The dental amalgam used in 'silver' fillings is a mixture of metals including mercury. Because of the similarity between the effects of mercury poisoning and some of the symptoms of multiple sclerosis such as tremor and weakness, there have been suggestions that mercury leaking from dental amalgam could cause or worsen MS.
The evidence to find out if any links exist between dental amalgam and neurological disorders was extensively explored by the European Commission in 2015. The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) concluded that there is insubstantial evidence to link dental amalgam and multiple sclerosis risk or worsening. A further study of the health of US dentists found no link between exposure to the mercury in fillings and acquiring MS, although there was a link between mercury exposure and tremor.
The World Health Organisation has supported a gradual phasing out of the use of dental amalgam by improving dental health and developing alternative filling materials. However there is no suggestion that dental amalgam fillings should be removed and replaced, a procedure that can be expensive. Do ask your dentist if you have any queries about options for filling materials.