2003 biologic width
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2003 biologic width






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2003 biologic width 2003 biologic width Presentation Transcript

  • 王英斌 20031221 Pre-prosthetic crown lengthening procedure
  • 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
  • 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
  • What is biologic width ? 何謂生理寬度 ?
  • 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
  • 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
  • Dimensions of human dentogingival junction
    • A nt. teeth 1.75 Premolar 1.97 Molar 2.08
    • Vacek JS et al 1994
    • epithlieum was variable ,but c.t. tissue
    • attatchment was consistent
    • Gargiulo AW 1961
    • Vacek JS et al 1994
    • The biologic width follows
    • the osseous scallop
    • The osseous scallop parallels the cemento-enamel junction circumferentially .
    Anterior teeth : scallop posterior teeth : flat
  • 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
  • The influence of margins of restorations on the periodontal tissues over 26 years
    • increased loss of attachment found in teeth sub-gingival restorations(>1mm) started slowly and could be detected clinically 1-3 years after the fabrication and placement of the restorations
    • Sch ätzle M et. al. J Clin Perio 2000;27:57-64
  • 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
  • Response to this invasion
    • Crestal bone loss
    • Gingival recession and localized bone loss
    • Localized gingival hyperplasia with minimal bone loss
    • Combination
  • Inflammatory Disease control first
  • Restorative –driven Esthetic –driven
  • Anterior crown lengthening
    • 2mm tooth structure—minimal retention and resistance form
    • 2mm – biologic width
    • 1mm – sulcus depth
    • 1.5mm –ferrule effect
  • Facial profile Smile line
    • Biotype of the periodontium (thick or thin)
    • Relationship of gingiva to the osseous crest
    • Relationship of preparation finish line to the osseous crest
  • 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
  • Aesthetic crown lengthening Should always first consider whether orthodontic extrusion extrusion is appropriate
  • The role of orthodontics in crown lengthening
  • 1. Root length(C/R) 4. Relative importance 2. Root form 5. Esthetics 3. Level of fracture 6. Endo/perio prognosis
  • Alveolar bone augmentation for implants by orthodontic extrusion Salama & Salama IJPRD 1993
  • Uneven gingival margins
    • Orthodontic movement to
    • reposition the gingival margin
    • Surgical correction of
    • gingival margin discrepancies
  • Probing labial sulcular depth of 2 central incisors Shorter tooth has deep sulcular depth Excisional gingivectomy Delayed passive eruption
  • Repositioning of the gingival margin by extrusion
  • 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
  • Repositioning of the gingival margin by intrusion
  • Posterior crown lengthening
    • 2mm tooth structure—minimal retention and resistence form
    • 2mm – biologic width
    • 1mm – sulcus depth
    • Restorability ??
    • For What ??
  • Crown-root ratio Non-CLP Surgically CLP Orthodontic extrusion
  • 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
  • Treatment choices 1 > extraction ?  implant 2 > CLP  bridge ??
  • Take into consideration about mucogingival condition
  • Crown-lengthening procedures
  • . Aesthetic osseous surgery 美觀性的齒槽骨手術
  • Buccal scalloped incision
    • Double-scalloped creates triangular soft tissue within the healthy gingiva that protects the furcation area of multi-rooted molars during healing
  • -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
    • 15-degree declining buccopalatal slope
    • The well-declined bucco-lingual interproximal slope prevents inter-dental gingival proliferate on and bridging,which ultimately lead to pocket formation
  • 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 temp crown or excavated caries line
    • 10/26 ( 38.5%) – radiographic FI
    • critical distance from the furcation = 4mm
  • Tooth fracture treatment with orthodontic extrusion
  • Stability of soft tissue dimension after surgery
    • Different surgical intervention
    • Surgical skill
    • Healing time
    • Patient age
    • Tissue biotype
  • Coronal displacement of the gingival margin
    • more pronounced in patients with thick tissue biotype
    • Individual variation
    • Not related to age or gender
    • Pontoriero R. et al JP 2001;72:841-848
  • Desired vs actual amount
    • Clinicians may be need to be more aggressive during surgical crown lengthening procedure ,esp. disto-lingual aspect
    • Herrero F. et al JP 1995;66:568-571
    • R ecommended
    • -- early definition of final margin
    • -- re-provisonalization 3weeks after the
    • surgical procedure
    • -- more aggressive removal of osseous structure
  • Timing for prosthetics
    • Mean tissue recession following surgery was 1.32mm , while 29% of sites demonstrated 1-4mm gingival recession between 6weeks and 6 M post-operatively .
    • Br ä gger U et al 1992
  • Timing for prosthetics
    • Definite crown preparation should not be made for at least 20W after surgery for ant. teeth
    • Wise MD 1985
    • The biological width was re-established to its original vertical dimension by 6 M
    • Lanning SK et al JP2003;74:468-474
  • Conclusion
    • There may be different ways of treating a disease,but there can be but one correct diagnosis
    • Morton Amsterdam 1974
  • Thanks for your attention !!