biologic width

0.97+1.07=2.04

BIOLOGIC WIDTH-THE NO BREACH ZONE PRESENTED BY: GUIDED BY:

DR. POOJA BHASALE DR. Q.J.A. SHAKIR(PROFESSOR) 1s t YR P.G. STUDENT DR. ARVIND SHETTY(HOD & PROF DR. D.Y. PATIL DENTAL COLLEGE NAVI MUMBAI

WHAT IS BIOLOGIC WIDTH?

INTRODUCTION

Concept of Biologic width is based on studies and analyses by, Gottlieb (1921), Orban and Köhler (1924), and Sicher (1959)

Cinical Periodontology & Implant Dentistry 5th edition Jan Lindhe

INTRODUCTION

Ingber et al(1977) first described “Biologic Width” and credited D.Walter Cohen for first coining the term.

The dimension of biologic width is not constant, it depends on the location of the tooth in the arch, varies from tooth to tooth, and also for each aspect of the tooth.

Its constancy can only be found in healthy dentition.(De Wall etal 1993)

It varies from 0.75 to 4.3mm in length.

SIGNIFICANCE OF BIOLOGIC WIDTH

Biologic width is the nature’s approach for protecting the periodontal ligament and alveolar crest

It acts as a shield which endures trauma, both mechanical and bacterial, to ensure longevity of a tooth and restoration.

Its integrity is indicative of gingival health, and is a guide for restorative procedures.

REASONS FOR BIOLOGIC WIDTH VIOLATION

Attempt to access sound tooth structure Existing caries (Class V ,II ) Resorption defects Traumatic injury (Subgingival fractures) Iatrogenic Improper identification of sulcus depth Injury during tooth preparation Overextended subgingival restorations

J KOIS Periodontology 2000. Val. 11, 1996,29

IMPLICATIONS OF BIOLOGIC WIDTH VIOLATION Persistent Gingival Bone Loss with Inflammation Gingival Recession

Carranza’s Clinical Periodontology 10th edition

THIN AND SCALLOPED

PERIODONTAL BIOTYPE

Gingival Recession Horizontal Bone loss

THICK AND FLAT PERIODONTAL

BIOTYPE

Chronic Gingival InflammationLocalised Gingival Hyperplasia with minimal bone lossIntrabony pocket formation

HOW DO WE IDENTIFY BIOLOGIC WIDTH VIOLATION?

BONE SOUNDING

RADIOGRAPHIC INTERPRETATION

ASSESSING THE RESTORATIVE MARGINS WITH

PROBE

CORRECTING BIOLOGIC WIDTH VIOLATIONS

Can be corrected or prevented by— 1.Surgically removing bone 2.Orthodontic extruding the

tooth

FACTORS DETERMINING THE TREATMENT PROTOCOL

ESTHETICS

GINGIVAL DISPLAY

GINGIVAL CONTOUR

CONDITION OF PERIODONTIUM

ALVEOLAR BONE MORPHOLOGY

WIDTH OF ATTACHED GINGIVA

TOOTH RELATED

POSITION OF TOOTH IN

ARCH

LOCATION OF THE VIOLATION

NUMBER OF TEETH

PRESENT

PRESURGICAL TREATMENT ANALYSIS

Determine the finish line prior to surgery

Bone sounding prior to surgery is performed for establishing the biologic width.

The biologic width requirements will determine the amount of alveolar bone removal

Smukler and Chaibi (1997)

PRESURGICAL TREATMENT ANALYSIS

The combination of biologic width and prosthetic requirements determines the total amount of tooth structure necessary for exposure.

Tooth surface topography, anatomy, and curvature are analyzed for determining

a. Osseous scallop b. Gingival form

Smukler and Chaibi (1997)

DECIDING THE SAFETY LINE Ingber et al (1977) suggested that a minimum

of 3 mm required from the restorative margin to the alveolar crest to permit adequate healing and restoration of the tooth.

Additional 0.5mm of bone removed as safety zone. (Kois1996)

Wagenberg et al.(1989),suggested that atleast 5-5.25mm of tooth structure should be above the osseous crest

Ref: Padbury Jr A, Eber R, Wang H-L.,J Clin Periodontol 2003

FERRULE EFFECT

For post and core restorations

5-6mm of exposed tooth structure

should be present above alveolar

crest

This takes in account the 2mm

ferrule length

Ref: Padbury Jr A, Eber R, Wang H-L.,J Clin Periodontol 2003

SURGICAL CROWN LENGTHENING

Width of Attached

gingiva

Adequate

Flap with Osseous

reduction

Inadequate

Apically Repositioned

Flap with Osseous

Reduction

FLAP WITH OSSEOUS REDUCTION

FLAP WITH OSSEOUS REDUCTION

Atlas of Cosmetic and Reconstructive Periodontal Surgery 3rd edition Cohen

APICALLY REPOSITIONED FLAP WITH OSSEOUS REDUCTION

Atlas of Cosmetic and Reconstructive Periodontal Surgery 3rd edition Cohen

LIMITATIONS OF SURGICAL CROWN LENGTHENING

Gingival recession following osseous reduction.

Loss of interdental papilla Gingival contour of treated

tooth crown higher than adjacent teeth.

Loss of attachment apparatus and recession in the adjacent teeth

Following removal of bony support, an inverse and Unfavorable crown root ratio.

ORTHODONTIC EXTRUSION

Ref:Felippe LA, Monteiro Junior S etal,Quintessence Int. 2003.

Slow orthodontic extrusion force

Rapid orthodontic extrusion with supracrestal fibrotomy

SLOW ORTHODONTIC FORCE EXTRUSION

RAPID ORTHODONTIC EXTRUSION