Written by Dr. Febin Mary George, BDS | Medically Reviewed by Dr. Shaista Salam, BDS, Dr. Zein El Hammouz, DDS, MFD/RCSI
Aligners and retainers appear very similar and can be easily confused owing to their clear plastic appearance. But, when comparing aligners vs. retainers closely, we realize how different they are from each other, most importantly in their respective treatment goals. While aligners bring the teeth to their desired positions, retainers ensure they remain in their final positions.
Let us start by understanding what each of them is:
Clear aligners: These are custom-made trays fabricated from clear plastic material and are used as a replacement for conventional metal braces to correct poorly aligned teeth.
Retainers: They are customized appliances made of either metal or plastic and can be either fixed or removable. Fixed retainers comprise thin wires attached to the inner side of the upper or lower teeth. On the other hand, removable retainers can be either wire type (the appliances are composed of a plastic surface and a wire component) or clear type (transparent plastic trays).
To understand the difference between aligners and retainers, let us learn more about the role they play in orthodontic treatment.
Aligners are designed to straighten your teeth
Like traditional braces, aligners apply gentle pressure on the teeth and gradually move the teeth into the desired positions. To bring about tooth movement, traditional braces use wire and brackets whereas aligners make use of clear thermoplastic material. At the end of every wear cycle (which could be one or two weeks), you shift to the next step of aligners.
Retainers help to maintain the position of your teeth
Once your aligners or braces have successfully aligned your teeth, it's important to wear retainers to keep them in their new position.(1) This is because teeth have an inherent "elastic memory" and will tend to move back to their original position before treatment. Wearing invisible retainers for a few years after treatment can prevent this movement and maintain the alignment of your teeth.
Aligners work towards fixing issues in the alignment of teeth that can affect the esthetics and function of the person.
As retainers are worn only after the orthodontic treatment is complete, their main goal is to anchor the teeth in their new positions and ensure that the treatment is a success.
You are expected to wear your aligners for a minimum of 22 hours per day, and remove them only while eating, drinking, and brushing your teeth. After your teeth have shifted to their intended positions, you'll transition to wearing a retainer for approximately six months, wearing it both during the day and at night (22-24 hours daily). Following this, most patients will only need to wear their retainers at night (12-14 hours daily) for an indefinite period.(2)
Every aligner tray is designed to bring about a specific amount of tooth movement within a period of one or two weeks, as per your wear cycle. Once the designated movement is achieved, the aligners need to be replaced with new ones.
Retainers should be worn for at least 3 to 6 months both morning and night. They can be replaced thereafter with new ones if needed.
The steps involved in the fabrication of aligners and retainers are almost similar. First, you will undergo an orthodontic evaluation, followed by a 3D scan of your teeth. Using the virtual model of your teeth, your aligners and retainers will be planned using a treatment planning software.
Both children and adults can undergo orthodontic treatment. Therefore, aligners and retainers are needed in both these age groups.
Owing to the smooth plastic material that is used to prepare them, aligners and retainers are quite comfortable. The accurate 3D impressions ensure a perfect fit with smooth margins that are gentle on the soft tissues of the mouth like gums.
They are both clear and nearly invisible. It may be difficult to distinguish between the two if you are not familiar.
You can talk to your dentist or orthodontist if you wish to straighten your teeth through clear aligners. Once your treatment is complete, your dentist will record a new imprint of your teeth and provide you retainers to hold the teeth in their new positions.
Aligners need to be worn for a minimum of 22 hours a day. The same holds true for retainers as dentists recommend wearing retainers both night and day for at least 6 to 12 months.
During orthodontic treatment, pressure from the aligners or braces stimulates a process called bone remodeling, or reshaping of the bone around the teeth.(3)
Post-treatment, even though your teeth have moved to their desired positions, the bone and surrounding tissues need time to adapt and stabilize fully. The bone remodeling process continues for some time, even after the braces are removed. If not properly supported during this phase, the teeth can gradually return to their original positions.
By wearing retainers, you help ensure that the newly formed bone has a chance to solidify and establish a strong connection with your teeth. It's like giving the plants in your garden enough time to take root and establish themselves in the soil.
It typically takes around 9 to 12 months for the new bone to solidify and stabilize around the teeth in their new alignment.
While wearing retainers, here are a few tips that you should follow:
Aligners vs. retainers: which one is right for you? Both aligners and retainers play important roles in orthodontic treatment. Aligners are primarily used to shift teeth into their desired positions, while retainers are used to maintain the achieved alignment. Aligners offer the advantage of being virtually invisible and removable, providing flexibility and convenience during treatment. On the other hand, retainers ensure that teeth remain in their final positions, preventing any potential relapse.
While aligners are effective for active tooth movement, retainers are crucial for long-term stability. Patients must follow their orthodontist's instructions regarding the duration and frequency of wear for aligners and retainers. Regular dental visits and communication with the orthodontist are essential to monitor progress and make any necessary adjustments.