Again, look at the cochrane review which states “Overall, the evidence suggests that amalgam restorations are effective, enduring, and safe, while composite resin restorations are more likely to fail and lead to secondary caries. However, the studies in this review were quite old, and composite resin materials have likely improved since the included studies were conducted. Patients and dental providers can discuss together which material they want to use when permanent teeth in the back of the mouth require fillings in the dental clinic. Governments around the world are trying to reduce the use of dental amalgam (according to the Minamata Convention on Mercury), and so each local area will have their own regulations and guidance. “ www.cochrane.org/evidence/CD005620_tooth-colored-resin-fillings-compared-amalgam-fillings-permanent-teeth-back-mouth
and the EU report on amalgam use posted above.
You are quite right we are exposed to mercury in both the placing of and removal of amalgams . However extensive peer reviewed analysis of multiple studies , not just one or two , has revealed no link between amalgam and increased morbidity or mortality. Tellingly in the populations most exposed to amalgam , in both their own mouths and in their everyday working life , ie dental staff there is no increase in morbidity or mortality when all well researched and reviewed papers are considered.
With any research there will always be papers that differ from the consensus. That is why reviews such as Cochrane are so important as they look at all papers, how well the research is put together , any bias, the number of subjects and methodology . They then collate them and provide a balanced view.
This has become increasingly important as people can make life changing decisions based on a flawed research paper eg Andrew Wakefield and MMR which has resulted in multiple fatalities and injuries because people didn’t not vaccinate their children based on a paper which, when reviewed properly, revealed serious flaws.
It is also why people should not confuse serious research that is peer reviewed and balanced against other papers with you tube videos and single group or opinion papers .