Metal-based dentures are usually made of cobalt-chromium, a very hard metal alloy that is strong and light. The missing tooth/teeth are made of acrylic (plastic) that is coated on to the metal framework.
Metal frame dentures can be designed with very thin minimalist bases that do not cover as much of the teeth and gums as plastic dentures. This and the good thermal conductivity of metal means that taste and speech may not be as affected as with plastic dentures. Hygiene may be better with a well-designed metal-based denture that does not cover as much of the remaining teeth, reducing the number of plaque traps and the potential for decay or gum disease.
The choice of metal or plastic base for a denture depends on several factors:
- Is this a long-term or short-term treatment?
For patients planning on receiving a fixed tooth replacement (a bridge or an implant), a plastic denture is a perfectly acceptable transitional budget solution.
- What is your budget?
Metal-based dentures are more costly and difficult to fabricate than plastic dentures. However, the metal framework can be reused in future dentures if it still fits the remaining teeth well.
- What is your time frame?
Metal-based dentures require more visits and chair time to fabricate and fit properly. If you require a tooth replaced within a short time, then a plastic denture is more suitable. Some patients may choose to have a temporary plastic denture made immediately before extraction and wear it during the 3-6 month bone healing period before making their definitive prosthesis (metal-based denture, bridge or implant).
- What is the prognosis for the remaining teeth?
Plastic dentures may be used as transitional dentures for patients in the terminal stage of periodontitis (gum disease) who will end up completely edentulous (toothless). The teeth that will eventually be extracted can be easily replaced by adding teeth to the plastic denture.
Metal denture bases usually cannot be modified to accommodate tooth additions.
- Do you tend to drop your dentures?
Plastic denture bases can crack on impact, for example, if the denture is dropped while cleaning or during removal from the mouth. A metal denture base will be more hard-wearing despite being thinner.