3.5.Which of the following statements concerning tooth wear is incorrect?

A、etiologyoftoothwearismultifactorial.
B、asopposedtocaries,adirectlossoftoothsubstanceisobservedwithoutthestageOfsubsurfacedemineralization.
C、toothwearisalwaysapathologicalprocess.
D、bothendogenousandexogenousfactorscontributetotoothwear.
E、symptomsoftoothwearshouldbeperiodicallymonitoredbythedentist.