BIOMATERIAL APPLICATIONS - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 528

TABLE 15.1. Orthopedic Biomaterials and Their Primary Uses

Material Primary use(s)

Metals

Ti alloy (Ti - 6%Al - 4%V), Co - Cr - Mo
alloy, Stainless steel

Bone plates, screws, TJA components,
screws, cabling

Polymers

Poly(methyl methacrylate) (PMMA),
Ultrahigh- molecular weight
polyethylene (UHMWPE), PLA,
PLGA, HA/PLGA, PCL

Bone cement, low friction inserts for bearing
surface in TJA, bone tissue engineering
scaffolds, bone screws

Ceramics

Alumina (Al 2 O 3 ), Zirconia (ZrO 2 ) Bearing surface TJA components, Hip joints

(Figure 15.2), coating on bioimplants, bone
fi ller, alveolar ridge augmentation

Composites

HA/collagen, HA/gelatin, HA/PLGA,
PLGA

Bone graft substitutes and tissue
engineering scaffolds

uses are listed in Table 15.1. These materials are generally used for either fracture
fi xation or joint replacement. More specifi c orthopedic applications within these
two categories are listed below.

• Fracture fi xation devices: spinal fi xation devices, fracture plates, wires, pins
and screws, intramedullary devices and artifi cial ligaments.
• Joint replacement: hip, knee, ankle, shoulder and other joint arthroplasty.

15.3.4 Dental Implantation
A dental implant is an artifi cial tooth root replacement and is used in prosthetic
dentistry to support restorations that resemble a tooth or group of teeth. There
are several types of dental implants; the most widely accepted and successful is
the osseointegrated implant, based on titanium that can be successfully fused into
bone, when osteoblasts grow on and into the rough surface of the implanted tita-
nium. This forms a structural and functional connection between the living bone
and the implant. Variations on the implant procedure are the implant-supported
bridge or implant-supported denture.
Three basic types of synthetic materials have been used for fabricating endos-
seous dental implants. These are metals and metal alloys, ceramics and carbons,
and polymers. Metals and metal alloys, used for clinical and experimental implants,
have included titanium and titanium alloys, tantalum, stainless steel, cobalt-
chromium alloys, gold alloys, and zirconium alloys, among others. These materials
are selected based on their high corrosion resistance, strength, rigidity, ease of
shaping and machining, and suitability for a wide range of sterilization techniques.
Although the mechanisms that lead to osseointegration with titanium implants