Biomedical Engineering Reference
In-Depth Information
FIGURE 21.1
TEM demonstrating exfoliation of organoclay nanoparticles (dark aggregates) in a monomer matrix
(100,000
magnification (50 nm scale)).
3
have already found applications in reinforced composites where there is a need for high-strength
and light-weight materials
[16]
. The smaller diameters and larger aspect ratios found for CNTs
is expected to lead to even higher strength composites. Recently, CNTs have been incorporated
into methyl methacrylate-based resins and found to substantially enhance their load-bearing
mechanical characteristics
[17]
. These studies suggest that the addition of CNTs in dental
implant materials will prevent fatigue and failure caused by forces in the oral cavity and extend
the life of dental restorations.
Another application of nanotechnology gaining significant interest is the use of nanoscaffolds for
pulp regeneration. At the nanolevel, these scaffolds may eventually prove to be applicable to therapies
ranging from pulp capping to complete pulp-dentin complex regeneration. This chapter aims to review
these uses of nanotechnology for current and future clinical applications in endodontics.
21.2
Clinical applications
21.2.1
Instrument modifications
Rotary instruments, especially those made of nickel
titanium (Ni
Ti) alloys, are widely used by
clinicians in everyday dental practice. Ni
Ti alloys possess many favorable characteristics such as
resistance against corrosion and more importantly super-elasticity and excellent shape memory that
allow it to navigate complex root canal systems for proper cleaning and shaping
[18]
. Despite these
favorable characteristics of rotary Ni
Ti alloys occur
leading to possible intracanal instrument fracture. Although a disarticulated instrument in the canal
may not directly result in failure of the endodontic procedure, the inability to clean beyond the frac-
tured instrument (
Figure 21.2
) may result
Ti instruments, fatigue and failure of Ni
in persistent endodontic disease requiring surgical
