The oral maxillo dental surgeon suggests sinus lift for an upper molar. the prosthodontist does not recommend the intensive procedure at all. hmm?

Different focus each: Oral surgeon extracts teeth/places implants. Prostho replaces the chewing parts or crowns of the teeth. If omfs recommends sinus lift to have enough bone for implant, it will likely be a better platform for future dental work. If prostho recommends no lift (no implant?), then talk to your gp for clarification/2nd opinion. At 59, 'average' bridge life 12-15 years; you til 85+! do the math!

Depends: Depends upon the end result you want to achieve. If you want individual teeth then the sinus graft will allow implants to replace missing teeth. If not then bridgework is a way of replacing missing teeth. You need to review the pros and cons of each procedure and see which one is right for you.

The best dentistry: Is generally obtained when the entire team of quality dentists agree on the treatment plan. I would do two things. First, have each dentist explain to you in detail why he\she recommends their approach. Have each of them explain to you each option with pros, cons and prognosis. See what makes sense to you. Second, find a surgeon (os or perio) and restorative dentist (gd or pros.) who agree on plan.

do it: The surgeon is responsible for assessing the adequacy of bone for an implant. If he feels such a procedure is necessary (and very common by the way) then i would ask the surgeon why he advises it but would likely go with his opinion over the prosthodontist. It is the surgeon who is placing the implant not the prosthodontist.

Why?: Why does the prosthodontist object? You should be seeing a team of doctors who are all on the same page. Each doctor should respect the opinions of the other experts.

Team Approach: Your dental team should be made up of dentists who can actually treat you. Third and fourth and fifth opinions over the internet are not helpful. What does the prosthodontist recommend? A denture? Many factors go into this decision, including height of bone and crown/root ratio. Have your team consult with each other and have them come to a decision.