The retention phase is the final and longest stage of any orthodontic process, stabilizing the results achieved by the aligners. After teeth move into their desired positions, the surrounding bone and ligaments require time to solidify around the new alignment. Without a retainer, teeth naturally shift back toward their original locations, a phenomenon known as orthodontic relapse. Choosing the specific type of retainer post-Invisalign is crucial for maintaining a straight smile.
Fixed Versus Removable Retainer Systems
Patients finishing Invisalign treatment choose between two categories of retention appliances: fixed or removable. Fixed retainers, sometimes called bonded retainers, consist of a thin metal wire custom-fitted and glued to the tongue-side of the front teeth, typically extending from canine to canine. The primary advantage is constant retention, ensuring the front teeth cannot shift, and requiring no compliance since the appliance is permanently in place.
The drawback to fixed retainers is the difficulty in cleaning, requiring special tools like floss threaders or a water flosser to prevent plaque buildup. Although called permanent, the bond can break or the wire can warp without immediate notice, leading to rapid shifting. Removable retainers fit over the teeth and are taken out for eating and cleaning, offering complete freedom for oral hygiene. This flexibility, however, introduces the risk that the retainer could be lost or not worn consistently.
Exploring Removable Retainer Options
The most common option for post-Invisalign retention is a clear, removable appliance, resembling the trays used during active treatment. Align Technology offers its proprietary clear retainer called Vivera, made from a thermoplastic material reported to be 30% stronger and more durable than standard clear retainers.
Vivera retainers are custom-made using the patient’s final digital scan, resulting in a precise, comfortable, and nearly invisible fit. A similar alternative is the Essix retainer, a vacuum-formed clear plastic appliance typically made from a thinner material. Both clear retainers are highly aesthetic and cover all the teeth, providing comprehensive stability.
A more traditional option is the Hawley retainer, which combines a metal wire spanning the front teeth with an acrylic plate that sits against the palate or floor of the mouth. Though more visible and bulkier, the Hawley design allows for easier adjustments if minor tooth movement occurs and permits the teeth to settle into a balanced bite. The Hawley retainer is known for its exceptional durability, often lasting five to ten years, significantly longer than the typical one to three-year lifespan of a clear plastic retainer.
Establishing the Post-Invisalign Wear Schedule
The initial wear schedule is the most demanding period and is crucial for stabilizing the new tooth positions. Orthodontists typically recommend wearing the retainer full-time (20 to 22 hours per day) for the first three to six months after active treatment. This commitment is necessary because the surrounding bone tissue is still soft, making the teeth highly susceptible to shifting.
After the initial stabilization period, the wear schedule phases down to nighttime use only. The patient wears the retainer for approximately eight hours while sleeping, transitioning retention to a nocturnal habit. Retention is generally a lifelong commitment, and most patients are advised to continue wearing their retainer several nights per week indefinitely to prevent persistent movement.
Essential Retainer Care and Longevity
Proper care ensures the longevity and hygiene of any removable retainer. Clear plastic retainers, like Vivera and Essix, should be cleaned daily by gently brushing them with a soft-bristled brush and mild soap. Avoid using toothpaste, as abrasive components can scratch the plastic surface, creating grooves where bacteria can accumulate.
A crucial maintenance point is avoiding exposure to heat, including hot water, dishwashers, or leaving them in a hot car, as high temperatures can permanently warp the material and compromise the fit. When not in the mouth, the retainer must be stored in its protective case to prevent accidental damage or loss. Removable retainers typically need replacement every one to five years, depending on the material and if the patient grinds their teeth.
For patients with fixed retainers, the focus shifts to maintaining oral hygiene around the bonded wire to prevent gum inflammation and tartar buildup. Specialized flossing tools, such as floss threaders or interdental brushes, are used to clean beneath the wire between each tooth. Regular dental check-ups ensure the fixed wire remains securely bonded and intact.