Removable appliances can be a practical solution for those who want to cover a gap in their smile right away and need more time and/or savings before exploring a more permanent option. For a single missing tooth, a "flipper" can be created to hold a false tooth in place for cosmetic purposes at a low cost of $300-$700. Flippers are supported by the palate (roof of the mouth), the gums, or the teeth, using acrylic or metal hooks. Complete retainers are also used to hold false teeth in the position of a gap for a similar $300-$700 fee. Much like the Invisalign concept, these clear retainers cover the full arch, which keeps the palate open and applies less pressure than appliances using individual anchor teeth. Though safer than the flippers, the retainers are not as discrete since they cover the front of the teeth. Both types of appliances must be removed for eating and alterations to speech can be a problem. An appliance intended to be more long-term is the partial denture, which includes one or more sections of false teeth fabricated into pink plastic designed to resemble the gums. These appliances are delivered to improve cosmetics as well as chewing function. The cost of a partial denture depends on the quality of materials and experience of the doctor. The most basic, standard-size partial denture can cost as little as $300, and a custom-fit appliance made with premium materials by a board-certified prosthodontist can cost over $6,000. The more you spend, the better your chances are to receive a partial denture you'll be able to tolerate. Upper jaw appliances tend to be more tolerable because they move less than lower jaw appliances. Some partial denture wearers use adhesives in order to keep appliances from falling out, though others prefer to avoid the bad taste and upset stomach. Adhesives often need to be reapplied after every meal which can be frustrating and time consuming. Those who are not able to chew with their partial dentures learn how to chew on their front teeth or mash the food against their gums. Many prefer this way of eating over the discomfort of sharp food particles pinching their gums when the appliance moves and food shifts underneath. Much like the cemented bridges, the increased dependence on surrounding natural teeth accelerates tooth loss and shortens the lifespan of the treatment. Even though the anchor teeth are not filed into pegs the way the cemented bridge anchors are, the hooks and clasps rub against the enamel and can cause teeth to chip and decay. Sometimes an additional crown can be added to an existing appliance when another tooth is lost, but typically a whole new appliance must be made when this occurs.