For a good UTF-8 processing, all elements of the chain must be UTF-8. You have to ensure that your template is UTF-8 : check the entered text and the HTML element <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> You have to ensure that all your PHP scripts are UTF-8 and not Ansi....
Your PHP code must be saved in UTF-8 (without DOM). Your database (if any) must store data in UTF-8. And your TBS template must be loaded with the option OPENTBS_ALREADY_UTF8. $TBS->LoadTemplate('document.docx', OPENTBS_ALREADY_UTF8); ...