Try using row.entity object..
On html side, define your input with ng-model="exapmle" as you probably did.. On angular side, get your textbox value with row.entity.example
An example which i did recently.. Look at last column def column..
$scope.gridOptions = {
data: 'accounts',
multiSelect: false,
showFilter: false,
showColumnMenu: false,
showSelectionCheckbox: false,
showGroupPanel: false,
showMenu:false,
showFooter: false,
enableRowSelection: false,
columnDefs: [
{field: 'username', displayName: 'Username', width:180},
{field: 'email', displayName: 'Email', width:250},
{field: 'role.displayTxt', displayName: 'Role', width:120},
{field: 'active', displayName: 'Active', width:80},
{field: '', displayName: ' ', width: 50,
cellTemplate: '<div class="grid-action-cell">' +
'<a class="btn-link" type="button" title="Edit" ng-href="#/accounts/{{row.entity.username}}">' +
'<i class="glyphicon glyphicon-edit" style="left:8px; top:8px;"></i>' +
'</a>' +
'</div>'
},
]
};