Invisalign typically closes small tooth gaps (1 to 2 mm) in 3 to 6 months, while larger gaps can take 6 to 18 months depending on how much movement is needed. Your specific timeline depends on gap size, how consistently you wear your aligners, and whether your teeth need additional adjustments after the initial set of trays.
Timeline by Gap Size
Gap size is the single biggest factor in how long your treatment will take. A small gap between your two front teeth, the kind that’s mostly cosmetic, usually measures 1 to 2 mm. These cases are straightforward. The teeth don’t need to travel far, and Invisalign can close them in roughly 3 to 6 months with a limited number of aligner trays.
Gaps larger than 2 mm require more trays and more time. If you have multiple gaps, or a single gap wider than 3 or 4 mm, expect treatment in the range of 6 to 18 months. Larger gaps also tend to involve more complex tooth movement, since teeth on either side of the space may have drifted or tilted over time. Your provider needs to not only close the gap but also position each tooth at the correct angle, which adds stages to the process.
Invisalign vs. Traditional Braces for Gaps
A 2024 comparative study in the Journal of Pharmacy and Bioallied Sciences found that Invisalign’s average treatment time was 18 months, compared to 24 months for conventional metal braces, across patients with mild to severe alignment issues. That six-month difference was statistically significant. For simple gap closures specifically, the advantage may be smaller since the overall treatment is shorter to begin with, but Invisalign is at least competitive with braces on speed and often faster.
The tradeoff is that Invisalign depends heavily on you. Braces work around the clock because they’re bonded to your teeth. Aligners only work when they’re in your mouth.
What Affects Your Treatment Speed
Daily Wear Time
Invisalign recommends wearing your aligners 20 to 22 hours per day. That leaves you roughly 2 to 4 hours for eating, drinking anything other than water, and brushing your teeth. Falling short of this consistently is the most common reason treatment takes longer than projected. Each aligner is designed to make a specific amount of movement over one to two weeks. If you’re only wearing it 16 hours a day, that movement doesn’t fully happen before it’s time to switch to the next tray, and the whole schedule drifts.
Tooth and Bone Biology
Teeth move through bone remodeling. Your body breaks down bone on one side of the tooth and builds it up on the other. This process varies from person to person. Younger patients tend to have faster bone turnover, which can speed things up. Conditions that affect bone metabolism, like osteoporosis, can complicate treatment and are sometimes a reason providers adjust their approach. The health of your tooth roots also matters. Teeth with short or compromised roots may need to be moved more slowly to avoid damage.
Number and Location of Gaps
A single gap between the front teeth is the simplest scenario. If you have spacing throughout your arch, or gaps in the back teeth where bone is denser and roots are larger, the timeline extends. Back teeth are harder to move with aligners in general because they require more force. Some providers use small tooth-colored attachments bonded to certain teeth to give the aligners better grip, which helps but can still add time for complex cases.
Refinements Can Add Time
Many Invisalign patients finish their initial set of trays and find that their teeth are close but not perfect. This is where refinements come in. Your provider takes new scans or impressions and orders additional trays to fine-tune the result. For gap closures, refinements are common because even a fraction of a millimeter of remaining space is visible between front teeth.
Refinement rounds typically add a few weeks to a few months. It’s worth factoring this in when you think about your total timeline. If your provider quotes you 6 months for a small gap, the realistic end-to-end timeline including refinements might be closer to 8 or 9 months. Most comprehensive Invisalign plans include refinements at no extra cost, but ask upfront so you know what’s covered.
Keeping Gaps Closed After Treatment
Gaps are one of the alignment issues most prone to relapse. Your teeth naturally want to drift back toward their original positions, especially in the first year after treatment. For front-tooth gaps (midline diastemas), many orthodontists recommend a permanent fixed retainer: a thin wire bonded to the back of your front teeth that holds them in place indefinitely. This is often paired with a removable retainer you wear at night.
Without consistent retainer use, there is a real chance your gap will reopen partially or fully. This is true regardless of whether you used Invisalign or traditional braces. The retention phase isn’t optional; it’s what makes your results last.
Cost for Gap Closure
Because gap-only cases are often simpler, they may qualify for Invisalign Express, a shorter treatment package designed for minor spacing or touch-ups. In 2025, Invisalign Express typically costs between $2,500 and $3,500. More complex or longer treatments using the full Invisalign system run higher. Many dental insurance plans cover a portion of Invisalign the same way they cover braces, and most providers offer payment plans that spread the cost over the length of treatment.