Traditional retainers, also known as Hawley retainers, consist of an acrylic base that rests against the inside surface of the teeth and some combination of wires and clasps that are embedded in the acrylic. When properly cared for, traditional retainers can provide many years of service. Your speech may be affected temporarily while first wearing this type of retainer, but once you get used to them your mouth will adapt and you will be speaking normally again in no time. Traditional retainers are very durable but they still must be handled carefully to avoid distorting the wire that rests over the front teeth, which can allow the teeth to start shifting again.
Bonded/ Fixed Retainers
This type of retainer is simply a thin metal wire that rests against the back of the teeth and is completely invisible to others. It is usually used on the lower front teeth, though it can also be used on the upper teeth in some cases. Bonded retainers are recommended when the front teeth were severely crowded and are prone to relapse, or to keep a large gap from reopening after the braces have been removed. The only disadvantage is that it takes longer to floss around the wire, and you need to be careful when eating sticky foods to prevent dislodging the retainer.
Clear Plastic Retainers
These retainers are made by sucking down a heated sheet of dental plastic over a model of your teeth. They are very similar to bleaching trays and night guards and are in fact made on the same equipment in the laboratory, but differ in thickness and how much of the teeth they cover. The main advantage of this retainer is cosmetics; there are no wires showing at all. Also, because the upper clear retainer does not cover the roof of the mouth, there is little or no effect on speech. The main disadvantage is that these retainers are a bit less durable than traditional Hawley retainers and may need to be replaced more frequently.