Which type of retainer is specifically designed to remain bonded to teeth after orthodontic treatment?

A fixed retainer is specifically designed to remain bonded to teeth after orthodontic treatment, providing continuous support and maintaining the positions of the teeth. Typically consisting of a thin wire, it is adhered directly to the lingual surfaces of the anterior teeth. This type of retainer is particularly beneficial in ensuring that teeth do not relapse into their original positions after braces have been removed, which is a common concern following orthodontic treatment.

In contrast, removable retainers are not bonded to the teeth and require the patient to put them in and take them out as directed. While effective, they rely on compliance from the patient to achieve desired retention. Prosthetic retainers are typically associated with dental prostheses and not specifically used for orthodontic retention. Transitional retainers serve a temporary purpose and are used in specific circumstances, such as in the time between orthodontic treatment and final retainer placement, rather than providing long-term retention. Thus, the fixed retainer is the appropriate answer for its intended purpose in maintaining tooth alignment post-orthodontically.