Mth ago silver filling replaced after 16yrs with a white filling.still painful ,sensitive dentist smoothed it for bite and said will try root canal?

This is a common: event when relatively DEEP cavities are filled with amalgam ("silver") and that filling finally Fails requiring replacement. Since decay usually accompanies such a situation the nerve of the tooth may be irritated with the new filling...thus requiring that he nerve be removed and root canal performed! hope this is helpful Dr Z

Sensitive filling: Doing a filling is a surgical procedure. Depending on depth and spread of decay under old filling, extensive material may have been removed. Sometimes the tooth cannot recover from the surgical shock, and root canal treatment becomes necessary. If you are concerned, seek a 2nd opinion.