BIOCERAMICS MATERIALS FOR THE FUTURE AWADESH KUMAR MALLIK MF2004, MRC, IISc, BANGALORE, INDIA.

Medical devices and implants are among the modern marvels that alleviate pain and suffering, as well as prolong and add to the quality of life Degenerative joint disease is recognised as an increasing problem for society, a direct result of an ageing population ( as life expectancy is increasing ) Increasing stress level of modern life-style leads to heart diseases. Heart valve disease has a devastating impact worldwide. Unhealthy life style increases the risk of cancer Social problem faced by anopthalmic human patients

Like information technology, healthcare technologies will depend heavily on developments in materials and their processing MF2004, MRC, IISc, BANGALORE, INDIA.

BEHAVIOR OF CERAMIC INSIDE THE HUMAN BODY Type of Attachment Type of Bioceramic Dense, nonporous, almost inert ceramics attach by bone ingrowth into the surface irregularities, by cementing the device into the tissue, or by press fitting into a defect (morphological fixation) Alumina, Zirconia For porous inplant bone ingrowth occurs, which mechanically attaches the bone to the material (biological fixation) Porous Hydroxyapetite, Hydroxyapatite coated porous metals. Surface-reactive ceramics, glasses, and glass-ceramics attach directly by chemical bonding with the bone ( bioactive fixation) Bio-active glass, Bio-active Glass-ceramics, Dense Hydroxyapatite Resorbable ceramics and glasses in bulk or powder form designed to be slowly replaced by bone Calcium Sulfate, Tricalcium Phosphate, Calcium phosphate salts, Bioactive glasses MF2004, MRC, IISc, BANGALORE, INDIA.

DIVERSE FUNCTIONS OF BIOCERAMICS Joint Prostheses Low Co-efficient of Friction for Lubricating Surfaces Surfaces on heart valves, Thromboresistence Materials that stimulate bone growth Harness radioactive species for therapeutic treatments MF2004, MRC, IISc, BANGALORE, INDIA.

Worldwide Orthopaedic Product Sales: By Market Segment and Geographic Region (US$ Billions) Explanation of market segments Reconstructive Devices: hip, knee, shoulder, elbow, wrist, ankle and digit implants Fracture Fixation: internal (plates, screws, nails, pins, wires) fixation and external fixation products Spinal Implants/Instrumentation: internal fixation devices and disectomy and vertebroplasty products Arthroscopy/Soft Tissue repair: scopes, cameras, instruments, soft tissue implants and repair kits Orthobiologics: bone graft substitutes, allograft, autogenous bone and soft tissue replacement products and viscoelastics Other Products: power equipment, casting materials, soft goods, bracing systems, bone growth stimulators, maxillofacial fixation products, diagnostics, cement and cement mixing/delivery systems, infection control equipment, pulsed lavage/irrigation systems, continuous passive motion machines, etc. Product Segment U.S. Ex-U.S. Total Change vs 1999 Reconstructive Devices $ 2.4 $ 4.9 9% Fracture Fixation $ 0.7 $ 1.4 Spinal $ 1.0 $ 0.5 $ 1.5 16% Implants/Instrumentation/Arthroscopy/Soft tissue repair $ 0.8 $ 0.4 $ 1.2 12% Orthobiologocs $ 0.2 44% Other Products $ 2.0 $ 1.1 $ 3.0 8% Total Market $ 7.0 $ 5.3 $ 13.1 MF2004, MRC, IISc, BANGALORE, INDIA.

DENTAL CERAMICS Teeth functional environment Material Flexural Strength (MPa) Fracture Toughness(MPa.m-2) Porcelains Feldspathic Leucite 60-110 120-180 1.1 1.2 Glass Ceramics Lab Cast/Cerammed premade/HIP 115-125 140-220 1.9 2.0 Alumina Alumina/Glass infilttrated spinel/glass infiltrated 400-600 325-410 3.8-5.0 2.4 Tooth Structures Dentine Enamel 16-20 65-75 2.5 1.0 Teeth functional environment subject to larger temperature variations than most other parts, coping with the cold of ice (0°C) through to hot coffee and soups. They also encounter pH changes in the range 0.5 to 8. the stresses associated with chewing where cyclic stresses may vary from 20 to about 100MPa Requirements of Dental Materials Have to be stable in the environment described above Have to be able to withstand the loads associated with chewing Aesthetics: With society becoming increasingly self conscious, any dental materials that are used in visible locations must have color and translucency as close to natural teeth as possible.

QUANTUM DOTS DYE CdSe quantum dots (QDs) are promising alternatives to organic dyes for biological labeling during long time period because of their bright fluorescence narrow emission, and high photostability. In the future, QDs could also be used as smart particles for diagnostic and therapeutic use in the body. However, concerns about the potential toxicity of Cd-containing nanoparticles are still there.

IMPROVING QUALITY OF LIFE HA is used as orbital (eye) implant to replace an eye lost to disease or injury. Tissue and blood vessels grow into the porous ceramic and as muscles become attached to the orbital implant, mobility of the implant is synchronized with that of the normal eye. Once a polymer cap with an iris and a pupil is placed over the implant, it is often difficult to discern a difference in appearance and movement between the two eyes. This new development is expected to revolutionize the treatment procedure after enucleation /evisceration surgery and rehabilitation of the anopthalmic human patients.

BIONIC EYE Macular Degeneration and Retinitis Pigmentosa: Malfunctioning of rods and cones cells (solar cells of eye) Manufacturing an artificial replacement for millions of rods and cones The first generation of artificial retinas consist of 100,000 tiny ceramic oxide microdetectors, each one twentieth the size of a human hair attached to a polymer film one millimetre by one millimetre in size. The film is designed to dissolve after a couple weeks, leaving the array in position on the retina. immediate goal is to develop a functioning artificial retina with resolution that mimics human sensors then attention can be brought to bear on colour vision replacement of some of the interconnecting neural cells that lead to the optic nerve