Metallic Implant Materials

Only available on StudyMode
  • Topic: Corrosion, Stainless steel, Titanium
  • Pages : 26 (6140 words )
  • Download(s) : 157
  • Published : April 10, 2007
Open Document
Text Preview
BIOMATERIALS – METALLIC IMPLANT MATERIALS

BY:
G.V.CHAKRAVARTHY
B.TECH FINAL YEAR
ROLL NO. 03501
DEPT. OF METALLURGICAL AND MATERIALS ENGINEERING

NATIONAL INSTITUTE OF TECHNOLOGY
(DEEMED UNIVERSITY)
WARANGAL ,ANDHRA PRADESH

BIO MATERIALS - METALLIC IMPLANT MATERIALS

INTRODUCTION

In surgery, a biocompatible material (sometimes shortened to biomaterial) is a synthetic material used to replace part of a living system or to function in intimate contact with living tissue. The CLEMSON UNIVERSITY ADVISORY BOARD for BIOMATERIALS has formally defined a biomaterial to be "a systematically and pharmacologically inert substance designed for implantation within or incorporation with living systems." By contrast a biological material is a material such as bone matrix or tooth enamel, produced by a biological system.

The use of biomaterials, as indicated in Table 1, include replacement of a body part that has lost function due to disease or trauma, to assist in healing, to improve function, and to correct abnormalities.

Table 1 Uses of Biomaterials

Problem areaExamples
Replacement of diseased or damaged part
Assist in healing
Improve function
Correct functional abnormality
Correct cosmetic problem
Aid to diagnosis
Aid to treatment
Artificial hip joint, kidney dialysis machine
Sutures, bone plates and screws
Cardiac pacemaker, contact lens
Harrington spinal rod
Augmentation mammoplasty, chin augmentation
Probes and catheters
Catheters, drains

Biomaterials can be classified from the point of view of the problem area that is to be solved (Table 1), the body on a tissue level, an organ level (Table 2), or a system level (Table 3). Also classified as metals, polymers, ceramics and composites (Table 4).

Table 2 Biomaterials in Organs

OrganExamples
Heart
Lung
Eye
Ear
Bone
Kidney
Bladder
Cardiac pacemaker, artificial heart valve
Oxygenator machine
Contact lens, eye lens replacement
Artificial stapes, cosmetic reconstruction of outer ear
Bone plate
Kidney dialysis machine
Catheter

Table 3 Biomaterials in Body Systems

SystemExamples
Skeletal
Muscular
Digestive
Circulatory
Respiratory
Integumentary
Urinary
Nervous
Endocrine
Reproductive
Bone plate, total joint replacements
Sutures
Sutures
Artificial heart valves, blood vessels
Oxygenator machine
Sutures, burn dressings, artificial skin
Catheters, kidney dialysis machine
Hydrocephalus drain, cardiac pacemaker
Microencapsulated pancreatic islet cells
Augmentation mammoplasty, other cosmetic replacements

Table 4 Materials for use in body

MaterialsAdvantagesDisadvantagesExamples
Polymers
Nylon
Silicones
Teflon
Dacron

Metals
Titanium
Stainless steel
Co-Cr alloys
Gold

Ceramics
Aluminum oxide
Carbon
Hydroxyapatite

Composites
Carbon-carbon
Resilient
Easy to fabricate

Strong, tough
Ductile

bio compatible, inert
Strong in compression

Strong, tailor made
Not strong
Deform with time
May degrade

May corrode
Dense

Brittle
Difficult to make
Not resilient

Difficult to make
Sutures, blood vessels, hip socket, ear, nose, other soft tissues

Joint replacement, bone plates & screws, dental root implants

Dental, hip socket

Joint implants, heart valves

HISTORICAL BACKGROUND

The use of biomaterials did not become practical until the advent of aseptic surgical technique in the 1860s. Earlier surgical procedures were generally unsuccessful as a result of infection. The earliest successful implants, as well as a large fraction of modern ones, were in the skeletal system. Bone plates which were introduced in the early 1900s to aid fixation of fractures broke as a result of unsophisticated mechanical design; they were too thin and had stress-concentrating corners. It was discovered that materials such as vanadium steel, which were chosen for good mechanical properties, corroded...
tracking img