Monti's getting a cavity filled

On Monti's brand new molar they found a small cavity. The dentist told
me her molars are really "groovy" and not in a cool way. She told me
there was a good chance that the cavity could have formed before it
erupted fully from the gum. Not sure if this was true but I sense she
was trying to ease my guilt. After they filled the tooth without
novocaine the dentist added a sealant on the molar.