Do dentists really do unnecessary treatments for children?

Im very disturbed I brought my 5yr old daughter to new dentist today for cleaning and a filing or two I was told at one time today she may have 4 cavities then it all moved so fast before I knew it she was sedated and had 7 yes 7 crowns silver crowns on molars. When the nurse came to let me know she was done she mentioned I think they fixed a Little more then mentioned when I saw her mouth I couldn't help but cry for her..We brush daily even floss her couple times a week she doesn't like candy or juice fed baby never had bottle or nuk. So she never complained about pain in teeth so was it necessary for such extensive measures they never explained or showed me xray or ever told me a plan shame on me this is my number1 baby so It breaks my heart to think she had to go through this........any thoughts? Is this odd? Am I over reacting? Lack of communication I just can't stop thinking about this. Thanks Amie very desperate for answers