Cobalt chrome dentures disadvantages

Cobalt chrome is a commonly used alloy to create the metal frameworks, serving as the pink denture base that acrylic false teeth are set into for both partial and complete dentures. It is also used to fabricate the metal clasp assemblies that help securely retain removable partial dentures because of its rigidity and durability.

While cobalt chrome dentures have some benefits, there are also significant disadvantages of this material that prospective denture patients should be aware of. Some of these downsides are related to aesthetics, biocompatibility, and long term performance, causing some to claim that they’re the worst dentures ever!

Patients should consider both benefits and drawbacks when selecting denture materials.

What is Cobalt Chrome?

Cobalt chrome is a hybrid alloy made from cobalt, chromium, nickel and molybdenum. It is very strong and resistant to wear and corrosion. These qualities make cobalt chrome suitable for dental applications like crowns, bridges and metal denture components.

Cobalt chrome was traditionally the standard material of choice for metal denture bases and frameworks. It can be formed very thinly while still providing strength and durability to support acrylic fake teeth.

The benefits of cobalt chrome metal dentures

Cobalt chrome allows for affordable yet strong and resilient metal denture bases in full or partial dentures that can endure chewing stress. Here are some of the pros:

Strength

Cobalt chrome is very strong, which allows metal frameworks to be made very thin yet still provide rigid support for the acrylic teeth. This prevents the denture base from fracturing or warping from chewing forces over time.

Durability

Cobalt chrome has excellent wear resistance and does not corrode easily in the oral environment, so it can endure years of use without losing integrity. This helps dentures maintain their structure longer before needing to be remade.

Affordability

Cobalt chrome alloy denture prices are relatively lower compared to gold alloys and some other metals used in dentistry. This can help keep down costs of metal components in partial and full dentures.

Easy repair

Small fractures or damage to cobalt chrome denture frameworks are simpler for dentists to repair compared to many polymers and resins. This can extend the lifespan of the dentures.

Disadvantages of Cobalt Chrome Dentures

While cobalt chrome has favorable physical properties, it is increasingly falling out of favor due to a number of drawbacks:

A. Aesthetics Issues

Unnatural tooth color

Cobalt chrome has a grayish metal color that can show through thin gum tissue giving an unattractive appearance. This is especially noticeable for upper dentures.

Metal exposure over time

The pink acrylic applied over the metal framework often wears thinner over time revealing more “metal mouth” appearance as the dentures age.

Visibility of metal clasps

The metal components like resin-retentive clasps can remain exposed and show through the teeth. These can be unappealing aesthetically.

B. Biocompatibility Problems

Metal sensitivity and galvanic reaction

Many patients are sensitive to nickel and other metals which can cause oral irritation, inflammation or allergic contact dermatitis. Galvanism between dissimilar alloys in the mouth accelerates metal corrosion and sensitivity.

Impaired taste

Metallic ions can interfere with normal taste sensation leading to ongoing issues with dysgeusia (altered taste perception), especially feeling like a constant metallic or salty taste in the mouth.

C. Long Term Wear Concerns

Decreased resin bond effectiveness

Bonding the acrylic teeth portion to cobalt chrome components weakens over 5-10 years requiring earlier denture replacement.

Internal abrasion of components

Cobalt chrome components eventually weaken through grinding and microscopic internal stress, risking denture fracture or deformation issues.

Permanent plaque retention

The microscopic abrasions in chrome cobalt surfaces contribute to plaque accumulation that breeds bacteria and can inflame gum tissue.

Unpredictable corrosion issues

Corrosion occurs slowly on chrome cobalt but releases metal ions and creates pits that collect more plaque. This leads to fluctuating performance and more rapid attachment loss.

Potential side effects from chrome dentures

Denture wearers using chrome appliances may face certain side effects from the long-term use of chrome dentures, including:

  • Metal Sensitivity – Chrome used in dentures contains nickel which can cause allergic reactions, redness, swelling, canker sores, and a burning sensation in those sensitive to metals.
  • Dermatitis – An itchy rash may occur where the denture base contacts gum tissue, signaling a metal allergy.
  • Taste Distortion – Metallic ions released over time can make food taste more salty or acidic due to taste perception changes.
  • Corrosion Issues – Slow corrosion of chrome produces rough surface areas that accumulate more plaque and breed higher oral bacteria levels over years of wear, irritating gums.
  • Metallic Taste – A persistent metallic or chemical taste in the mouth is common with extended chrome denture use as metal ions diffuse into saliva.

It is best to test for metal sensitivity beforehand to see if non-metal denture materials may be better suited and prevent side effects in metal-sensitive patients from long term chrome denture use.

What are the Alternatives?

Given the disadvantages of cobalt chrome like aesthetics, biocompatibility, reduced longevity and hygiene issues, many modern dentists now favor alternative materials. These include:

Metal-Free Options

Advanced polymer resins can replace convention metal frameworks allowing for thin, resilient non-metallic bases. Thermoplastics like nylon and fiber-reinforced acrylic are also used effectively for pink bases that prevent show-through.

Titanium

Titanium offers metal strength without risk of corrosion. It is thinner but very rigid and bonds better to acrylic teeth. It is more naturally white in color for less show through. No allergic sensitivity or metallic taste occurs as with cobalt chrome.

Zirconia

Zirconia is a white, tooth-colored ceramic that is exceptionally strong and thin. It hides much better under gum tissue than metals with very natural aesthetics.

Talk to Your Dentist about Modern Denture Materials

Aesthetics, longevity, comfort, and hygiene should be carefully considered when choosing the materials for your dentures and balance against costs. Many quality alternatives now exist to traditional cobalt chrome with advanced polymers and resins avoiding the drawbacks of metal.

Speak to your prosthodontist about which options best suit your needs and preferences in partial or full dentures. While cobalt chrome allows thin, inexpensive denture bases, its overall performance leaves much to be desired for many patients.

Authors

  • Editorial team

    A team comprising oral health care professionals, researchers, and professional Writers, striving to impart you with the knowledge to improve your oral health, and that of your loved ones. 

  • Lilly

    Lilly, aka, Liza Lee, is a passionate community oral health officer and our lead writer. She's not only well-versed in performing a multitude of dental procedures, including preventive, restorative, and cosmetic, but also an avid writer. Driven by the significant oral health burden all around her, Lilly strives to build capacity and promote oral health. She envisions making a lasting impact by advancing research, prevention, and promotion efforts to alleviate oral health disparities. Please share your views and opinions on my posts.

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