1. The quality of the mill is unstable and the degree is poor. 2, the mill due to its inherent lack of structure, poor degree. 3, the power of the hanging mill is large, the degree is good. 4, high speed tooth machine, high degree. 1, the mill handle is thick, not easy to control. 2, the mill is a soft shaft, not easy to operate 3, the hanging mill must have a hook suspension, the handle is inconvenient to control. 4, dental machine operation is convenient and flexible. 1, the low price of the mill is generally dozens to more than 100 yuan. 2, the price of the mill is more than 200-300 yuan, which is slightly higher than the electric mill. 3, the price of hanging mill in 200-400 yuan, slightly higher than the electric mill. 4, the price of dental machine is high, more than 400 yuan, higher than the price of electric mill, table mill and hanging mill. Selection comparison: the power of the hanging mill is large, the degree is also good, but the suspension is troublesome, the noise is larger, and the use of large carved parts is suitable. Tooth machine can play for the details of the engraving, easy to operate, the function is better than the table mill, the electric mill, but the price is slightly higher. Reference: Encyclopedia - Electric mill