durability. Furthermore, full porcelain bond with other teeth differently when compared to gold restorations.
Therefore, a glass ionomer cement can’t be used because a few patients can be highly sensitive to this bonding procedure than others, and may experience prolonged tooth sensitivity after the placement.
Full porcelain crowns are best-suited for:
• Front teeth or any tooth, where cosmetic results are the main concern
Full porcelain crown might not suit for:
• Patients who grind and clench in excess
• Patients who are sensitive to bonding materials and techniques (testing is important)
• Patients who don’t have a healthy tooth structure to support this type of restoration
• Doesn’t conduct cold or heat and thus, reducing sensitivity to temperatures
• Produces a more natural and lifelike result
• Non-reactive. Hence, good for patients who have metal sensitivities
• Might damage the opposing teeth
• Fractures easily when compared to other dental crown materials
4. PFG (Porcelain Fused to Gold) crowns
Porcelain fused to gold crown has a thin alloy layer, which contains about 60% of gold. It is then enclosed with porcelain, which is shaped like a tooth, giving it a natural and a lifelike look than crowns solely made of metals.
But since gold alloy has to be masked completely, a dense amount of porcelain has to be used. Now, this doesn’t look that natural when compared to dental crowns that are made only of porcelain.
Porcelain crowns offer a better result than full gold crowns. The gold base serves two purposes here:
• Allows the use of glass-ionomer cement
• Serves as a shield to the tooth even if porcelain tends to fracture
However, PFG crowns aren’t as popular as they once used to be. This is because the gold base builds an opacity automatically in the porcelain, which doesn’t look that natural in the mouth when compared to porcelain crowns fused to other materials such as zirconium.
Besides this, when it is used on the front teeth, it can occasionally show an opaque metal edge, especially at the gum line whenever recession occurs. And definitely, for patients with metal sensitivities or allergies, any crown with a base of metal alloy might not be an appropriate choice.
But a PFG crown is still a good option for patients who might have these crowns restored already and yet are looking to match with the existing work.
PFG crown is best-suited for:
• Patients who already have a few PFG crowns restored and would want to match with them
• Patients who have issues with all porcelain crowns or porcelain-fused-to-zirconium crowns, but still want good cosmetic results than full gold crowns
PFG crown might not suit for:
• Back teeth and front teeth
• Patients who have metal sensitivities or allergies (test can be done)
• Patients who tend to grind and clench often
• More durable than a full porcelain crown
• Offers better cosmetic results
• Allows the use of a glass ionomer cement, which tend to be less sensitive when compared to full-porcelain bonding methods
• The gold base guards the tooth even if the porcelain fractures
• Since the crown’s metal part is a gold alloy, it tends to be less reactive for patients with metal allergies
• A PFG crown is less expensive when compared to a crown that is made purely from gold alloy
• Since only the crown’s upper part is made of porcelain, it gives a natural look when a patient smiles
• A dark line might appear at the gum line, which is less appealing. This usually happens when there is a gum recession
• A PFG crown is expensive when compared to all-porcelain crown
• People who have thermal sensitivity can experience discomfort while consuming cold or hot foods. However, this is just a temporary issue
• Porcelain might fracture the metal base
5. PFZ (Porcelain Fused to Zirconia) crowns
PFZ (Porcelain fused to Zirconia) crowns serve as a good alternative to traditional PFM (Porcelain Fused to Metal) restorations. This crown type serves durability, aesthetics, and strength.
As the name implies, “porcelain fused to zirconia” is created when porcelain is combined with zirconium oxide.
Since the base of zirconia has a nice, white shade, it is layered carefully with porcelain in order to match the final restoration. The PFZ crowns are crafted using CAD (Computer Aided Design) technology.
Most dentists prefer zirconium because this material doesn’t produce a chemical reaction inside the mouth (note: ZiO2 is completely biocompatible).
PFZ crown is best-suited for:
• Patients who are looking for a complete crown restoration with excellent cosmetic results with durability being a priority
PFZ crown might not suit for:
• Patients with certain metal sensitivities and allergies (it is important to take a test in prior)
• Has a smooth, translucent look
• Gives better cosmetic results
• Allows the use of a glass ionomer cement
• Bases and crowns milled from computerized scans make the margins accurate
• Less expensive when compared to gold-based/gold crowns
• Can be reactive, especially if the patient is sensitive to metal
• Not suitable for a partial tooth restoration
While considering dental treatment, it is vital to talk to your dentist first. The information written above is solely intended to help you understand about dental crown materials better.
Bear in mind that every individual is different, and so is his or her anatomical considerations and health conditions. These aspects have a bigger influence on the kind of dental treatment one wants to take. Remember that every type of dental crown tends to decay, especially at the margins. Also, it requires re-cementing regularly as the tooth flex with use.
Besides these, a tooth in need of a crown might also call for a “root canal treatment.” Therefore, we advise you to get as much as information you can for your treatment options with your dentist.