A dental implant is a fixed titanium screw used to replace the tooth root system. A prosthetic tooth is placed on top of the implant.
The pros of an implant are that bone loss is comparable to your natural teeth. Aesthetics and function is virtually the same as your natural teeth. The main benefit over a bridge is there is no need to destroy two healthy teeth for support. There are many benefits over a partial denture and doing nothing if cost is not the main concern.
The con is that dental implant process can be 3 appointments over a period f 2-6 months. The cost is $3-4k and will take more time and money if bone loss has already occurred. So the sooner the less costly.