Dentists - are they car mechanics reincarnated?

I used to go to a very expensive dentist, who was awesome but really expensive. We used to call the office "the dentist to the stars"! He really is amazing, has done wonderful things for my less than perfect teeth situation, but the cost was a ton and then we moved and he was farther away... well, I found one closer to home that has good reviews online. I went about a year ago. He fixed the veneer that fell off my baby eye tooth. Got my teeth cleaned 4 months ago and he immediately started harping on me about when I was going to get my baby tooth pulled and have an implant put in for $4000+, and when I wanted to schedule an implant procedure for my missing molar, which he quoted at around $6,000. Um, never? Let me first say I have had braces twice, retainers and now have a retainer with a fake tooth in it to replace a molar I never formed (gotta love genetics). I have the retainer because I do not want to spend $10,000 just to have two unimportant teeth replaced - just so I have a full set. I have already spent at least half of that just on braces alone, and I know plenty of people who are missing teeth here or there and live perfectly happy pretty lives. Most people don't even notice when someone is missing teeth, unless they're really visible gaps!

Another thing this dentist showed me was the white lines between some of my teeth on my xray. He told me they were cavities forming and I needed to come back in two weeks to have two of the "bad ones" filled, and floss twice a day and use mouthwash daily to try to "reverse the damage" on the others. Said I would most likely have 9 cavities that needed filling, all between my teeth. I was devastated, I don't have any cavities except for in my baby tooth (yes, I'm 32 and still have a baby tooth). I just couldn't stomach that and haven't gone back for my fillings.

Well today I took Big Kid to the orthodontist for a consult, his adult eye teeth have stalled because his baby teeth are in the way. They confirmed they need to be pulled. While there I realized he has white lines between most of his molars - so I immediately asked if they were cavities, because no one mentioned them at last week's cleaning! Both the orthodontist and my son (who shadows a pediatric dentist because he wants to be one someday) told me that white spots are where your teeth touch on an xray, and dark spots are cavities forming.

So is the dentist I went to who wanted to fill "all my cavities" a joke or what? Everyone who wrote reviews of him online said the office was wonderful, I know people who take their families to the same office! I feel like a mechanic just tried to take advantage of me because I brought my car in for an oil change, and they tell me I need a transmission. The difference is I know cars very well, don't know dentistry at all. Now I need to worry about crooks in our health care industry?! Greeeaaaat.