Good Evening guys,
First of all, I want to heavily heavily apologize for coming back after like half a month, the reason why I didn't reply was because I discovered a dos program that at least let me convert stl to stp files but sadly I still got the same result.
I actually gave up and sent it to my client, but I had another problem (models were able to be opened in max but client couldn't access them)
I'm gonna now clarify the kind of model I was given to convert.
To avoid problems in the future, I was given stl files of teeth which were high quality (as checked out in max with smoothing and whatnot) but when I was given the original stps the client gave me, the problem was they felt like a low poly model that you would've baked a normal map onto lol (I'm more of a game artist and all that so forgive me for not understanding everything in stl and stp files).
I'm aware 3Ds Max isn't a nurb program so doing stp files there isn't going to work, but I'll use a screenshot from 3Ds Max to show the original stl model, the client's stp file, and the stp file i made (from left to right)
Basically,
Purple = Client's stl I have to convert
Bluish Green = Original STP client has a problem with
Red = Mine I converted successfully
I have the wireframe too in the fourth image to show.
Generally I also want to thank you people for replies, and my apologies for not replying to all.