3. INTRODUCTION
Investigations are an extension of the physical examination in which tissue,
blood, other specimens are obtained from the patient and subjected to
microscopic, biochemical, microbiological or immunologic examination
3
4. TYPES OF INVESTIGATIONS IN ORAL
DISEASES
4
CHAIR SIDE INVESTIGATIONS LABORATORY TESTS
1. Pulp vitality tests 1. Biopsy
2. Diagnosis of tooth fracture 2. Haemotology test
3. Plaque disclosing agents 3. Biochemistry test
4. Caries detection 4. Microbiology test
5. Diagnostics in early detection of pre-cancerous lesion 5. Serological test
6. Exfoliative cytology, Fine needle aspiration
7. Salivary flow test
8. Diascopy test
9. Diagnostic nerve block
10. Culture and sensitivity test
6. Pulp Vitality tests
These are widely used as diagnostic aids in assessing the status of the
pulp.
USES:
Prior to operative procedures when pulp health may be in question
To check if the orofacial pain is from teeth or not
Post trauma assessment of pulp
Assessment of anesthesia
Assessment of teeth which have been pulp capped or which require deep
restorations
6
7. DISADVANTAGES
Test may be difficult to use on
posterior teeth because of limited
access
Excessive heating may result in pulpal
damage.
FALSE POSITIVE RESPONSE
Excessive calcification.
Recent trauma.
Patients taking premedication.
Immature apex.
7
8. Different methods of pulp testing 8
Conventional methods
Thermal pulp test
Electrical pulp test
Test cavity
Anaesthetic test
Advanced method
Laser Doppler flowmetry (LDF)
Pulp oximetry
Dual wavelength spectrophotometry
Hughes probeye camera
Transillumination with fibreoptic light
Plethysmography
9. 1. Thermal pulp tests
One of the most common symptom associated with a symptomatic
inflamed pulp is pain elicited by thermal stimulation.
These are two types:
Cold test
Heat test
9
10. Cold test 10
Mechanism
Cold thermal testing causes contraction of the dentinal fluids within the dentinal tubules
Resulting in rapid outward flow of fluid within the parent tubules
The rapid movement of dental fluid results in ‘hydrodynamic forces’ acting on the A
delta nerve fibres within the pulp-dentin complex
Leading to sharp sensation lasting for the duration of the thermal test
11. Methods of cold test 11
Ice sticks Wrap a slice of ice in a wet gauze & place it against the buccal surface of the test
tooth while comparing the reaction with the control tooth.
Pencils of ice can also be used.
CO2 snow/ dry ice B.P: -72degree C
A solid stick of CO2 gas through a custom made plastic cylinder applied to the
buccal surface of the teeth.
Used mostly in cases where a tooth has a full coverage metallic restoration.
Various compressed gases Ethyl chloride (B.P -41 degree C) sprayed on cotton pledget which forms ice
crystals and applied to the tooth.
Dichlorodifluoromethane (DDM) (B.P -0degree C)
Ice-cold water Tooth under investigation isolated by rubber dam and bathed with water from a
syringe
12. Heat test 12
Mechanism
Heat testing causes expansion of dentinal tubules
Resulting in rapid inward flow of fluid within the patent tubules
The rapid movement of dentinal fluids results in ‘hydrodynamic forces’ acting on the A delta nerve
fibres within the pulp-dentin complex
Leading to sharp sensation lasting for the duration of the thermal test
13. Methods of heat test 13
Warm sticks of
temporary stopping
• Gutta percha stick is used.
• The teeth to be tested are coated with petroleum jelly to prevent sticking of GP to
the teeth.
• GP warmed over the flame until it becomes soft and glistens.
• Applied to middle 1/3rd of facial surface of crown resulting in response within less
than 2 sec.
• 5 sec application increases temperature at pulpo-dentinal junction less than 2
degree C.
Hot water bath • Tooth isolated with rubber dam then bathed with warm water from a plastic
syringe for 5 sec or till the patient begins to feel pain.
• Temperature gradually increased if no response is obtained rather than producing
unnecessary pain by beginning with excessively hot water bath.
• Time consuming but produces most accurate response.
14. 2. Electrical pulp tests (EPT)
Mechanism: Application of electric current on the tooth surface stimulates intact a
delta nerves in the pulp-dentin complex.
Instrument:
EPT is a battery operated instrument which is connected to a probe that is applied to the
tooth under investigation.
Functions by producing a pulsating electrical stimulus, the initial intensity of which should
be at a very low value to prevent excessive stimulation and discomfort.
The intensity of the electric stimulus is then increased steadily at a pre-selected rate and
reading noted when patient experiences warm or tingling sensation.
It is not a quantitative measurement of pulp health, just provides evidence that A delta fibres
are healthy to function.
14
15. Steps in electric pulp vitality test
15
Inform patient about nature of test
Isolate tooth by placement of interproximal plastic strip, cotton gauze or by use of rubber dam
Dry the tooth
Supporting metal clip hung at the corner of the mouth to complete the circuit.
If metal clip not available, pt. asked to touch the tester probe to complete the circuit
Apply conducting medium on to the tooth surface or to the tip of the test probe
Tester applied on tooth surface adjacent to the pulp horn (incisal 3rd region of anteriors and mid-
3rd of posterior teeth at the tip of mesiobuccal cusp.
Electrode to not touch the gingiva
Initiate delivery of electric current to the tooth
Readings from pulp tester noted and compared with normal adjacent teeth
16. Disadvantages
Cannot be used on patients having cardiac pacemakers.
Does not suggest health or integrity of pulp; just indicates presence of vital
sensory fibres in the pulp.
Does not supply any information about the vascularity of the pulp which is
the true determinant of pulp vitality.
16
False positive responses
Patient’s anxiety
Saliva (transfer to gingival tissue)
Metallic restorations (transfer to
adjacent teeth)
False negative responses
Premedications
Immature teeth
Trauma
Poor contact with teeth
Inadequate contact media
Partial necrosis of vital pulp
17. 3. Test cavity
Used only when other forms of diagnosis have failed.
Test cavity made by drilling through the enamel-dentin junction of an unanaesthetized
tooth.
Drilling done at slow speed and without a water coolant.
Sensitivity or pain felt by the patient is an indication of pulp vitality, no endo treatment
indicated.
Sedative cement placed in cavity and search for source of pain is continued. If no pain is felt,
cavity preparation continued until pulp chamber reached.
If pulp is necrotic, endo treatment done painlessly without anaesthesia
17
18. 4. Anaesthetic test
A single tooth is anaesthetized at a time until pain
disappears and localized to a specific tooth.
Infiltration or intraligamentary injection at the most
posterior teeth and if pain continues then the tooth
mesial to it is injected till pain totally disappears.
If max or mand. teeth pain not identified then IANB
given hence, localizing the pain.
Last resort and is advantageous over ‘test cavity’ since
no iatrogenic damage is possible.
18
19. 5. Pulp oximetry
Widely used technique for recording blood oxygen
saturation levels during administration of i.v.
anaesthesia.
By measuring changes in oxygen saturation pulp-
oximetry is able to detect pulpal inflammation or partial
necrosis in teeth.
A pulse oximetry uses a probe contains:
A diode emits light in two wavelengths
Red light- approx. 660nm
Infrared light- approx. 850nm
A photo detector diode detector/sensor which will detect
the light once passed through teeth.
19
20. Advantages
Effective & objective method
In cases of impact injury (blood supply
intact but nerve supply damaged)
Pulpal circulation detected independent
of gingival circulation.
Pulp pulse reading are reproducible.
Smaller and cheaper oximeters are now
available for routine clinical use
Drawbacks
Background absorption associated with
venous blood tissue constituents not
differentiated.
Probes should be specific for the
anatomy of the tooth as oxygen
saturation values from teeth routinely
register lower than the readings from
patients finger.
20
21. Mechanism 21
The probe is placed on the labial surface of the tooth crown and the sensor on the palatal surface
The light (red and infrared) passes through the tooth
Oxyhemoglobin absorb more infrared as compared to red light, while deoxyhemoglobin absorb red
Vital tooth/more vascular so red light detected by sensor (as infrared absorbed)
If tooth non vital/less vascular then infrared light detected (red light absorbed)
The device will compare ratio of amplitudes of transmitted infrared with red light
Absorption curves for oxygenated and deoxygenated Hb to determine oxygen saturation levels
22. Cracked Tooth Syndrome
Refers to incomplete fracture of a vital tooth that involves the
dentin, occasionally extending to pulp.
Symptoms:
Sensitivity to cold
Pain while releasing pressure after biting on food or hard objects
Symptoms of pulpitis when pulp is involved
Periodontal disease if fracture extends to root.
Mand. 2nd molar > Mand. 1st molar > Max. PM commonly affected.
22
24. a. Dental history
H/o any masticatory accidents, para functional habits like bruxism, past
dental treatments, dietary habits, betel nut chewing, trauma or accidents
24
25. b. Visual examination
Useful but cracks not easily visible without the aid of magnifying loupes.
25
26. c. Tactile examination
Running the tip of a sharp probe along the tooth surface produces a
clicking sound when it passes over the fracture line.
26
27. d. Bite test
Rubber wheel, wooden stick or tooth slot fracture detector placed on the cusp of the
suspected tooth and ask the patient to bite down with moderate pressure and then release.
Pain during biting or during releasing pressure is a classic symptom.
Pain on biting- apical periodontitis.
Pain on releasing pressure- cracked tooth syndrome
Pain relieved due to biting- periapical abscess
Fract-finder or tooth slot used on each individual cusp and pt. asked to bite thus, allowing
selective pressure on one cusp
27
28. e. Transillumination
Fibreoptic light source combined magnification should be used for transillumination.
Light beam directed in a horizontal direction perpendicular to plane of suspected
crack. Cracks block the light beam from reaching the part of tooth beyond fracture
whereas sound tooth transmit light through the crown.
Before transillumination, tooth should be cleaned and light source placed directly on
tooth.
A fibre optic hand piece used for this purpose. Composite curing light not
recommended.
If tooth has restoration, it maybe necessary to remove it to expose fracture line.
28
29. f. Dye staining
Gentian violet or methylene blue stains used to highlight fracture lines.
Disadvantage:
takes atleast 2-5 days to be effective and requires placement of provisional restoration.
placing a provisional restoration undermines structural integrity of tooth and further
propagates the crack.
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30. Plaque disclosing agents
Dental plaque deposition brings about inflammatory changes in the periodontium
that can lead to destruction of tissues and loss of attachment.
Dental plaque is transparent, colorless and not easily visible, therefore it is desirable
to use plaque disclosing agents to identify areas where plaque deposition is evident.
A disclosing agent is a selective dye in solution, tablet or lozenge form used to
visualize and identify dental biofilm on surface of teeth.
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31. Different plaque disclosing agents
Iodine preparation
Mercurochrome preparations
Bismark brown
Merbromin
Erythrosine
Fast green
Fluroscein
Two tone solution (old plaque: blue; new: red)
Basic fuschin
Buckley’s solution
Berwick’s solution
Talbot’s solution
Iodogycerol solution
Metaphen solution
Allura red
31
32. Purpose
Detecting location of plaque on tooth
Demonstrating presence of plaque to patients
Determining the efficacy of home care procedures
Detecting irregular and rough surfaces that habitually take up stains
Personalized patient instruction and motivation
Self-evaluation by patient
To evaluate effectiveness of oral hygiene maintenance.
32
33. Methods 33
Painting • Tell the patient to rinse to remove food particles and heavy saliva. Apply water based
lubricant generously to prevent staining of lips.
• Dry the teeth with compressed air, retracting cheeks or tongue.
• Use cotton pellet to carry solution to the crowns of the teeth.
• Direct patient to spread the agent all over surfaces of teeth with tongue.
• Examine the distribution of agent and request the patient to rinse if indicated
Rinsing A few drops of concentrated preparation are placed in a paper cup and water is added for
the appropriate dilution.
Instruct patient to rinse and swish the solution over all tooth surface.
Tablet or wafer Patient chews half a wafer, swishes it around for 30-60 sec and rinses.
34. Inference 34
Condition Appearance
Clean tooth Do not absorb the coloring agent
Pellicle Stains as a thin relatively thin covering
Bacterial plaque Appears darker and more opaque
For two-tone dye Red biofilm: newly formed, thin, usually supragingival
Blue biofilm: thicker, older more tenacious; usually seen at and just
below gingival margin
35. Caries detection
Caries is a microbial disease of the calcified tissues of the
teeth, characterized by demineralization of the inorganic
portion and destruction of organic substance of teeth which
leads to cavitation.
Methods:
Non radiographic methods:
Conventional
Advances
Radiographic methods:
Conventional methods
Advances in radiographic techniques
35
37. Tactile examination
Explorer used to detect softened tooth structure.
Explorer sticks indicating there is decay beneath.
Advantages:
Easy and traditional method.
Disadvantages:
Sharp edges of explorer may fracture the demineralized
enamel.
Use of sharp explorer tip within a pit and fissure can
cavitate the enamel and create and opening through
which cariogenic bacteria can penetrate.
37
38. Visual examination
Based on cavitation, surface roughness, opacification and discoloration of clean and
dried teeth under adequate light source.
Advantages:
Preferred over probing due to its harmful effects.
Disadvantages:
Very small lesion is difficult to detect
Discoloration of pits and fissures which is found in normal and healthy teeth can be
mistaken for caries.
38
39. Ultraviolet illumination
Natural fluorescence of enamel as seen under UV light
decreased in areas of less mineral content such as
carious lesion, artificial demineralization and
developmental defects.
Caries appear as dark spots against a fluorescent
background
Advantages:
More sensitive method as compared to visual and tactile
method
More reliable results
Disadvantages:
Difficult to differentiate developmental defects and caries
Not a quantitative method
39
40. Fibreoptic transillumination (FOTI)
Results in opacity of demineralized tooth structure over more than translucent healthy
structures.
Decalcified areas will not let light pass through as much as it does in a healthy area,
generating a shadow corresponding to decay.
Advantages:
Non-invasive method
Useful in patients with posterior crowding
No radiation hazard
Comfortable to patients
Disadvantages:
Not possible in all anatomic locations
Considerable intra and inter observer variations
40
41. Digital fibreoptic transillumination
(DIFOTI)
Similar to FOTI but here the resultant image is captured by a digital
electronic charged coupled device camera (CCD) and send to a
computer where it is analyzed.
Advantages:
Non invasive
Clear signals of different types of frank caries
Shows surface changes associated with early demineralization
Disadvantages:
Not able to measure the depth of the carious lesion
Cannot differentiate between carious lesions and stained pits and fissures.
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42. Dye penetration
Detector dyes allows precise assessment of depth and surface for demineralized areas in
incipient caries in pit, fissures and smooth surfaces.
E.g.: Procion dye, Calcein, Zyglo ZL-22, Basic fuscin in propylene glycol
Advantages:
Non invasive
Easy procedure
Disadvantages:
Dyes can be carcinogenic
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43. Conventional radiographs
Uses x-ray radiation for detection of caries which appear radiolucent due to
demineralization.
Different technique: IOPAR & bitewing radiograph
Advantages:
Visually undetectable lesions can be easily detected
Extension of caries can be seen
Disadvantages:
Use of ionizing radiations
Requires x-ray source, film and processing equipment
43
44. Digital radiography
In the place of films, CCD, CMOS and PSP sensors are used.
Advantages:
Low radiation dose as compared to conventional
Measurement, enhancement and enlargement can be done
Images can be stored in digital media
Less chances of film related faults
Processing equipment not required
Disadvantages:
Expensive
Sensors are sensitive to handle
Sensors are stiff and uncomfortable to patient
44
45. Diagnodent
A device that emits red laser light which is absorbed by the tooth and fluoresces which is
captured by the detector probe and transferred to machine where it is read out.
Readings: 0-no fluorescence, 99-max; fluorescence more intense in carious part.
Advantages:
Good reproducibility
Confirms healthy tooth structure before sealants are placed
Serves a s patient education tool
Removes doubt when diagnosing hidden caries
Disadvantages:
Expensive
Chances of false positive results
Sensitive to stains
45
46. Biopsy
Removal of living tissue for the purpose of microscopic examination and
diagnosis.
TYPES:
Incisional
Excisional
Punch
Brush
FNAC/FNAB
Bone marrow biopsy (Trephine biopsy)
Shave
Curettage
Electrosurgery/ laser biopsy
46
47. 47Indications Contraindications
Any lesion that persists for more than 2 weeks no
apparent aetiologic cause
Normal anatomic and racial variations (physiologic
pigmentation, linea alba, Fordyce’s granules)
Any inflammatory lesion that persists more than 10-14
days even after removal of local irritant.
Acute/sub-acute inflammatory conditions due to
bacterial and viral infections
White/red/mixed lesions for finding if they are
benign/malignant/precancerous
Proximity of lesion in vital anatomic, vascular, neural or
ductal structures and lesions in difficult surgical areas
Ulcers that fail to heal and persists >3 weeks Malignancies where seeding of cancerous cells due to
incision is suspected
Persistent swelling without clear diagnosis Infrabony lesions should not be biopsied prior to
investigational aspiration
Lesions interfering with local function (fibroma,
papilloma, mucocele, pyogenic granuloma)
Pulsative lesions, large hemangiomas and A-V
malformations
To diagnose and determine specific type of neoplasm Compromised health of the patient, h/o bleeding
diasthesis
All lesions that do not respond to well established
treatment modalities
48. a) Incisional/ diagnostic biopsy
A biopsy sample which is a representative part of the
lesion.
INDICATION:
Size >1cm
When management can be planned only after diagnosis
When excision is prohibited due to hazardous location of
the lesion
INCISION:
Incision margin should be elliptical/wedge shaped,
converge in ‘V’ to join sublesional tissue and should
involve 2-3mm margin of normal tissue
48
49. b) Excisional biopsy
It is the removal of the entire lesion with (also a perimeter
of surrounding normal tissue excision) during the surgical
diagnostic procedure.
INDICATIONS:
Lesion <1cm
Lesion that appears benign on clinical examination, e.g.:
papilloma, irritational fibroma, mucocele, pyogenic
granuloma.
PRINCIPLE: Same as incisional and also biopsy must
include some normal tissue along with lesion.
49
50. c) Punch biopsy
Usually a variant of incisional biopsy which uses
especially designed punch forceps for removal of
tissue.
Instrument: Circular blade+plastic handle
Principle:
Punch held perpendicular to skin and gently rotated
with firm downward pressure, till subcutaneous
depth is reached
Punch lifted, a column of tissue comes along with it
and the incised tissue is released using a scalpel
blade/forceps.
50
51. d) FNAC/FNAB
Uses a needle and syringe to penetrate a
lesion for aspiration of its contents.
INDICATIONS:
All lesions that contain fluid
Intraosseous lesion to rule out vascular lesion
ADVANTAGE:
Relatively painless
Yields information about nature of lesion with
minimal patient discomfort
Inexpensive, speedy result, high accuracy
Low risk of complications
Readily repeatable
Useful in debilitated patients
51
52. PROCEDURE 52
To aspirate fluid
Insertion of needle
Aspiration
See the color, contents of the fluid
Send for biochemical examination
To remove tissue as biopsied by needle
Insertion of needle
Aspiration
Back and forth movement
Release of negative pressure
Needle and syringe separated
Air drawn into syringe and needle attached
Contents blown onto slide
Stain and see on microscope
53. 53
Aspiration of Inference Example
Inability to aspirate fluid Bony lesion Osteoma, FD, ossifying
fibroma
Straw-colored fluid Cystic lesion Radicular cyst, dentigerous
cyst
Brownish fluid/straw
colored fluid with blood
Infected cyst Infected radicular cyst,
infected dentigerous cyst
Aspiration of thick
pultaceous creamy fluid
Cystic lesion Keratocystic odontogenic
tumor (OKC)
Aspiration of pus Inflammatory/infectious
process
Palatal abscess, submucosal
abscess
Aspiration of blood Vascular lesion Aneurysmal bone cyst,
central hemangioma
Aspiration of air (no fluid) Traumatic bone cyst, static
bone cyst
Traumatic bone cyst, static
bone cyst, solid
ameloblastoma
54. e) Brush biopsy
This technique consist of the use of brush which captures the
epithelial cells.
INDICATIONS:
Red & white lesions
Lesions that require long term follow up
Chronic ulcerations
Mucosa that is traumatized, atrophic and ulcerated
CONTRAINDICATIONS:
Lesions with intact normal epithelium like fibromas, mucocele,
hemangiomas
TECHNIQUE: Brush is rotated until slight bleeding is observed
indicating that the brush has reached the basement membrane.
Cellular aggregate from the brush is transferred to a slide, fixed
and then analyzed
54
55. INTERPRETATION:
-ve: no epithelial abnormality;
atypical: abnormal atypical changes of uncertain diagnostic importance,
+ve: definitive cellular evidence of dysplasia and carcinoma,
inadequate: incomplete trans epithelial specimen
ADVANTAGES:
Non invasive, easy,
Patient acceptance
No topical or local anesthetic required
DRAWBACKS:
Lack of tissue architecture
Not useful for diagnosis of connective tissue and pigmented lesions
False –ve results if specimen is inadequate
55
56. Exfoliative cytology/ Cytosmear
Study of cells which exfoliate or abrade from the mucosal
surface.
Principle: When epithelium becomes seat of any
pathological condition, the cells may shed along with
superficial cells.
Indications:
Herpes simplex infection
Herpes zoster
Pemphigus
White sponge nevus
Candidiasis
Red and white lesions of the oral cavity
56
57. PROCEDURE:
Clean the surface of debris and mucin
Vigorously scrape the entire surface of the lesion several times with moistened tongue
blade or metal cement spatula.
Collected material is spread on a slide
Fixing of smear before it dries; fixative allowed to stand for 30mins to air dry.
Examine in microscope
57
Class Inference Feature
Class I Normal Normal cells observed
Class II Atypical Presence of minor atypia but no evidence of malignant changes
Class III Indeterminate Not clear cut suggestive of cancer, can be precancerous, biopsy
recommended
Class IV Suggestive of cancer Few cells with malignant characters or many cells with borderline
characteristics
Class V Positive for cancer Obvious malignant cells, biopsy recommended
58. ADVANTAGES:
Not substitute but an adjunct to biopsy
Quick, simple, painless, blood less procedure
Helps as a check against false positive biopsy
Less cost
Valuable for screening lesions where biopsy not
needed
Helpful in follow up conditions of recurrent
carcinomas
LIMITATIONS:
Presence and extent of invasion not assessed
Most benign lesions of oral cavity do not lend
themselves to cytological smear
Negative cytology does not rule out cancer
58
59. Saliva collection methods
INDICATIONS:
To check flow rate of saliva (sialometry) in cases of hyposalivation
To check biochemical, immunological changes (sialochemistry)
METHODS:
Collected as:
- mixed saliva - individual major gland saliva
- stimulated saliva - unstimulated saliva
59
60. Collection methods
Unstimulated saliva
Pt. advised to refrain from intake of food
or beverage (even smoking, chewing
gum is prohibited) 1 hour before the
test.
The subject is advised to rinse their
mouth with distilled water several times
& then relax for 5 min
Swallow to begin trial
Make little movement and do not
swallow
Use different methods like draining,
spitting, etc. to collect saliva.
Stimulated saliva
Same instructions.
To make saliva stimulation either of
the following methods are used:
Ask pt. to chew a piece of paraffin
Every 1 min, ask pt. pt. to spit saliva
into the tube without swallowing
Gustatory stimulation with application
2% citric acid solution. The solution is
dropped on the tongue every 30-sec
& after 2 min the pt. spits into test
tube.
60
61. 61
Technique Advantage Disadvantage
Draining method Requires the patient to
allow saliva from the
mouth to collect in a
graduated pre-weighed
cylinder by tilting their
head
• Reliable and
reproducible
• Whole saliva samples
preferred for DNA
analysis
• Evaporation of saliva
• Uncomfortable and
inconvenient for some
patients
62. 62
Technique Advantage Disadvantage
Spitting method The pt. is allowed to
accumulate the saliva in the
mouth and then
expectorate into graduated
pre-weighed cylinder, every
60 sec for 2-5mins
• Can be used for
both stimulated &
unstimulated saliva
Less reliable than
draining as there is
chance of stimulation in
case of unstimulated
saliva collection
63. 63
Technique Advantage Disadvantage
Swab (absorbent
method)
Uses pre-weighed gauze
sponge that is placed in pts.
mouth for set amount of
time.
After collection sponge is
weighed again and volume
of saliva determined
gravimetrically
Detects presence of
saliva using simple and
easy method
• Less reliable than draining
method as there is chance
of stimulation of glands
• Alters the concentration of
some salivary components
64. 64
Technique Advantage Disadvantage
Suction method Uses an aspirator or saliva
ejector to draw saliva from the
mouth into a test tube
Does not depend on
patient collaboration
cooperation
Less reliable than
draining & spitting
method as there are
chances of stimulation
65. Collection method of individual saliva 65
Parotid gland • Carlson Crittenden device which is a double chambered metal cup with two outlet tubes.
• Inner chamber positioned over parotid duct orifice while suction is applied to outer
chamber which holds cup in place
66. 66
Submandibular
& sublingual
gland
• Collected by an alginate held collector called segregator which is positioned over
Wharton’s duct.
• As saliva produced, it flows through tubing and collects in pre-weighed vessel
• Modification by using orthodontic cribs or clasps can be used to enhance stability
67. 67
Minor salivary
gland
• Capillary tube method:
Either 1µL, 5µL, 10µL capillary tubes used to collect from dried, everted surface of the
lower lip. Time noted to fill particular tube to calculate flow rates.
• Filter paper method:
A sterile 2mm filter paper used. The periotron device gives definite value based on
conductivity change from which the secretion rate can be determined after appropriate
calibration.
68. Diascopic test
A test used for blanchability performed by applying
pressure with a finger or glass slide and observing color
changes.
Used to determine whether a lesion is vascular
(hemangioma), nonvascular (mucocele) or hemorrhagic
(petechiae or purpura)
PROCEDURE:
INFERENCE: Hemorrhagic lesions and non vascular
lesions do not blanch while vascular lesion blanched
68
Put a slide over the lesion and apply pressure
Check for blanching
69. Diagnostic analgesics blocking
Since orofacial pain is a complex process skillful analgesic
blocking of muscles of masticatory system, maxillofacial
region and TMJ used for diagnosis of orofacial pain.
SIGNIFICANCE:
Essential for differentiating primary from secondary pain
Diagnostic nerve block can be used as therapeutic modalities
CONTRAINDICATIONS:
Severe acute cases of muscles injury, trauma or pain
Allergies to anaesthetics used
Patient with active bleeding difficulties, diasthesis or
anticoagulants
Pt. with cellulitis of the area
69
70. Types and significance of diagnostic
blocks
70
Significance Includes
Nerve block injection To locate exact branch of nerve to cause
pain
• Max. NB
• Mand. NB
• IANB
Muscle injection To determine source of pain from muscles &
also for treatment of MPDS
• Masseter
• Temporalis
• Lateral & medial pterygoid
• Sternocleidomastoid
• Trapezius
• Digastric
Intracapsular injections Therapeutic & diagnostic purpose if TMJ is
source of pain
• Inj. Directly into TMJ
• Auriculotemporal N.
Pulp vitality To anaesthetize a single tooth at a time till
pain disappears & localized to a specific
tooth
• IANB to identify max or
mandibular involvement
• Intraligamentary inj. for
localization of specific tooth
71. Patch test 71
It is a method used to determine whether a specific substance causes allergic
inflammation of a patient’s skin/mucosa or not.
It relies on the principle test of type IV hypersensitivity reaction reaction.
INDICATIONS:
Allergic contact stomatitis
Allergic contact cheilitis
Oral lichenoid reaction
Burning mouth syndrome
Orofacial granulomatosis
Recurrent apthous stomatitis
Angioedema
72. 72To check single allergens
To check multiple allergens
Tiny quantities of 25-150 allergens in
individual square plastic or round
aluminium chambers applied to the
upper back
They are kept in place with the help of
hypoallergenic adhesive tape
Patch left undisturbed for atleast 48hrs
Avoid taking any immunosuppressive medications
a week before testing
Take suspected allergen in a base like
petroleum jelly
Put onto filter paper and place it on the
body on the upper back
Patch is then covered with cellophane and
covered by leucoplast tape
Reaction measured at 48hrs and 72 hrs
73. INFERENCE 73
Inference Appearance seen
Negative (-) No reaction
Irritant reaction (IR) Minor rash
Weak positive (+) Elevated red or pink plaques
Strong positive (++) Papules-vesicle lesion
Extreme reaction (+++) Severe redness, itching, blisters or
ulcers