Teeth grinding and jaw clenching—collectively known as bruxism—can place considerable forces on the teeth. Over time, this may contribute to tooth wear, chipped or fractured teeth, damaged fillings and crowns, and sensitive or uncomfortable teeth. Some people also experience tired jaw muscles or morning jaw discomfort.
A night guard, sometimes called an occlusal guard or occlusal splint, can provide a protective surface between the upper and lower teeth while you sleep. For patients who are damaging their teeth through grinding or clenching, a custom-made appliance can be an important part of protecting both natural teeth and existing dental work.
However, night guards are sometimes promoted as if they can cure grinding, permanently correct the bite or reliably eliminate TMD and jaw pain. The evidence is more nuanced. This guide explains what night guards are genuinely useful for, their limitations, how they differ from retainers and sports guards, and when you should speak to your dentist.
What Is a Night Guard?
A night guard is a removable dental appliance worn over either the upper or lower teeth, usually while sleeping. Dentist-made guards are individually fitted to the patient’s teeth and bite.
Depending on the clinical situation, a night guard may be made from a hard acrylic-type material, a softer material or a combination of materials. There is no single design that is best for every patient.
The appliance creates a physical barrier between the teeth. Instead of repeatedly grinding natural tooth surfaces or restorations directly against each other, the opposing teeth contact the guard.
This means that the guard itself becomes a replaceable protective surface. It does not necessarily stop the muscles from clenching or grinding.
What Is Bruxism?
Bruxism describes repetitive jaw-muscle activity that can involve clenching, grinding or bracing the jaw. It can occur while you are awake or while you are asleep.
Sleep bruxism happens during sleep and may occur without you being aware of it. Some patients only discover it because a partner hears grinding noises or because their dentist notices patterns of tooth wear or damaged restorations.
Awake bruxism more commonly involves prolonged tooth contact, clenching or jaw bracing during the day, often without actual grinding movements.
Bruxism is not automatically a disease in every person. The important question is whether the activity is contributing to pain, significant tooth wear or damage that requires management.
How Can a Dentist Tell If You Grind Your Teeth?
A dentist may suspect bruxism after examining your teeth, jaw and dental history.
Possible signs include:
- Flattened or polished areas of tooth wear
- Chipped or fractured teeth
- Repeatedly fractured fillings or other restorations
- Changes in the shape of the biting surfaces
- Reports of grinding noises during sleep
- Jaw-muscle tenderness or fatigue
- Morning jaw discomfort in some patients
However, tooth wear alone does not prove that you are currently grinding your teeth. Wear accumulates over time and may also be caused or worsened by factors such as dental erosion.
A dental examination allows your dentist to look at the overall pattern rather than relying on one sign alone.
What Are Night Guards Good For?
1. Protecting Teeth From Grinding Wear
The clearest role of a night guard is protecting the teeth from direct grinding contact.
Repeated tooth-to-tooth contact can gradually wear away enamel and change the shape of the teeth. In more advanced cases, wear can expose the underlying dentine, shorten teeth and affect their appearance or function.
A night guard places a protective material between the two dental arches, so the guard receives much of the direct mechanical contact instead of the opposing tooth surfaces.
It cannot rebuild enamel that has already been lost, but it may help protect against further mechanical grinding damage.
2. Protecting Fillings, Crowns and Other Dental Work
Heavy grinding does not affect only natural teeth. Dental restorations are also exposed to repeated forces.
A night guard may therefore be recommended for patients who grind and have:
This can be particularly important following significant restorative or cosmetic dentistry because repeatedly repairing fractured dental work can be considerably more complicated than replacing a worn night guard.
3. Protecting Teeth That Have Already Become Worn
If teeth already show significant wear, protecting the remaining structure can become especially important.
Worn teeth may have thinner enamel, exposed dentine or changes to their original shape. A dentist can assess whether the wear appears active and whether protection, monitoring or restorative treatment is appropriate.
A night guard cannot reverse existing wear, so patients with significant tooth-surface loss may need a broader treatment plan.
4. Helping Some Patients With Jaw-Muscle Symptoms
Some people with bruxism and jaw-muscle discomfort report that symptoms improve when using an appropriately designed splint. However, this benefit should not be guaranteed.
The evidence that occlusal splints consistently reduce TMD pain is mixed, particularly for chronic TMD.
Night guards should therefore not be promoted as a universal cure for jaw pain. TMD encompasses several different muscle and joint conditions, and treatment may involve education, temporary changes during flare-ups, jaw exercises, physiotherapy and other conservative approaches.
Does a Night Guard Stop Teeth Grinding?
Not necessarily. This is one of the most important misconceptions about night guards.
A night guard can protect the teeth even if grinding or clenching continues underneath the appliance.
Studies examining whether splints reduce sleep-bruxism muscle activity have produced inconsistent results. Some people show temporary changes in muscle activity, while others continue to grind while wearing the appliance.
For this reason, the primary aim is usually protection rather than promising to switch bruxism off.
Does a Night Guard Relax Your Jaw Muscles?
It can affect how the teeth contact and may make some patients feel more comfortable, but it is too strong to say that every custom guard automatically “relaxes the jaw muscles”.
Jaw-muscle pain has many possible influences, and an appliance that helps one patient may not significantly change another patient’s symptoms.
If the primary problem is persistent jaw pain rather than tooth damage, the cause should be assessed rather than assuming that a night guard alone will solve it.
Do Night Guards Help With TMD or TMJ Pain?
Sometimes, but the answer depends on the specific condition.
TMD is an umbrella term covering disorders affecting the jaw muscles, temporomandibular joints and related structures. A splint may be considered in selected cases, particularly where bruxism is also damaging the teeth, but current evidence does not support treating every TMD patient with a night guard.
Current specialist guidance recommends beginning with conservative, reversible treatments and avoiding appliances that permanently change the bite.
If a splint makes your jaw pain noticeably worse or causes a persistent change in the way your teeth meet, stop using it and contact your dentist.
Read more about jaw problems and TMD at Glow Dental.
Can a Night Guard Help With Headaches?
Bruxism and jaw-muscle pain can occur alongside headaches, and some patients notice morning facial or temple discomfort when they have been clenching heavily.
However, a night guard should not be promoted as a general treatment for headaches or migraine. Headaches have many possible causes, and not every morning headache is caused by grinding.
If headaches are frequent, severe, new or unexplained, appropriate medical assessment may be needed rather than assuming that the cause is dental.
Can a Night Guard Prevent Cracked Teeth?
A guard can reduce direct grinding contact and may help protect teeth that are being subjected to heavy bruxism forces, but it cannot guarantee that a tooth will never crack.
Cracks can develop for many reasons, including existing large fillings, previous dental treatment, tooth structure, trauma and biting unexpectedly on very hard objects.
If you experience sharp pain when biting or releasing your bite, or one tooth has suddenly become painful, arrange an examination rather than relying on the night guard to solve the problem.
Do Night Guards Protect Veneers and Composite Bonding?
They can be particularly useful when bruxism poses a risk to cosmetic restorations.
Composite bonding and porcelain veneers are designed to function in the mouth, but repeated heavy grinding can increase the mechanical forces placed on them.
Where a dentist identifies significant bruxism, protecting completed cosmetic work with an appropriately designed guard may form part of the long-term maintenance plan.
Can a Night Guard Protect Crowns and Bridges?
Yes, a guard may also be considered where a patient with significant grinding has extensive crowns or bridgework.
The appliance needs to be accurately fitted around existing restorations. If you have a new crown or other substantial dental treatment after your guard was made, the old appliance should be checked because it may no longer fit correctly.
Does Grinding Cause Gum Recession or Loose Teeth?
It is too simplistic to say that bruxism directly causes gum recession or periodontal disease.
Gum recession has several recognised causes, including periodontal disease, tooth position and traumatic brushing. Similarly, loose teeth are commonly associated with loss of periodontal support rather than ordinary grinding alone.
Heavy occlusal forces may complicate an existing dental or periodontal problem in some patients, but a night guard should not be advertised as a way of preventing gum disease.
If you have bleeding gums, recession or concerns about gum health, a dental hygiene assessment or periodontal assessment may be more appropriate.
Night Guard vs Retainer: Are They the Same Thing?
No. A night guard and an orthodontic retainer have different primary purposes.
A night guard is designed mainly to protect teeth from grinding or clenching forces. A retainer is designed to hold teeth in their corrected positions after orthodontic treatment.
You should therefore not replace an orthodontic retainer with an ordinary night guard without professional advice.
In some circumstances a dentist or orthodontist can plan an appliance that accommodates both retention and bruxism, but this needs to be designed specifically for your teeth.
Can You Wear a Night Guard After Invisalign?
Patients who complete Invisalign treatment normally need orthodontic retention to reduce the risk of teeth moving back towards their previous positions.
If you also grind your teeth, tell your dentist or orthodontist before switching appliances. They can determine whether you should continue with retainers, use a specially designed appliance or follow another retention plan.
An ordinary night guard should not automatically replace your Invisalign retainer.
Can You Wear a Night Guard With Braces or Invisalign Aligners?
A conventional night guard may not fit when fixed braces, Invisalign aligners or bonded orthodontic attachments are present.
Do not force an old guard over orthodontic appliances. Teeth are deliberately moving during orthodontic treatment, so an appliance made before treatment may quickly become unsuitable.
If grinding is causing problems during orthodontic treatment, discuss it with your dentist or orthodontist so that protection can be planned safely.
Night Guard vs Sports Mouthguard
A night guard and a sports mouthguard are also different appliances.
A sports mouthguard is designed to absorb and distribute forces from sudden impacts to the mouth during sport. A night guard is designed for prolonged wear while sleeping and for managing tooth-to-tooth contact from bruxism.
You should therefore not routinely use one as a substitute for the other.
If you need protection for contact or high-impact sport, see Glow Dental’s custom-made sports guards.
Custom Night Guard vs Shop-Bought Night Guard
Over-the-counter night guards are commonly available as generic or “boil-and-bite” appliances. They may provide a physical barrier between the teeth, but the fit and bite contacts are much less individually controlled.
A dentist-made appliance has several practical advantages:
- It is made to fit your individual teeth
- The dentist can select an appropriate material and design
- The way the opposing teeth contact the appliance can be checked and adjusted
- The guard can be designed around crowns, bridges or other restorations
- Fit can be reviewed if symptoms or dental treatment change
This does not mean that a custom appliance will necessarily stop bruxism better than every shop-bought guard. The main advantage is the ability to assess, fit and monitor the appliance professionally.
Hard vs Soft Night Guards: Which Is Better?
There is no single material that is best for everybody.
Hard stabilisation splints are commonly used because their surface can be precisely adjusted to the bite and they can be relatively durable. Softer guards may be suitable for selected patients, but they behave differently and may wear more quickly in a heavy grinder.
Your dentist can recommend the design based on the reason you need protection, the condition of your teeth, existing restorations, your bite and the severity of the wear.
Upper or Lower Night Guard: Which Is Better?
Night guards can be made for either the upper or lower teeth.
The choice depends on your bite, missing teeth, restorations, comfort and the type of appliance being prescribed. There is no universal rule that an upper guard is always better than a lower one.
How Is a Custom Night Guard Made?
The process normally begins with a dental examination to establish why the appliance is being considered.
The dentist may assess:
- Patterns of tooth wear
- Cracks or fractured restorations
- Your bite
- Jaw-muscle or joint symptoms
- Existing crowns, veneers or fillings
- Whether another condition could be contributing to the symptoms
Impressions or a digital scan can then be used to create an appliance that fits your dental arch. Once fitted, the dentist can check comfort and how the opposing teeth contact the guard.
If you have not had your teeth checked recently, find out what happens during a dental examination at Glow Dental.
How Do You Know If You Need a Night Guard?
A night guard may be worth discussing with your dentist if you have evidence of repeated mechanical damage from bruxism.
Possible reasons include:
- Progressive grinding wear on the teeth
- Repeated chipped teeth
- Fractured fillings or other dental restorations
- A partner regularly hearing you grind your teeth during sleep
- Existing cosmetic or restorative dental work that needs protection
- Morning jaw-muscle fatigue together with other evidence of bruxism
Jaw clicking alone is not automatically a reason to wear a night guard. Painless clicking is common and often does not require treatment.
Can a Night Guard Cause Cavities?
A night guard does not inherently cause tooth decay. However, good oral and appliance hygiene is important because the guard sits closely against the teeth for several hours.
Brush your teeth thoroughly and clean between them before inserting the guard. Putting a night guard over teeth covered in plaque or food debris is not good oral hygiene.
The appliance itself should also be cleaned regularly according to your dentist’s or manufacturer’s instructions.
Regular hygiene appointments can help manage plaque, tartar and gum health, while routine examinations allow your dentist to check for early signs of decay.
How Should You Clean a Night Guard?
After removing your night guard, rinse it thoroughly and clean it gently using the method recommended for the material from which it is made.
General care usually includes:
- Rinsing the appliance after each use
- Cleaning it gently with a soft toothbrush
- Using cool or lukewarm rather than very hot water
- Allowing it to dry as recommended
- Keeping it in a clean ventilated case
- Cleaning the storage case regularly
Avoid boiling water or exposing the guard to high temperatures because some materials can distort.
Highly abrasive toothpaste can also scratch some appliance materials, so follow the cleaning instructions supplied with your particular guard rather than assuming ordinary toothpaste is always suitable.
Can a Dirty Night Guard Cause Bad Breath?
Yes. Plaque, saliva and microorganisms can accumulate on an appliance that is not cleaned regularly and may contribute to unpleasant odour or taste.
Clean both your teeth and the appliance before wearing it overnight. Persistent bad breath despite good oral hygiene can have other causes and is worth discussing with your dentist or hygienist.
Can a Night Guard Change Your Bite?
A properly prescribed appliance should be monitored so that it does not cause an unwanted permanent change in your bite.
Poorly fitting appliances, damaged guards and certain partial-coverage appliances can potentially change tooth position or the way the teeth meet if used inappropriately over a prolonged period.
If your bite feels persistently different after removing your guard, the appliance feels increasingly tight or loose, or your teeth appear to be moving, stop using it and arrange a review.
Can a Night Guard Make Jaw Pain Worse?
It can in some people.
If an appliance is uncomfortable, changes the way the jaw closes or aggravates an existing TMD problem, symptoms can increase rather than improve.
This is why current TMD guidance recommends that intraoral appliances should be reversible and should not be designed to permanently alter the bite.
If pain becomes worse after starting a night guard, contact your dentist rather than simply forcing yourself to continue wearing it.
How Long Does a Night Guard Last?
There is no fixed lifespan. A guard may last for a considerable period in one patient but wear much more quickly in someone who grinds heavily.
Its lifespan depends on:
- The material and thickness
- The intensity of grinding
- How frequently it is worn
- Changes to your teeth or dental work
- How the appliance is cleaned and stored
Signs that a guard needs reviewing include cracks, holes, sharp or rough areas, significant thinning, distortion or a change in fit.
Bring your night guard to routine dental appointments so that the dentist can inspect both the appliance and your teeth.
Can You Keep Using the Same Night Guard After Dental Treatment?
Not always.
A new filling may have little effect on the fit, but a new crown, bridge, veneer, implant restoration or significant change to the shape of a tooth can alter how the appliance seats.
Never force an old guard into place following substantial dental treatment. Ask your dentist to check whether it can be adjusted or whether a new appliance is required.
Does a Night Guard Treat Sleep Apnoea?
No. A standard bruxism night guard is not a treatment for obstructive sleep apnoea.
Some patients with obstructive sleep apnoea are treated using a different type of dental appliance known as a mandibular advancement device. This positions the lower jaw differently to help maintain the airway and serves a very different purpose from an ordinary grinding guard.
If you regularly snore loudly, wake choking or gasping, experience pauses in breathing during sleep or have significant unexplained daytime sleepiness, speak to an appropriate healthcare professional rather than treating the problem with an ordinary night guard.
Does Everyone Who Grinds Their Teeth Need a Night Guard?
No. Bruxism does not automatically require treatment.
The decision depends on whether it is causing clinically meaningful consequences such as progressive tooth wear, fractures, restoration failure or other symptoms.
The aim should be to treat the patient rather than simply treating the fact that some grinding activity occurs during sleep.
Frequently Asked Questions About Night Guards
Will a night guard stop me grinding my teeth?
Not necessarily. A night guard mainly provides a protective surface between the teeth. Bruxism may continue while the appliance is being worn.
Can a night guard fix TMD?
There is no evidence that a night guard can reliably cure every form of TMD. Splints may help selected patients, but current evidence for TMD pain is mixed and other conservative treatments may be more appropriate. See our TMD and jaw problems page.
Can a night guard stop headaches?
It should not be considered a general headache treatment. If jaw-muscle activity contributes to morning discomfort, managing bruxism may help some patients, but persistent headaches require appropriate assessment.
Can I use a sports mouthguard as a night guard?
They are designed for different purposes. A sports mouthguard protects against sudden impact, while a night guard is designed for prolonged contact from grinding and clenching during sleep.
Can a night guard replace my Invisalign retainer?
Not automatically. A retainer keeps orthodontically moved teeth in position, whereas a night guard primarily protects against bruxism. If you have completed Invisalign and also grind your teeth, your dentist or orthodontist should plan an appropriate appliance.
Should a night guard feel tight?
A newly fitted guard should feel secure, but it should not cause significant pain. If the appliance is extremely tight, difficult to remove, causes persistent tooth pain or no longer fits correctly, have it checked.
Can I wear a night guard every night?
If your dentist has prescribed it for nightly use and it remains comfortable and well fitting, that may be appropriate. Follow the instructions for your particular appliance and bring it to dental reviews periodically.
Can a night guard damage my teeth?
An appropriately designed and monitored guard is intended to protect the teeth. However, a damaged, poorly fitting or inappropriate appliance can cause problems, which is why changes in fit, pain or bite should be reviewed.
So, What Are Night Guards Good For?
The best-supported role of a night guard is protecting teeth and dental restorations from the mechanical effects of significant grinding and clenching. It provides a replaceable surface between the teeth and can be particularly valuable for patients with progressive tooth wear, repeated fractures or extensive restorative or cosmetic dentistry.
Night guards can also form part of the management plan for selected patients with jaw symptoms, but they should not be presented as a guaranteed cure for bruxism, TMD, headaches or muscle tension. They also do not automatically replace orthodontic retainers and are different from sports mouthguards and sleep-apnoea appliances.
If you think you grind your teeth, the first step is to establish whether it is actually causing damage and whether a night guard is appropriate for you. Glow Dental can assess your teeth, restorations, bite and jaw during a dental examination.
If you also experience jaw pain, stiffness, locking or painful clicking, find out more about TMD and jaw problems at Glow Dental. If you are new to the practice, you can also learn more about becoming a new patient.
Sources and Further Reading
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Glow Dental
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