Firstly, as this is a language learners' site, I hope you don't mind me correcting the sentence:
I did not read until the teacher came in.
In most variants of English, we don't address teachers by their profession. The only one I can think of is doctor. We do address people by their office, though: mayor, governor, professor, prime minister, but only when calling out to them: "Mayor! Governor! Professor!" But not _"Teacher! Lawyer! Electrician!"
When using it in a sentence, you should always use a determiner:
... and so on.
As for your main question, in all senses I can think of, this implies that you continuously did not read.
The unmarked (usual) reading of the sentence is closest to the first, i.e.:
I did not read before the teacher came in, and started reading when the teacher came in.
I wouldn't use the second one at all. This seems highly marked (unusual) and you would probably say something like:
I haven't read (at all, today)
The third one is highly marked and there would be a large pitch movement at "read" to indicate it:
I didn't read until the teacher came in (, I wrote until the teacher came in)
And the emphasis is on you not reading until the teacher came in - you might have been writing until the teacher came in.