If you're looking for an affordable option when it comes to replacing missing teeth, full or partial dentures are a great choice.
When they replace all missing teeth in one arch, they are called complete dentures, and are retained by suction and muscles.
When they replace only some missing teeth, they are called partial dentures and are held in place by the remaining teeth. These can often be designed so that more teeth can be added to the denture as other teeth are lost.
If you would like a denture that can retain better, or perhaps permanently, there are options available for implant-supported or implant-retained dentures.