A clear aligner is not a mouthguard: for any contact or collision sport, take the aligner out, wear a properly fitted mouthguard for the game, and put the aligner straight back in afterwards. The Australian Dental Association's consumer site teeth.org.au says a mouthguard works by absorbing and spreading the impact of a knock to the face, and Sports Medicine Australia reports that wearing one can reduce the risk of dental injury by more than half. A thin aligner shell does neither job, so playing sport with clear aligners means deciding, sport by sport, when the tray comes out and what replaces it.
Written by Dr James Tran, BDent (University of Sydney), MICOI, GradDip (Oral Implants), general dentist at Lumi Dental in Melrose Park.
The short version
- Aligners are thin, absorb no shock, and can crack or cut the lip under a knock.
- For rugby, league, AFL, football, basketball, netball, hockey and combat sports, swap the aligner for a mouthguard at the gate and swap back at the final whistle; our comparison of custom versus boil-and-bite mouthguards explains the difference.
- Aligners move teeth every one to two weeks, so a custom mouthguard made now fits only briefly. A boil-and-bite guard, a guard made over the aligner, or a custom guard once the teeth are stable are the options.
- Non-contact exercise is aligner-in: running, swimming, cycling, gym and rowing.
- The 22-hour target leaves about two hours a day out. A game plus warm-up uses most of it, so meals need planning on match days.
- Drink water only with aligners in; a sports drink under a tray holds sugar and acid against the teeth.
The single rule: an aligner is not a mouthguard
In my experience most aligner patients have never been told what their tray can and cannot do. It is a clear thermoformed shell designed to press on teeth, not to cushion them. Sports Medicine Australia lists a thickness of around 4 millimetres among the features of a good mouthguard; an aligner is a fraction of that. So the rule is simple. If the sport involves contact with other players, equipment or the ground, the aligner comes out and a mouthguard goes in. If it does not, the aligner stays in.
Why an aligner does not protect your teeth
A mouthguard absorbs the energy of a blow, spreads it across the arch, and keeps the lips and cheeks clear of the tooth edges. teeth.org.au lists the injuries it prevents as broken jaws, fractured, cracked or knocked-out teeth, and cut lips and tongues. An aligner fails on each count: the plastic is too thin to absorb much, it grips the teeth rather than cushioning them, and under a direct knock it can crack and leave a sharp edge against the lip. None of this is a reason to avoid sport during treatment, only a reason to plan it.
What the Australian guidance says about mouthguards
The Australian Dental Association's policy on oral injuries sorts sport into four levels of risk. Mouthguards are strongly recommended for off-road bike riding, skateboarding, rock climbing, trampolining, combat sports, football, basketball, squash and field hockey. Where head protection is already worn, such as full-face helmets in ice hockey, the need may fall away, and swimming, athletics, aerobics and rowing carry too little risk to warrant one. teeth.org.au adds that cricket, netball, touch football and soccer cause dental injuries too.
On the type of guard, the policy is direct: a custom-fitted mouthguard is the most effective protection, and over-the-counter guards are better than nothing but vary with design and thickness. The same policy notes that boil-and-bite guards may be appropriate during orthodontic treatment, which is the exception that matters here. teeth.org.au also encourages every Australian club to adopt a "No Mouthguard, No Play" policy, so check what your club requires.
Sport by sport: aligner in or out
| Sport | Aligner in or out | Protection needed |
|---|---|---|
| Rugby union, rugby league, AFL, combat sports | Out for training and games | Mouthguard every session; club policy may make it mandatory |
| Football (soccer), basketball, netball, hockey, touch, cricket fielding | Out for games and contact drills | Mouthguard; the ADA lists basketball and hockey as strongly recommended |
| Skateboarding, mountain biking, trampolining, climbing | Out | Mouthguard; falls and equipment cause the injuries |
| Road cycling or cricket batting with a helmet | Usually in | Head protection may remove the need; ask the treating clinician |
| Running, gym, swimming, yoga, rowing, athletics | In | None |
The table follows the ADA risk levels and teeth.org.au; the decision for your sport is made at a review.
Mouthguards during aligner treatment: the fit problem
A custom mouthguard is made from a mould or 3D scan of the teeth as they are today, and teeth.org.au notes it can last several seasons once you have stopped growing. During aligner treatment the teeth are deliberately not staying still: the compliance study below describes aligner changes every one to two weeks, so a custom guard made in week two may be loose by the finals. Orthodontics Australia makes the same point about braces: a custom guard cannot easily be remoulded as teeth shift, while a boil-and-bite can be. Three approaches are usual.
A boil-and-bite guard for the season
The usual compromise. It is the option the ADA policy accepts during orthodontic treatment, it can be re-softened as the teeth move, and Sports Medicine Australia suggests replacing it each season anyway. The trade-off is that home fitting can leave parts thinner than others.
A guard made over the aligner
Some clinicians mould the teeth with the current aligner in place so the guard sits over the tray. It keeps the hours up on a long tournament day but still goes out of date as trays change. That is a conversation for your review.
A custom guard once the teeth are stable
Near the end of treatment, or once you are in retainers, tooth position settles and a custom guard from a fresh 3D scan keeps its fit. For the teenagers I see in winter codes, that often means a boil-and-bite this season and a custom guard next.
Wear time arithmetic: fitting a game into 22 hours
Aligners only work when they are in. A retrospective study of 2,644 adults in clear aligner treatment, published in a PubMed Central journal, used 22 hours a day as the minimum and found that only 36.0 percent of patients were fully compliant and 25.7 percent poorly compliant. Twenty-two hours in means about two hours out, and a 90-minute game plus warm-up is close to two hours on its own. If the tray is already out for the match, I usually suggest eating and drinking in that same window, then rinsing and re-seating the tray before you leave the ground; the rest of the day is aligner-in and the target holds. If the tray also comes out for three separate meals, the day drifts to three or four hours out. One such day does little harm; a season of them is why trays stop fitting. Our guide to clear aligners at work, meetings, coffee and wear time applies the same arithmetic to weekdays.
Water, sports drinks, attachments and chewies
With aligners in, drink water and nothing else. A sports drink sipped through a tray pools between the plastic and the enamel and stays there, sugar and acid together, until the tray comes out; our post on sports drinks and tooth erosion explains what that does over a season. If you want electrolytes during a long event, have them while the tray is out, then rinse and re-seat it. Attachments, the small tooth-coloured bumps bonded to some teeth, can catch on a mouthguard; a boil-and-bite moulded with them in place usually settles over them. Chewies, the foam rolls you bite on to seat a tray, earn their place on match days: a few minutes after the tray goes back in closes any gap.
If a tray cracks, is lost or a tooth is knocked
Trays travel badly in a kit bag, so keep the case in a zipped pocket, never wrapped in a towel on the bench. If a tray cracks or disappears at a game, wear the previous tray if you still have it and ring the practice on the next working day; our guide to a lost or damaged aligner tray sets out the steps. If a tooth is knocked loose or out during play, follow our knocked-out tooth first aid guide, do not force a tray over a loosened tooth, and ring Lumi Dental's emergency dentist line for a same-day assessment.
How we approach this at Lumi Dental
Clear aligner treatment at Lumi Dental in Melrose Park is planned by a dentist from a 3D intraoral scan, and the same scanner records tooth position for the custom sports mouthguards the practice makes. For patients who play contact sport, the mouthguard plan is part of the aligner plan from the first visit. Specialist orthodontic cases are referred to registered specialists. Read more about clear aligners at Lumi Dental.
Questions patients ask
Can I play sport with Invisalign or other clear aligners in?
Yes for non-contact sport such as running, swimming, cycling and the gym, where the aligner stays in. For contact and collision sport, take the aligner out, wear a fitted mouthguard, and put the aligner back in straight after the game.
Can I wear a mouthguard over my aligners?
Some clinicians make a guard over the aligner, but a standard mouthguard is not designed to sit over a tray. Ask the clinician treating you first; for most patients the simpler answer is tray out, guard in.
Do I need a custom mouthguard while my teeth are moving?
Not usually, because a custom guard made now fits only until the teeth move on. The ADA policy accepts boil-and-bite guards during orthodontic treatment; a custom guard follows once the teeth are stable.
Will two hours of sport ruin my aligner wear time?
Not if it is the only time the tray is out that day. Eat and drink in the same window, rinse, re-seat the tray and use chewies. The problem is sport plus three separate meals, repeated across a season.
My teenager plays rugby and wants aligners. Is that a problem?
No, but the mouthguard plan is agreed before the first tray: usually a boil-and-bite re-fitted through the season, with a custom guard later. Our guide to clear aligners for teenagers covers what parents should watch.
Thinking about clear aligners? Complimentary aligner consult in Melrose Park
If you are in Melrose Park, Ryde, Parramatta, Ermington, Rydalmere or nearby and play sport, book a complimentary aligner consultation and bring your mouthguard, or read more about clear aligners at Lumi Dental.
Sources
- Australian Dental Association, teeth.org.au: Sports mouthguards
- Australian Dental Association: Policy Statement 2.2.5, Prevention and Management of Oral Injuries
- Sports Medicine Australia: Sports dental injuries fact sheet
- PubMed Central: Factors influencing patient compliance during clear aligner therapy, a retrospective cohort study
About the author
Dr James Tran is a general dentist at Lumi Dental in Melrose Park. He holds a BDent from the University of Sydney and a Graduate Diploma in Oral Implants, and is a Member of the International Congress of Oral Implantologists (MICOI).
This article is general information only and is not a substitute for an examination and individual advice from a registered dental practitioner. Suitability for any treatment varies from person to person.
