Aluminum nitride and zirconia, zirconia is more wear-resistant. The density of zirconia ceramic structural parts is higher than that of aluminum nitride ceramics, alumina is more common and cheaper, and has good temperature resistance. Zirconia has better wear resistance and higher service temperature than aluminum nitride, but its thermal shock resistance is poor. Therefore, aluminum nitride, zirconia and zirconia are more wear-resistant. Zirconia is a commonly used material in dental plastic surgery. In the unprocessed state, it is a white odorless crystal, which is almost insoluble in water, hydrochloric acid and dilute sulfuric acid.