In a case in which more than one mode of treatment is possible, the patient should be informed about all the possibilities rather than have one treatment proposed on a "take it or leave it" basis.  Some dentists prefer to do implant cases over bridge cases.  Still,  the procedure should not be overused and/or oversold.   

In the top drawing to the left, the patient has two good natural teeth on either side of the missing tooth space.  The space can be filled by using either a three-unit bridge  (left) or a one tooth implant (right).  The patient has / should be given a choice:  a fixed bridge or an implant. (More on bridges.)

Bridge Pros: Implant surgery (and the involvement with a surgeon/periodontist) is not needed and surgical risks are avoided. A simple bridge like the one above can often be done in 3-4 visits at the general dental office. 

Bridge Cons: Both teeth on either side of the space must be crowned and their enamel removed in the bridge preparation.  This is a consideration where the patient has perfect, unfilled teeth, even though patients are usually quite happy with bridges (Note that the bridge is permanent and does not come out like a denture and it is tooth-like in appearance). Shaving off enamel for a bridge preparation is not as invasive as having an implant placed in your jawbone so this aspect of "saving enamel" may be over emphasized.   If the teeth are already crowned or weak from fillings this preparation of abutment teeth is not a serious consideration.

Note that, had the patient been missing the rear anchor tooth, an implant would have been the only possibility for avoiding a  removable partial denture.

You can see that, while I certainly think implants have their place, I also  believe the good old reliable bridge option is being dismissed too readily by some dentists.  Implants come in expensive kits, "systems"  that are expensive and patented.  A specialist is needed to perform the surgery.  Implant system manufacturers and surgeons/periodontists  do not benefit if the choice is a bridge.

The point here is not that dentists are putting finances above the patient's needs (most are not, or not consciously); the point is that the patient has a right to know all modes of possible treatment and all risks and benefits of each and to decide for him or her self.  If you feel coerced or feel that a certain treatment is being "sold" to you,  do a little research and get another opinion.