Can an extraction be done without needing a bone graft if done very carefully?

My dentist referred me to an oral surgeon to extract #'s 3 & 4. Having only those two & #'s 6-11, I decided I would like to get top dentures. Before my dentist is able to make a mold, 3 & 4 need to come out. I went to the oral surgeon and, after x-rays, was told that a bone graft would need to be pushed up in to the sockets because they're in my sinus area. I have Medi-Cal (California's version of Medicaid). It will cover the cost of the extractions but not the bone graft which will cost $900. This was, and still is, extremely upsetting. For the past 4 months I've been going to the dentist once a week fixing the damage from many years of neglect. After a couple of extractions, filliings and a root canal, all that are left are 28-21, 6-11 (in very poor shape) and 3 & 4. Medi-Cal(Denti-Cal) won't cover partials unless there is a full denture on the opposite arch. Unable to chew food and the top being in such bad shape, I told my dentist the best thing would be a top denture. That same day I needed an unexpected extraction of #13. He took another look at my x-rays he agreed and gave me the referral for the extractions. He said everything could be done and dentures in within a month and a half at the most. Being surprised by the news from the oral surgeon, I went outside their office and called my dentist to tell him and ask why he wouldn't have known this was going to happen. He said that the root isn't in the sinus but very close and if done very carefully, will not need a bone graft. I went back inside and told them and they argued otherwise. So now I'm stuck and screwed because I don't know if I even have any options and being told two different things by the doctors. As well as only having Medi-Cal as coverage. I couldn't even find anything about this from Google without it being needed for implants and that's it. Can you please help? Thanks