The homemade teeth I made were out of A36 and they lasted just fine. Like anything made out of steel, that digs in the dirt. If there is some wear showing, surface weld it so it continues to wear. It is not like we are moving thousands of cubic of yards of soil here, if we did, then we would be buying bucket loaders.
I did project "Endless Haul" last year, digging and hauling gravel out of my gravel pit for my Tiny House, and it was still only 700 cubic yards. I did it with a straight cutting edge, but it does help to have teeth to break up the gravel before the bucket gets there.