Another wrong conclusion. Much of my work is in quartz or sandstone rock and i find the greenteeth have been much more durable due to increased carbide surface area. I use about 60 new teeth per year grinding 325 run hours. I can get the dull Teeth re-sharpened @$2.75 per tooth. By the way, running my big diesel 325 hours is producing what a mid-size 25hp. would in 1200 hours. You first stated that you trash canned the greenteeth after one month, now you say it was 90 days?? I don't like how far the greenteeth throw chips but durability,productivity and annual cost of replacement teeth are positives not negatives.IMO