When your braces are removed, the retention phase begins. This phase of treatment is essential to maintain your final orthodontic result. Retainers are needed to hold the teeth in alignment while the gums and bone surrounding the teeth adapt to their newly straightened positions. Wearing retainers exactly as instructed is the best insurance that the treatment improvements will last. Retainers are made from acrylic, metal, or clear plastic. Often, permanent retainers that are secured to the back of the teeth are used to ensure stability.