Build Up, Large Filling, or Crown?

[DentalQuestions]

So, my dentist recommended a crown. I decided to get a second opinion to make sure I actually needed it because I don't really have that kind of money. Second dentist said something to this affect: "We could do a large filling instead of a crown, but you would have to be extra diligent with flossing and cleaning this tooth." I went back to my original dentist and asked him if he could do a large filling instead of a crown. He said, "It wouldn't really be a large filling, it would be a build up. It could last you a few years, but it's hard to say for sure."

Could a build up be another term for a "large filling"? How should I go about deciding what to do? How long could a build up last? Any tips or advice is helpful, thank you !

 

[honestdoc]

A lot of dentists in the US including myself (in the past) use the dental procedure code D2950 for core build up incorrectly. It is done for supporting the crown. Maybe you can provide x-rays and images because it is hard for us predict (even when we have all the information).

 

[DentalQuestions]

A lot of dentists in the US including myself (in the past) use the dental procedure code D2950 for core build up incorrectly. It is done for supporting the crown. Maybe you can provide x-rays and images because it is hard for us predict (even when we have all the information).

https://imgur.com/TLd6ApO

I think it's tooth 18? Bottom left molar. The second dentist did say that when looking at the actual tooth, the preexisting filling looks "thinner" than it looks in the x-ray, making it easier to do a filling instead of a crown? Thank you!

 

[MattKW]

Bottom left molar, 3rd from back? That would be UNS #19. It looks like it might have an onlay on it already that is is in reasonable condition. Do you know what sort of filling material it's made of? Is it composite or a ceramic? Why is a replacement suggested?
And I assume you know about deep decay in #12?