ionic ion-nav-buttons ng-if not work for first load

I have a table view, when I click one cell will call my PixCtrl controller. If I check connection work, I will get data by $http.get, if not I will use sqlite. This is work. I want my ion-nav-buttons is dynamic. But when I first click, that is not work. I must do it again that will show. I have no idea how to fix it. and I had use console to watch it, and that is correct each time, how can I fix it for the first click.

thanks your help.

controller

.controller('PixCtrl', function($scope, $sce, $stateParams, SQLService, $http....) {
    ...

    if ( ! $rootScope.noConnection) {
      $http.get('http://pixnettest-lighter.c9.io/content.php?id=' + $stateParams.pixnetId)
      .success(function(data, status, headers, config) {
        var pix_data = {
          ...
          html_comment_count: datas[0].comment_count,
          ...
        };
        $scope.pix_content = pix_data;
      });

    }
    else  {
      // get by sqlite data

      var pixnet_data = {
        ...
        html_comment_count: content.comment_count,
        ...
      };

      $scope.pix_content = pix_data;
    }

    ...

    $scope.checkMComBtn = function(comment_count) {
      var intValue = parseInt(comment_count) || 0;
      console.log('intValue ' , intValue);

      if (intValue > 0) {
        return 1;
      }
      else {
        return 0;
      }
    }
});

view

<ion-view on-swipe-right="onSwipeRight()" ng-init="initEvent()">
  <ion-nav-buttons side="right"  ng-if="checkMComBtn(pix_content.html_comment_count)">
    <button class="button">Message</button>
  </ion-nav-buttons>
  ...
</ion-view>