Delaying a decision is always an alternative. However, delaying treatment for long can be a risky alternative after teeth have been lost. Teeth need each other for support. Replacing teeth can prevent a chain reaction of problems that can affect your entire mouth.
When a tooth is lost, the biting force changes on the teeth next to the space, and they begin to shift. When a tooth no longer has anything to chew against, it can begin to extrude out of its socket. As your bite changes, your jaw joint may be damaged. And it's much harder to clean teeth that have shifted, so harmful plaque and tartar can accumulate, causing cavities and periodontal disease.
If you have some remaining teeth, then a partial denture may be an alternative to implants. A partial denture is held in place by clips or special attachments. It can do a nice job of replacing missing teeth.
A bridge might also be an alternative if you have remaining teeth. There are several types of bridges, but, unlike an implant, they all use the neighboring teeth as anchors.
If you now wear a denture, then replacing or relining it may allow you to continue to use your denture.