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9 Questions About Clear Aligners, Answered

Do clear aligners really work? Are clear aligners and clear braces the same thing? And so on.

Jeff Craven
Contributing Writer

After changing insurance, I recently visited a new dentist for a routine cleaning.

“You had braces,” he said. I did, about 15 years ago — and although I lost my retainer years ago, the evidence of my teeth moving precisely into place over several years as an awkward teenager were still there.

We talked about a lot of things — my wisdom teeth getting taken out at 19, my childhood orthodontist going a little overboard with my fillings, and how we might correct some of the little imperfections in my mouth that have slowly presented themselves over time.

One option is clear aligners - a choice more and more people are making. A report from Market Research Future found the industry is set to grow by over 20% between 2018 and 2023. This growth is not just inside an orthodontist’s office, as would-be patients are turning to companies that support at-home monitoring for teeth straightening, rather than regular doctor visits.

Considering clear aligners yourself, but still have questions? We’ve got you covered.

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1. What, exactly, are clear aligners?

“Aligners are clear trays made of a thermoplastic polyurethane resin material taking on the shape of your teeth,” Dr. Jacqueline Fulop-Goodling, an orthodontist in New York City, told The Impression.

These plastic devices are created from molds of your teeth, which can be created either through putty impressions at an orthodontist’s office or digitally after an orthodontist takes a 3D scan of your teeth. The orthodontist will plot the movements your teeth need to make using software and create a series of clear aligners, each representing a step in the treatment process.

Over time, a person using clear aligners will exchange their plastic trays for new ones—the number of clear aligners you need will depend on how much your teeth need to move.

2. How do clear aligners work?

The science behind clear aligners is a lot like the science behind braces: it has to do with force placed on the teeth.

“Force placed continually on a tooth causes cellular and bony changes, resulting in tooth movement,” Dr. Ed Shaheen, of Shaheen Orthodontics in Ladue, Missouri, told The Impression. “Those forces can be applied with something as simple as sucking one’s thumb to more specifically directed force deliver systems such as traditional braces or aligners.”

When a clear aligner tray puts force on a tooth, it creates inflammation in the periodontal ligament, the tissue that connects your teeth to the alveolar bone underneath. This inflammation activates cells that break down bone (osteoclasts) in the direction of the force, while cells that build up bone (osteoblasts) create new bone in the space left behind. As a tooth moves, the bone around it is essentially remodeled.

Movement of teeth is dictated by the “artistic eye and knowledge of your orthodontist,” said Dr. Fulop-Goodling. “What's very important to know is that if you go to 5 different offices, you can end up with 5 different smiles,” she said.

3. How long have clear aligners been around, anyway?

While the delivery of clear aligners at home is new, the technology behind them is not.

“They have been used in their current computer-assisted form for over twenty years,” said Dr. Shaheen. “They have been used in more limited situations much longer than that.”

In 1945, Dr. Harold Kesling developed the first plastic tooth positioning device. In the past, clear aligner technology was possible, but not as feasible because orthodontists had to create aligners manually by taking new impressions at every patient visit. It wasn’t until Align Technology, Inc. created a software program to create the clear aligners digitally in 1998 that the modern concept of clear aligners as we know it today came into being.

“Scanning technology has allowed models (digital and physical) be more accurate, which in return allows the aligners to fit more ideally,” said Dr. Fulop-Goodling.

4. What are clear aligners made of?

While it can vary by manufacturer, clear aligners are made from plastic polymers that are moldable at high temperatures (thermoplastic) such as polyethylene terephthalate glycol-modified (PET-G), polypropylene, polycarbonate (PC), thermoplastic polyurethane (TPU), and ethylene vinyl acetate, among others.

Recently, the European Union and FDA have raised concerns that some compounds in plastics like Bisphenol A and phthalate plasticizers are a potential health risk. In response, clear aligner companies have created aligners that do not have these materials.

Although there are countless different clear aligner companies in the market, the vast majority of them have their aligners made by one of the larger companies, such as Align Technology, ClearCorrect, or CA Clear Aligner. (Candid’s aligners are manufactured by ClearCorrect.)

5. Are clear aligners really effective?

“Absolutely,” said Dr. Fulop-Goodling.

While the exact success rate of clear aligners is hard to say, some companies have begun sharing numbers in studies. In the case of Invisalign, the success rate is 85% across 6 million patients, said Dr. Fulop-Goodling.

Of course, the effectiveness of clear aligners is ultimately tied to whether you choose to wear their aligners for the required amount of time. “It's like purchasing a gym membership and not going. With an experienced practitioner, successful treatment plan and good patient compliance, success is imminent,” she said.

6. What’s the difference between at-home clear aligners and the clear aligners you get in-office?

“The at-home aligners and the in-office aligners are exactly the same,” said Dr. Shaheen.

In more severe cases, like in situations where a tooth needs to move in three dimensions or an overbite or underbite needs to be corrected, a patient could still use clear aligners, but should instead be monitored closely by an orthodontist in a conventional office setting, he added.

7. How much do clear aligners cost?

It varies. A general rule is, more time means more money. If the correction is more complicated, it will probably cost more money, said Dr. Fulop-Goodling.

“A patient who is in treatment with a doctor's office for 6 months should pay less than another patient whose treatment is spanning 2 years,” she said. “The time depends on the amount of crowding, spacing or bite correction needed.”

Cost can also vary by brand. Because some remote aligner companies have limited doctor involvement, cost may be lower is because esthetics like facial profile and smile line are not being considered, she added. “The computer is generating the aligners and from an overall health standpoint, the computer also does not take the health of a person's teeth (like cavities), gums (like gingivitis) and bone (like periodontal disease) into consideration,” she said. “You are paying for the fabrication of the aligners only — made by a computer.”

8. Are clear aligners right for every case?

“Aligners are not indicated for every case,” said Dr. Shaheen. “As the technology progresses, they, however, can be used in more and more treatment scenarios.”

So, who are clear aligners right for? People who don’t want to have braces fixed to their teeth all the time, and who maybe don’t have time to visit their orthodontist as often.

And who may it not be a great choice for? Patients who need orthodontic surgery or a device that widens their palate (skeletal palatal expander), said Dr. Fulop-Goodling. Clear aligners may also be a personal preference based on your needs, she added.

“I just finished a patient who was a fitness instructor and they chose clear braces stuck to their teeth because he/she said that they eat multiple small meals during the day and did not want to constantly take the aligners in and out of his mouth,” she said.

9. Are clear braces and clear aligners the same thing?

Nope. “Clear braces are traditional braces (brackets cemented to teeth active by arch wires), but made of clear material rather than metal,” said Dr. Shaheen, while “clear aligners are clear, removable appliances directed to move the teeth.”

Both use similar forces to move teeth, but are successful at different types of tooth movement. Clear braces are better in cases where a tooth needs to be rotated or pulled down, while clear aligners are better at expanding, rounding out, or widening a smile, said Dr. Fulop-Goodling.

“Diagnosing a patient is key in the success of which modality is the best for their patient,” she said. “This is why having a doctor involved in creating a healthy and beautiful smile is the key to the success of your overall orthodontic treatment.” ✧


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Want straighter teeth?
Find out if Candid clear aligners are right for you.