How much harmful of silver filling?i ve 3 silvr fillings in my teeth.earlier it was white filling.which one is better?

Both have good/bad: The silver (amalgam) filling material is one of the most studied materials in dentistry. There is no evidence of any danger in any reliable study, and there has been many. That being said, you will likely get 5 different answers from 5 different dentists. Both have good and bad properties, and when used in the right circumstances with the correct techniques, both can be a very reliable fillings.

Types of fillings: After over 150 years of use, research and studies, to date, not one single valid study to prove any harm from amalgam fillings. Composite fillings bond to teeth and look more aesthetic. Amalgam fillings tend to wear less, but stain teeth over time and suffer marginal breakdown. There are indications for both, I use both but prefer composite bonded fillings most of the time.