Dentist put pressure on upper front teeth pushing outwards why?

I was recently having a crown replaced on a wisdom tooth. The dentist for some reason put pressure on my upper front teeth for about a minute pushing slightly outwards. I have a crown and an implant in those 4 upper front teeth. What was he doing? Could that kind of pressure damage my teeth, crown, or implant? I wish I had just opened my eyes and asked him what he was doing. Now I'm left really wondering what he was up to. Any ideas or similiar experiences or advice really appreciated. Thanks.