Different investigations in prosthodontics/ dental crown & bridge courses

DIFFERENTDIFFERENT
INVESTIGATIONS ININVESTIGATIONS IN
PROSTHODONTICPROSTHODONTIC
TREATMENTTREATMENT
INDIAN DENTAL ACADEMYINDIAN DENTAL ACADEMY
Leader in continuing Dental EducationLeader in continuing Dental Education
www.indiandentalacademy.comwww.indiandentalacademy.com

INTRODUCTION

CONTENTS:
EVALUATION OF DIFFERENT SYSTEMS
-CARDIOVASCULAR SYSTEM
-RESPIRATORY SYSTEM
-HEPATOBILIARY SYSTEM
-KIDNEY
-AIDS
-DIABETES
-BLOODwww.indiandentalacademy.comwww.indiandentalacademy.com

EVALUATION OF THE INTRAORAL AND
EXTRAORAL STRUCTURES:
-TMJ
-GINGIVAL INFLAMATION
-IMPLANT DENTISTRY
-SALIVARY GLAND
-ATTACHMENT APPARATUS
AND VITALITY OF TEETH
-PERIODONTAL STATUS
-COMPUTED TOMOGRAPHY
-MAGNETIC RESONANCE
IMAGING
SUMMARY AND CONCLUSIONwww.indiandentalacademy.comwww.indiandentalacademy.com

INVESTIGATIONS OF CARDIOVASCULAR
SYSTEM:
ELECTROCARDIOGRAPHY: It is used to
elucidate cardiac arrhythmias and conduction
defects, and to diagnose and localize
myocardial hypertrophy,ischaemia or infarction.
It may also give information about electrolyte
imbalance and the toxicity of certain drugs.
BASIS: Electrical activation of a heart cell
causes a depolarization of its membrane. This
depolarization is propagated along the length of
the cell/fiber and transmitted to adjoining cells.
The result is a moving wave front of
depolarization which passes through the heart.www.indiandentalacademy.comwww.indiandentalacademy.com

This sets up electric currents that can be
detected by surface electrodes amplified and
displayed in a graphic form.
EINTHOVEN’S LAW:
“If the electrical potentials of any two of the
three bipolar limb electrodes are known at any
given instant the third one can be determined
mathematically from the first two by summing
up the first two”
RADIOLOGY:
A chest radiograph is useful for:
-Determining the size and shape of the heart
-State of pulmonary blood vessels and lung
fields. www.indiandentalacademy.comwww.indiandentalacademy.com

Mostly P-A projections are preferred in full
inspiration.
A-P projection is used if the patient is non
ambulatory i.e., restricted to bed.
Lateral or oblique projections maybe useful in
detecting aortic or mitral valve calcification.
ECHO-DOPPLER ECHOCARDIOGRAPHY:
BASIS: Sound waves reflected from moving
objects such as intracardiac RBC’s undergo a
frequency shift. The speed and direction of
movement of the red cells can be detected in
the heart chambers and great walls.

INDICATIONS:
-Assessment of LV function
-Diagnosis of valve disease.
-Identification of vegetations in
endocarditis.
-Detection of pericardial effusion.
-Structural heart disease.
CT:
Useful for imaging the chambers of the heart,
the great vessels, the pericardium and the
surrounding structures.
MRI:
Generate multiple slices of the chambers and
great vessels of the heart.www.indiandentalacademy.comwww.indiandentalacademy.com

RADINUCLIDE IMAGING: Study the cardiac function
non invasively. The gamma rays are detected by
means of a planar or tomographic camera and permits
images of the heart to be reconstructed.
CORONARY ARTERY ANGIOGRAM: This provides
detailed information about the extent of coronary
artery disease.
PLASMA BIOCHEMICAL MARKERKERS:MI causes a
detectable rise in the plasma concentration of
enzymes and proteins that are normally concentrated
within cardiac cells :
Creatine Kinase,Troponin T,Troponin I,Aspartate
aminotransferase,Lactate Dehydrogenase.

INVESTIGATION OF RESPIRATORY DISEASE
IMAGING:
Chest Radiograph
-Bronchial Carcinoma
-Pulmonary Tuberculosis
-Pulmonary/mediastinal
abnormality
CT:
Determine the size and position of a pulmonary
nodule or mass and whether calcification or
cavitation was present.

VENTILATION PERFUSION IMAGING:
The main value of this technique is in the
detection of pulmonary thromboemboli.
Xe gas is inhaled in-Ventilation scan
Tc labelled albumin IV-Perfusion scan
ENDOSCOPY:
Laryngoscopy,Bronchoscopy, mediastinoscopy,
Pleural aspiration and biopsy
SKIN TESTS:
The Tuberculin Test

IMMUNOLOGIC AND SEROLOGIC TESTS:
Sputum, pleural fluid, throat swabs, blood and
bronchial washings and aspirates can be
examined for bacteria,fungi and viruses
HISTOPATHOLOGY AND CYTOLOGY:
Examination of biopsy material from
pleura,lymph node or lung often allows a tissue
diagnosis to be made .Eg.,Malignancy
LUNG FUNCTION TESTING:
Spirometry,flow volume curves, lung volumes,
arterial blood gas oximetry

INVESTIGATIONS OF THE RENAL AND
URINARY TRACT:
Tests of function:
Blood urea is a poor guide to renal function as
it varies with protein intake ,liver metabolic
capacity and renal perfusion .
Serum Creatinine is a more reliable guide
as it is produced from muscle at a constant rate
and almost completely filtered at the
glomerulus.Thus creatinine clearance provides
a reasonable approximation of the GFR.

INTRAVENOUS UROLOGY:
1st
choice for:
-Definition of the collecting system and the
ureters.
-Examining the renal papillae,stones and
urothelial malignancy.
PYELOGRAPHY:
Means direct injection of contrast medium
into the collecting system from above or below.
used to identify the cause and site of urinary
tract obstruction.
RENAL ARTERIOGRAPHY AND
VENOGRAPHY,CT,MRI RADIONUCLIDE STUDIES
AND RENAL BIOPSYwww.indiandentalacademy.comwww.indiandentalacademy.com

INVESTIGATION OF HEPATOBILIARY DISEASE
Liver Function Tests
Tests to determine the severity and activity of
liver disease.
-Biochemical Tests: Serum Albumin and
Serum Bilirubin
-Coagulation Tests
Liver Biopsy:
It can confirm the severity of liver
damage and provide etiological information
performed needle through intercoastal space
using LA.

IMAGING TECHNIQUES:
Ultrasound
CT
Cholangiography
MRI
Hepatic Arteriography

Acquired immune deficiency syndrome
The following investigations maybe carried out
in a case suspected to have AIDS:
HIV-1 Enzyme Immunoassay
ELISA
HIV-1 Western blot test
Indirect immunofluorescence Assay
Radioimmunoprecipitation Assay
Rapid Latex Agglutination Assay
Dot Immunobinding
P24 Antigen Capture Assay
DIRECT HIV DETECTION
HIV Culture
Measuring Viral nucleic acids

ELISA
BASIS: Solid phase indirect antibody detection
system using colorimetry for assessment using
a spectrometer.
USE: Used as a screening test for susceptible
individuals and in blood banks. Has high false
positive but low false negative results.
READING: The speed and intensity of the
colorimetric reaction that follows is directly
proportional to the amount of bound enzyme
and the intensity is recorded as the optical
density (OD) of the reaction mixture and iswww.indiandentalacademy.comwww.indiandentalacademy.com

quantitated by means of a spectrometer
calibrated to read at the optimal wavelength of
substrate material.
HIV-1 WESTERN BLOT TEST
BASIS: It is based on electrophoresis where the
purified viral proteins are transferred
electrophoretically to nitrocellulose paper. The
patients’ sera are reacted with these
nitrocellulose paper {Towbin et al} which gives
a colorimetric reaction for visual screening.
USE: Used as a confirmatory test. Gives low
false positive and false negative results.www.indiandentalacademy.comwww.indiandentalacademy.com

INDIRECT IMMUNOFLUORECENCE
ASSAY/RADIOIMMUNOPRECIPITATION ASSAY
These are substitutes for Western blot assay.
They require fluorescent microscope which are
not readily available.
however, they are relatively simple and require
minimum technical skill.
P24 ANTIGEN CAPTURE ASSAY:
The serum P24 antigen capture assay is used in
prognostic stratification and is useful for clinical
decision making and staging and management
of the patient. www.indiandentalacademy.comwww.indiandentalacademy.com

INVESTIGATIONS FOR DIABETES MELLITUS
URINE TESTING:
Glucose
Ketones
Proteins
BLOOD TESTING
Glucose
Glycated hemoglobin
Blood lipids
FRUCTOSAMINE TEST

Glucose
Testing urine for glucose is the usual procedure
for detecting diabetes,using sensitive glucose
specific dipstick methods. If possible testing
should be performed on urine passed 1-2 hours
after meals since this will detect more cases of
diabetes than a fasting specimen.
The greatest disadvantage of urine glucose
testing is the individual variation in renal
threshold. Apart from diabetes the most common
cause for glycosuria is a low renal threshold for
glucose which is common during pregnancy and
in young people.

In some individuals a rapid but transitory rise of
blood glucose follows a meal and the
concentration exceeds the normal threshold;
glucose will be present in the urine. This response
to oral glucose load is benign and is called
alimentary glycosuria.
KETONES:
Identified by nitroprusside reaction which is
primarily specific for acetoacetate. The test is
conviniently carried out using tablets or dipsticks
for ketones.
DIFF DIAGNOSIS: fasting, strenuous exercise,
high fat diet.

PROTEINS:
Dipstick testing for albumin is a standard
procedure to identify the presence of renal
disease in people with diabetes.
BLOOD TESTING:
GLUCOSE:
When symptoms suggest diabetes the diagnosis
may be confirmed by a random blood glucose
concentration greater than 11mmol/l. when
random blood glucose levels are elevated but are
not diagnostic of diabetes ,glucose tolerance is
usually assessed either by a fasting blood glucose
estimation or by the oral glucose tolerance test.

The diagnostic criteria for diabetes mellitus as
recommended by the WHO is follows:
GLYCATED HEMOGLOBIN:
It provides an accurate and objective measure of
glycaemic control over a period of weeks to
months.
BASIS: Several minor components of adult
hemoglobin (HbA1) are increased in diabetes by
slow non enzymatic covalent attachment of
glucose(glycation). There is a close relationship
between the glycated hemogobin and the blood
glucose levels.

HEMATOLOGY
HEMOGLOBIN(Hb)
Females :12 -16 gm/ml
Males :14 -18 gm/ml
HEMATOCRIT(HCT)
Measure of the packed red cell volume in a
volume of blood.
Females:37-47%
Males:40-52%
RED BLOOD CELL COUNT(RBC)
Females:4.5-5.5millioncells/cumm
Males:4.5-6.2millioncells/cumm

WHITE BLOOD CELL COUNT(WBC)
Normal range is 5-11,000cells/cumm
Values above and below the range are called
LEUKOCYTOSIS and LEUKOPENIA respectively.
DIFFERENTIAL WHITE CELL COUNT:
Neutrophils:50-70%
Lymphocytes-25-40%
Monocytes-3-8%
Eosinophils-1-4%
Basophils-0-1%

RED CELL INDICES
MCV:
It indicates the volume of average red cell.
MCV=HCT*10/RBC
Normal range is 82-98cumicrons
MCH:
Indicates the hemoglobin content of the
individual red cell.
MCH=Hb*10/RBC
Normal range is 27-32micromicrogm
MCHC:
Average amount of hemoglobin in 100ml of blood
MCHC=Hb*100/HCT
Normal range is 32-38gm/100ml.www.indiandentalacademy.comwww.indiandentalacademy.com

It is elevated only in hereditary spherocytosis and
reduced in microcytic anemias.
RETICULOCYTE COUNT:
They are immature erythrocytes that account for
0.5-1.5% of the red blood cells. Increased in
treatment of various anemias and blood loss.
SEDIMENTATION RATE:
Females:0-20mm/hr
Males:0-10mm/hr
It is a non specific test and rise in ER indicates
infections, infarctions, trauma or tumor.
COAGULATION TESTS:

PROTHROMBIN TIME:
Normal range:11-15sec
It is prolonged in factor I,II,V,VII and X
deficiencies and occurs with anticoagulant
therapy, cirrhosis, hepatitis, obstructive jaundice,
colitis and salicylate therapy.
PARTIAL THROMBOPLASTIN TIME:
Normal value:25-40 sec
It is prolonged in factor VIII,IX,XI,XII,I,II and X
deficiencies and also in heparin therapy.
However with patients on anticoagulant therapy,
a more reliable test the INR is used.

INTERNATIONAL NORMALIZED RATIO:
Due to the availability of differing
thromboplastins the WHO(’78) recommended
that the PT be standardized.It is calculated as:
INR=(PT/mean normal PT)ISI
As a result the INR is essentially the same
regardless of which thromboplastin a particular
lab uses .
If INR<3 Surgery is safe
If INR<4 Consider surgery
If INR>4 Avoid surgery

SEQUENTIAL MULTIPLE ANALYSER-12
It is a biochemical survey of 12 blood
constituents that help in screening patients for a
variety of diseases. Some of the important values
are as follows;
TOTAL PROTEIN:
Normal value:8-11mg/100ml
ALBUMIN:
Normal value:3.5-5gm/100ml
Increased in dehydration
Decreased in kidney diseases,liver diseases and
GIT diseases.

CALCIUM :
Normal value:8.5-10.5mg/100ml
Increased in hyperparathyroidism and malignancy
with bone metastasis.
Decreased in hypoparathyroidism,
pseudohypoparthyroidism, tetany,
hypoalbumibaemia, acute pancreatitis, renal
failure and starvation.
PHOSPHORUS:
Normal value:2.5-4.5mg/100ml
CHOLESTROL:
Normal value:150-300mg/100ml
Increased in idiopathic and secondary
hypercholestrolemia…
nephrosis,diabetes,hypothyroidism.www.indiandentalacademy.comwww.indiandentalacademy.com

URIC ACID
Normal value:2.5-8mg/100ml
Increased in gout,renal
failure,leukemia,lymphomaetc.
Decreased with the use of uricosuric
drugs,Wilson’s disease
ALKALINE PHOSPHATASE:
NORMAL VALUE:1.5-4.5 Bodansky units
Increased in hepatic obstruction,increased
osteoblastic activity eg.,Paget’s
disease,hyperparathyroidism,tumors of bone
Decreased in hypophosphatasia,hypothyroidism
and malnutrition.

LACTATE DEHYDROGENASE(LDH):
Normal value:90-200mU/ml
Increased in MI, pulmonary embolus, pulmonary
infarction.
SERUM GLUTAMIC OXALOACETIC
TRANSAMINASE(SGOT):
Normal value:10-50mU/ml
Increased in MI, hepatitis
SERUM PYRUVIC TRANSAMINASE(SGPT):
Normal value:6-36mU/l.
Increased in liver damage severely and in heart
damage mildly.

ACID PHOSPHATASE:
Normal value:0.5-11mU/ml
Increased in carcinoma prostate.
AMYLASE:
Normal value:60-150 Somogyi Units,
Increased in diseases of the pancreas,salivary
gland disease.
CREATINE PHOSPHOKINASE(CPK):
Normal value:5-50I mU/ml.
Increased in MI,cerebral infarction,malignant
hyperthermia.

URINALYSIS
Normal urine is straw to amber in color, clear in
appearance, has a faint aromatic odor with a
specific gravity of 1.010 and pH of 4.8-7.5.
Urine is tested for proteins, glucose, ketone,
hemoglobin, bilirubin, Bence-Jones protein.
Microscopic examination is done for WBC,RBC,
Epithelial cells, Casts and Crystals.

THE TEMPOROMANDIBULAR JOINT
The following investigations are of interest:
Plain radiography
Conventional tomography
Computed tomography
MRI
Arthrography
Arthroscopy
electromyography

PLAIN RADIOGRAPHY
Three types:
1.O.P.G
2.Transcranial View
3.Transorbital View
LIMITATIONS:
-Very limited aspect of the joint is exposed in
the radiograph
-30-60% change in the bone deposition to be
visible in the radiograph
-these lead to under diagnosis of the joint
pathology.

SOME RADIOGRAPHIC AND CT FINDINGS IN
THE TMJ:
Haziness of the joint space-Acute
inflammation of the joint
Posterosuperior displacement of the condylar
head-impingement over the posterior wall of
fossa.
Restricted movement of the condyle-
uni/bilateral muscular spasm or beginning of
ankylosis.
Erosion/enlargement/hyper mobility of the
condyle-Osteoarthritis/chronic
arthritis/subluxation respectively.

CONVENTIONAL TOMOGRAPHY:
-superior to radiography as they depict a
greater portion of the joint.
-Provide a series of sectional radiographs which
reproduce changes in the central portion of the
joint.
-It can detect only established lesions.
-Radiation dose to the joint is high
-Cost is high.
COMPUTED TOMOGRAPHY:
-Provides images without the superimpositions
inherent in the conventional tomography.
-Permits multiple plane reconstructions
-Expense and radiation is higher .www.indiandentalacademy.comwww.indiandentalacademy.com

ARTHROGRAPHY:Injecting a water soluble,
iodine containing material into the lower joint
space .
-Used to confirm perforations, adhesions or
fragmentation of the meniscus.
-Limitations……Invasiveness technical difficulty.
MRI:
-It is the technique of choice to detect disc
abnormalities.
-No radiation,non invasive technique.
-Medial, lateral displacements.

ARTHROSCOPY:
Latest method that permits examination of the
interior of the joint with the help of fiber optic
telescope. It is limited to the upper joint space.
ELECTROMYOGRAPHY:
Provides an objective means of monitoring
changes in the muscle activity. This is very
valuable in diagnosing MFDS.

CLINICAL EVALUATION OF GINGIVAL
INFLAMMATION:
Clinical evaluation of the degree of gingival
inflammation includes the assessment of the
redness and swelling of the gingiva along with
assessment of gingival bleeding.
Gingival bleeding is a more sensitive clinical
indicator of early gingival inflammation and also
it is more objective as colour changes require a
subjective evaluation.
Another method to assess the degree of
gingival inflammation by measurement of the
gingival crevicular fluid flow.

Techniques:
Intrasulcular Method
Extrasulcular Method
Absorbing paper strips
Twisted threads
Micropipettes
Inracrevicular washings
In the Brill Technique the paper is placed into
the pocket until resistance is encountered.
AMOUNT:The amount of fluid can be measured
by substracting the weights of the paper or
thread before and after placement in the
pocket. www.indiandentalacademy.comwww.indiandentalacademy.com

An electronic method has been developed for
measuring the fluid collected on a blotter
{Periopaper} employing an electronic tranducer
{Periotron}
Mean crevicular fluid volume in proximal spaces
from molar teeth range from 0.43to 1.56 micro
liters.

DIAGNOSIS OF DENTAL CARIES
The ideal caries diagnostic test must be:
Accurate
Sensitive
Specific
Reproducible
Reliable
Not transfer S.mutans or other bacteria from
affected area to unaffected areas.
Cost effective

1.CLINICAL METHOD:
Greene Verdiman Black in 1924 suggested the
use of a sharp explorer. If there was a catch
then the surface was counted as being
decayed.
THE USE OF MIRROR AND SHARP PROBE:
Most common method. Sticky fissures may not
be carious.
A MIRROR AND A BLUNT PROBE
EXAMINATION:
The blunt probe is used to remove the plaque
and debris ant the mirror is used to visually
examine the fissure for decay.

2.RADIOGRAPHIC METHOD:
Bite wing radiographs are used for detection of
interproximal caries. Today bite wing
radiographs are also used for detection of
hidden occlusal dentine lesions.
3.TOOTH SEPERATION:
Orthodontic modules or bands are used to
achieve seperation and caries is detected
visually or by taking impressions of the
approximal surfaces.

3.VISIBLE LUMINESCENT SPECTROSCOPY:
The visible emission spectra fluorescent
lifetimes for decayed and non decayed regions
of teeth differ. Quasi monochromatic light from
a tungsten source disperesed with a grating
monochromator was focussed on the teeth.
This is a non radiological non invasive clinical
method to detect dental caries.
4.FLUORESCENCE:
Acid dissolution of structures results in local
decrease in fluorescence in area of acid
exposure. This has been used to detect dental
caries.

5.CARIES DETECTOR DYES:
Silver nitrate,methyl red , alizarin stain have
been used to detect carious sites by change of
colour. The altered areas have more reactive
calcium that reacts with carboxylic and sulfonic
acid groups of dyes.
6.XERORADIOGRAPHY:
These demonstrate a broader latitude of
enhancement called “edge exposure”. Due to
these small structures and areas of subtle
density differences are made more visible. This
offers convenience, reduction in radiation dose
and is economical too.

6.ULTRA SOUND:
Uses a sonar device in which a beam of
ultrasound waves is directed against the tooth
surface and if reflected is picked up by an
appropriate receiver. It cannot be used where
access is limited like interproximal areas.
7.DIAGNODENT:
It enables to recognize at an early stage
pathological changes that prove difficult or
even impossible to detect initial
lesions,demineralization changes affecting the
tooth enamel. The incidence of
fissure,approximal and residual caries can be
identified.

A laser diode provides pulsed light of a defined
wavelength that is directed onto the tooth.
When the incident light meets a change in
tooth substance it stimulates fluorescent light
of a different wavelength. This is translated
through the hand piece into an acoustic signal
and the wavelength is then evaluated by an
appropriate electronic system in the
Diagnodent control unit.

INVESTIGATIONS FOR IMPLANT DENTISTRY
1.RIDGE MAPPING:
This determines the labio lingual width of the
bone which is the recipient site of an
osseointegrated implant. The periapical
radiographs are adequate for determining the
ridge height and for developing a general
assessment of bone health and quality.
Adjacent teeth provide guidance for
establishing the emergence profile of a fixture.
2.PERIAPICAL RADIOGRAPH:
Exposures must be made with a collimated
beam, a long target to film distance and a
paralleling technique.www.indiandentalacademy.comwww.indiandentalacademy.com

3.OCCLUSAL FILMS:
Are sometimes used in the set up for CT
examinations in the mandible. Data from these
images are used to map the areas to be
scanned and to measure the distance between
teeth or distance along the ridge.
4.LATERAL CEPHALOMETRIC IMAGES:
Measures the labiolingual dimensions of
alveolar crests and also the alveolar height.
5.PANORAMIC RADIOGRAPHY:
It is used in conjunction with ridge mapping
and other diagnostic aids and not as a primary
imaging test for implant planning.

6.COMPUTED TOMOGRAPHY:
It normally images the entire arch and
produces 50 to 60 images at defined locations
in addition to panoramic, axial and other views.
Only CT can offer “life size” images so that
precise measurement can be made.
Newer imaging modalities like “ tuned aperture
computed radiography” have been developed to
improve the quality and accuracy of the image
by eliminating or minimizing overlapping and
distortion related to patient movement.

DIAGNOSTIC APPROACH TO THE PATIENT
WITH SALIVARY GLAND DISEASE:
SALIVAR GLAND IMAGING:
Ultrasonography
Sialography
Radionuclide imaging
Computed tomography
Magnetic resonance imaging
SALIVA COLLECTION:
WHOLE SALIVA:
Whole saliva is the mixed fluid content in the
mouth. Method of collection whole saliva are:
-

-Draining
-Spitting
-Suction
-Absorbent(swab) method
The draining method is passive and requires
the patient to allow saliva to flow from the mouth
into a pre weighted test tube or graduated
cylinder for a time period.
In the spiting method, the patient allows
saliva to accumulate in the mouth and then
expectorates into a pre weighed graduated
cylinder every 60 seconds for 5 minute4s.
The suction method uses an aspirator to
draw saliva from the mouth into a test tube for a
definite time period.www.indiandentalacademy.comwww.indiandentalacademy.com

The absorbent method uses pre weighed gauze
sponge in patient’s mouth for a set amount of
time.
-Unstimulated whole saliva rates of <0.1 mL/min
-Stimulated whole saliva rates of <1.0 mL/min
These rates are considered abnormally low and
indicative of marked salivary hypo function.
Stimulated saliva from individual glands is
obtained by applying a sialagogue such as citric
acid to the dorsal surface of the tongue.
Of the above methods,unstimulated whole saliva
collection is the most valuable method of
assessing salivary gland function.

METHODS TO INVESTIGATE THE ATTACHMENT
APPARATUS AND VITALITY OF TEETH
MOBILITY-DEPRESSIBILITY TESTING:
1ST
Degree Mobility: Noticeable movement of the
tooth in the socket
2ND
Degree Mobility: Movement of a tooth within
a range of 1 mm.
3RD
Degree Mobility: Movement greater than
1mm or when the tooth can be depressed.

ELECTRIC PULP TESTING:
Although pulp vitality is dependent on intra
pulpal blood circulation, no practical clinical test
has been devised to test circulation. The electric
tester, uses nerve stimulation instead. The
objective is to stimulate a pulpal response by
subjecting a tooth to an increasing degree of
electric current. A positive response is an
indication of pulp vitality and helps in determining
the normality or abnormality of the pulp. No
response can be an indication of pulp necrosis.
The pulp tester cannot be solely depended on
for testing the pulp vitality. For example a false
positive response can occur when moist
gangrenous pulp is present in a canal.

Another cause of confusion can occur in
multirooted teeth in which the pulp is partially
necrotic, with some nerve fibers still vital in one
or more of the root canals.
A false negative result can occur in:
Calcification
Extensive restorations
Pulp protecting base
Recently traumatized teeth recently erupted
teeth with incomplete root formation
Sedative medication taken by the patient
Patients with an unusually high pain threshold.

THERMAL TESTING:
These involve the application of cold and heat to
a tooth , to determine sensitivity to thermal
changes. A response to cold indicates a vital pulp
regardless whether the pulp is normal or
abnormal. A heat test is not a test of pulp vitality.
An abnormal response to heat usually indicates
the presence of a pulpal or periapical disorder
requiring endodontic treatment.
ANESTHETIC TESTING
TEST CAVITY

INVESTIGATIONS OF THE PERIODONTAL STATUS
OF THE TEETH:
DETECTION OF POCKETS:
Exploration with a periodontal probe. The probe
end should be inserted parallel to the vertical axis
of the tooth and walked circumferentially around
each surface of each tooth to detect the areas of
deepest penetration. Care should be taken to
detect interdental craters and furca.
Probing force of 0.75N have been found to be
well tolerated and accurate.
Gutta percha points or caliberated silver points
can be used with the radiograph to assist in
determining the level of attachment of pockets.

AMOUNT OF ATTACHED GINGIVA:
It is the distance between the mucogingival
junction and the projection on the external
surface of the bottom of the gingival sulcus or
periodontal pocket.
USE OF CLINICAL INDICES IN DENTAL
PRACTICE:

CONVENTIONAL TOMOGRAPHY:
Is a process by which an image of a layer within
the body is produced while the images of
structures above and below that layer are made
invisible by blurring.
This blurring is accompanied by the
simultaneous movement of the X-ray tube and
film during the exposure. The X-ray tube and the
film can move synchronously in a variety of
parallel and non parallel but opposite directions.
The blurring of objects outside a focal plane
is accomplished most effectively by compound
movements and least by linear movements.
USE:TMJ and other facial structures.

COMPUTED AXIAL TOMOGRAPHY
PRINCIPLE (RADONM,1917): “An image of a 3-D
structure could be created using an infinite set of
all its two dimensional projections”
CT scanners produce digital data measuring
the extent of X-ray transmission through an
object. This numeric al information may be
transformed into a density scale and used to
generate or reconstruct a visual image.
It consists of:
The Gantry
The Computer
The Operating Console

DENTAL APPLICATIONS
Pathologic Processes:
Identify pathology allows 3-D reconstruction to
assist in treatment planning. Has the ability to
identify low contrast structures. Eg.,blood vs.
solid tissue, cyst vs. tumor.
Paranasal Sinuses:
It is effective in imaging bony and reactive or
neoplastic soft tissue changes that can occur in
the sinuses.
Assessment of trauma:
Image of fractures without the potential
complications associated with extremes of head
position. 3-D images can be constructed in
axial,coronal or sagittal orientations.www.indiandentalacademy.comwww.indiandentalacademy.com

Implant: Used to improve greatly the
pretreatment assessment of intraosseus implant
sites. CT makes it possible to reformat the
original data into a number of new configurations.

MAGNETIC RESONANCE IMAGING
BASIS: It detects the presence of hydrogen
nuclei in the body through their resonance in a
powerful magnetic field which aligns the nuclei
along the field. Once the radio waves are turned
off the hydrogen nuclei will return to their
preferred alignment with the magnetic field and
give off multiple signals of their own.
MRI is the process of locating these individual
signals in 3-D and creating a image from their
relative signal intensities.
DISADVANTAGES: Long scan time
Pacemaker, insulin pumps may get damaged
It is very costly for the patient.

SUMMARY AND CONCLUSION

REFERENCES
1. Malcolm A. Lynch “Burkets Oral medicine”, 9th
edition.
2. Vincent T. Devita “AIDS Etiology, Diagnosis, Treatment
and Prevention”. 4th
edition.
3. Choudhary “Concise medical physiology”. 2nd
edition.
4. Guyton and Hall “Textbook of medical physiology”. 9th
edition.
5. S.G. Damle “Pediatric Dentistry”. 1st
edition.
6. Vinod Kapoor “Textbook of Oral & Maxillofacial surgery”.
1st
edition.
7. Grossman “Endodontic Practice”. 11th
edition.
8. Goaz White “Oral Radiology – Principles and
interpretation”.
9. DCNA “Applications of digital imaging modalities for
dentistry”. April 2000.www.indiandentalacademy.comwww.indiandentalacademy.com

10. DCNA “Temporomandibular disorders and Orofacial pain”.
Jan 1991.
11. DCNA “Cariology”, Oct 1999.
12. DCNA “Dental implants”. Jan 1998.
13. Davidson “Principles and practice of Medicine”. 19th
edition.
14. Bouchers “Prosthodontic treatment for edentulous patient.
9th
edition.
15. Carranza Newman “Clinical periodontology”. 8th
edition.
16. McCracken’s “Removable partial prosthodontics”. 9th
edition.
17. Daniel M. Laskin “Oral and Maxillofacial Surgery”. Vol. 1, 1st
edition.
18. R. Anant Narayan “Textbook of Microbiology”. 1st
edition.

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