Violation
If a tooth has an inadequate ferrule, which of the following is/are effective strategies to increase tooth structure available for crown preparation? 1. Surgical crown lengthening. 2. Sub-gingival preparation and prolonged temporization. 3. Orthodontic eruption. 4. Elective endodontic treatment gaining retention from a post in the root.
(1) and (3)
All of the above.
(1) (2) (3)
(4) only
(2) and (4)