This sir is perfectly fine.
It was a simple filling procedure wherr your tooth was restored with composite filling.
It is a very routine procedure.
Your friends might have had a very deep cavity
hence probably RCT was carried
out on then or indirect pulp capping or some other procedure was done.
Hope there is no pain in your new filling and you need not worry the dentist
must have done a fine job.
Hope this answers your query.