A growing awareness of esthetic dentistry has almost certainly resulted in an increase in the number of patients requesting all-ceramic or porcelain-fused-to-metal restorations at your practice. Despite the increasing popularity of these cosmetically-pleasing crowns and bridges, there are still occasions when full-cast metal restorations will be a better choice for repairing posterior teeth. In fact, all-metal restorations can be an excellent option for patients whom you know are less concerned about achieving perfect esthetics and simply want the best protection for their teeth. Modern dental alloys have been engineered to provide excellent physical properties, meeting a wide variety of patient requirements.
Pros of Choosing Full-Cast Crowns and Bridges
A full-cast metal restoration is extremely unlikely to break or fail and can be good for patients who have badly damaged posterior teeth. It’s also exceptional when a full-cast fixed dental bridge is needed. When preparing a tooth for a full-cast crown, it’s necessary to prepare all axial walls and the occlusal surface, and this preparation helps provide greater retention than opting for a conservative restoration on the same tooth. Where a furcation deficit is present, it may be possible to re-contour the lingual and buccal walls to help improve a patient’s oral hygiene.
Full-metal crowns can be highly biocompatible, especially when a noble or precious metal alloy is chosen. Metal alloy (gold crowns in particular) have extremely good biocompatibility with gingival tissue and are unlikely to promote any allergic reactions. They are not susceptible to accumulating plaque, offer good corrosion resistance, and do not absorb fluids. Full-cast metal crowns have a high tensile strength which is an advantage when preparing the tooth because the crown doesn’t need to be very thick, allowing you to preserve more of your patient’s original tooth. The strength of modern dental alloys allows our dental lab to create a much thinner restoration compared to a PFM or all-ceramic crown. A full-cast crown can be a particularly good choice when space is limited.
While full-cast metal crowns and bridges are very strong and are unlikely to be fractured by chewing forces, they are extremely kind to opposing dentition, reducing the risk of excessive wear because they offer a similar coefficient to tooth enamel. If the risk of wear to opposing teeth is a concern, it’s typically better to choose precious or semi precious dental alloys when planning your patient’s treatment because these are softer yet still very durable. Additionally, the coefficient of expansion is similar to natural teeth.
Cons of Choosing Full-Cast Crowns and Bridges
The major disadvantage of choosing a full-cast metal crown or bridge is its appearance. It’s important that your patient is aware that their new restoration will be quite visible in the mouth whenever they smile or laugh if in the same “smile zone”. Precious metal and gold crowns and bridges can be expensive depending on the market cost of gold. In rare occasions, micro-gaps may be present after casting, which could increase the risk of decay. But if the crown has been fabricated in a high noble metal, it may be pliant enough to allow for minor adjustments.
It is important to check your patient doesn’t have any metal allergies, particularly if you would prefer not to use a precious or semiprecious metal. Base-metal alloys frequently contain nickel, beryllium, or chrome which can promote an allergic reaction. It is also important to discuss whether your patient wishes to have a white or yellow crown or bridge, as obviously the choice of alloy will dictate its color.
Please be reminded that our experienced technical team is here to assist you should you wish to discuss a case in more detail.