Bruxism can significantly affect the longevity of coronas dentales. Learn more about this condition, how it can impact your restoration material choice, and how long the crown may last.
What Is Bruxism and How Does It Damage Crowns?
Bruxism refers to the involuntary grinding or clenching of your teeth. It often occurs at night, while you sleep (though daytime bruxism also exists), and it puts significant pressure on your jaw and teeth.
If you have a dental restoration, such as a crown, bruxism can cause significant damage to it. Dental crown longevity is reduced because bruxism places serious stress on the material. It can cause microcracks and surface wear, and can increase crown fracture rates exponentially for those made out of porcelain, metal, or zirconia.
You can spot early signs of damage to your crown by watching for chipping, flattening, margin breakdown, and even new decay at the tooth-restoration junction. You may notice that your crown is looser and that the tooth opposite the crown has signs of damage. These signs can warn that a catastrophic fracture is near.
On average, crowns can last between 10 and 15 years. If you have bruxism, however, the longevity of the restoration will be reduced. Because of this, it’s essential to take proactive measures such as wearing a night guard, making occlusal adjustments, or implementing behavioral modifications to reduce instances of bruxism.
How Do You Assess Bruxism Risk Before Choosing A Crown?
To understand whether you have bruxism, your dental professional will conduct an assessment. They will ask questions about symptoms like:
- Nocturnal tooth grinding
- Daytime clenchingJaw soreness in the morning
- Tooth wear
- Dolores de cabeza
- Daytime sleepiness
- Medications
They will also perform a physical exam. They’ll inspect your teeth for surface wear, gum recession patterns, temporomandibular joint disorder, as well as occlusion and crown failure. The professional will document the wear pattern and differentiate occlusal wear from chemical damage to make the process of selecting crown materials easier.
If needed, you may be referred to specialists for specific treatments. For example, a sleep medicine expert may be involved if obstructive sleep apnea is suspected. Behavioral strategies can help manage bruxism, and a custom nightguard may also be recommended.
How Do Crown Materials Compare For Patients With Bruxism?
Crown material selection is a vital aspect of getting these restorations.
Gold (Metal Crowns)
Metal crowns have a significant lifespan, often lasting more than 15 years. Because metal can be bent and stretched under force, it will be less likely to cause damage to the opposing teeth. It can also be repaired. Metal crowns are visible, however, so they may not be the right choice for front teeth.
Porcelain-Fused-to-Metal (PFM)
PFM crowns have a powerful metal substructure topped with porcelain to offer the aesthetics you need for both front and back teeth. These are durable restorations. They can last between 10 and 15 years. Under heavy bruxism, porcelain crowns can chip easily.
Zirconia
Zirconia crowns can last more than 10 years and have very strong fracture resistance. If surface finishing is poor, however, these crowns can cause damage to the opposing tooth.
Lithium Disilicate
Lithium disilicate crowns are made of porcelain that looks exactly like your natural teeth, making them a good choice for visible-tooth restorations. They can bond very well with your teeth, making them less likely to fall out. They do have less fracture resistance than a full-zirconia crown, but also cause less wear on the opposing tooth.
Composite or Indirect Resin Crowns
These crowns are easier to repair than most others on the list, but they also have a shorter lifespan for people with heavy bruxism. Typically, they will last from three to seven years. They don’t cause damage to opposing teeth.
What Preparation And Bonding Protocols Improve Crown Durability?
Occlusion and crown failure are linked, so preparing the tooth surface and the area can help prevent these issues. The first step is to reduce the tooth. The material of the crown will determine how much is removed.
Typically, the occlusal reduction you will need for ceramic crowns is 1.5 mm to 2.00 mm. For porcelain-fused-to-metal options, the reduction should be 1.0 mm to 1.5 mm. When possible, it’s necessary to have a 2.00 mm ferrule, which is the dentin that is located at the neck of a tooth with a crown.
Your dentist should carefully determine the margins, considering tissue health and the crown material. This can assist with crown placement precision, which is integral for longevity.
The cement used to bond the crown to the tooth must also be carefully chosen. The material the crown is made of will determine the exact amount of cement needed.
What to Expect From Design Occlusion For A Patient Who Bruxes
When dentists design the occlusion for a crown, it’s important to understand the type of bruxism the patient has. For predominantly lateral bruxism with strong anterior guidance, for example, the best option could be a mutually protected occlusion.
There will be other variations depending on the severity and impact bruxism has on your teeth.
The dentist may also need to adjust tooth anatomy if you grind your teeth. Once the necessary changes have been made, you will need to schedule checks at two and four weeks after the appointment to ensure the occlusion design is effective.
Your dentist will also prescribe custom nightguards (occlusal guards). These guards prevent your teeth from pressing against each other while you sleep. For severe bruxism, an occlusal splint may be necessary. This is made of a hard material to prevent clenching.
What Protective Devices Should Be Prescribed And How?
Just as with dental crown options, there are a few types of protective devices that can help your bruxism. The type and severity of the condition play a role. The most common options include:
- Boil-and-Bite Nightguards: These are nightguards that you bite into shape and are best suited for mild to moderate bruxism
- Soft Thermoplastic Dual-Laminate: These nightguards have a soft interior and hard exterior and are most appropriate for moderate to severe bruxism
- Custom Hard Acrylic Splints: These are hard nightguards that prevent you from clenching your jaw and can help those with severe bruxism or those who have restorations
The material the nightguard is made of has to be carefully chosen. Some options, like ethylene-vinyl acetate, are soft and comfortable but wear away more rapidly. Hard polymethyl methacrylate is a good choice if you have dental crowns.
The crown material selection will play a role, too, since some options, like gold, may benefit more from soft nightguard materials.
Your dentist will also look at the arch of the nightguard. Lower arch nightguards are typically the better option for bruxism. Upper arch appliances are more appropriate when opposing restorations need protection.
Your dentist should offer clear instructions on how to start using the nightguard. Usually, you begin by wearing it for up to four hours every night for the first few days. You can then progress to wearing it the whole night. You need to clean the night guard daily and store it in a dry place to prevent bacterial growth.
After a follow-up a few weeks after you begin using the device, your next appointment will typically be about six months later.
What Decisions Guide Crown Selection For Bruxism?
One of the first things that can help improve clinical outcomes is identifying the severity of the bruxism. To do this, dentists will assess your symptom history and examine the wear facets on your teeth. It’s also possible that they will conduct an electromyography or polysomnography.
The severity of the bruxism will then help with the decision of the materials for the crowns you get. This will help achieve the crown longevity you need. At the same time, your dentist will consider your aesthetic preferences and the type of preparation you prefer for your crowns.
It’s also necessary to consider opposing tooth wear. This can be one of the most important preventative strategies for fractures. In many cases, CAD/CAM zirconia is a good option to prevent chipping.
Your remaining tooth structure will also impact the decision. If you have limited remaining dentin, your dentist will likely recommend restorations that help maintain it.
Metal and ceramic options are a good choice because they don’t require significant removal of your existing enamel but still offer strength and protection. Crown lengthening may be another option.
The decision should take into consideration cost and maintenance, too. Some dental crown materials, such as gold, can last for decades and are more affordable than ceramic options.
What Other Crown-and-Bruxism Questions Matter?
A choice that more people are turning to is same-day crowns, but are these a good choice for bruxism? When comparing lab-manufactured crowns with those made with CAD/CAM technology, remember that CAD/CAM options are made with zirconia, which is resistant to fractures. They can improve clinical outcomes.
Age also plays a role in dental crown choice when dealing with bruxism. For younger people who need crowns, the more conservative options are usually the best. They should also start using night guards to protect their crowns from grinding forces during sleep.
For elderly people, healing tends to be slower. Sedation could be a concern, too, so longer procedures to prepare teeth for restorations that require sedation are typically not the right choice.
Vitally, if you notice pain, bleeding, or signs that any current restoration has failed, quickly make an appointment with your dentist for help.
1. Can Botox Reduce Bruxism-Related Crown Damage?
Yes, injections of botulinum toxin into certain jaw muscles can help reduce bite force and grinding activity. This can result in lower wear on restorations.
It may be an option to consider if you’ve experienced several crown fractures and night guards aren’t as effective as you need. It’s a temporary solution, however, and could have some side effects.
2. When Can a Nightguard Be Fitted After Crown Placement?
To protect crowns from grinding forces, you can use a night guard. It can be fitted if the cement has dried and the restoration is stable. Resin-based luting cements can take a bit longer to fully set, so if that is what your dentist used, you may not be able to obtain a night guard on the same day as the restoration.
Even when you do get the nightguard, you’ll have to avoid very heavy biting for about 24 hours. If you experience discomfort or see changes in the margins of the restoration, you’ll need to return to your provider for a check-up.
3. Are Temporary Crowns at Higher Risk in Bruxers?
Temporary crowns can fracture more easily if you have bruxism. They may even debond and fall out. Your dentist can help by polishing the edges of the teeth opposing the restoration and by assisting you in choosing strong, reinforcing materials.
Cementation strategies can also help, with more powerful bonding protecting the crown more easily.
You will need to wear a night guard and may need to stick to softer foods so you don’t place any further stress on the restoration. Make sure to visit your dentist if anything seems off.
4. Can Crowns Worsen TMJ or Jaw Pain?
If you have TMJ or jaw pain, crowns could cause slight changes to your bite that worsen symptoms. You may need to switch to a softer diet to allow your jaw to adjust to the crowns, use a night guard for relief, and consider physiotherapy to alleviate muscle strain.
5. Do Crowns Trap More Plaque in Bruxers?
Crowns themselves don’t trap more plaque, but this can occur if the restorations have sloppy margins or crown maintenance falls below what’s necessary. There are oral hygiene practices for crowns that can help prevent further decay, including flossing and brushing with an appropriate fluoride toothpaste.
One concern is that people with bruxism tend to have rougher surfaces on certain teeth, allowing bacteria to settle there. Opposing tooth wear can also cause this.
Dealing with teeth grinding doesn’t have to put your smile at risk. Dr. Brett Langston can help you choose the right crowns and design a custom nightguard to protect your teeth and keep your smile looking great. Book a consultation today and get a plan made just for you.
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