Re: how to remove resistant tartar?
They do make similar tools in plastic, though they aren't strong, usually. Lemme tell you, when one of those plastic tips breaks off...EGAD!
Since you aren't "ingesting" the metal tool, it shouldn't have any effect on your general health. I'm a chicken about this stuff too - I've got 2 teeth that really need attention and I just cannot abide going to the dentist! It's not even like he's mean, hurtful, or careless, either! I just can't tolerate the smells and the frequencies of the power tools. Ack.
Come to think of it, I should get one of those tools, myself. I have a box FULL of them that I use for sculpting and I could probably use one of them, I guess.
Best of luck to you - and, post back with your progress/results from scaling your teeth. I need some courage and you might be the one to pass it on! (grin)