recent advances in testing and evaluation in prosthodontics/fixed orthodontics courses in india

RECENT ADVANCES IN TESTING AND
EVALUATION IN PROSTHODONTICS
INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

The reasonable man adapts himself to the world; the
unreasonable one persists in trying to adapt the world to
himself. Therefore all progress depends on the
unreasonable man.
George Bernard Shaw (1856 - 1950), Man and
Superman (1903) "Maxims for Revolutionists"
INTRODUCTION

The Transformation
Tensile testing machine,Model TKG 1000
Fine testing machines Miraj,India
At BVB college of engineering HUBLI
Universal Hydraulic Test Systems
LX MODEL

• Leading provider of testing equipment
• Products test mechanical properties and performance of various materials
,components and structures in a wide array of environments.
• It purchased SATEC systems in Inc in 1998
• Today it’s a brand name for instron’s hydraulically powered universal testing
machines.
• Dental applications mainly include
-Tensile and shear adhesion
-Flexural strength
-Wear testing

• Alignment error with angularity and
concentricity of the specimen can
make pure tensile and shear testing
difficult.
• The ISO 11405 and 7405 standards
seek to address this problem with
fixtures that ensure specimen
alignment during test set up.
• Instron testing fixtures meet and
exceed the requirement.
Tensile and shear adhesion
Shear adhesion fixture
Specimen preparation
accessory
Fixtures enable tensile
adhesion
of dental materials to be
evaluated

• ISO 6872 outlines to accommodate the
small specimen size a miniature bend
fixture with the ability to incorporate
different anvil diameters.
• Instron’s 3-point bend fixture is
engineered to ensure high precision of
span distances and centering.
• The unit features and include various
sized anvils with mounting in a V slot
for high anvil parallesim.
Flexure strength
Micro 3-point bend fixture for flexural tests

• Wear is an important factor in longevity of dental restorative material
• Research focuses on two main areas
1) Use of standard mastication cycle to evaluate
comparative wear on a range of dental materials
2) Identification of different wear mechanism
• Instron’s dental wear simulator can be used for both,
- comparative wear studies and
-investigation of wear mechanisms
Wear testing

• The control system coupled with flexibility of
the simulator design,opens a range of testing
opportunities for dental researchers.
• Loading profiles can be varied to simulate not
just mastication but also bruxing and clenching.
FastTrack 8872 system with
biaxial fixture enabling mastication
cycle to be simulated

• Universal material testing machine Capable of tension, compression,
flexure, peel, shear friction testing, cyclic & bend test.
1) Universal electromechanical testing systems
2) SATEC series universal hydraulic testing systems
Universal electromechanical testing systems
• an electromechanical drive supplies torque to precision ball screws ,these
screws via their rotation create very well controlled linear motion in the frame
cross head. This crosshead reacting against the base of the system creates
the force necessary for specimen testing.
• Software's used are MERLIN,and SERIES lX
Products

• Available in following models
5800 series
• Encompasses instrons highest performance control
and data acquisition electronics, highest quality load
frames and selection two fully integrated modular
software packages:
-MERLIN
-SERIES Lx

5500 series
• Features advanced digital technology and a fully integrated modular
software package(window based) to enable flexible application solutionsfor
a wide range of standard and specialized test.
• These electronics can control the frame using any combination of load,
strain, or speed rates - often a requirement for today's testing standards.
Automatic recognition and calibration of transducers ensure safe and proper
testing
• Designed to work with Merlin™, Series IX™, and Partner™ materials
testing software

User Control Panel
• Provides instant access to test functions, such as start and
stops, balance load, reset gage length, and jog
• Adjustable and convenient positioning on the system load
..Desktop5500UserPanel[1].swf frame
• Control panel buttons are designed to give tactile and visual
feedback, which allows for safer and more practical testing

3300 series
• an affordable system for quality control
and production line testing.
Micro tester
• Designed for static and dynamic
testing and performs tensile
,compression,flexure, cyclic and shear
tests on a variety of materials and also
miniature specimen.

SATEC series universal hydraulic
testing systems
• Developed for high capacity tension,
compression, flexure and shear
testing, the SATEC™ series of
universal testing machines include
some of the most rugged and durable
machines ever made.
• LX Models
New single footprint design features a
large single test space for the ultimate
in adaptability
LX Model
Lxdesign.swf

• DX Models »
New single footprint design features two test
spaces.
• kN Models
High-end universal hydraulic load frames
provide large test openings and fast speeds
for high capacity static testing .
• 5590 HVL Models
Cost effective solution for high capacity
universal testing is available in 9 models
• 5599 VTL Models »
The solution for universal testing when
loading heavy tensile specimens is critical
DX Model
Dxdesign.swf

Materials Testing Software
Instron gives us the flexibility of Windows®
based software packages for use with
its testing systems. All packages
provide:
• Automatic test control and data
collection
• Results analysis and reporting
• Support for the features of their
compatible electronic controllers

Universal Materials Testing Software
Bluehill™ Software
Fully-integrated, modular software package
providing the most powerful and flexible
materials testing package available with a
web-like interface
Series IX™ Materials Testing Software
Materials testing software that automates
tension, compression, flexure, shear, peel,
tear, and relaxation testing
Partner™ Software
For static hydraulic, electromechanical and
torsion test systems
Merlin™ Software
Fully-integrated suite of application modules for
all types of materials and component testing

Specialized Testing Software
ATA Computerized AutoTesting System
Wilson-Wolpert's hardness testing software
DYNATUP® IMPULSE™
Data acquisition & analysis software for impact
testing
FastTrack2™ Applications Suite
Advanced fatigue and sequence loading applications
Partner™ Spring Testing Software
Software designed specifically for testing springs
and spring type productswww.indiandentalacademy.com

• Contact Information:
Tara Lefave
Public Relations
One Washington Mall, 10th Floor
Boston MA 02108
USA
Phone: 617-367-0100 ext 127
E-mail: tlefave@gr2000.com
• Web site-www.instron.com
• Sriram institute for industrial research Banglore.(Instron universal testing machine model no.4505,made in U.K)
Related articles where the machine / equipment is used:
1. Barzilay I. Myers M.L. Cooper L.B. Graser H.N. “Mechanical and chemical
retention fo laboratory cured composited to metal surfaces”. J. Prosthet. Dent.
1988; 59: 131-136.
2. Caeg C. Leinfelder K.F., Lacefield W.R. Bell W. “Effectiveness of a method used
in bonding resins to metal”. J. Prosthet. Dent. 1990; 64: 37-41.
3. Fredrickson E.J. Patrick J. Stevens, Maurice L. Gress “Implant prosthodontics
clinical and laboratory procedures”. St. Louis Mosby 1995.
4. Jones R.M., Moore B.K. Goodacre C.J. Munozuiveros C.A. “Microleakage and
shear bond strength of resin and porcelain veneer bonded to cast alloys”. J.
Prosthet. Dent. 1991; 65: 221-228.
5. Appeldoorn R.E., Wilwerding T.M. and Barkmeier W.W. “Bond strength of
composite resin to porcelain with newer generation porcelain repair system”. J.
Prosthet. Dent. 1993; 70: 6-11.
6. Bailey J.H. “Porcelain-to-composite bond strengths using four organo silane
materials”. J. Prosthet. Dent. 1989; 61: 174-177.

Denture Abrasion Tester
• Denture abrading testing machine is electrically
operated and designed to simulate the masticatory
movements.
• Consists of upper and lower member to which casts
along with dentures can be attached.
• Upper member is fixed whereas the lower member
moves in an oscillatory manner at a distance of 6 mm
in either direction from the centre.
• It oscillate at the rate of 60 cycles per min.A load of 4
kg is applied on the upper member to simulate the
masticatory force during the abrasion process.
• It has a counter attached to it ,to determine the
number of cycles that are over.
Denture abrading testing machine

Upper and lower denture fixed In the denture abrading testing machine
Study done at our college to compare abrasion on various acrylic teeth set.
Dscn0753.mov

Related articles where the machine / equipment is used:
1. Armand A. Lugassay and Evan H. Greener “Abrasion resistance of some dental
materials”. J. Prosthet. Dent. 1972; 83: 157-158.
2. Ahmad S. Al-Hiyasat, William P. Saunders and George M. Smith “Three body wear
associated with three ceramics and enamel”. J. Prosthet. Dent. 1999; 82: 476-481.
3. Charles H. Gibbs “A relationship between the chewing movements and the border
movements at the first molar region”. J. Prosthet. Dent. 1981; 90: 126-130.
4. Coffey J.P. “In vitro study of the wear characteristics of natural and artificial teeth”. J.
Prosthet. Dent. 1985; 54: 273-279.
5. John C. Mitchem “The continued in vivo evaluation of the wear of the restorative
resins”. J. Am. Dent. Assoc. 1985; 111: 961-964.
6. Julian B. Woelfel “Five year cephalometric study of mandibular ridge resorption with
different posterior occlusal forms. Part I: Denture construction and initial comparison”.
J. Prosthet. Dent. 1976; 36: 602-623.
7. Louisa I. Gallegos “In vitro two body wear of three veneering resins”. J. Prosthet. Dent.
1988; 60: 172-178.
8. Richard L. Myerson “The use of porcelain and plastic teeth in opposing dentures”. J.
Prosthet. Dent. 1957; 7: 625-633.
9. Sheldon Winkler, George E. Monasky and Jason Kwok “Laboratory wear investigation
of resin posterior denture teeth”. J. Prosthet. Dent. 1992; 67: 812-814.
10. Von Fraunhofer J.A., R, Razavi and Z. Khan “Wear characteristics of high strength
denture teeth”. J. Prosthet. Dent. 1988; 59: 173-175.

Scanning electron microscope
•Uses electrons rather than light to
Form image
•Advantages
-Large depth of field
-Image of high resolution
-Preparation of sample easy
-Important tool in Dentistry for
qualitative study of surface texture
Scanning electron microscope

JEOL JFC-840A SEM at Dept of Metullargy I.I.Sc
BANGLORE

Beam's Path through the Column
The electron beam hits the
sample, producing secondary
electrons from the sample.
These electrons are collected
by a secondary detector or a
backscatter detector, converted
to a voltage, and amplified. The
amplified voltage is applied to
the grid of the CRT and causes
the intensity of the spot of light
to change. The image consists
of thousands of spots of varying
intensity on the face of a CRT
that correspond to the
topography of the sample.

• Sample Chamber
The photo on the left shows the sample chamber located at
the base of the column. The second photo shows the lens and
detectors located inside the sample chamber.

The lens that focuses the beam of electrons towards the sample is in the center
of the picture. The parts off to the right of the sample are different detectors.
One is for detecting the secondary electrons and the other is for detecting the
backscattered electrons. The operator has the power to choose and switch
detectors for use on each sample. Using the secondary electron detector
produces a clear and focused topographical image of the sample. The
backscatter electron detector produces an image that is useful when
determining the make-up of the sample. Each element in the sample appears aa
different shade, from almost white to black.
Objective Lens

Stage
• .
A prepared sample is mounted on a
specimen stub and placed on the
stage www.indiandentalacademy.com

Magnification: X 100 Magnification: X 150
Hypodermic Needle
Dentist Drill
Magnification: X 50
Repaired Porcelain-Metal surface
Magnification: X 150

SEM Photomicrograph(x500)
Of unglazed Porcelain
Of unglazed Porcelain
Of glazed Porcelainwww.indiandentalacademy.com

Environmental SEM
• The development of the ESEM has filled the longtime
desire of scientists to view specimens and
processes in their natural state.
• The ESEM allows the examination of specimens
surrounded by a gaseous environment. This means
that a specimen viewed in the microscope does not
need to be conductive and therefore does not need
to be coated with a conductive material. Even liquids
can be viewed in the microscope.

Stereomicroscope
• Stereo microscopes, also
called dissecting microscopes,
are really two
compound microscopes which
focus on the same point from
slightly different angles.
Olympus SZX7 with galilean
Optics,two independent and
Parallel zoom optical paths

Olympus STEREOMICROSCOPE
SZX7
•This allows the specimen to be
viewed in three dimensions
•Stereo microscopes are relatively low
power compared with compound
microscopes, usually below 100x

Photomicrograph of titanium
10.5x magnification before
Placing in oral cavity
Photomicrograph of titanium
10.5x magnification afterplacing
In oral cavity for 7 days and
Stained with disclosing solution
Olympus DF Plapo IX PF,Japan.
Stereomicroscope used for the
Study.
Study done at our college
To see effect of oral prophylayctic
Instrumentation on the surface
Texture of artificial crown materials

Related articles :
1. Bernard G. Gantes and Rolf Nilveus “The effect of different hygiene instruments on Titanium
surfaces: SEM observations”. Int. J. Periodont. Rest. Dent. 1991; 11: 225-239.
2. Clifford Chan and Heiner Weber “Plaque retention on teeth restored with full ceramic crowns: A
comparative study”. J. Prosthet. Dent. 1986; 56: 666-671.
3. Dennison J.B., Fan and Powers “Surface roughness of microfilled composites”. J. Am. Dent. Assoc.
1981; 102-859-862.
4. Frieda Von Giese Brookshire, Nagy, Dhuru, Ziebert and Choda “The qualitative effects of various
types of hygiene instrumentation on commercially pure titanium and titanium alloy implant
abutments: an in vitro and scanning electron microscope study”. J. Prosthet. Dent. 1997; 78: 286-
294.
5. Jerry J. Garnick and Dent “A scanning Electron Micrographical study of root surfaces and
subgingival bacterial after hand and ultrasonic instrumentation”. J. Periodontol 1989; 60: 441-447.
6. Siegrist B.E., Breex MC, Gusberti FA, Joss A. and Lang NP “In vivo early human dental plaque
formation in different supporting substances. A scanning electron microscopic and bacteriological
study”. Clin. Oral Implant Research 1991; 2: 38-46 (Abstract-Medline).
Related web sites:
• www.mos.org
• www.itg.uiuc.edu/ms/equipment/microscope
• www.caledoptical.com/microscope
• www.unitronusa.com/m_triadasp

Fluorescent Microscope
• The fluorescent microscope is used to
visualize specimens that fluoresce,
that is to say, emit light of a different
color (always a higher wavelength)
than the light absorbed by the
specimen.
• Fluorescence occurs either because
of naturally occurring fluorescent
materials in the cells (such as
chlorophyll and related molecules) or
because the cells have been stained
with a fluorochrome
Fluorescent microscopewww.indiandentalacademy.com

Sectioned specimen
(type III casting alloy,NPG
Crown) showing microleakage
Along the axial wall.
Flourescent microscope used
In the study
Study done at our college to see
Microleakage beneath full cast
Crowns, diffusion of polysaccharide
And dextran-in vitro

Related articles :
1. Anusavice K.J. “PHILLIPS’ Science of Dental Materials”. W.B. Saunders Company, 10th
Edition,
Pg.555-582.
2. Alani A.H., Toh C.G. 1997 “Detection of microleakage around dental restorations: A review”. J.
Operative Dent. 22; 173-185.
3. Graver H., Trowbridge H., Alperstein K., 1990 “Microleakage of castings cemented with Glass
Ionomer cement”. J. Operative Dent. 15: 2-9.
4. Goldman M., Laosonthorn P., White R.R., 1992 “Microleakage and the Dental pulp”. J. Endodontics,
18: 473-5.
5. Kidd EAM, 1976 “Microleakage: a review”. J. Dent. 4: 199-206.
6. Kawamura R.M. et al 1983 “Marginal seal of cast full crowns: an in vitro study”. Gen. Dent. 4: 282-
284.
7. Myers M.L. et al 1983 “Marginal leakage of contemporary luting agents. J. Prosthet. Dent. 50(4):
513-515 66: 763-766.
8. Tjan AHL et al 1980 “The effect of thermal stress on the marginal seal of cast gold full crowns”. J.
Am. Dent. Assoc. 100: 48-51.
9. Warfvinge J, Dahlen G., Bergenholtz G. 1985 “Dental pulp response to bacterial cell wall material”.
J. Dent. Res. 64: 1046-1050.
Related websites:
 www.wortburg.edu/biology/fluorescentmicroscope

Travelling Microscope
It is called a traveling microscope because the lens can move horizontally along
the base by means of a screw system. The microscope could read to 0.00025 of
an inch (0.0064mm), and was made by Abraham and Dancer of Manchester in
around 1843.
Travelling Microscope

Travelling microscope measuring the amount
Of incisal pin rise from incisal table.
•Use of travelling microscope in a
Study to evaluate the fit of
Denture bases and changes in
Vertical dimension due to rebasing

Related articles :
1. Anderson G.C., Schulte J.K. and Arnold T.G. 1988 “Dimensional stability of injection and
conventional processing of denture base acrylic resin”. J. Prosthet. Dent. 60(3): 394-398.
2. Anthony D.H. and Peyton F.A. 1959 “Evaluating dimensional accuracy of denture bases with a
modified comparator”. J. Prosthet. Dent. 9(4): 683-692.
3. Bowman J.F. and Javid N.S. 1977 “Relining and rebasing techniques”. Dent. Clin. North Am. 21:
369-379.
4. Chen J.C., Lacefield W.R. and Castelberry D.J. 1988 “Effect of denture thickness and curing cycle
on the dimensional stability of acrylic resin denture bases”. Dent. Mater. 4: 20-24.
5. Garfunkel E., 1983 “Evaluation of dimensional changes in complete dentures processed by
injection=pressing and the pack-and press technique”. J. Prosthet. Dent. 50(6): 757-761.
6. Kotwal K.R., Monotoya M.L., Charles C. 1998 “Minimizing incisal pin opening during complete
denture processing”. J. Prosthet. Dent. 60: 642-643.
7. Lechner S.K. and Lautenschlager E.P. 1984 “Processing changes in maxillary complete dentures”.
J. Prosthet. Dent. 52(1) : 20-24.
8. Mainieri E.T., Boone M.E. and Potter R.H. 1980 “Tooth movement and dimensional change of
denture base materials using two investment methods”. J. Prosthet. Dent. 44(4): 368-373.
9. Mirza F.D. 1961 “Dimensional stability of acrylic resin dentures: Clinical evaluation”. J. Prosthet.
Dent. 11: 848-857.
Related web sites:
• www.prinho.com/prod03b.html.

LASERS
• The word "laser" stands for "light
amplification by stimulated emission of
radiation
• Lasers are possible because of the way
light interacts with electrons
• Depending on the particular lasing
material being used, specific
wavelengths of light are absorbed (to
energize or excite the electrons) and
specific wavelengths are emitted (when
the electrons fall back to their initial
level).

Laser measurement with the surface profilometer
•The stylus profilometers are used to asses the surface roughness.
Solarius LaserScan surface profilometer
Complex multilayered
structures can be
precisely measured with
the LaserScan

Profilometer unit with the specimen
To asses the surface roughness
After scaling
Study was done at our college to see the
Effect of oral prophylactic instrumentation
On the surface texture of artificial crown
material

Related articles :
1. Massimo Fuzzi, Zaccheroni, Vallania “Scanning Electron Microscopy and Profilometer evaluation of
glazed and polished dental porcelain”. Int. J. Prosthodont. 1996; 9: 452-458.
2. Siegrist BE, Brecx MC, Gusberti FA, Joss A and Lang NP “In vivo early human dental plaque
formation in different supporting substances. A scanning electron microscopic and bacteriological
study”. Clin. Oral Implant Research 1991; 2: 38-46 (Abstract-Medline).
3. Quirynen M. and Bollen C.M.L. “The influence of surface roughness and surface free energy on
supra and subgingival plaque formation in man: A review of the literature”. J. Clin. Periodont. 1995;
22: 1-14.
Related web sites:
• www.photonics.com.
• www.solarius.com.
Contact information:
Solarius Laser S.A.Ul. Wynalazek6
62-677 Waszawa
Poland
Email:market@solariuslaser.com.pl

Atomic Absorption Spectrophotometer
• Atomic absorption
spectrophotometry provides
accurate quantitative analyses for
metals in water, sediments, soils
or rocks. (Samples are analyzed in
solution form, so solid samples
must be leached or dissolved prior
to analysis.)
• Atomic absorption units have four
basic parts: interchangeable
lamps that emit light with element-
specific wavelengths, a sample
aspirator, a flame or furnace
apparatus for volatilizing the
sample, and a photon detector.
Perkin Elmer 30303B Atomic
Absorption Spectrophotometer

• In order to analyze for any given element, a lamp is choosen that produces
a wavelength of light that is absorbed by that element.
• Sample solutions are aspirated into the flame. If any ions of the given
element are present in the flame, they will absorb light produced by the lamp
before it reaches the detector
• The amount of light absorbed depends on the amount of the element
present in the sample.
• Absorbance values for unknown samples are compared to calibration
curves prepared by running known samples

Atomic absorption spectrophotometer
Used for the study.(chemistry dept
Karnataka Univ Dharwad)
•Study was done at our college to
Evaluate metallic ion release in saliva
Having different pH.
•Nikel and Chromium ion release in the
Artificial saliva was estimated using
Atomic absorption spectrophotometric
analysis after 24 hr.

Contact Information:
• Department of Geology
Colgate University
13 Oak Drive
Hamilton, NY 13346
• Ph 315/228-7212
Fax 315/228-7187
rapril@mail.colgate.edu
Related articles where:
1. American Dental Association Reports. 1982 “Biological effects of nickel containing dental alloys”. J. Am. Dent.
Assoc. 104: 501-505.
2. American Dental Association Workshop, 1984 “Biocompatibility of metals in dentistry”. J. Am. Dent. Assoc., 109:
469-471.
3. Arne Hensten-Pattersen and Nils Jacobsen 1991 “Toxic effects of dental materials”. Int. Dent. J. 41: 265-273.
4. Bumgardner JD and and Lucas LC 1995 “Cellular response to metallic ions released from nickel chromium dental
alloys”. J. Dent. Res. 74(8): 1521-1527.
5. Geis-Gerstorfer and Weber H. 1987 “In vitro corrosion behavior of four Ni-Cr dental alloys in lactic acid and sodium
chloride solutions”. Dent. Mater. 3(6): 289-295.
6. Linda C Lucas and Lemons J.E. 1992 “Biodegradation of restorative metallic systems. Adv. Dent. Res. 6: 32-37.
7. Luis Blanco-Dalmau, Alberty H.C. and Parra J.S. 1984 “A study of nickel allergy”. J. Prosthet. Dent. 52(1): 116-119.
8. Svein Espevik 1978 “Corrosion of base metal alloys in vitro”. Acta-Odontol Scand. 36: 113-117.
Related websites:
 www.bucksci.com/atomic.html.
 www.thomasregister.com
 www.colgate.com

Photoelasticity
PHOTOELASTICITY ; a method of examining transparent polymer models of
structures etc. to isolate stress concentrations and other weak zones. The
model is placed between crossed circular polarizing filters (eg Polaroid
sheets) and a force applied. The technique also enables residual stress to
be shown in transparent articles .
Photoelasticity in dentistry
• When photoelastic material is subjected to force, optical properties change
in direct proportion to the stresses developed. The material becomes
“birefringent” and a colorful interference pattern is observed when polarized
light passing through the stressed material splits into two beams.

• A fringe is defined as a line
separating the red and green color
bands. A fringe order will consist
of a sequence of color bands,
including fringe line
• The zero fringe order is black and
indicates no stress. Stress can be
quantified and localized by
counting the number of fringes
and density.
• Stress can be quantified and
localized by counting the number
of fringes and density.
• The closer the fringes, the steeper
the stress gradient, indicating an
area of stress concentration
• Models are placed in polariscope
Photoelastic set-up

Study done at our college to compare the
Stress behaviour in bone around simulated
Natural tooth with PDL and two osseointegrated
Implant designs by FEA and Photoelastic
Stress analysis
al replica of first
ndibular molar fitted
thick photoelastic sheet
mulating bone,a thin silicon
bbercoated onto the tooth
t simulating PDL
Metal replica of conical
Non screw type implant
Fitted into a pre cast
Photoelastic sheet
Simulating bone.
he photoelastic bench consisting of
olariscope, load cell and a telemicroscope
Used in the study.
Fringes produced in
Photoelastic sheet apical
To the first mandibular
Molar, when it is loaded
Fringes produced in
Photoelastic sheet apical
To the first conical non-screw
Implant on loading

Two-dimensional Photoelastic Stress Analysis of Traumatized Incisor
Bulent TOPBASI,Mahir GUNDAY, Mustafa BAS, Cafer TURKMEN
• Correspondence: Dr. Bulent Topbasi, Department of Restorative Dentistry, Marmara University, Faculty of
Dentistry, Buyuk Ciftlik Sok. No: 6 80200 Nisantasi, Istanbul, Turkey. Tel: +90-212-2319120-205, Fax: +90-
212-2465247. E-mail: btopbasi@hotmail.com
• Dent Mater. 2003 Mar;19(2):106-17.
• Reflection photoelasticity: a new method for studies of clinical mechanics in prosthetic dentistry.
Fernandes CP, Glantz PO, Svensson SA, Bergmark A.
Department of Prosthetic Dentistry, Faculty of Odontology, Lund University, Malmo, Sweden.
claudiof@lab.uva.br
Related articles
1. Assif D. “Photoelastic analysis of stress transfer by endodontically treated teeth to the
supporting structure using different restorative techniques”. J. Prosthet. Dent. 1989; 61: 535-
43.
2. Craig R.G. “Experimental stress analysis of dental restorations. Part 1: 2-D photoelastic stress
analysis of inlays”. J. Prosthet. Dent. 1967; 17: 277-91.
3. Clelland N.L. “A photoelastic and strain gauge analysis of angled abutments for an implant
system”. Int. J. Oral Maxillofac. Implants 1993; 8: 541-58.
4. Deines D.N. “Photoelastic stress analysis of natural teeth and three osseointegrated implant
designs”. Int. J. Perio and Rest. Dent. 1993; 13: 540-49.
5. El-Ebrashi M.K. “Experimental stress analysis of dental restorations. Part 3: The concept of
geometry of proximal margins”. J. Prosthet. Dent. 1969; 22: 333-35.
Related web sites:
 www.ndt.net/articles.
 www.pearsoned.com. www.indiandentalacademy.com

Pressure Transducer
• A pressure transducer is a transducer that converts pressure into an analog
electrical signal.
• Although there are various types of pressure transducers, one of the most
common is the strain-gage base transducer
• The conversion of pressure into an electrical signal is achieved by the
physical deformation of strain gages which are bonded into the diaphragm
of the pressure transducer and wired into a wheatstone bridge configuration.

• Pressure applied to the pressure transducer produces a deflection of the diaphragm
which introduces strain to the gages. The strain will produce an electrical resistance
change proportional to the pressure.
Entran's family of subminiature
and miniature load cells are
among the smallest load & force
sensing devices in the world

• For use in Dentistry they are of two
types
-Strain gauges type
-Pneumatic type
Strain gauges bonded
To the mandibular
Record base
Study done in our college to determine biting force
On movement of mandibular record bases during
Jaw relation record.
Record base with bonded strain
Gauges placed in the patient’s
Mouth and connected to the digital
Power meter.
Two strain gauges connected in
Wheat stone bridge configuration

Pressure transducer with T-tubes,
Meter,pressure valve and straight
Rods attached to nylon tubes for
Recording bite force on individual
Posterior teeth of both sides.
Recording of maximum bite force on
First molar teeth of both side,attached to
PC for recording the bite force.
A Computer-aided evaluation of bite force generation between posterior teeth.
Study Done in our college.

Dent Mater. 2003 Mar;19(2):118-26.
A novel sensor for bite force determinations.
Fernandes CP, Glantz PO, Svensson SA, Bergmark A.
Department of Prosthetic Dentistry, Faculty of Odontology, Lund University, Malmo,
Sweden. claudiof@lab.uva.br
Related articles:
1. Boos R.H. “Physiologic denture technique”. J. Prosthet. Dent. 1956; 6: 726-740.
2. Dukes B.S. “An evaluation of soft tissue response following removal of ill-fitting
dentures”. J. Prosthet. Dent. 1980; 43: 251-253.
3. Edwards and Boucher C.O. “Anatomy of the mouth in relation to complete
dentures”. J. Am. Dent. Assoc. 1942; 29: 331-345.
4. Howell A.H. and Manly R.S. “An electronic strain gauge for measuring oral forces”.
J. Dent. Res. 1948; 27: 705-712.
5. Kelsey C.C., Fredrick and Reid “A method of measuring pressure against tissue
supporting functioning complete dentures”. J. Prosthet. Dent. 1976; 35: 376-383.
6. Kydd W.L. and Daly C.H. “The biologic and mechanical effects of stress on oral
mucosa”. J. Prosthet. Dent. 1982; 47: 317-329.
Related websites:
www.entran.com

Study done in or college to compare phonetic
Sound in two different pontic design of maxillary
Anterior fixed partial denture
The recordings were analyzed at Dept of speech
Pathology and audiology,NIMHANS,Banglore
Samples were transferred into a voice modulator
Device,which further transferred it into a
Spectrograph using a VAGHMI-SSL Package
Software on the computer.Recording of linguo dental sounds
Voice modulator with computer
Spectrographic illustration of
Recorded sounds
Voice Modulator

Related articles:
1. Burnett C.A. “Mandibular incisal portions for English consonant sounds”. Int. J.
Prosthodont. 1999; 12(3): 263-271.
2. Burnett C.A. and Clifford T.J. “Closest speaking space during the production of sibilant
sounds and its value in establishing the vertical dimension of occlusion”. J. Dent. Res.
1993; 72(6): 964-967.
3. Cherici G. and Lawson L. “Clinical speech considerations in prosthodontics:
Perspectives of the prosthodontist and speech pathologist”. J. Prosthet. Dent. 1973;
29(1): 29-39.
4. Kessler H.E. “Phonetics in denture construction”. J. Am. Dent. Assoc. 1957; 54: 347-
351.
5. Mehringer E.G. “The use of speech patterns as an aid in prosthodontics
reconstruction”. J. Prosthet. Dent. 1963; 13(5): 325-328.
6. Ritchie G.M. and Yusnidar T.A. “Sonographic analysis of speech sounds with varying
positions of the upper anterior teeth”. Journal of Dentistry, 1981; 10: 17-27.
7. Shaukat A.C., Karlind T.M. and Richard J.G. “Effects of immediate dentures on certain
structural and perceptual parameters of speech”. J. Prosthet. Dent. 1978; 40(1): 8-12.
8. Zitzmann N.V. and Marinello “Clinical and technical aspects of implant supported
restorations in the edentulous maxilla: the fixed partial denture design”. Int. J.
Prosthodont. 1999; 12(4): 307-312.

FINITE ELEMENT ANALYSIS
• Technique of discretizing a continuum into simple geometric shapes –
elements-enforcing material properties and governing relationships on these
elements –giving due consideration to loading and boundary conditions
which result in a set of equations, the solution of which gives the
approximate behavior of the continuum.
• With Finite Element Analysis software, the exact strength of an object may
be determined
• This information is beneficial whether you deal with high volume products
(plastic parts, motors), large scale structures (bridges, towers), or anything
in between

• FEA uses the computer to perform thousands of stress calculations that are
impossible manually
• Methodology of application of FEM
1) Pre-processing( editing
2) Processing: solution of the assembled.
3) Post-Processing: Analysis of the result.
Discretization of the given problem
Developing element properties
Imposition of boundary conditions

•
Scanned bucco-lingual section
Of putty index
Mold space based on the
Dimensions and shape obtained
From the putty index
Study done at our college to see dimensional changes in the
Mold space due to variations in temperature and its position
In the casting ring.using finite element analysis using Nastran/
Patran commercially available FEM software.
Two dimensional bucco-lingual section of
Mold space,positioned in the center of the
Casting ring
Displacement in the
Investment material
Depicted in colour coded
format
Displacement of individual
Selected nodes in x and y
Axiswww.indiandentalacademy.com

Related articles:
1. Castillo R.D., Ercoli C., Graser G.N., Tallents R.H. and Moss M.E. “Effect of ring liner and
casting ring temperature on the dimension of cast posts”. J. Prosthet. Dent. 2000; 84: 32-7.
2. Chandrupatla and Belagundu “Introduction to FEM in Engg. By – PHI Publications.
3. Curtis R.V. “Stress-strain and thermal expansion characteristics of a phosphate-bonded
investment mould material for dental superplastic forming”. J. Dent. 1998; 26(3): 251-258.
4. Daryl L. Lagan “ A first course in FEM by – 3rd
edition, Thompson Brooks/Cole-2002.
5. Earnshaw R. “The effect of casting ring liners on the potential expansion of a gypsum-
bonded investment”. J. Dent. Res. 1998; 67(11): 1366-1370.
6. Jones D.W. “Thermal analysis and stability of refractory investments”. J. Prosthet. Dent.
1967; 18(3): 235-241.
7. Soo S., Palmer R., Curtis R.V. “Measurement of the setting and thermal expansion of
dental investments used for the superplastic forming of dental implant superstructures”.
Dent. Mater. 2001; 17: 247-252.
8. Wu M., Schadlich-Stubenrauch J., Augthun M., Sahm P.R., Spiekermann H., “Computer
aided prediction and control of shrinkage porosity in titanium dental castings”. Dent. Mater.
1998; 14: 321-328.
9. Yang H.S., Lang L.A., Guckes A.D. and Felton D.A. “The effect of thermal change on
various dowel-and-core restorative materials”. J. Prosthet. Dent. 2001; 86: 74-80.
Related websites:
 www.ryan-engineering.com.
 www.hks.com
 www.lusas.com www.indiandentalacademy.com

ELECTROMYOGRAM
• An electromyogram (EMG) is a test that is used to record the electrical
activity of muscles. When muscles are active, they produce an electrical
current. This current is usually proportional to the level of the muscle
activity. An EMG is also referred to as a myogram
• EMGs can be used to detect abnormal muscle electrical activity that can
occur in many diseases and conditions, including muscular dystrophy,
inflammation of muscles, pinched nerves, peripheral nerve damage
(damage to nerves in the arms and legs), amyotrophic lateral sclerosis
(ALS) (also known as Lou Gehrig disease), myasthenia gravis.

• An EMG is most often performed when patients have unexplained muscle
weakness. The EMG helps to distinguish between muscle conditions in
which the problem begins in the muscle and muscle weakness due to nerve
disorder.
• There are two types of EMG: intramuscular EMG and surface EMG
(SEMG).
• Intramuscular EMG (the most commonly used type) involves inserting a
needle electrode through the skin into the muscle whose electrical activity is
to be measured.
• Surface EMG (SEMG) involves placing the electrodes on (not into) the skin
overlying the muscle to detect the electrical activity of the muscle.

ELECTROMYOGRAPHY for analyzing
masticatory function utilizes self-adhesive
disposable silver chloride skin electrodes.
They are usually placed bilaterally on the
skin overlying the mid-masseter, anterior
temporalis, posterior temporalis and anterior
digastirc muscles. Muscle activity is analyzed
in both rest and function, at baseline initial
readings and after relaxation therapy by
ultra-low-frequency neural stimulation.
• Surface electrodes are preferred over
needle or wire electrodes because they are
painless and non-invasive and they record
the broad range of activity of the entire
muscle
A smoothed EMG signal is shown on the screenshot

ELECTROSONOGRAPHY
• Electrosonography utilizes a pair
of vibration transducers held in
place over the temporomandibular
joints by a very lightweight
headset. Vibrations from each joint
during opening and closing of the
lower jaw are monitored by the
transducers, amplified, and input
to a computer for processing,
display and analysis. Joint sounds
can be examined for loudness,
duration, and frequencies present.
The condition of the jaw joints can
be objectively documented over
extended periods of time and their
status accurately evaluated.
Electrosonography - Recording
TMJ sounds

ELECTROKINETIC JAW TRACKING
• ELECTROKINETIC JAW TRACKING is accomplished by placing a tiny
magnet with adhesive, non-intrusively, within the lower lip vestibule beneath
the teeth when they are in occlusion.
• A sensor array is anchored around the face by an ear and nose frame that
is secured behind the head by velcro bands.
• The sensor array records incisor point movement in three dimensions by
measuring the magnetic field .
• The information is fed to a computer, which digitizes the data into such
frames of reference as sagittal, frontal, anterior, posterior, vertical, lateral,
and velocity of movementwww.indiandentalacademy.com

• Functional activities such as opening,
closing, chewing, swallowing, and rest
position can be analyzed.
Neuromuscular status such as degree
of relaxation or dysfunction can be
recorded, documented, analyzed and
saved for future comparison.
Electrokinetic Jaw Tracking

Related article:
1. Ritchie G.M. and Yusnidar T.A. “Sonographic analysis of speech sounds with
varying positions of the upper anterior teeth”. Journal of Dentistry, 1981; 10:
17-27.
2. Brown B. : Biofeed back: An exercise in “self-control”. Saturday review March
22, 1975; pp22-27.
3. Sylman Feldman, Robert J. Leupold and Leah M. Staling : Rest vertical
dimension determined by electromyography with biofeedback as compared to
conventional methods. JPD, 1978; 40(2): 216-219.
4. Krajicek D. Jones, P. Radzyminski, S. Rose D. and Unti E. :Clinical and
electromyographic study of mandibular rest position. J. Prosthet. Dent. 11:
826, 1961.
5. Shpuntoff H. and Shpuntoff W : A study of physiologic rest position and centric
position by electromyography. J. Prosthet Dent. 6: 621, 1956.
6. Thompson J.R. : The rest position of the mandible and its significance to dental
science. J. Am. Dent. Assoc. 33: 151, 1946.
7. Lytle R :Vertical relation and neuromuscular perception. J. Prosthet. Dent. 14:
12, 1964.
8. Moyers R.E. : Some physiologic considerations of centric and other jaw
relations. J. Prosthet. Dent. 6: 183, 1956.

Digital Photographic records
• A digital camera is also known as non-film camera
• Difference between a conventional
Camera and digital camera is that instead
Of light falling on photosensitive film it
Falls on a image sensor.
• Two types of sensor are there
1)CCD(charge coupled device)
2)CMOS(complementary metal-oxide
sensor)
CCD SENSOR

• A digital photograph is made up of
number of pixel.
• It is evident when we zoom in to a very
large extent.
• Digital cameras are of three common
types.
1)Point and shoot
2)Prosumer cameras
3)High end SLR cameras
1)Point and shoot 2)Prosumer cameras
3)High end SLR
cameras

DIGITAL RECORDS

Digital Image analysis
• Digital image analysis is a process of discovering ,identifying and
understanding patterns that are relevant to the performance of an image
based task. The main steps are:
a.Image acquisition
b.Image storage
c.Image processing
d.image communication
e.Image display

Study done at our college to determine colour
Changes of resin based veneering materials
On exposure to various food stains,utilizing
Digital image analysis
National M5 VHS movie camera
And pentium III computer monitor.
A close up view of the test sample
Being evaluated. www.indiandentalacademy.com

Related articles:
1. Brauer G.M. 1988 “Colour changes of composites on exposure to various energy
sources”. Dent. Mater. 4: 55-59.
2. Chan K.C., Fuller J.L., Hormati A.A. 1980: The ability of foods to stain two composite
resins”. J. Prosthet. Dent. May 43(5): 542-545.
3. Fusayama T., Hirano T., Kono A. 1971 “Discoloration test of acrylic resin fillings by an
organic dye”. J. Prosthet. Dent. 25(5): 532-539.
4. Hersek N., Canay S., Uzun G., Yildiz F., 1999 “Color stability of denture base acrylic
resins in three food colorants”. J. Prosthet. Dent. 81(4): 375-379.
5. Jain A.K. 1995 “Fundamentals of digital image processing. Prentice Hall Englewood
Cliffs, NJ.
6. Johnston W.M., Kao E.C. 1989 “Assessment of appearance match by visual
observation and clinical colorimetry”. J. Dent. Res. 68(5): 819-822.
7. Moser J.B., Wozniak W.T., Muller T.P., Moore B.K., 1978 “Use of the Munsell system
to compute color difference in composite resins”. J. Dent. Res. 57(11-12): 958-963.
8. Pratt W.K. 1991: Digital image processing recorded, 2nd
edition, New york; Wiley
Interscience.
9. Um M., Ruyter I.E. 1991 “Staining of resin-based veneering materials with coffee and
tea”. Quintessence Int. 22(5): 377-386.
10. Yeh C.L., Powers J.M., Miyazawa Y. 1982 “Color of selected shades of composites by
reflection spectrophotometry”. J. Dent. Res. 61(10): 1176-1179.

long long way to go…
The list is endless…
• Digimatic callipers
• Interpupillary measuring device
• Hounsfield tensometer
• Ion sputtering device
• Electronic torque movement key
• Cinematography
• Holography
• Electropolishing unit
• Perthometer M4P

Conclusion
The path to our destination is not always a
straight one. We go down the wrong road, we
get lost, we turn back. Maybe it doesn't matter
which road we embark on. Maybe what matters
is that we embark.
– Barbara Hall, Northern Exposure, Rosebud,
1993

THANK YOU

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