ionic2 modal ion-navbar vs ion-toolbar

  <ion-toolbar>
      <ion-title>Modals</ion-title>
      <ion-buttons end>
         <button outline  (click)="closeModal()">
          New Item
         </button>
      </ion-buttons>
  </ion-toolbar>

but when I use ion-navbar it doesn't display anything? the sample code uses ion-navbar

  <ion-navbar>
      <ion-title>Modals</ion-title>
      <ion-buttons end>
         <button outline  (click)="closeModal()">
          New Item
         </button>
      </ion-buttons>
  </ion-navbar>