Calling the Dispose method has the same effect as calling the Close method. Use the Dispose method to close the SPSite object and release resources when you are finished using the object. Do not reuse the object or objects that are obtained through the object after it is closed.

If you create an SPSite object, you can use the Dispose method to close the object. However, if you have a reference to a shared resource, such as when the object is provided by the GetContextSite method or Site property (for example, SPContext.Current.Site), do not use the Dispose method to close the object, but instead allow Windows SharePoint Services or your portal application to manage the object. For more information about object disposal, see Best Practices: Using Disposable Windows SharePoint Services Objects.

The following code example shows how to use the Dispose method.

SPSite oSiteCollection = new SPSite("http://" + 
    System.Environment.MachineName + "/sites/Site_Collection");
...
oSiteCollection.Dispose();