This document discusses crown lengthening procedures and biological width. It notes that crown lengthening surgery should remove enough bone to allow for 2mm of tooth structure, the biological width of 2mm, and 1mm sulcus depth for non-post-core teeth. For teeth requiring posts, an additional 1.5mm ferrule effect space is needed. The document outlines factors to consider for crown lengthening like tissue biotype, tooth anatomy, and restorability. It recommends more conservative bone removal lingually and waiting at least 20 weeks after surgery before final crown preparation.

1. 王英斌 20031221 Pre-prosthetic crown lengthening procedure

2. The predictability of the esthetics may be determined by the patient’s presenting anatomy rather than the clinician’s ability to manage state-of-the-art procedures Kois J. 2001

4. What is biologic width ? 何謂生理寬度 ?

5. Dentogingival complex Ginigival sulcus 0.69mm Junctional Epithelium 0.97mm ( 0.71-1.35mm) Connective tissue attachment 1.07mm ( 1.06-1.08mm ) Biologic width

6. Epi. attachment 1.14 (0.32-3.27) Connective tissue attachment 0.77 (0.29-1.84) Sulcus depth 1.34 (0.26-6.03) Vacek JS et al 1994

9. Ferrule effect (1.5mm) 360 degree metal collar of the crown surrounding the parallel walls of the dentin extending apical to the shoulder of the preparation Libman& Nicholls 1995 IJP pulpless tooth– post&core Spear F. 1999 compendium

13. Inflammatory Disease control first

14. Restorative –driven Esthetic –driven

16. Facial profile Smile line

19. Relationship of gingiva to the osseous crest ( dentogingival complex ) Normal crest (85%) facial FGM –crest : 3mm inter-proximal : 4mm high crest (2%) low crest (13%) Kois j 1994 – bone sounding

20. Aesthetic crown lengthening Should always first consider whether orthodontic extrusion extrusion is appropriate

21. The role of orthodontics in crown lengthening

22. 1. Root length(C/R) 4. Relative importance 2. Root form 5. Esthetics 3. Level of fracture 6. Endo/perio prognosis

23. Alveolar bone augmentation for implants by orthodontic extrusion Salama & Salama IJPRD 1993

25. Probing labial sulcular depth of 2 central incisors Shorter tooth has deep sulcular depth Excisional gingivectomy Delayed passive eruption

26. Repositioning of the gingival margin by extrusion

27. 是否有磨耗 ?? the incisal edges abraded ?? Incisal edge is thicker labiolingually than the adjacent tooth Abraded Intrude the short central incisor Stablized at least 6M

28. Repositioning of the gingival margin by intrusion

31. Crown-root ratio Non-CLP Surgically CLP Orthodontic extrusion

33. Treatment choices 1 > extraction ?  implant 2 > CLP  bridge ??

34. Take into consideration about mucogingival condition

35. Crown-lengthening procedures

36. . Aesthetic osseous surgery 美觀性的齒槽骨手術

38. -Apically positioned 0.5-1mm apical to osseous crest -Provides the interproximal soft tissue for primary flap adaptation Palatal scalloped incision shape of the incision follows the radicular morphology and the depth should be at the level of palatal osseous crest or slightly at the level to that after osteoplasty and ostectomy are accomplished

41. Tooth fracture treatment with orthodontic extrusion

49. Thanks for your attention !!