Dentosphere : World of Dentistry

# Which of the following structure is not found in a living pulp ? A. Collagen fibers B. Haversian fibers C. Non myelinated nerve fibers D. Reticulum # The dental pulp contains nerve endings / receptors for: A. Pain B. Pressure C. Proprioception D. Temperature # The dental pulp is derived from : A. Dental papilla B. Dental Sac C. Odontoblasts D. Stellate reticulum # Pulp responds to all stimuli by pain because it has only: A. Free nerve endings B. Krause end bulbs C. Pacinian corpuscle D. Ruffini corpuscle # All of the following are true about functions of dental pulp EXCEPT: A. Formation of dentin B. Nerve supply to dentin C. Sends impulse to CNS D. Nerve supply to enamel through fibers # Odontoblasts are derived from : A. Undifferentiated mesenchymal cells B. Histocytes C. Macrophages D. Lymphocytes # The primary function...

SELECT THE TOPIC YOU WANT TO PRACTICE. # LOK SEWA  AAYOG PAST QUESTIONS Medical Entrance Preparation MCQs # Digestive System and Nutrition MCQs # Reproductive System MCQs # MCQs on Sense Organs # Nervous System MCQs # Cardiovascular System MCQs # Endocrine System MCQs # Assorted Dental MCQs - Part 1 #AIIMS MDS ENTRANCE EXAM YEARWISE COLLECTION *** AIIMS Nov 2001 *** AIIMS Nov 2002 *** AIIMS Nov 2003 *** AIIMS Nov 2004 *** AIIMS Nov 2005 *** AIIMS Nov 2006 *** AIIMS Nov 2007 Part 1 *** AIIMS Nov 2007 Part 2 *** AIIMS Nov 2008  *** AIIMS Nov 2009 *** AIIMS Nov 2010 *** AIIMS Nov 2012 *** AIIMS Nov 2013 *** AIIMS Nov 2014 *** AIIMS Nov 2015 *** AIIMS May 2016 *** AIIMS May 2015 *** AIIMS May 2014 *** AIIMS May 2013 *** AIIMS May 2012 *** AIIMS May 2011 # DENTAL MATERIALS *** Amalgams *** Physical Properties *** Metallurgy *** Impression Materials *** Dental Ceramics and Miscellaneous *** Gypsum Products *** Dental Cements *** Restorative Resin...

Q. Discuss the types of calcification. The mineralisation of body tissues with calcium is a normal physiological process in tissues like bones and teeth, termed as physiological calcification. However, sometimes the visceral tissues and other soft tissues may also get calcified in many diseased states, which is called pathological calcification. In addition to the calcium salts, smaller amounts of iron, magnesium and other minerals may also be deposited. Pathological calcification can be broadly classified into two types: Dystrophic Calcification and Metastatic Calcification. Dystrophic calcification: When the deposition takes place in dead or dying tissues, then it is termed as dystrophic calcification. The serum calcium levels are normal and the calcium metabolism is not deranged. Though hypercalcemia is not a prerequisite for dystrophic calcification, hypercalcemia can exacerbate it. It is seen in areas of tissue necrosis of any type. It is almost always present in the ather...

Q. Mention differences between necrosis and apoptosis. Ans : Though both necrosis and apoptosis are events of cell death, they do differ in various ways. The differences can be observed under following parameters : a) Cell Size The cell is enlarged (swelling) in necrosis whereas the cell is reduced (shrinkage) in apoptosis. b) Fate of Nucleus In necrosis, nucleus undergoes series of changes like pyknosis ( irreversible condensation of chromatin in the nucleus of a cell ) , karyorrhexis (fragmentation of nucleus) and karyolysis (complete dissolution of the chromatin of a dying cell due to the enzymatic degradation). But, in Apoptosis, nucleus undergoes fragmentation into nucleosome size fragments c) Plasma Membrane The plasma membrane is disrupted and is full of leakages in case of necrosis but, it is intact in cells undergoing apoptosis. Only the orientation of lipids in plasma membrane is altered in apoptosis. d) Cellular contents Due to ruptured plasma membrane, ce...

Q. Define Necrosis. Enlist its types with an example of each. Ans: Necrosis is the type of cell death that is associated with loss of membrane integrity and leakage of cellular contents culminating in dissolution of cells, largely resulting from the degradative action of enzymes on lethally injured cells. Types of Necrosis: i) Coagulative Necrosis - underlying tissue architecture is preserved, - affected tissues take on a firm texture - characteristic of infarcts in all of the solid organs except the brain ii) Liquefactive Necrosis - seen in focal bacterial or fungal (occasionally) infections - the dead cells are digested completely, transforming the tissue into a liquid viscous mass - seen often in hypoxic death of cells within CNS iii) Caseous Necrosis (Caseous = Cheese like) - Encountered most often in foci of tubercular infection - friable yellow white appearance of the necrotic region - area of caseous necrosis is often enclosed within a distinctive i...

Poster for Oral Health Awareness : World Oral Health Day 2017 , Designed By: Raman Dhungel, BPKIHS,Dharan, Nepal. FDI World Dental Federation (Federation Dentaire Internationale), has decided to celebrate 20th March 2017 as the world oral health day with a theme "Live mouth Smart". The first World Oral Health Day was celebrated on 20th March 2013 by FDI World Dental Federation. Since then, every year , on 20th March it is celebrated across the globe by organising various campaigns and programs to raise Oral health awareness. The themes for World Oral Health Day till date are: 2013: Healthy Teeth for Healthy Life 2014: Brush for a Healthy Mouth! 2015: Smile For Life! 2016: It all Starts Here. Healthy Mouth. Healthy Body 2017: Live Mouth Smart. Good oral health leads to good overall health. Share the message of World Oral Health Day and spread Oral Health Awareness.

# During the formation of primary teeth: A. Enamel forms more cervically than dentin B. Enamel forms faster than dentin C. Dentin forms faster than enamel D. Processes of their cells remain in content with each other # Matrix vesicles : A. Are found in mantle dentin B. Contain collagen C. Produce alkaline phosphatase D. Inhibit mineralization # Transmission of stimulus across dentin is: A. Direct activation of nerve endings B. Correlated with the innervation density of the dentin C. Stimulus induced fluid flow D. There is no transmission of stimulus across dentin # During hydrodynamic theory movement of fluids in dentinal tubules cause: A. Movement of odontoblasts B. Touch the nerves of the pulp to cause pain C. Minimum effect on odontoblast D. Stimulation of odontoblastic process # Which of the areas of the tooth is most sensitive during cavity preparation : A. Enam...

# S-Shape of dentinal tubule is due to: A. Incremental deposition B. Peritubular dentin C. Crowding of odontoblasts D. Due to excess amount of organic component # The formation of which of the following does not represent normal physiological process of dentin formation? A. Primary and secondary dentin B. Secondary dentin and Circumpulpal dentin C. Tertiary dentin and Sclerotic dentin D. All of the above # All of the following is true about dentinal tubules except: A. Inner pulpal layer contains more dentinal tubules than outer dentin layer B. The diameter of dentin tubules ranges from 5 to 7 micrometer C. The diameter of dentinal tubule is more at pulpal layer than outer layer D. The bonding is more difficult is more difficult on the inner layer of dentin compared to outer surface # Fluid flow , in and out of the dentinal tubules is proportional to the tubule diameter by: A. Third power of the...

# Formula of hydroxyapatite crystal is : A. Ca3(Po4)2.CaCO3 B. 3Ca3(Po4)2. Ca(OH)2 C. CaPo4. Ca(OH)2 D. None of the above # The type of dentin that is formed prior to root completion is : A. Inter tubular dentin B. Peritubular dentin C. Circumpulpal dentin D. Secondary dentin # Accentuated incremental lines in dentin due to disturbances in matrix and mineralisation process is: A. Incremental lines of Retzius B. Incremental lines of von Ebner C. Contour lines of Owen D. None of the above # The pain transmission through dentin is : A. Direct neural stimulation B. Fluid or hydrodynamic theory C. Transduction theory D. All of the above # Which of the following is correct ? A. Reparative dentin is characterized by having fewer and more twisted tubules than normal dentin and may include odontoblasts B. Dead tracts appear black in transmitted and white in reflected light C. S...

# The dentin receptors are unique because: A. They elicit pain to hot and cold B. They elicit pain to touch and pressure C. They elicit pain to chemicals D. Elicit only pain as a response # The main bulk of dentin is formed by : A. Peritubular dentin B. Mantle dentin C. Inter tubular dentin D. Predentin # The zone of dentin most recently formed and uncalcified is known as: A. Mantle dentin B. Circumpulpal dentin C. Predentin D. Secondary dentin # Inter globular dentin results due to: A. Failure of coalescence of calcospherites B. Fracture of the dentin C. Artifact in light microscopy D. Disturbance in dentinal tubules # Dentinogenesis by odontoblasts first behins at : A. Pulpal end B. Cusp tip C. Tooth bud stage D. Cervical area # Sclerotic dentin has following features : A. Caries susceptible B. Insensitive C. Hypersensitive D. Re...

# Dentinal tubules are : A. Concave B. Straight C. S-Shaped D. None of the above # The cells that form secondary dentin are: A. Cementoblasts B. Fibroblasts C. Odontoblasts D. Osteoblasts # Dead tracts in ground section appears as: A. Dentinal tubules B. Coarse fibril bundles arranged at right angle to the dentinal surface C. Black in transmitted light and white in reflected light D. White in transmitted light and dark in reflected light

# Chemico-parasitic theory of dental caries is proposed by : A. G.V. Black B. Miller C. Gottlieb D. Schwartz # Which of the following organisms is found in deep carious lesions rather than in incipient lesions ? A. Streptococci B. Lactobacilli C. Veillonella D. Bacteroides # Pioneer bacteria in dental caries are in: A. Enamel B. Dentin C. Pulp D. Cementum # The most pronounced effect on the oral microflora of a reduction in rate of salivary flow is a : A. Significant increase in number of oral bacteria B. Shift towards more acidogenic microflora C. Significant decrease in number of oral bacteria D. shift towards more aerobic microflora # Ammonia causes: A. increase in plaque formation B. increase in calculus formation C. decrease in plaque formation D. precipitation of salivary proteins # Cavity formation in a tooth, due to dental caries is due to: A. Destructive potential of Streptococcus mutans B. Destructive potentia...

# Streptococcus mutans is considered to be a principal etiologic agent of caries because it produces acid and it: A. forms a gelatinous matrix B. metabolizes substrate from saliva C. derives energy from enamel constituents D. lives symbiotically with lactobacillus # Miller put forth the acidogenic theory of dental caries in the year: A. 1890 B. 1920 C. 1924 D. 1980 # For a bacterium to be seriously considered in the etiology of dental caries, it must : A. exist regularly in the dental plaque B. produce extracellular amylopectins C. be lethal for gnotobiotic animals D. produce intracellular dextrans # Initiation of dental caries depends upon: A. formation of large amount of acid B. availability of carbohydrate food C. viscosity of saliva D. Localisation of acid over tooth surface # Caries, all are true except: A. Lactobacillus is the main causative organism in plaque B....