All you need to know about the disadvantages of dental crowns

disadvantages of dental crowns

Dental crowns are widely used in dental patients, especially to cover and protect root canal-treated teeth. Dentists advise them due to their numerous benefits. However, they have some drawbacks as well in certain circumstances. Here, I will discuss in detail the disadvantages of dental crowns.  

Before jumping to our main topic, I want you to know very briefly why we put crowns on teeth and give a short overview of different crown materials. If you want to skip this part, then go directly to the disadvantages of dental crowns. 

Let’s get started:

What is a dental crown?

Dental crown or cap is a cover use protect discolored or destroyed weakened tooth (root canal-treated tooth). It is made with a strong and safe material and resembles in shape and size to your natural tooth. 

What patients receive dental crown?

The following circumstances indicate the placement of a crown on the teeth:

  • Tooth discoloration due to fluorosis that cannot be corrected by other teeth whitening methods. 
  • To cover and protect a root canal-treated or cracked tooth.
  • To cover teeth badly destroyed by decay. 
  • As a part of a bridge to replace a missing tooth. 
  • To cap a dental implant stump. 

What are the disadvantages of dental crowns?

Despite having numerous advantages, dental crowns also have some disadvantages. The following are the disadvantages of dental crowns:

Tooth cutting for the crown placement is an irreversible process

For crown preparation, a tooth cutting or reduction is required with a dental drill to make space for the crown. Tooth cutting is an irreversible process. However, it provides benefit to the root-treated teeth as crown coverage strengthens the weakened, fragile and dead tooth.

Risk of nerve damage or sensitivity in vital discolored teeth 

Excessive tooth cutting in healthy discolored teeth (stained teeth), teeth with altered shape (peg shaped upper front tooth), or misaligned teeth (rotated teeth) can cause sensitivity or damage to the nerve, especially in young patients.

Also, if at a later stage, these teeth become infected or painful and require a filling or root canal treatment. The crown needs to be removed and restored with a filling, and a new crown is placed, costing a lot of money and inconvenience to the patient.

Tooth cutting as a part of the bridge irreversibly removes the healthy tooth structure

In patients where crown cutting of a healthy tooth is required as part of a bridge, it can be disadvantageous for a healthy tooth. In such a case, replacing a missing tooth with a dental implant is more suitable than cutting and crowning the adjacent two healthy teeth to replace the middle one with a prosthesis.

tooth Sensitivity and discomfort following crown placement 

Procedure of crown placement

Crown placement usually takes 2-3 appointments to complete.

During crown preparation, a tooth is trimmed about the size of the future crown. An impression of the trimmed tooth is obtained and sent to the laboratory.

Meanwhile, a temporary crown is placed over the prepared tooth to protect it. A crown preparation usually takes a week or ten days.

Due to the crown cutting, you may experience some sensitivity to hot, cold, and pressure after every appointment, and it takes a couple of weeks to disappear. 

After the crown placement, the cement used to bond the crown may irritate the inner pulp leading to pain and sensitivity following the treatment. Also, removing the protective (smear) layer from dentin during the crown placement potentially exacerbates the sensitivity of the pulp. 

Furthermore, patients often experience pain or sensitivity when biting down after the crown placement. This pain is usually caused by the crown being too high, impeding the teeth or jaw closure.

The problem can easily be fixed by adjusting the height of the crown. 

Crown failure due to Poor marginal fit in porcelain dental crowns

A crown should snugly fit on the prepared tooth like a glove. A good marginal fit or adaptation of the crown is a critical factor in determining its longevity. 

The poor marginal seal can be an issue with porcelain crowns that allow plaque accumulation, cement dissolution, and seepage of fluid to the tooth resulting in tooth decay. 

The percolation of fluid into the tooth is the primary cause of crown failures, leading to tooth hypersensitivity, tooth discoloration underneath the crown, and tooth decay. 

Less durability of porcelain crowns

The durability of the crown depends upon the material of the dental crown. Metal crowns are highly durable but have poor aesthetics. Despite their durability, silver crowns aren’t acceptable to patients. On the contrary, all ceramic crowns have superb color-matching properties but are brittle and prone to breakage or fracture. 

All ceramic crowns need to be at least 2mm thick to be strong enough to bear the forces acting on them in the mouth throughout the day. This increased thickness may give an unaesthetic bulbous appearance on the front teeth, making them noticeable. 

Crowns are stronger than natural teeth with the potential to wear the opposing teeth

The increased hardness of crowns can be disadvantageous to natural teeth. Ceramic crowns are 1.5 times more rigid than enamel, and zirconia is 4.5 times harder than enamel. 

The rigid ceramic wears the opposing teeth. However, smooth and polished crowns are less prone to cause damage than rough and coarsely made crowns. Therefore, please ensure to get a crown from a reputable dental practice.  

For the same reason, people with a habit of grinding teeth are unsuitable for porcelain and zirconia crowns. Placement of porcelain or zirconia on worn-out teeth with exposed dentin can damage the teeth as dentine is 4.2 times less rigid than enamel. 

Cracked crowns need replacement costing you more money 

Another disadvantage of porcelain crowns is that they are brittle and fragile, and prone to breakage. 

Minor minor chips can be smoothened with a dental drill. However, more significant defects can be repaired by bonding dental composite, but these repair doesn’t last long and require replacement. 

The crown needs to be replaced before bacteria can penetrate the sound tooth or recontaminate the root-treated tooth, resulting in tooth decay. 

Zirconia crowns can be used instead because of their durability and excellent color-matching properties with natural teeth, but they cost an arm and a leg. 

High cost of Dental crowns 

Dental crowns are expensive, especially if they are not covered by private dental insurance. 

After the tooth canal treatment, patients try to avoid a crown due to its increased cost. On average, a crown costs $1000 to $1500. 

Metal crowns are the cheapest dental crowns. However, most patients decline them due to their silver color. Moreover, pfm crowns are low-cost dental crowns preferred by most patients due to their color-matching properties. 

Different types of crowns

The crowns placed on the teeth are made up different materials and each material has certain pros and cons. The dentist’s recommendation is based on the individual case requirement, and patient’s affordability.

Emax crowns 

Emax crowns are made of lithium disilicate. They are made from a single block of lithium disilicate. They are metal-free crowns and don’t have a metallic base. Following are the lithium disilicate advantages and disadvantages:

Emax advantages

  • They are thin and require less tooth removal.
  • They are translucent and give a more life-like appearance to the teeth. So, they provide the best match for your teeth.
  • They are tough and durable and last for a long time. 
  • There is metal in the crown so that no grey line can be seen. 
  • They can be placed on the front or back teeth

Emax crowns disadvantages 

  • They can’t be placed on the dark teeth because they reflect light, and the teeth appear yellow. 
  • They are high-end products and cost a fortune.
  • They can fracture during the crown trial if made thinner than the recommended thickness
  • They only provide single-tooth coverage and are not suitable to be used as a bridge. 

Pfm crowns 

Porcelain fused to metal crowns has been successfully used to cover teeth for 50 years. They have metal coping inside that makes them stronger. They are given on the back teeth because the metal coping gives a dark hue to the teeth and makes them unsuitable for front teeth. 

Pfm crown advantages

  • They are durable, and 97% of crowns have ten years survival rate.
  • They are cheaper than other tooth-colored crowns. 

Pfm crown disadvantages

  • Requires substantial tooth removal to accommodate both metal and porcelain. 
  • Prone to fracture due brittle nature of porcelain.
  • Not suitable for front teeth due grey color reflecting from the metal coping.
  • The grey line along the gums may appear after some time and requires crown replacement.
  • Difficult to adapt to gum margins
  • Pfm has a mean 5-year survival rate of 70%.

Porcelain jacket crowns

They are made up entirely of porcelain with no metal coping. They are light and translucent crowns suitable for front teeth restorations. 

Porcelain jacket crowns advantages 

  • The clarity of porcelain jacket crowns provides good matching with the front teeth.
  • Good tissue response when crown margins are placed slightly below the gum margins. 
  • Provide good retention on the tooth.

Porcelain jacket crowns disadvantages 

  •  They are prone to breakage due to the brittle nature of the material. 
  • It can be placed on a single tooth only, not as a bridge 
  • It can’t be given if you have a habit of teeth grinding 
  • It can’t be given on very short or thin teeth as it requires more removal of tooth substance to make the crown thick to withstand breakage. 

Zirconia dental crowns 

Zirconia dental crowns are ceramic crowns. There are two types of zirconia crowns. Monolithic zirconia crowns are made out of a single block of zirconia. However, zirconia is layered with different ceramic powders to make it more translucent and blends better with natural teeth. Following are the zirconia dental crowns advantages and disadvantages:

Zirconia dental crowns advantages 

  • It is resistant to chipping, fracture, and staining over other ceramic crowns because it is fabricated from a single zirconia block. 
  • Layered zirconia are ideal for front teeth because they are more translucent. 
  • Monolithic zirconia are given in back teeth because of their high strength. 
  • It lasts over 20 years and is three times stronger than porcelain crowns. 
  • They cause less abrasion (loss of enamel due to constant rubbing) to the opposing teeth as compared to other porcelain crowns and are given if you have a habit of teeth grinding. 

Zirconia dental crowns disadvantages 

  • Monolithic zirconia is darker in shade and challenging to match with the front teeth. 
  • Zirconia crowns are more costly than other ceramic crowns due to higher manufacturing costs. They usually cost between $1000-$3000. 

Weighing Advantages and disadvantages of dental crowns

There is no doubt that dental crowns cover and protect the weekend and fragile root canal-treated teeth. That’s the main advantage of dental crowns that supersedes their disadvantages. 

In situations like the one mentioned above, where crown placement offers more benefits, dentists often add one or more things to your daily practice that help to counter the side effects of dental crowns. In others, it may be best to opt for alternatives to save the teeth from unnecessary damage. 

Here are some options:

It is best to avoid porcelain and zirconia crowns in patients with the habit of night grinding. Metal or gold crowns can be used instead. However, if you already have a porcelain or zirconia crown, start wearing a night guard to avoid any damaging effects of the crown on the opposing teeth during night grinding. 

A crown as a part of a bridge may not be the best option to cut a healthy tooth to replace a missing tooth. A dental implant is the ideal alternative in this case. The patient goes for a bridge as it’s fixed to the teeth and costs less than dental implants. 

Also, healthy stained or discolored teeth unresponsive to other whitening treatments may require crowns. Now minimal or no-preparation veneers are available that require less tooth cutting and covers 3/4 part of the tooth. 

Furthermore, if you have crooked teeth, you can get crowns on the misaligned teeth to improve your smile. However, braces correct them by aligning them in the new position without jeopardizing the tooth’s integrity. 

Conclusion

Dentists advise dental crowns for their endless benefits, especially in covering and protecting root canal-treated teeth.

Like every other thing, dental crowns have some disadvantages, be it the crown itself or related to specific material. Here is a list of disadvantages of dental crowns: 

  • Irreversible removal of Tooth to make room for the crown.
  • Tooth cutting as a part of the bridge irreversibly removes the healthy tooth structure while replacing the extracted or removed tooth. Also, tooth cutting can cause sensitivity or risk of nerve damage in healthy discolored teeth.
  • You may experience sensitivity and discomfort following crown placement.
  • Crown chipping can be a problem with porcelain crowns. Extensive damage, however, requires replacement costing you more money.  
  • Crown failure also occurs in porcelain crowns due to poor marginal fit.
  • The high cost of dental crowns can be an issue for patients. 

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