implants. Advantages: This is the least expensive option for the replacement of teeth. The least invasive, no surgery needed (usually). Disadvantages: Quite often rely solely on the mucosa for support, do not tend to be as stable as the other options. Very difficult to keep clean and can exacerbate any oral hygiene issues. They are difficult to learn to use. Quite often require complex muscular control to hold them in place. Not as efficient as other options. Foods such as apples and nuts will often have to be avoided. Dental Implants: To replace a single tooth, a screw (the implant) is placed into the jaw bone, which a false tooth is screwed onto. Implants can also be used to support bridges or dentures. Advantages: They are much more realistic than the other options. They have similar efficiency and aesthetics to an actual tooth. They do not require the destruction of the adjacent teeth like bridges. They last 5-8 times longer than both bridges and dentures. Despite the initial higher cost, it pays off in the long term. Much easier to maintain, with oral hygiene procedures being rather similar to an actual tooth. Disadvantages: Cost: they are very expensive. A single implant will cost between £2000-3000 on average. Surgery: Their placement requires quite invasive surgery. With surgery comes risks (e.g. infection, swelling, bleeding). Replacement: The actual implant itself rarely requires replacement, but the actual abutment, or tooth sitting on top of the implant will. This needs replacing on average every 10–15 years. Time: Once an implant has been placed, the tooth replacement does not occur immediately. Implants take time for bone integration. The majority require 3 to 6 months before the final restoration is placed. Clinical classification A classification system has been developed by the American College of Prosthodontists. The classification are based on diagnostic findings, which is used to help practitioners determine appropriate treatments for patients. The diagnostic criteria used to classify edentulism are: Location and extent of the edentulous areas Condition of abutment teeth Occlusal scheme Residual ridge There are four categories which are Class I, II, III and IV. Class I: Minimally compromised This class is most likely to be successfully treated with complete dentures. The characteristics include: Residual bone height of 21mm or more measured at the lowest vertical height of the mandible shown on a panoramic radiograph. Residual ridge morphology resists horizontal and vertical movement of