[Vuejs]-Vuetify – how to reset the child component in the v-dialog

Add a v-if on your component with the value used for toggle the dialog:

<v-dialog v-model="dialog" width="800">
       <template v-slot:activator="{ on, attrs }">
          <v-btn depressed color="primary" v-bind="attrs" v-on="on" @click="dialog = true">
             <v-icon color="white">mdi-plus-thick</v-icon>
             <span class="ml-2">Cihaz Ekle</span>
          </v-btn>
       </template>
       <Create v-if="dialog"/>
    </v-dialog>