Aligners are custom-made, removable plastic trays that gradually shift your teeth into straighter positions. They work like braces but without metal brackets or wires, using a series of slightly different trays (typically swapped every one to two weeks) that apply controlled pressure to move teeth over time. Most treatments involve anywhere from a handful of trays for minor corrections to 50 or more for complex cases, with the full process lasting several months to over two years depending on how much movement is needed.
How Aligners Move Your Teeth
Each set of aligner trays is designed from a digital scan of your mouth. The trays are manufactured so that each one is slightly different from the last, nudging specific teeth fractions of a millimeter at a time. When you put in a new tray, it feels snug because it represents where your teeth should be, not where they currently are. Over the course of a week or two, your teeth shift to match the tray, and then you move on to the next one.
For more complex movements like rotations, vertical shifts, or adjustments to the angle of a root, aligners alone sometimes can’t generate enough leverage. That’s where attachments come in. These are small, tooth-colored dots of composite material bonded to specific teeth. Think of them as tiny handles that give the aligner something to grip. The tray presses against these attachments to guide teeth in directions that a smooth plastic shell couldn’t manage on its own. Attachments make aligners capable of correcting moderate to severe alignment issues that once required traditional braces.
What Aligners Can and Can’t Fix
Aligners handle a wide range of orthodontic problems: crowding, spacing, overbites, underbites, crossbites, and mild to moderate crookedness. For these everyday cases, they produce results comparable to traditional braces.
They do have limits. Severe skeletal jaw discrepancies, teeth that haven’t fully erupted, and cases requiring significant root movement or vertical pulling of teeth into position are generally better suited for conventional braces. Most orthodontists consider fixed braces superior for controlling all types of tooth movement and achieving precise bite contacts in complex situations. If your case falls into that more complicated category, your provider may recommend braces or a hybrid approach that combines both.
Major Aligner Brands and Materials
Not all aligners are made from the same plastic, and the material matters more than you might expect. Invisalign uses a patented material called SmartTrack, engineered to be easy to snap on and off while staying gentle on your gums and cheeks. Spark aligners use a material called TruGen, which is thinner and more flexible. Many orthodontists consider Spark the most comfortable option available. ClearCorrect uses a tri-layer material designed to apply consistent pressure, and its trays are notably thinner than Invisalign’s, though that thinness can make them less durable and more prone to cracking.
Your orthodontist or dentist typically chooses the brand based on the software tools they prefer, their training, and what works best for your specific tooth movements. The brand matters less than the skill of the clinician planning your case.
Daily Wear Requirements
Aligners only work when they’re in your mouth. The target is 20 to 22 hours per day, which means you remove them only to eat, drink anything other than water, and brush your teeth. That leaves roughly two to four hours of total “out” time across the entire day.
Falling below that threshold has real consequences. Teeth respond more slowly or unpredictably, and they can drift back toward their original positions during long breaks, a phenomenon called spring-back. When that happens, the next tray may not fit correctly, which can mean extra office visits, additional refinement trays, or a longer overall treatment. Consistency is the single biggest factor you control in determining whether your treatment stays on track.
Cleaning and Daily Care
Rinse your aligners every time you take them out, whether it’s for a meal, a snack, or brushing. At least once a day, gently brush them with a soft toothbrush and a mild, unscented soap or a cleaning solution designed specifically for aligners. You can also use aligner cleaning tablets for a deeper soak.
A few things will damage the trays quickly. Hot water warps the plastic, even from a warm tap. Toothpaste is too abrasive and scratches the surface, making trays cloudy and harder to clean over time. Colored or scented soaps can stain or leave residue. And drinking coffee, tea, or red wine while wearing your trays will discolor them. Stick to plain water when the trays are in.
Common Side Effects
Some discomfort is normal, especially in the first day or two after switching to a new tray. Your teeth are being pushed into new positions, so mild soreness and pressure are expected and typically fade within a few days.
Beyond that initial adjustment, aligners can cause gum irritation, swelling, or minor bleeding from the pressure on soft tissue. Dry mouth is common because the trays reduce saliva flow. Some people experience mild headaches, a sore throat, or temporary nausea when starting treatment. Lip swelling or irritation from the edges of the trays is also reported occasionally.
A less obvious risk is root resorption, where the roots of teeth gradually shorten under sustained orthodontic pressure. This happens with traditional braces too, and is typically mild, but it’s something your provider monitors with periodic imaging. Allergic reactions to the aligner plastic are rare but possible, ranging from mild itchiness and irritation of the inner cheeks to, in very uncommon cases, more significant hypersensitivity responses.
What Treatment Costs
Prices vary significantly based on how complex your case is. For minor corrections requiring only a few trays, expect to pay roughly $1,800 to $3,500. A mid-range case with 10 to 14 aligners typically falls between $3,000 and $4,500. Comprehensive treatment for moderate to complex problems, which may include unlimited trays over a set period, generally runs $4,500 to $8,000 or more.
Many dental insurance plans cover aligners the same way they cover braces, often up to a lifetime orthodontic benefit (commonly $1,000 to $2,000). Most orthodontic offices also offer monthly payment plans that spread the cost over the length of treatment. Ask about both before committing.
What Happens After Treatment
Finishing your last aligner tray isn’t the end of the process. Teeth have a strong tendency to drift back toward their original positions, especially in the first year after treatment. To prevent this, you’ll wear retainers.
For the first several months after your active treatment ends, retainers follow the same 20 to 22 hours per day schedule as your aligners. Once your teeth stabilize, you transition to nighttime-only wear. Most orthodontists recommend continuing to wear retainers at night indefinitely. Skipping this step is the most common reason people see their teeth shift years after finishing orthodontic treatment. The retainers themselves look and feel similar to aligners: clear, thin plastic trays molded to your final tooth positions.