Aren't mercury-based amalgam teeth fillings more durable than other techniques because the metal is more plastic that other fillings which are more brittle?
Last time I read about that, the risks for mercury exposure was for dentists, not patients.
Amalgam fillings are more durable than composite fillings, but the latter are much cheaper and they can still have a lifetime of 20 years or more.
Ceramic facets or ceramic crowns are more durable than amalgam fillings, as long as they are not used in a way that could fracture them, e.g. by attempting to crush nuts or the like with the teeth.
There isn't one version/mix of composite/plastic. I know this because when I was younger, I got a filling and it got wrecked quite quickly. They then said they'd use a different mix but it was the last resort. I forgot the pros and cons. But I can say that approx 20 years later, my filling got replaced and the dentist (a different one, for sure) said 'this stuff breaks so quickly'.
Last time I read about that, the risks for mercury exposure was for dentists, not patients.