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By Joanna M. | Director of Telehealth Clinical Operations | Fact-Checked for Clinical Accuracy
When you order a custom night guard online, the first decision is rarely material or thickness — it is whether to protect one arch or both. Some UK labs sell a single guard by default and charge extra for the second; others ship a pair. This guide explains what each option actually protects, who needs which, and how the maths works out at UK prices.
A night guard sits between your teeth and absorbs the forces of clenching and grinding. The NHS describes bruxism as a top-against-bottom action — your upper and lower teeth meet under pressure through the night. A single upper guard shields the upper teeth from direct wear and can cushion the lower teeth too, but the lower arch itself has no appliance on it.
A pair puts a guard on each arch. That means both the upper and lower tooth surfaces are covered, and the grinding force is distributed across two appliances rather than concentrated through one. For moderate to heavy grinders — and for anyone whose dentist has flagged wear on both arches — that is the more complete protection.
A single guard makes sense when:
The trade-off is coverage. If your grinding pattern shifts — and it often does over time, or with stress — the unprotected arch takes the full force. You can always add a second guard later, but you will usually pay a second single-guard price.
A pair is the safer default when:
Because NewSmile's UK night guard pair is £109 for both arches, the per-guard cost is roughly £54.50 — noticeably less than buying two single guards separately from labs that price per arch.
| Option | What you get | Typical UK cost | Per-guard cost |
|---|---|---|---|
| Single guard (per-arch lab) | One arch only | Priced per arch | One full single-guard price |
| Two single guards bought separately | Both arches | Roughly double a single | Two single-guard prices |
| NewSmile pair | Both arches | £109 | ~£54.50 each |
| Private dentist (single) | One arch, in-clinic | £300–£600 | £300–£600 each |
The £300–£600 private dentist range is the clinic benchmark UK online labs position themselves against. The key point: once you want both arches, a pair at a single combined £109 price almost always beats buying two singles, because per-arch labs charge you twice.
Not in the way most people expect. A custom-fit guard is thin and moulded to your teeth, so wearing one on each arch does not feel like having a mouthful of plastic — each appliance is contoured to its own arch. Some grinders actually find a pair more stable, because the two guards seat against each other rather than one guard sliding against bare teeth.
Comfort ultimately comes down to fit, not count. A well-moulded single guard can feel barely noticeable; a poorly fitting pair will be uncomfortable on both arches. That is why the at-home impression step matters regardless of how many guards you order.
Most single guards are made for the upper arch, but lower-arch guards are equally valid — the choice often follows where your grinding is worst or what your dentist prefers. NewSmile ships a pair, so you are covered on both regardless of which arch you grind on most. If you wear retainers after aligner treatment as well, NewSmile's custom retainers are ordered separately from its night guards.
Protect both arches for one UK price
NewSmile's custom night guard pair is £109 — both arches, home impression kit, no dentist visit, ordered through the UK store and shipped as soon as production is complete.
If you grind on both arches — which the NHS notes is common in bruxism — you benefit from two, one on each arch. If your grinding is mild and clearly on one arch, a single guard can be enough to start.
A pair is usually cheaper. NewSmile's UK pair is £109 for both arches (~£54.50 per guard), whereas buying two single guards from per-arch labs typically costs more in total.
Either works. Most single guards are upper-arch, but lower guards are equally valid and the choice usually follows where your grinding is worst. A pair covers both, so the arch question becomes irrelevant.
They are different appliances — a night guard absorbs grinding force, a retainer holds teeth in position. If you need both, NewSmile sells custom retainers separately from its night guards; ask your dentist how to schedule wearing each.
Most custom night guards last one to three years depending on how heavily you grind and how well you clean them. A pair has the bonus that if one arch wears out first, the other still protects you while you reorder. See our best night guard UK 2026 ranking for the full brand landscape, and the UK night guard pricing guide for what £109 actually buys.
By Joanna M. | Director of Telehealth Clinical Operations | Fact-Checked for Clinical Accuracy
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