Stages og osseointegration

Stages Leading Up To Osseointegration

STAGE I:  Inflammatory response to bone damage during drilling procedures

STAGE II: Osteoclastic activity removes any clot or necrotic matter

Stages of Osseointegration

    Primary Mesenchymal Cells differentiate into osteoblasts & lay down osteoid

Stages of Osseointegration

  

Woven bone laid down

Stages of Osseointegration

   Lamellar Bone laid down

Surgical & Post Surgical Factors That Prevent Osseointegration

   Heating of bone beyond 47 C

   Poor vascular supply & low oxygen  tension to site of implant placement

   Micromovemnets beyond 150 um during initial healing phase at bone- implant interface

Surface Coatings of Implants

Surface Coatings of Implants

Ø Titanium plasma spray

Ø Abrasions using TiO2 blasting

Ø Blasting & etching using alumina & sulfuric or hydrochloric acid

Ø Anodizing

Ø Cold working (dimpling)

Ø Sintering

Ø Magnetron sputtering using calcium sulfate apatites

Ø Bead compaction methods

Advantages of Surface Coatings

Surface Design of Implants

Surface Roughness of Implants

   Speeds up bone apposition

   Any grooves in the surface guide cell migration along their direction thereby allowing bone to adhere to even the tiniest irregularity

   Better interlock & biomechanical response

   Accentuates ability of Ti to integrate without inflammation.

Position , number and angulation of implant

Position of the Implant

   Depends on bone quality & quantity

   Minimum distance between implant & adjacent natural tooth: 5mm

   Minimum distance between two adjacent implants from their centres:7mm

Number of Implants

Ø Depends on

a)  Bone available

b)  Span length

c)   Occlusion

d)  Type of prosthesis

Ø Increasing the number of implants decreases the force per implant

Implant Angulation

   Implants may have to be angulated rather than along the long axis of the missing tooth when:

Ø Position, quality & dimension of bone is not ideal

Ø To avoid unaesthetic proclination of anteriors

Ø Multiple implants

Bone formation on titanium

Bone formation on titanium

Length of Implant

   Ranges from 6mm to 20mm

   It is the measured from the height of the crest of the ridge to 1mm from the nearest anatomic limitation

   Aim in selecting length is bicortical stabilization

Diameter of the Implant

   Must be such that atleast 1 mm of healthy bone remains around the implant both buccally & lingually

   Bone density also governs implant width.

   Wider implants have better bone contact & greater cross section at the neck of the implant.

Material of the Implant- Titanium

Material of the Implant- Titanium

   The property of osseointegration is virtually exclusive to titanium.

   When Ti is exposed to atmospheric conditions forms a passivation oxide layer

   More extensive layer about 10nm in thickness formed in vivo

   Also been hypothesized that the actual Ti interface to the implant is a hydrated Ti peroxy matrix.

Factors affecting Osseointegration

Factors affecting Osseointegration

Osseointegration can be affected by

   Bone present

   Implant placed

Bone factors affecting osseointegration

   Sufficient thickness & quality  of bone

   History of  Diabetes Mellitus

   Habits like smoking & bruxism

Implant properties affecting Osseointegration

   Material

   Dimensions of Implant

   Surface coatings

Surface design

Weiss' theory of fibrosseous integration

Weiss' theory of fibrosseous integration

   There is a fibrosseous ligament formed between the implant & the bone.

   This ligament is equivalent to the periodontal ligament found in the gomphosis.

   He advocated early loading of the implant.

Osseointegration by Branemark

Osseointegration by Branemark

   Implants integrate such that bone is laid very close to the implant without any intervening connective tissue

   Implants should be left out of function during the healing period for osseointegration to occur.

Types of Integration

Types of Integration

Fibro- Osseous Integration

  Proposed by Weiss

    Osseointegration proposed

     By Branemark

HISTORY OF Osseointegration

HISTORY OF Osseointegration

   1952- Branemark coined the term Osseointegration

Branemark,  a Swedish surgeon, while conducting research into the healing patterns of bone tissue, accidentally discovered that when pure titanium comes into direct contact with the living bone tissue, the two literally grow together to form a permanent biological adhesion. He named this phenomenon "osseointegration 

Branemark’s Definition of Osseointegration

Branemark’s Definition of Osseointegration

  Branemark, a pioneer in implantology, has stated that osseointegration is a continuing structural & functional existence possibly in a symbiotic manner, between differentiated, adequately remodeled, biologic tissues & strictly defined & controlled synthetic components, providing lasting, specific clinical function without initiating rejection mechanisms.

Dental Implant - OSTEOINTEGRATION

OSTEOINTEGRATION

What is OSSEO INTEGRATION

Originally it was defined as a direct structural & Functional connection between ordered living Bone & the surface of a load bearing implant.

It is now said that an implant is regarded as

osseointegrated when there is no progressive

relative movement between the implant & the

bone with which it has direct contact.