Type II Diabetes Causes

# Obesity, genetic profile, and aging all contribute to the development of Type II diabetes. Of the following, which is the most important additive factor for these three conditions in the development of Type II diabetes?

A. elevated hepatic ketogenesis
B. elevated pancreatic glucagon secretion
C. impaired renal clearance of glucose
D. muscle resistance to insulin

Answer: D - Muscle resistance to insulin is the most important additive factor for these three conditions in the development of Type II diabetes. The progressive loss of skeletal muscle sensitivity to insulin leads to increased rates of visceral cell lipolysis and pancreatic beta-cell compensation.

Parasympathetic Cranial nerves

# # All of cranial nerve have parasympathetic outflow except :
A. 5th nerve
B. 7th nerve
C. 3rd neve
D. 9th nerve

The correct answer is A. 5th nerve

Cranial nerves having parasympathetic now are 3,7,9 and 10.
Preganglionic parasympathetic neuron cell bodies are located in certain cranial nerve nuclei of the brain stem and in the grey matter of the second to fourth sacral segments of the spinal cord. Efferent fibres, which are myelinated, emerge from the CNS only in cranial nerves III, VII, IX, and X and in the second to fourth sacral spinal nerves. Preganglionic parasympathetic neurons are cholinergic. 

The only cranial nerve which arises on the dorsal aspect   -       Trochlear
The cranial nerve with longest intracranial coarse              -        Abducent
The cranial nerve with longest coarse                                 -       Vagus
The cranial nerve involved in raised intracranial tension   -       Abducent nerve
Cranial nerve carrying parasympathetic fibres                      -       3,7,9,10
Commonest cranial nerve affected in spinal anesthesia     -       Abducent nerve
Cranial nerve involved in Bell's palsy                                 -       VII Nerve
Cranial nerve involved in Ramsay Hunt Syndrome             -       VII nerve
Cranial nerve arising from the pons                                    -     V, VI, VII, VII nerves
Pure sensory nerves                                                          -       1,2,8
Branchiomeric nerves                                                       -       5.7.9,10,11

Referred pain in Orofacial region:

# ___________most often refer pain to the temporal region,
while _________most often refer pain the ear.
A. Maxillary second premolars, mandibular molars
B. Maxillary molars, mandibular molars
C.  Maxillary second premolars, mandibular premolars
D. Maxillary molars, mandibular premolars

The correct answer is A. Maxillary second premolars, mandibular molars.

If careful diagnosis does not reveal the affected tooth, other teeth and related anatomic structures
become suspect. Pulpitis in one tooth may cause pain in other areas - the pain is referred.

Site of Pain Referral                             Pulp of Tooth Causing Pain
Forehead region                                    Maxillary incisors
Nasolabial area                                      Maxillary canines. premolars
Temporal region                                     Maxillary second premolars
Ear. angle of jaw, or posterior                 Mandibular molars
regions of neck
Mental region of mandible                        Mandibular incisors, canines. and premolars
Zygomatic, parietal, and occipital              Maxillary molars
regions of head
Opposing quadrant or to other                      Maxillary and mandibular molars
teeth in the same quadrant

Important: The nerve endings of cranial nerves VII, IX, and X are widely distributed within the subnucleus caudalis of the trigeminal (V) nerve. A profuse intermingling of these nerve fibers creates the potential for the referral of dental pain to many sites.

Orofacial pain can be the clinical manifestation of a variety of diseases involving the head and neck region. The cause of the pain must be differentiated between odontogenic and nonodontogenic.

Characteristics of nonodontogenic involvement:
• Episodic pain with pain-free remissions
• Trigger points
• Pain travels and crosses the midline of the face
• Pain that surfaces with increasing stress
• Pain that is seasonal or cyclic
• Pain accompanied by paresthesia

Hydrolysis of Lactose, Maltose and Sucrose

# Which of the following statements is TRUE? (MAN-95)
a) The hydrolysis of lactose yields glucose and galactose
b) The hydrolysis of maltose yields glucose and fructose
c) The hydrolysis of sucrose yields only glucose
d) All of the above statements are true

The correct answer is A. The hydrolysis of lactose yields glucose and galactose

Maltose2 glucose units
Sucrose1 glucose + 1 fructose
LactoseGalactose + glucose
StarchWater soluble amylose and a water soluble amylopectin
InulinPolymer of fructose

Chromic gut Suture vs Plain gut Suture

# Advantage of chromic gut over plain is:
A. Delayed resorption
B. Increased strength
C. Less irritation
D. Less tissue reaction

The correct answer is A. Delayed resorption.

  • Chromic gut sutures consist of the plain gut that has been treated with chromium trioxide. This results in a delay in the absorption rate.
  • Because retention of sutures beyond a few days is not recommended in endodontic surgery, the use of chromic gut sutures offers no advantage.
  • Also, evidence indicates that plain gut is more biocompatible with oral soft tissues than is the chromic gut. The gut suture material is marketed in sterile packets containing isopropyl alcohol.
  • When removed from the packet, the suture is hard and non-pliable because of its dehydration. Before using gut sutures should be hydrated by placing them into sterile, distilled water for 3 to 5 minutes.
  • After hydration, the gut suture material will be smooth and pliable with manipulative properties similar to silk.

# Benzodiazepine antagonist is:

# Benzodiazepine antagonist is:
A. Flumazenil
B. Naloxone
C. Furazolidone
D. Dapsone

The correct answer is A. Flumazenil

Benzodiazepine act by enhancing presynaptic or postsynaptic inhibition through a specific receptor which is integral part of gabba receptor Cl-channel complex.

Flumazenil is a BZD analogue which has little intrinsic activity but it competes with BZDs as well as inverse agonists for BZD receptor and reverses their depressant or stimulant effects respectively. Flumazenil is the drug of choice for benzodiazepine overdose.

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?
A. Calcium hydroxide liner
B. ZnO liner
C. Light cure GIC liner
D. Lining with varnish

The correct answer is A. calcium hydroxide liner

Deep caries excavation close to the pulp, which may result in either an undetected pulpal exposure or a visible pulpal exposure, should be covered with a calcium hydroxide liner that can stimulate formation of dentin bridges (reparative dentin) over the exposure.

For amalgam restorations, deep excavations not encroaching on the pulp should be covered with a glass-ionomer material that will contribute to thermal protection and provide mechanical protection from amalgam condensation forces at thicknesses of I to 1.5 mm or greater.

Bonding of Composite resin to tooth

# Bonding of composite resins to tooth structure is by: (KAR-01)
a) Covalent bond
b) Ionic bond
c) Mechanical
d) Vander waal forces

The correct answer is C. Mechanical

Bonding of composites to tooth structure occurs by micromechanical retention. Acid etching creates micro porosities into which the resin penetrates resulting in resin tag formation. These tags penetrate to a depth of 5 - 10 ┬Ám but their lengths are dependent on the enamel etching time.

Advantages of Dental Composite Resins:

# The main advantage of composites over unfilled direct filling resin is their: (KAR-97)
a) Higher solubility in saliva
b) Lower modulus of elasticity
c) Esthetic excellence
d) Lower thermal co-efficient of expansion

The correct answer is D. Lower coefficient of thermal expansion.

Advantages of composites over unfilled resins:
  • Lower coefficient of thermal expansion
  • Low polymerization shrinkage
  • Low water absorption
  • High abrasive resistance
Disadvantages of composites:
  • Less color stability
  • Less smooth finish than unfilled resins

Hyperplastic Tissue Management in Complete Dentures

# The most common reason why hyperplastic tissue is removed during the construction of a complete denture is that:
a) It interferes with the arrangement of the teeth
b) It is unaesthetic to construct a denture on a hyperplastic tissue
c) It interferes with the stability of the denture
d) All of the above

The correct answer is C. It interferes with the stability of the denture.

The most important reason for the treatment of hyperplastic tissue before the construction of complete or removable partial dentures is to provide a firm, stable base for the denture. 

Functional cusp reduction

# The amount of functional cusp reduction required for metal-ceramic crown is -
a) 1.0 - 2.5 mm
b) 1.5 - 2.0 mm
c) 2.0 - 2.25 mm
d) 1.85 - 2.10 mm

The correct answer is B. 1.5 -2.0 mm. 

Metal ceramic restorations require a 1.5 - 2 mm reduction in the functional cusp and 1.0 - 1.5mm reduction in the non-functional cusp. 

Gutta percha removal

# Best method to remove gutta-percha in retreatment procedures:
A. Hand instrumentation
B. Automated instrumentation
C. Rotatory instruments
D. Ultrasonic instruments

The correct answer is A. Hand instrumentation

The coronal portion of gutta-percha obturations should always be drilled out, preferably by means of endodontic drills such as the Gates-Glidden or Peeso. Gutta-percha may be dissolved (solvent technique) or removed in its solid form (Solid gutta-percha techniques). Dissolving avoids the use of excessive force in the negotiating of gutta-percha-obturated canals.

Extrusion of solvent into the periapical tissues should be prevented.

Solvents of gutta-percha: Gutta-percha is soluble in chloroform, ethyl chloroform, carbon disulfide, carbon tetrachloride, benzene, xylene, eucalyptol oil, halothane, and rectified white turpentine.

Retreatment of solid objects other than gutta-percha, either a silver point or a fragment of an instrument or post, cannot be easily grasped and pulled out. A readily accessible solid object may be withdrawn from the canal by a variety of instruments, including Stieglitz or Perry pliers, a modified Castroviejos needle holder, or a Caulfield silver point extractor. Ultrasonic Vibration, bypassing with hand instruments and Intermittent irrigation, alternating sodium hypochlorite with hydrogen peroxide or RC-Prep, may float the object coronally through the effervescence they create.

Special grasping devices. The Masserann technique- Masserann and alternative extractors. The Masserann kit consists of an extractor into which the object to be retrieved is locked. An assortment of end-cutting trepan burs are used in anticlockwise rotation, to provide access for the extractor. 

Endodontic retreatment

# Endodontic retreatment:
A. Is as technically challenging as original treatment
B. Has a poorer prognosis than original treatment
C. Is performed only on endodontic failures
D. Has different objectives than primary treatment

The correct answer is B. has a poorer prognosis than the original treatment

Post and Core in Endodontics

# In restoring an endodontically treated tooth for post core, an absolute minimum of apical fill of gutta percha to be left over to prevent leakage is:
A. 1 mm
B. 2 mm
C. 3 mm
D. 4 mm

The correct answer is D. 4mm

Since there is greater leakage when only 2-3 mm of Gutta-percha is present, 4-5 mm should be retained apically to ensure an adequate seal. Although studies indicate that 4 mm produce an adequate seal, stopping precisely at 4 mm is difficult, and radiographic angulation errors could lead to retention of less than 4 mm. Therefore, 5 mm of gutta-percha should be retained apically. 

Concentration of EDTA used during BMP:

# Concentration of EDTA used during biomechanical preparation (BMP) is:
A. 20% at pH 7.4
B. 15% at pH 5.0
C. 15% at pH 7.3
D. 25% at pH 7.4

The correct answer is C. 15% at pH 7.3

EDTA has a property of chelate formation with calcium salts. Disodium salt of EDTA is used in endodontic therapy for dissolving pulp stones. 

Length of a Peeso reamer is:

# Length of a Peeso reamer is:
A. 28-32 mm
B. 30-35 mm
C. 35-40 mm
D. 40-45 mm

The correct answer is A. 28-32 mm

- Standard Peeso reamer is of 32 mm length.
- Short Peeso reamer is of 28 mm length.

Cardiac glycosides:

# Which of the following is called cardiac glycosides?
A. Digitalin
B. Belladonna
C. Reserpine
D. Colchicum

Cardiac glycosides are a class of organic compounds that increase the output force of the heart and increase its rate of contractions by acting on the cellular sodium-potassium ATPase pump. Their beneficial medical uses are as treatments for congestive heart failure and cardiac arrhythmias; however, their relative toxicity prevents them from being widely used.

Cardiac glycosides can be more specifically categorized based on the plant they are derived from, as in the following list. For example, cardenolides have been primarily derived from the foxglove plants Digitalis purpurea and Digitalis lanata, while bufadienolides have been derived from the venom of the cane toad Bufo marinus, from which they receive the “bufo” portion of their name.

Cardiac glycosides have long served as the main medical treatment to congestive heart failure and cardiac arrhythmia, due to their effects of increasing the force of muscle contraction while reducing heart rate. Heart failure is characterized by an inability to pump enough blood to support the body, possibly due to a decrease in the volume of the blood or its contractile force. Treatments for the condition thus focus on lowering blood pressure, so that the heart does not have to exert as much force to pump the blood, or directly increasing the heart's contractile force, so that the heart can overcome the higher blood pressure. Cardiac glycosides, such as the commonly used digoxin and digitoxin, deal with the latter, due to their positive inotropic activity. On the other hand, cardiac arrhythmia are changes in heart rate, whether faster (tachycardia) or slower (bradycardia). Medicinal treatments for this condition work primarily to counteract tachycardia or atrial fibrillation by slowing down heart rate, as done by cardiac glycosides.

Nevertheless, due to questions of toxicity and dosage, cardiac glycosides have been replaced with synthetic drugs such as ACE inhibitors and beta blockers and are no longer used as the primary medical treatment for such conditions. Depending on the severity of the condition, though, they may still be used in conjunction with other treatments.

Middle meningeal artery:

# The middle meningeal artery: (MAN -95)
a) Enters the skull through the foramen ovale
b) Supplies the superolateral surface of the ipsilateral cerebral hemisphere
c) Runs a subdural course within the cranial cavity
d) Gives an interior branch which runs deep to the pterion

The correct answer is D. Gives an interior branch which runs deep to the pterion

The middle meningeal artery enters the middle cranial fossa through the foramen spinosum. In middle cranial fossa, it has an extradural course and divides into anterior frontal branch and posterior parietal branch.

The frontal branch is closely related to the motor area of the cerebral cortex. It is the commonest source of extradural hemorrhage and results in hemiplegia of the opposite side. The parietal branch is closely related to the cerebrum and its involvement result in contralateral deafness. 

AIIMS MDS MCQs Nov 2007 Part 1 with Answers

# Which one of the following is a junction of frontal, parietal, temporal and greater wing of sphenoid bone?
 A. Pterion
 B. Lambda
 C. Vertex
 D. Inion

# A non synovial joint with dense connective tissue between two bony surfaces is termed as:
 A. Synchondrosis
 B. Syndesmosis
 C. Symphysis
 D. Suture


14th MARCH 2019

B.P. Koirala Institute of Health Sciences, Dharan, Nepal
5th year BDS
Paper - IV 

Time - 2 Hours
 Total Marks: 80
Maximum Marks - 40
1. Explain the pathophysiology of osteomyelitis of jaws.   (4)

2. Discuss the clinical features of trigeminal neuralgia and enlist different treatment options. (2+3=5)

3. Enlist FOUR clinical features of zygomatic arch fracture. Add a note on Gillies temporal approach to indirect reduction. (2+3=5)

4. Enlist the clinical test to diagnose oro-antral communication and add a note on management of oroantral communication. (2+4=6)

5. Discuss briefly on different types of dislocation and enumerate the surgical procedures for the management of chronic recurrent temporomandibular joint dislocation . (3+3=6)

6. Mention the difference between ridge extension and ridge augmentation procedure based on their indication. Describe any one ridge extension procedure. (1+4=5)

7. With the help of a well labeled diagram, discuss WAR lines. (4)

8. Mention different theories of the mechanism of action of local anesthetic and explain the most accepted theory. (2+3=5)


Maximum Marks: 40
I. A 50-year-old male weighing 70 kg, presented to the maxillofacial clinic for extraction of grossly decayed 16. He also gave a history of coronary artery bypass graft surgery, which was done at BPKIHS 3 years back.
Q.1 Will this patient require antibiotic prophylaxis prior to extraction?     1
Q.2 Enlist the cardiac conditions requiring antibiotic prophylaxis for infective endocarditis as per the latest guidelines.     4
Q.3 Calculate the maximum number of cartridges of lignocaine with vasoconstrictor that is recommended for this patient.    5
Q.4 Enlist contraindications for exodontia.    5

II. A 45-year-old male presented to the OMFS department with a complaint of swelling over the right side of face from the last 6 months. There is no history of trauma or toothache.
On examination there .was a bony hard swelling over the right angle region with buccal and lingual cortices expansion with clinically missing 48.

OPG of the patient revealed a multilocular radiolucent area extending from distal of 47 till the ramus of the mandible with a radio-opaque tooth-like structure resembling 48 on the inferior aspect of the radiolucent lesion.

Aspiration from the lesion revealed a creamy white viscoid fluid.

Q.5 Enlist the differential diagnosis for this case.    (1)
Q.6 Formulate a provisional diagnosis and briefly discuss about findings to support the diagnosis.   (1+2=3)
Q.7 Discuss the different treatment options for a jaw cyst and its indications.      (3+3=6)
Q.8 Name the agents used to reduce the recurrence. Write down its composition and advantages. (1+2+2-5)

III. 31-year-old Mr. Rupesh visited the department of oral and maxillofacial surgery with a complaint of reduced mouth opening for 3 days. He also reports having a toothache in right lower wisdom tooth which was on and off from the last 6 months which used to regress on medications.

On examination, there was no appreciable facial swelling extra orally. However, he had significant trismus to make intraoral examinations impossible. With little to be seen intra-orally the uvula seemed to be pushed towards the left side.

OPG was taken which revealed an impacted mesioangularly impacted 48. No other abnormalities were detected in the OPG.
Q.9 Mention your provisional diagnosis for this case.    2
Q.10 Enlist the principles for the management of facial space infection.    5
Q.11 Enlist the life-threatening complication if it is untreated.     3

Moth eaten appearance is seen in all except:

# Moth eaten appearance is seen in all except:
A. Osteomyelitis
B. Hemorrhagic cyst
D. Osteosarcoma

The correct answer is C. OKC

'Moth eaten appearance' is seen in lesions of bone which shows lytic activity. 
Seen in:
- Osteomyelitis - Acute suppurative and chronic both
- Osteosarcoma
- Osteoradionecrosis
- Ewing Sarcoma
- Langerhans cell histiocytosis
- Hemorrhagic cyst

Radiolucency between maxillary central incisors

# A radiolucency seen between the maxillary central incisors is most commonly due to:
A. Periapical cyst
B. Nasopalatine cyst
C. Globulomaxillary cyst
D. Nasoalveolar cyst

The correct answer is B. Nasopalatine cyst

Nasopalatine cyst (Incisive canal cyst) - Most common fissural cyst, usually asymptomatic, may complain of tender swelling of palate. Radiographic characteristics- well demarcated round, oval or heart shaped radiolucency between and above maxillary central incisors; rarely just lateral to the midline; lesion crosses midline, teeth are vital. 

Dentin Desensitizing Agent

# The dentin desensitizing agents that acts by precipitating proteins in dentinal tubular fluid is: (MHCET 2014)
A. Strontium chloride
B. Potassium oxalate
C. Fluoride
D. Hydroxyethyl methacrylate

The correct answer is A. Strontium chloride.

After professional diagnosis, dentinal hypersensitivity can be treated simply and inexpensively by home use of desensitizing dentifrices.

Strontium Chloride Dentifrices
Ten percent strontium chloride desensitizing dentifrices are found effective in relieving the pain of tooth hypersensitivity.

Potassium Nitrate Dentifrices
Five percent potassium nitrate dentifrices are found to alleviate pain related to tooth hypersensitivity.

Fluoride Dentifrices
Sodium monofluorophosphates dentifrices are effective mode of treating tooth hypersensitivity.

Strontium chloride is the most important constituent in home care dentifrices intended to be used for the treatment of dentinal hypersensitivity. Topical application of concentrated strontium chloride on an abraded dentin produces a deposit of strontium that penetrates dentin to a depth of approximately 10-20 micrometers and extend into dentinal tubules. 

Ref: Textbook of OPERATIVE DENTISTRY, Nisha Garg, 3rd Edition, Page 445

Direct Pulp Capping

# Which of the following are true about direct pulp capping?
A. Mechanically exposed teeth have a greater success rate than carious exposures
B. Final restorative materials do not affect success
C. Generally, individual teeth involved in a fixed prosthesis are candidates for direct pulp capping
D. All of the above

The correct answer is A.  Mechanically exposed teeth have greater success rate than carious exposures.

What is Fluoride bomb?

# The ‘FLUORIDE BOMBS’ is related to:
A. A fluoride  capsule with high ppm of fluoride varnish
B. A hypoplastic lesion on tooth seen in fluorosis areas
C. Undiagnosed hidden caries
D. Procedure to treat rampant caries

The correct answer is C. Undiagnosed hidden caries.

  • Occult or hidden caries is used to describe such lesion which is not clinically diagnosed but detected only on radiographs.
  • Occult lesions are seen with low caries rate which is suggestive of increased fluoride exposure.
  • It is believed that increased fluoride exposure encourages remineralization and slows down the progress of the caries in the pit and fissure enamel while the cavitation continues in dentin, and the lesions become masked by a relatively intact enamel surface.
  • These hidden lesions are called 'fluoride bombs' or fluoride syndrome.

# Calcium hydroxide is advocated as an inter appointment intracanal medication because of

# Calcium hydroxide is advocated as an inter appointment intracanal medication because of:
A. Its ability to dissolve necrotic tissue
B. Its antimicrobial property
C. Its ability to stimulate hard tissue formation
D. Its powerful bleaching effect

The correct  answer is B. Its antimicrobial property. 

Most studies report culture reversals during the interappointment period when active antibacterial dressing is not used in the root-canal system between appointments. The reversals are due to regrowth of residual bacteria or recontamination by bacterial leakage around the access cavity

Classical and well-controlled studies (Sundqvist’s group) evaluated the effect of various root-canal treatment procedures on the microbiota both qualitatively and quantitatively. They tested the effect of mechanical preparation, saline or sodium hypochlorite irrigation (0.5%, 5.0%, 5.0% with EDTA), the addition of ultrasonic activation to the irrigation and calcium hydroxide dressing; each addition to the chemical canal preparation improved the antibacterial effect, reducing residual bacteria further. They found the antibacterial action to reduce the number of bacteria from an initial range of 10^2–10^8 cells to 10^2–10^3 fewer cells after initial debridement, further reducing down to no recoverable cells (from the prepared part of the root-canal system) after interappointment dressing with calcium hydroxide.

Reference: Endodontics, 4th Edition, Kishor Gulabivala, Yuan-Ling Ng, Page no. 83

Initial dissolution of Tooth Substance by Acid

# In the carious process, the initial dissolution of the tooth substance by acid takes place in which of the following place?
A. Below the dentin Surface
B. Below the enamel surface
C. On the enamel surface
D. Towards the dentin

The correct answer is B. Below the Enamel Surface.

The top portion of the tooth remains intact and it's the subsurface which looses the minerals. This is the stage where it's called as incipient lesion. Once the top protion breaks, it's called a cavitated lesion.

Digestive System and Nutrition - MBBS BDS Entrance Examination

The correct answers are highlighted in green.

# Micelles are the bodies related to:
 A. Secretion of hormones
 B. Secretion of enzymes
 C. Absorption of minerals
 D. Absorption of fat

# Movements of circular muscles in the stomach is called
 A. Digestion
 B. Absorption
 C. Excretion
 D. Peristalsis

Sites of Various Metabolic Pathways

Sites Metabolic Pathways
  • Citric acid cycle
  • Oxidative phosphorylation
  • Fatty acid oxidation
  • Electron transfer
  • Synthesis of ketone bodies
  • Protein Synthesis
Golgi Complex
  • Glycoprotein synthesis
  • RNA Synthesis
  • Cholesterol synthesis
  • Glycolysis
  • Fatty acid synthesis
  • Glycogenesis
  • Glycogenolysis
  • HMP shunt
  • Gluconeogenesis
In both mitochondria and cytosol
  • Urea Cycle
  • Gluconeogenesis

# Clotting factor common to extrinsic and intrinsic pathway is:

# Clotting factor common to extrinsic and intrinsic pathway is:
A. Factor II
B. Factor III
C. Factor V
D. Factor VII

The correct answer is C. Factor V.

Prothrombin activator that is formed in intrinsic and extrinsic pathways converts prothrombin
into thrombin in the presence of calcium (factor IV). 

Once formed thrombin initiates the formation of more thrombin molecules. The initially formed thrombin activates Factor V. Factor V in turn accelerates formation of both extrinsic and intrinsic prothrombin activator, which converts prothrombin into thrombin. This effect of thrombin is called positive feedback effect. 

# Acid etching is done to:

# Acid etching is done to:
A. Decrease microleakage
B. Decrease polymerization shrinkage
C. Decrease Coefficient of thermal expansion
D. Decrease porosity in restorative material

The correct answer is A. Decrease microleakage.

Acid-etching transforms the smooth enamel into an irregular surface  and increases its surface free energy. When a fluid resin-based material is applied to the irregular etched surface, the resin penetrates into the surface, aided by capillary action. Monomers in the material polymerize, and the material becomes interlocked with the enamel surface.The formation of resin microtags within the enamel surface is the fundamental mechanism of resin-enamel adhesion.

As measured in the laboratory, shear bond strengths of composite to phosphoric acid-etched enamel usually exceed 20 megapascals (MPa) and can range up to over 50 MPa, depending on the test method used. Such bond strengths provide adequate retention for a broad variety of procedures and prevent leakage around enamel margins of restorations.

# Iron content in 3M Nickel based steel crowns is:

# Iron content in 3M Nickel based steel crowns is: (MAN -01)
a) 20%
b) 40%
c) 60%
d) 10%

The correct answer is D. 10 %.

Composition of stainless steel crowns:
Stainless steel (18-8) austentic type of alloy is used. Eg.: Rocky mountain and unitek.
Iron -                 87%
Chromium - 17%
Nickel -         12%
Carbon -          0.08 - 1.15%

Nickel base crowns. Eg.: Iconel 600 and 3M crowns
Iron                     -  10%
Chromium -    16%
Nickel - 72%
others - 2%

# A gingival wall is difficult to obtain in primary molar when it extends too far gingivally in class II cavities because: (MAN-97)

# A gingival wall is difficult to obtain in primary molar when it extends too far gingivally in class II cavities because: (MAN-97)
a) Facial pulp horn may be exposed
b) Inclination of cervical enamel rods occlusally
c) Of marked cervical constriction
d) Prime contact is broad and flat

The correct answer is C. of marked cervical constriction.

Gingivally the enamel rods have an occlusal direction in primary teeth so bevel is not required as there will be no unsupported enamel rods. It is difficult to obtain gingival wall when lesion extends too far gingivally in primary molar due to the presence of marked cervical constriction.

# Dose adjustment of all of the following drugs will be required in patient with severe liver cirrhosis EXCEPT:

# Dose adjustment of all of the  following drugs will be required in a patient with severe liver cirrhosis EXCEPT:
a) Lorazepam
b) Theophylline
c) Paracetamol
d) Metronidazole

The correct answer is A. Lorazepam.

Most of the BZDS are metabolized in the liver to produce active products (thus long duration of action). Active metabolites may result in cumulative effects. After metabolism, these are conjugated
and are excreted via kidney. Estazolam, lorazepam, oxazepam, temazepam and triazolam are directly conjugated without metabolism to active products. These drugs are thus short-acting and do not
accumulate on repeated administration. Further these drugs can be safely administered in liver failure and in elderly because these are conjugated directly without undergoing metabolism in the liver.
(Mnemonics: @ TO-LET; Short-acting drugs are Triazolam, Oxazepam, Lorazepam, Estazolam and Temazepam,). Compounds with shorter half life are favored in patients with sleep-onset insomnia whereas longer acting BZDS are favored in patients with day time anxiety.

Adverse effects
Benzodiazepines are much safer than barbiturates (less chances of respiratory depression and coma) and also have less abuse potential. However, these drugs can also impair learning and memory
Flunitrazepam is a tasteless BZD and is implicated as a date rape drug due to its propensity to cause dose dependent amnesic effects.

Benzodiazepine Antagonist
Flumazenil is the substance that acts as competitive antagonist at BZD receptor. It blocks the depressant action of benzodiazepine, zolpidem and zaleplon as well as the convulsant action of inverse agonist (like B-carotene).  It is administered i.v. for the treatment of BZD poisoning (specitie antidote) and can also be used to reverse BZD anaesthesia.

# Of the following local anesthetics, which has intrinsic vasoconstrictive action? (MAN -97)

# Of the following local anesthetics, which has intrinsic vasoconstrictive action? (MAN -97)
a) Cocaine
b) Procaine
c) Xylocaine
d) Bupivacaine

The correct answer is : A. Cocaine

All local anaesthetics except cocaine are synthetic compounds and they are vasodilating in nature. Cocaine is a natural local anaesthetic agent and causes local vasoconstriction.

 (Cocaine increases the vasoconstrictive action of adrenaline. If LA with adrenaline is given risk of death is more in cocaine abusers. So they are known as  'walking time bombs.'

Which of the following is the preferred local anesthetic technique for hemophilics? (MAN -01)

# Which of the following is the preferred local anesthetic technique for hemophilics? (MAN -01)
a) Nerve block
b) Supraperiosteal
c) Intraligamentary
d) Field block

The correct answer is C. Intraligamentary.
 In hemophilics to avoid complications,  Intraligamentary  (an intraosseous technique) method of local infiltration technique is preferred. In this technique, the solution is deposited in depth of gingival sulcus. The needle should be inserted apically into the bone until resistance is met.

# Which of the following may least be used as an abutment: (PGI -2K)

# Which of the following may least be used as an abutment: (PGI -2K)
a) Tooth with minimum crown
b) Tooth with short tapered crown and conical roots
c) Rotated and tipped tooth
d) Pulp treated tooth

The correct answer is: B. b) Tooth with short tapered crown and conical roots

# Epitheloid cells are seen in all of the following except (MAN -02):

# Epitheloid cells are seen in all of the following except (MAN -02):
a) Tuberculosis
b) Granulation tissue
c) Syphilis
d) Sarcoidosis

The correct answer is : B. Granulation Tissue

Epitheloid cells are a collection of modified macrophages present in granuloma. Granulomas occur in Tuberculosis, Leprosy, syphilis, Actinomycosis, Sarcoidosis, etc.

# The wetting of an adherent surface by an adhesive is related to: (AIPG-01)

# The wetting of an adherent surface by an adhesive is related to:
A. Surface texture of the adherent
B. Surface energy of the adherent
C. Nature of the adherent that is crystalline or amorphous
D. Surface tension of the adherent

The correct answer is B. Surface energy of the adherent.

The property of wetting and adhesions are directly related to surface energy of adhesives. Substances with low surface energy like teflon are often used to prevent the adhesion of films to a surface. Metals because of their high surface energy, interact vigorouslywith liquid adhesives.

The surface energy of many restorative materials is higher when compared to that of tooth. So, there is greater tendency for the surface and margins of restorations to accumulate debris. This property will explain the relatively high incidence of marginal caries seen around dental restorations.

What is Proportional Limit?

# The proportional limit is defined as:
A. The maximum stress in a structure
B. The minimum force required to cause a structure to break
C. The maximum stress that can be induced without permanent deformation
D. The maximum elongation under tension that
 can be measured before failure

The correct answer is C. The maximum stress that can be induced without permanent deformation.

Stresses above proportional limit cause plastic deformation. This stress is called yield strength or proof stress. It  is the greatest stress, produced in a material such that stress is directly proportional to the strain. 

Phillip's Science of Dental Materials, 12th ed. Page no 57.

Most Common reason for removal of Impacted Mandibular third molars:

# Most common reason for the removal of impacted mandibular third molars is:
 A. Referred pain
 B. Recurrent pericoronitis
 C. Chronic periodontal disease
 D. Orthodontic treatment

The correct answer is B. Recurrent Pericoronitis

Pericoronitis is an inflammatory lesion occurring around the impacted or partially erupted tooth. An incomplete eruption of the tooth provides a large stagnation area for food debris under the gingival flap. This becomes infected easily and results in inflammation of the pericoronal flap. It exhibits chronic inflammation for a long period. If the debris and bacteria are deeply entrapped, an abscess may form which is called a pericoronal abscess. It is a mixed infection and various bacteria of the dental plaque (particularly anaerobes) play a significant role in the development of pericoronitis.

Clinical Features: The mandibular third molar is the commonly involved tooth. Pain and swelling of the pericoronal tissue around the affected tooth, difficulty in chewing, and difficulty in opening the mouth are the usual complaints. The patient may be mildly ill with fever, malaise, and regional lymphadenopathy.

Management: Entrapped food debris must be removed. When the upper tooth is involved, it should be grounded or extracted if it is malposed. Radiograph helps in assessing the position of the involved tooth. If impacted, the tooth must be removed. And if it is in a favorable position, surgical removal of the pericoronal flap is advocated after acute symptoms subside. The administration of antibiotics helps to relieve the symptoms and prevents the spread of infection to the adjacent tissue spaces.

Ref: Shafer's Textbook of Oral Pathology, 7E, Page: 400

AIIMS MDS Nov 2007 MCQs - Part 2

# In lead poisoning, gingival discoloration presents as:
A. Blue black line
B. Yellow line
C. Grayish black line
D. Steel gray line

# Dilaceration occurs due to:
A. Trauma to the tooth germ during root development
B. Abnormal displacement of the tooth germ during root development
C. Abnormal displacement of enamel epithelium during tooth development
D. Abnormal displacement of ameloblasts during tooth development

AIIMS MDS Nov 2007 MCQs - Part 1

# Which one of the following is a junction of frontal,parietal, temporal and greater wing of sphenoid bone?
A. Pterion
B. Lambda
C. Vertex
D. Inion

# A non synovial joint with dense connective tissue between two bony surfaces is termed as:
A. Synchondrosis
B. Syndesmosis
C. Symphysis
D. Suture

Radiographically, driven snow appearance is seen with:

# Radiographically, driven snow appearance is seen with:
A. Adenomatoid odontogenic tumor
B. Calcifying odontogenic cyst
C. Calcifying epithelial odontogenic tumor
D. Keratocyst

The correct answer is C. Calcifying Epithelial Odontogenic Tumor

- Scattered flecks of calcification throughout the radiolucency has given rise to the descriptive term driven snow appearance.
- Lesion appears as diffuse or well circumscribed unilocular radiolucency.
- Combined radiolucency and radioopacity with irregular bony spicules producing honeycomb pattern
- Scattered flecks of calcification give driven snow appearance
- Sometimes, lesion is totally radiolucent and in association with unerupted tooth

Zones of Dentinal Caries

ZONE 1 Normal Dentin
Zone 2 Subtransarent Dentin
  • Zone of demineralization (by acid from caries)
  • Damage to the odontoblastic process is evident.
  • However, no bacteria are found in the zone.
  • Stimulation of the dentin produces pain, and the dentin is capable of remineralization.
Zone 3 Transparent dentin
  • Softer than normal dentin
  • Further loss of mineral from the intertubular area.
  • Stimulation of this region produces pain. There are no bacteria present.
  • The collagen cross-linking remains intact in this zone, can serve as a template for remineralization.
  • The intact collagen of the intertubular dentin, and thus this region remains capable of self-repair, provided the pulp remains vital.
Zone 4 Turbid dentin
  • Turbid dentin is the zone of bacterial invasion 
  • Widening and distortion of the dentinal tubules which are filled with bacteria.
  • There is very little mineral present and the collagen in this zone is irreversibly denatured.
  • The dentin in this zone will not self-repair.
  • This zone cannot be remineralized and must be removed prior to restoration
Zone 5 Infected Dentin
  • The outermost zone, infected dentin, consists of decomposed dentin that is teeming with bacteria.
  • There is no recognizable structure to the dentin.
  • Absence of collagen and mineral content.
  • Great numbers of bacteria are dispersed in this granular material.
  • Removal of infected dentin is essential to sound, successful restorative procedures as well as prevention of spread of the infection

# Whenever the caries cone in enamel is larger or at least the same size as that in dentin, it is called as:

# Whenever the caries cone in enamel is larger or at least the same size as that in dentin, it is called as:
A. Residual caries
B. Recurrent caries
C. Forward caries
D. Backward caries

Forward Caries. Forward caries is where the caries cone in enamel is larger or at least the same size as that in dentin.

Backward Caries. When the spread of caries along the DEJ exceeds the caries in the contiguous enamel, caries extends into this enamel from the junction.

Ans is C: Forward caries (Ref: Sturdevant's Art and science of operative dentistry 4th ed., p 274)

# DPT vaccine does not provide immunity against:

# DPT vaccine does not provide immunity against:
A. Tetanus
B. Diphtheria
C. Polio
D. Whooping cough

The correct answer is C. Polio.

The vaccine DPT stands for Diphtheria, Pertusis (Whooping cough) and Tetanus. 

# I.V. Diazepam in a patient on a dental chair can cause: [AIIMS 2007 NOV]

# I.V. Diazepam in a patient on a dental chair can cause: [AIIMS 2007 NOV]
A. Tinel’s Sign
B. Verrill’s Sign
C. Bell’s sign
D. Coleman’s sign

The correct answer is B. Verrill's Sign.
Verrill's  sign has 3 Symptoms which indicate  the correct level after  diazepam sedation.
- 50% eyelid ptosis
- Blurring of vision
- Slurring of speech 
Verrill's Sign

# Tinel's Sign: Tinel sign was used earlier as an indicator of the start of the nerve regeneration. It is elicited by percussion over the divided nerve, which result in tingling sensation in part supplied by peripheral section.

# Coleman's sign: Seen in mandibular fractures. Ecchymosis in the lingual sulcus is pathognomic of mandibular fracture.

 # Bell's Sign: Bell's phenomenon (also known as the palpebral oculogyric reflex) is a medical sign that allows observers to notice an upward and outward movement of the eye, when an attempt is made to close the eyes. The upward movement of the eye is present in the majority of the population, and is a defensive mechanism. 

# Local anesthetic with adrenaline if injected intravenously, what will be the result? ( AIIMS 2014, AIPG 2013)

# Local anesthetic with adrenaline if injected intravenously, what will be the result? ( AIIMS 2014, AIPG 2013)
A. Hypertension with Tachycardia
B. Hypotension with Tachycardia
C. Hypotension with Bradycardia
D. Hypertension with Bradycardia

The correct Answer is: A. Hypertension with Tachycardia.

 # In a hypertensive patient on B-blockers, an injection of Local anesthesia + Adrenaline will cause:
A. Hypertension and Tachycardia
B. Hypertension and Bradycardia
C. Hypotension and Tachycardia
D. Hypotension and Bradycardia

The correct answer is B. Hypertension and Bradycardia.

  • There are two separate drug interaction considerations with local anesthetics, the anesthetic itself and the vasoconstrictor.
  • Hypertensive events have been documented in patients taking B blockers, Furazolidone, Tricyclic antidepressants, methyl dopa, and the antihypertensive drugs guanethidine and Rauwolfia alkaloids.
  • Beta blocker interactions are potentially the most serious ones and cause hypertension and bradycardia. 

Why do people have crooked teeth?

Mal-aligned teeth or crooked teeth are problematic not only aesthetically but also from a health point of view. Irregularly placed teeth when present are difficult to clean and maintain hygiene, affect the speech, alters the facial profile and decreases the quality of smile and overall confidence of the person.

Let's see what are the causes of having crooked teeth.

1. Heredity and Evolution
During the course of evolution, the size of man's jaw has been decreasing gradually. Before thousands of years it is believed that human's used to have long jaws and even four molars. Present day human has smaller jaws and even third molars are impacted and need to be removed surgically these days.

Also, heredity also plays an important in proper alignment of teeth. If any of the parents have crooked tooth, the offsprings may also inherit the same.

2. Tooth size arch length discrepancy
When the jaws are smaller and they cannot accommodate all the teeth in the arch properly, the teeth get displaced out of arch due to crowding. Decrease arch length may be due to actual enlargement of tooth, also called Macrodontia, or may be due to retarded growth of maxilla or mandible. Moreover due to consumption of more soft and refined foods, the jaw growth is deficient and the teeth fail to accommodate.

Also the arch length is lost when the deciduous tooth are removed early due to caries or the mesiodistal width of teeth is reduced due to proximal caries. The permanent successor teeth  cannot get enough space to erupt in the arch and become crooked.

3. Habits
Abnormal habits like mouth breathing, tongue thrusting and thumb sucking also exert unnatural forces on the orofacial structures and cause malocclusion.

When diagnosed and treated early, orthodontic treatment can have best outcome and restore natural and healthy smile. Even after the growth phase is completed, crooked teeth can be aligned using fixed archwires and brackets by your Orthodontist. Please visit your nearest Orthodontist if you have got any crooked tooth.

MCQs in Public Health Dentistry - Biostatistics

The correct answers are highlighted in green.

# The arithmetical average of a number of observations is called :
 A. Mean 
 B. Median
 C. Range

 D. All of the above

# Which of the following correlates highest correlation between variables ? 
 A. r= + 0.25 
 B. r= + 0.5 
 C. r= - 0.75 
 D. r= + 2 

Gemination, Twinning, Concrescence and Fusion of Teeth


  • An attempt at division of a single tooth before calcification, resulting in incomplete formation of two teeth.
  • The resultant structure will have two completely or incompletely separated crowns with a single root and root canal.
  • It is difficult to differentiate between gemination and a case in which there has been fusion between a normal tooth and a supernumerary tooth.

The division of a single tooth resulting in one normal and one supernumerary tooth. The number of teeth will be more than normal.

  • A form of fusion of cementum after completion of root formation
  • The teeth are united by cementum only.
  • Maxillary molars are frequently involved
  • Union of two normally separated tooth germs.
  • If the union occurs before calcification, the two teeth are completely united to form a single Large tooth.
  • If the union occurs after calcification, there is union of roots only. The tooth may have separate or fused root canals.
  •  Fusion of teeth is more common in deciduous teeth.

MCQs on Pathology - Growth Disorders and Neoplasia

The Correct answers are highlighted in GREEN.

# Burkitt's lymphoma is associated with the proliferation of: (AP -99)
a) T- cell
b) B - cell
c) Lymph vessels
d) Lymph nodes

# Incidence of most common malignant tumors in men in India is in:
a) Lungs
b) Oral cavity
c) Prostate
d) Liver

MCQs in Microbiology - Virology Part 2

The correct answers are highlighted in green.

# The classic opportunistic infection in acquired immune deficiency syndrome is: (KAR-2000)
a) Aphthous stomatitis
b) Pneumocystis carinii pneumonia
c) Herpetic gingivostomatitis
d) Tuberculosis

# In which of the following immunization is given after infection is started: (AP-2004)
a) Influenza
b) Poliomyelitis
c) Herpes
d) Rabies

MCQs on Microbiology - Virology Part 1

The correct answers are highlighted in green.

# HIV is transmitted by all of the following routes except: (AP-14, MAN-2002)
a) Saliva
b) Needle prick injury
c) Blood transmission
d) Sexual intercourse

# A rise in the anti-HBc immunoglobulin in a patient indicates: (MAN-2000)
a) Acute infection
b) Carrier state
c) Prodromal phase
d) Convalescence

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