This document discusses the various applications of Fourier transform infrared (FTIR) spectroscopy in medicine and dentistry. It begins by describing how FTIR is used to identify functional groups and elucidate molecular structures through analysis of absorption peaks. It then explains how FTIR can be used to identify substances, study the progress of chemical reactions, detect impurities, and enable quantitative analysis. The document also discusses applications of FTIR in analyzing human tissues and biofluids to diagnose diseases and cancers. It provides examples of FTIR analysis of human hair and teeth. In conclusion, FTIR spectroscopy is presented as a valuable clinical tool for analyzing biomolecular changes in tissues and assessing factors like degree of conversion in dental composites

1. Application
FTIR in
Medicine and
Dentistry
Prof.Dr. Amer A. Taqa
University of Mosul, College of Dentistry
DBS. Department

2. • Infrared spectroscopy is widely used in industry as
well as in research. It is a simple and reliable
technique for measurement, quality control and
dynamic measurement. It is also employed in
forensic analysis in civil and criminal analysis.
• Some of the major applications of IR spectroscopy
are as follows:

3. Identification of functional group and structure
elucidation
• Entire IR region is divided into group frequency
region and fingerprint region. Range of group
frequency is 4000-1500 cm-1 while that of finger print
region is 1500-400 cm-1.
• In group frequency region, the peaks
corresponding to different functional groups can be
observed. According to corresponding peaks,
functional group can be determined.
• Each atom of the molecule is connected by bond
and each bond requires different IR region so
characteristic peaks are observed. This region of IR
spectrum is called as finger print region of the
molecule. It can be determined by characteristic
peaks.

4. Identification of substances
• IR spectroscopy is used to establish whether a given
sample of an organic substance is identical with
another or not. This is because large number of
absorption bands is observed in the IR spectra of
organic molecules and the probability that any two
compounds will produce identical spectra is almost
zero. So if two compounds have identical IR spectra
then both of them must be samples of the same
substances.
• IR spectra of two enatiomeric compound are
identical. So IR spectroscopy fails to distinguish
between enantiomers.

5. • For example, an IR spectrum of benzaldehyde is
observed as follows.
• C-H stretching of aromatic ring- 3080 cm-1
• C-H stretching of aldehyde- 2860 cm-1 and 2775 cm-
1
• C=O stretching of an aromatic aldehyde- 1700 cm-1
• C=C stretching of an aromatic ring- 1595 cm-1
• C-H bending- 745 cm-1 and 685 cm-1
• No other compound then benzaldehyde produces
same IR spectra as shown above.

6. Studying the progress of
the reaction
• Progress of chemical reaction can be determined
by examining the small portion of the reaction
mixture withdrawn from time to time. The rate of
disappearance of a characteristic absorption band
of the reactant group and/or the rate of
appearance of the characteristic absorption band
of the product group due to formation of product is
observed.

7. Detection of impurities
• IR spectrum of the test sample to be determined is
compared with the standard compound. If any
additional peaks are observed in the IR spectrum,
then it is due to impurities present in the compound.

8. Quantitative analysis
• The quantity of the substance can be determined
either in pure form or as a mixture of two or more
compounds. In this, characteristic peak
corresponding to the drug substance is chosen and
log I0/It of peaks for standard and test sample is
compared. This is called base line technique to
determine the quantity of the substance.

9. • Due to its sensitivity to the chemical information and
strcture of the molecule, infrared spectroscopy can
play an important role in new applications such as
in
• the life-science field and not only in the traditional
fields of physics and chemistry.
• Spectroscopic techniques are simple, reproducible,
non-destructive without particular sample
preparation. As a result, they provide information for
the functional groups, bonds and molecular
structure.

10. • In 1949 Blout, Mellors and Woernley in 1952 reported
that infrared spectra of human and animal tissues
could provide information on the molecular
structure of tissues. These studies met with limited
success due to non-developed instrumentation
available and little knowledge of spectroscopic
properties of biological molecules and the
complexity of the
• samples.

11. • The rapid experimental and theoretical
development took place in 1970s, where Fourier
Transform interferometers interfaced to digital
computers.
• According to a wide range of studies, it has been
proved that FT-IR spectroscopy has been a
significant clinical technique, which provides
detailed information of the chemical components
of the tissues (proteins, lipids, carbohydrates, DNA).
By analyzing chemical and biochemical changes,
specific spectral features are to be considered for a
diagnostic evaluation.

15. Difference IR spectrum of two healthy
patients is very small
0
.2
.4
.6
.8
1
1.2
1.4Absorbance
1750 1700 1650 1600 1550 1500 1450
Wavenumber (cm-1
)
difference

16. Spectral deviations between “healthy” and “ill”
patients, exhibiting different RIAR values
-.15
-.1
-.05
0
.05
.1
.15
.2
Arbitrary
1700 1600 1500 1400 1300 1200 1100 1000 900
Wavenumber(cm-1
)
1550 RIAR
720 RIAR
20 RIAR
-.15
-.1
-.05
0
.05
.1
.15
.2
1600 1500 1400 1300 1200 1100 1000 900

17. Distribution between different types of diseases of 820 “ill”
patients measured by FTIR spectra of their skin
820 personsTotal
(5%)40 personsAllergy
(8%)67 personsDiabetes
(9%)74 personsLesions of nervous system
(10%)82 personsDiseases of gastrointestinal segments
(33%)270 personsCancerous diseases
(35%)287 personsDiseases of cardiovascular system
820 personsTotal
(5%)40 personsAllergy
(8%)67 personsDiabetes
(9%)74 personsLesions of nervous system
(10%)82 personsDiseases of gastrointestinal segments
(33%)270 personsCancerous diseases
(35%)287 personsDiseases of cardiovascular system

18. Comparison of human hair infrared spectra of a healthy (lower trace,
full line) and a breast cancer patient (upper trace, dashed line)
1800 1700 1600 1500 1400 1300 1200 1100 1000 900
Wavenumber(cm-1)
Absorbance
0.5 A.U.

19. In pharmaceutical

22. In biological

24. In Dentistry

25. Infrared Spectroscopic Identication of Chosen Dental Materials
and Natural Teeth

31. INFRARED SPECTROSCOPY: A TOOL FOR DETERMINATION OF THE
DEGREE OF CONVERSION IN DENTAL COMPOSITES

32. References
• Ajaj 2013, 2:9
http://www.progressbiomaterials.com/content/2/1/
9
• Vasiliki Dritsa FT-IR Spectroscopy in
Medicine,National Technical University of Athens,
NTUA
• Greece
• Luciene Gonçalves Palmeira MORAES1,, Renata
Sanches Ferreira ROCHA1,, Lívia Maluf
MENEGAZZO1,,Eudes Borges de ARAÚJO2,, Keizo
YUKIMITU2
• , João Carlos Silos MORAES3J Appl Oral Sci.
2008;16(2):145-9
• Michael C. Martin,Advanced Light Source Division

33. Thanks for
your attention!