2003 biologic width

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  • 1. 20031221 Pre-prosthetic crown lengthening procedure

2. The predictability of the esthetics may be determined by thepatients presenting anatomyrather than the clinicians ability to manage state-of-the-art procedures Kois J.2001 3. Contents

  • How much should I have appropriate distance between osseous crest and final margin?
  • Esthetic consideration
  • Restorative consideration
  • Stability of soft tissue dimension after surgical CLP
  • Conclusion

4. What is biologic width ? ? 5. Dentogingival complex Ginigival sulcus 0.69mm Junctional Epithelium0.97mm ( 0.71-1.35mm) Connective tissue attachment 1.07mm ( 1.06-1.08mm ) Biologic width 6. Epi. attachment1.14 (0.32-3.27) Connective tissue attachment0.77 (0.29-1.84) Sulcus depth1.34 (0.26-6.03) Vacek JS et al1994 7. Dimensions of humandentogingival junction

  • A nt. teeth1.75Premolar1.97Molar2.08
  • Vacek JS et al 1994
  • epithlieum was variable ,but c.t. tissue
  • attatchment was consistent
  • Gargiulo AW 1961
  • Vacek JS et al 1994

8.

  • The biologic width follows
  • the osseous scallop
  • The osseous scallopparallels the cemento-enamel junction circumferentially .

Anterior teeth : scallop posterior teeth : flat 9. Ferrule effect (1.5mm) 360 degree metal collarof the crownsurrounding the parallel wallsof the dentin extending apicalto the shoulder of the preparationLibman& Nicholls1995 IJP pulpless tooth post&core Spear F. 1999 compendium 10. The influence ofmargins of restorationson the periodontal tissues over 26 years

  • increased loss of attachmentfound in teeth sub-gingivalrestorations(>1mm) started slowly andcould be detected clinically 1-3 yearsafter the fabrication and placement of the restorations
  • Sch tzle Met. al. J Clin Perio 2000;27:57-64

11. Osseous crest-final margin

  • Supra-gingival margin
  • Not need post-core tooth
  • 2(B)+0.5-1(safe) =2.5-3mm
  • Post-core tooth
  • 2(B)+1.5(F)+0.5-1(safe) = 4-4.5mm
  • Subgingival margin
  • Not need post-core tooth
  • 2(B)+0.5-1(safe)+1(sulcus) =3.5-4mm
  • Post-core tooth
  • 2(B)+1.5(F)+0.5-1(safe)+1(sulcus) = 5-5.5mm

12. Response to this invasion

  • Crestal bone loss
  • Gingival recession and localized bone loss
  • Localized gingival hyperplasia with minimal bone loss
  • Combination

13. InflammatoryDisease control first 14. Restorative drivenEsthetic driven 15. Anterior crown lengthening

  • 2mm tooth structureminimal retention and resistance form
  • 2mm biologic width
  • 1mm sulcus depth
  • 1.5mm ferrule effect

16. Facial profile Smile line 17. 18.

  • Biotype of the periodontium (thick or thin)
  • Relationship of gingiva to the osseous crest
  • Relationship of preparation finish line to the osseous crest

19. Relationship of gingiva to the osseous crest ( dentogingival complex ) Normal crest (85%) facialFGM crest : 3mm inter-proximal : 4mmhigh 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 orthodonticsin crown lengthening 22. 1.Root length(C/R)4. Relative importance2.Root form5. Esthetics 3.Level of fracture6. Endo/perio prognosis 23. Alveolar bone augmentation for implantsby orthodontic extrusionSalama & Salama IJPRD 1993 24. Uneven gingival margins

  • Orthodontic movement to
  • reposition the gingival margin
  • Surgical correction of
  • gingival margin discrepancies

25. Probing labialsulcular depth of 2central incisors Shorter tooth has deepsulcular depth ExcisionalgingivectomyDelayed passive eruption 26. Repositioning of the gingival marginby extrusion 27. ?? the incisal edges abraded ?? Incisal edge is thickerlabiolinguallythan the adjacent tooth Abraded Intrude the shortcentral incisor Stablized atleast 6M 28. Repositioning of the gingival marginby intrusion 29. Posterior crown lengthening

  • 2mm tooth structureminimal retention and resistence form
  • 2mm biologic width
  • 1mm sulcus depth

30.

  • Restorability ??
  • For What ??

31. Crown-root ratio Non-CLP Surgically CLP Orthodontic extrusion 32. Kennedy Class I & II distal-most mand. P 2

  • Pulpless teeth are commonly avoided as abutment for an RPD ,especially if terminal abutment is for distal extension
  • Kratochvil FJ 1988

33. Treatment choices 1>extraction ? implant2> CLP bridge ?? 34. Take into consideration about mucogingival condition 35. Crown-lengthening procedures 36. . Aesthetic osseous surgery 37. Buccal scalloped incision

  • Double-scallopedcreates triangular soft tissue within the healthy gingiva that protects the furcation area of multi-rooted molars during healing

38. -Apically positioned0.5-1mm apicalto osseous crest-Provides the interproximal softtissue for primary flap adaptation Palatal scalloped incision shape of the incisionfollows the radicularmorphology andthe depth should be at thelevel of palatal osseous crest or slightly at the level tothat after osteoplasty and ostectomy are accomplished 39.

  • 15-degree declining buccopalatal slope
  • The well-declined bucco-lingual interproximal slope prevents inter-dental gingival proliferateon and bridging,which ultimately lead to pocket formation

40. Crown lengthening in mand. molars : A 5-year retrospective radiographic analysis Dibart S. et al J P 2003 ;74:851-821 Critical distance from the furcation (CDF) furcation entrance to the margin of the tempcrown or excavated caries line

  • 10/26 ( 38.5%) radiographic FI
  • critical distance from the furcation =4mm

41. Tooth fracture treatment with orthodontic extrusion 42. Stability of soft tissue dimension after surgery

  • Different surgical intervention
  • Surgical skill
  • Healing time
  • Patient age
  • Tissue biotype

43. Coronal displacementof the gingival margin

  • more pronounced in patients withthicktissue biotype
  • Individual variation
  • Not related to age or gender
  • Pontoriero R. et al JP 2001;72:841-848

44. Desired vs actual amount

  • Clinicians may be need to bemore aggressiveduring surgical crown lengthening procedure ,esp. disto-lingual aspect
  • Herrero F. et al JP 1995;66:568-571

45.

  • R ecommended
  • --early definitionof final margin
  • --re-provisonalization3weeksafter the
  • surgical procedure
  • --moreaggressiveremoval of osseous structure

46. Timing for prosthetics

  • Mean tissue recession following surgery was 1.32mm , while 29% of sites demonstrated 1-4mm gingival recession between 6weeks and6 Mpost-operatively .
  • Br gger U et al 1992

47. Timing for prosthetics

  • Definite crown preparation should not be made forat least 20Wafter surgery for ant. teeth
  • Wise MD 1985
  • The biological width was re-established to its original vertical dimension by6 M
  • Lanning SK et al JP2003;74:468-474

48. Conclusion

  • There may be different ways of treating a disease,but there can be but one correct diagnosis
  • Morton Amsterdam1974

49. Thanks for your attention !!