Hi there Lala!
My sister worked in a dental lab so it gave me a small insight of what happens!
In dental labs; they essentially work on the supplies (equipment) dentists use. They make teeth mounds, examine dental apparatus etc.
Dental technicians are essentially work in the background. Once the dentist has examined a patient and know what need to happen; they pass that information to the technicians so they can work on it and provide their service. They would be the people who make teeth mounds for observation and for braces.
Hope this helped :)
