Single Crowns or Bridges?

Dr. Stevens asks: There are two basic schools of thought in replacing teeth with dental implants
and crowns and bridges. One approach is to replace each tooth with a dental
implant and a crown. The other approach is to use pontics and cantilevers.

What are the arguments both pro and con to each approach? Which one has worked well in your practice? In addition, I am now getting beyond replacing single teeth and getting into fixed multiple unit restorations. I really would appreciate some advice here. What approach should I take? Do I do single crowns or bridges? Thanks for comments.