Spark Aligners vs Invisalign: Cost and Results Compared

Invisalign was the first widely used clear aligner system and is still the best known, but it is no longer the only clinician-led option. Spark, made by the orthodontic company Ormco, is one of the main alternatives offered by UK orthodontists. Both systems work the same way: your teeth are scanned, a digital treatment plan is designed, and a series of custom trays moves your teeth in small steps. The differences are in the material, the planning software and some of the features.

How are Spark and Invisalign similar?

The fundamentals are identical:

• Treatment is planned and supervised by a dentist or orthodontist, not ordered direct to you.
• Trays are changed every one to two weeks.
• You wear them for about 22 hours a day, removing them to eat and drink anything but water.
• Attachments and elastics are used where needed. See Invisalign attachments.
• Refinement trays may be added at the end to perfect the result.
• Retainers are needed afterwards to keep the teeth straight.

Compare typical fees for every treatment, in central and outer London, in our London Invisalign and braces price index.

How are they different?

Material and comfort. Spark trays are made from a different plastic, which many patients describe as very clear, smooth-edged and comfortable. Invisalign's SmartTrack material is designed to apply gentle, constant force and is also comfortable. Comfort is personal; both feel tight for the first day or two of each new set.

Staining and clarity. Spark is often chosen by people who care most about the trays staying clear for the full wear period. In practice, staining with either system mostly comes from drinking coffee, tea or coloured drinks with trays in. Our guide to eating, drinking and vaping with Invisalign applies to both.

Planning tools. Each system uses its own software. Invisalign's has more years of data and a wide range of features for specific movements; Spark's is built for orthodontists and offers fine control of the plan. The quality of the plan depends on the clinician using it.

Features for complex cases. Invisalign offers some proprietary features, such as specific bite ramps and an option for correcting a retruded lower jaw in growing teenagers. Spark offers its own features and attachment designs. For very complex cases, your orthodontist may have a clear reason to prefer one system.

Do Spark aligners work as well as Invisalign?

For the cases they are planned for, both systems can produce excellent results. Aligner outcomes depend more on:

• Case selection: whether aligners are the right appliance at all. See Invisalign vs braces.
• Planning: how carefully movements are staged and attachments placed.
• Wear: trays only work when worn for the prescribed hours.
• Monitoring: regular reviews to catch teeth that are not tracking.
• Retention: retainers at the end.

How much do Spark aligners cost compared with Invisalign?

Most of what you pay for with any clinician-led aligner treatment is the orthodontist's time: assessment, records, planning, reviews, refinements and retention. The trays themselves are a smaller part of the fee. As a result, Spark and Invisalign are usually priced in a similar range at the same practice for a similar case. In London, adult Invisalign typically starts from about £2,650 to £2,800, and complex cases cost more. See Invisalign cost in the UK and London for a full breakdown and cheapest Invisalign in London for ways to compare fees fairly.

Spark vs Invisalign: which should you choose?

• Choose Invisalign if you want the most established system or your orthodontist recommends a specific Invisalign feature for your case.
• Choose Spark if your orthodontist offers it, you value tray clarity, and the plan meets your goals.
• Either way, judge the treatment by the plan and the clinician: ask to see your digital simulation, how many refinements are included and how retainers are handled.

What about direct-to-consumer aligners?

Spark and Invisalign are both supplied only through dental professionals who examine you in person. That is different from home aligner kits, where supervision is limited. In-person assessment means gum health, bite problems and tooth roots are checked before teeth are moved, which is why we do not recommend unsupervised aligners.

Questions to ask before you choose

• Which system do you recommend for my teeth, and why?
• How many aligners and refinements are included in the fee?
• How often will I be seen, in person or by remote monitoring?
• What happens if my teeth stop tracking?
• Are retainers included, and what do replacements cost?

Is treatment time different between Spark and Invisalign?

Treatment time is driven by how far your teeth need to move and how consistently you wear the trays, not by the brand. Both systems change trays every one to two weeks, and both can include refinements at the end. If one system's plan for your case is noticeably shorter, ask your orthodontist why; it may reflect different staging rather than faster movement. Our guide to how long Invisalign takes gives typical timescales by case type that apply to clinician-led aligners generally.

Is Spark or Invisalign more comfortable?

Patients who have worn both often say Spark trays feel smoother at the edges, while others find no real difference. All aligners cause pressure for the first day or two of each set, and attachments can feel rough on the lips at first. If you are worried about discomfort, our guide does Invisalign hurt? explains what to expect and how to manage it.

Retainers after Spark or Invisalign

Whichever aligner you choose, the finished result needs retention. Clear retainers made from your final scan, often combined with a bonded wire behind the front teeth, are typical. Some brands offer their own retainer sets; standard clear retainers work just as well when worn consistently. See retainer costs for prices.

Can you switch from Invisalign to Spark mid-treatment?

It is possible in principle, because a new plan can be made from a fresh scan, but it is rarely necessary and usually means new records and a new fee. If you are unhappy with progress, the first step is a review with your orthodontist to find out why teeth are not tracking.

Get a recommendation for your case

At a consultation we scan your teeth, discuss which aligner system suits your case and give you a written fee. Request a consultation through our form.

Frequently asked questions

Related guides

• Invisalign Cost in the UK and London: 2026 Prices
• Invisalign vs Braces: Cost, Speed and Results Compared
• How Much Do Braces Cost in London and the UK? (2026)
• How to Clean Invisalign Aligners
• Is Invisalign Worth It? Pros, Cons and Cost
• London Invisalign and Braces Price Index 2026
• Orthodontists in London: Invisalign and braces
• Areas of London we cover