If needing to replace 10 teeth on your upper arch, I would recommend 6 implants. This would provide enough structure for great functionality and great cosmetics. I would not recommend placing less than 6, because you would have an increased chance of implant failure in the future. With the cost of implants these days, no patient wants to have one fail a few years from now, only to have to pay to have it redone, if possible. I always tell patients to make sure that their teeth cannot be saved, prior to having them all pulled. I know this may not apply to you, but you would be amazed at how many people have come to me for a second opinion on dental implants and I tell them that I can save their teeth.Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMD