What people don't realize is the shank the bucket also wears. When new the teeth fit snugly. But as time goes on and dirt gets between the tooth and shank the steel wears. Hard soil and rocks make it worse. I have two buckets for my backhoe. One always loses teeth while the other came from a guy who lived in a sandy location. He never dug roots or rocks so the shanks are like new and it has never lost a tooth.