1. In the process of tooth development, which of the following statements are true? a. The basement membrane separating the inner dental epithelium from the dental mesenchyme is composed of type I and III collagen.
b. Blood vessels become established in the dental papilla during the cap stage. c. Mature ameloblasts appear before odontoblasts mature. However, the formation of enamel takes place following the deposition of dentin.
d. The II collagen mRNA increase with odontoblastic differentiation.
e. Ameloblasts form enamel spindles near the future dentinoenamel junction (DEJ). 2. von Korff fibers are best described as which of the following?
a. The first-formed collagen fibers formed between preodontoblasts. b. Unmyelinated sensory fibers in the cell-free zone of Weil
c. Odontoblastic processes interposed between ameloblasts d. Silver-stained ground substance located between odontoblasts
3. Which of the following statements regarding root development is false? a. Root development begins after completion of enamel formation.
b. The inner epithelium, the stellate reticulum, and outer enamel epithelium form Hertwig's epithelial root sheath.
c. The dental sac disintegrates upon induction of dentin formation and remnants persist as the Epithelial Rests of Malassez.
d. Accessory canals in the root are formed when there is discontinuity in the root sheath.
4. Which of the following statements regarding dentin is correct?
a. Mantle dentin is the first formed dentin and has collagen fibers that run perpendicular to the DEJ.
b. Dentin deposited after eruption is termed secondary dentin.
c. Dentinal tubules make up 50% of the dentin volume and they exhibit extensive terminal ramifications.
d. Calcification of dentin results in an organic component composed of noncollagenous matrix components.
5. Which of the following statements regarding the tubular structure of dentin is correct?
a. Peritubular dentin and intertubular dentin are the same composition, except for the fact peritubular dentin lines the tubule.
b. Peritubular dentin has a lower-collagen content when compared to intertubular dentin and is more susceptible to removal by acids.
c. Intertubular dentin is more highly mineralized when compared to peritubular dentin.
d. Peritubular dentin defines the tubule size and is common to all mammals. 6. Which of the following statements regarding dentin permeability is true?
a. Remains constant regardless of the depth of a cavity preparation because of a pulpal tissue pressure of 10.3 mm Hg
b. Increases as the pulp and dentin border is approached (primarily because the tubular surface area increases)
c. Is lower in radicular dentin because of tubular sclerosis
d. Increases near the pulp and dentin border as the hydrostatic pressure in the tubules decreases
7. Which of the following statements regarding tight junctions in the odontoblastic layer is true?
a. They regulate permeability of extracellular substances between the odontoblastic layer and the predentin.
b. They permit low-resistance pathways for electrical excitation when the odontoblastic process is distorted.
c. They provide a mechanism for intracellular materials to be exchanged.
d. They are infrequent but when found are located in the basal portion of the cells. 8. Which of the following statements regarding production of collagen by the odontoblast is correct?
a. Type I collagen is manufactured in the cellular cytoplasm, packaged by the Golgi complex, and released by reverse pinocytosis.
b. Tropocollagen is synthesized in the rough endoplasmic reticulum (RER) and packaged in the Golgi complex. Vesicles consisting of collagen fibrils migrate into the odontoblastic process and are released.
c. The Golgi complex packages collagen precursors (e.g., proline) into vesicles that are released into the predentin. These then precipitate to form tropocollagen and, eventually, collagen fibrils.
d. Synthesis begins in the RER with procollagen being packaged in the Golgi complex. Vesicles are formed and release tropocollagen in the predentin matrix. 9. Which of the following statements regarding dendritic cells is false?
a. Dendritic cells are similar to Langerhans' cells and play a significant role in induction of T-cell immunity.
b. Although not normally present in the healthy pulp, dendritic cells appear during inflammation and, like macrophages, are phagocytic.
c. Considered accessory cells, the dendritic cell participates in antigen recognition and presentation.
d. Dendritic cells are primarily found in lymphoid tissues.
10. Which of the following statements regarding the extracellular matrix of the pulp is false?
a. The extracellular matrix changes with eruption of the tooth as the chrondroitin sulfate concentration decreases and the hyaluronic acid and dermatan sulfate fraction increase.
b. The proteoglycans regulate the dispersion of interstitial solutes.
c. The state of polymerization of the ground substance regulates osmotic pressures. d. The water content of the extracellular matrix is relatively low, giving the tissue a colloidal consistency and limiting movement of components within the tissue.
11. Teeth with immature root development often are unresponsive to electrical pulp testing because which of the following?
a. Myelinated fibers are the last structures to appear in the developing pulp.
b. Predentin and intratubular fibers are not present until root formation is complete. c. There is a relative hypoxic condition of the pulp during developmental glycolysis. d. Electrical stimulation of autonomic fibers decreases blood flow and depresses A- delta fiber activity.
12. Each of the following statements support the hydrodynamic theory for pain,
a. Odontoblasts have a low-membrane potential and do not respond to electrical stimulation.
b. Placement of local anesthetics on dentin does not alter the pain response. c. There is a positive correlation between fluid movement in the tubules and the discharge of intradental nerves.
d. Forty percent of the tubules in the area of pulp horns contain intratubular nerve endings.
e. The presence of a smear layer decreases dentinal sensitivity.
13. Which of the following statements regarding a patient that has a sharp, short sensation to cold that resolves immediately with removal of the stimulus is correct?
a. The patient's response indicates inflammation and tissue damage. b. A-delta and C fibers are responsible for the painful sensation. c. A-delta and A-beta fibers are being stimulated.
d. C-fibers are responding to the release of inflammatory mediators, such as bradykinin and substance P.
14. Which of the following statements regarding pulpal bloof flow is correct? a. Blood flow within the pulp is homogenous with arteriovenous anastomoses maintaining an even flow.
b. Unmyelinated, sympathetic fibers innervating the arterioles and venules produce vasoconstriction.
c. The pulpal blood flow is the highest of oral tissues because of the relatively high metabolic activity of the pulp.
d. Accessory and lateral canals provide adequate collateral circulation.
15. Which of the following statements outlines the most significant factor influencing the pulp's response to injury and compromised healing?
a. Inflammatory cells, such as polymorphonuclear leukocytes and B-lymphocytes, are not found in the normal pulp.
b. There is a lack of a collateral circulation.
c. Odontoblasts are end line cells incapable of replication. d. The fact that the pulp may not have a lymphatic system. e. The environment of the dental pulp is low compliant.
16. Which of the following statements regarding age changes in the pulp are false? a. There is a decrease in the cellularity and collagenous fibers, especially in the radicular pulp.
b. Odontoblasts decrease in size and may disappear completely in some areas, particularly the pulpal floor of multirooted teeth.
c. There is a reduction in the nerves and vasculature of the pulp. d. There is an increase in peritubular dentin.
e. The pulp demonstrates an increased resistance to the action of proteolytic enzymes.
CHAPTER 12:
PATHOBIOLOGY OF THE PERIAPEX
1. Inflammation of the periapical tissue is sustained by which of the following? a. Stagnant tissue fluid
b. Necrotic tissue c. Microorganisms d. All of the above
2. Acute, apical periodontitis is characterized by which of the following? a. A focus of neutrophils within the lesion
b. A focus of granulomatous tissue in the lesion
3. A periapical, true cyst communicates with the root canal; however, a periapical- pocket cyst does not.
a. True b. False
4. The most important route of bacteria into the dental pulp is from which of the following?
a. The general circulation via anachoresis b. Exposure to the oral cavity via caries c. The gingival sulcus
5. The least important factor influencing the pathogenicity of endodontic flora is which of the following?
a. Microbial interaction
b. Endotoxins released after bacterial death c. Exotoxins released by living bacteria d. Enzymes produced by bacteria
6. Which of the following statements regarding neutrophils is accurate? a. They are nonspecific phagocytes.
b. They have a single pathway for intracellular killing.
c. They are mobilized primarily to neutralize bacterial endotoxins. d. All of the above are accurate.
7. Which of the following statements regarding T-lymphocytes are accurate? a. They are thyroid-derived cells.
b. They concentrate in the cortical area of lymph nodes and also circulate in the blood.
d. All of the above statements are accurate.
8. Which of the following statements regarding B-lymphocytes are accurate? a. They were originally discovered in an avian gut-associated organ.
b. They account for the majority of circulating lymphocytes. c. They produce antibodies.
d. All of the above statements are accurate.
9. The function(s) of macrophages include(s) which of the following? a. Phagocytosis of microorganisms
b. Removal of small foreign particles c. Antigen processing and presentation d. All of the above
10. Which of the following statements regarding osteocytes is accurate? a. They originate as monocytes in the blood.
b. They respond only to mediators released by osteoblasts. c. They are mononuclear cells capable of bone demineralization. d. They form a ruffled border away from the bone surface.
11. Which of the following statements regarding acute apical periodontitis is accurate?
a. It is limited to the periodontal ligament (histologically). b. It is detectable radiographically.
c. It may heal if induced by a noninfectious agent. d. All of the above statements are accurate.
12. Which of the following statements regarding chronic, apical periodontitis is accurate?
a. It is a neutrophil-dominated lesion encapsulated in a collagenous connective tissue.
b. It may contain epithelial arcardes or rings.
c. It represents a continuous, slow process that is asymptomatic. d. It is a predominance of B-cells over T-cells.
13. Which of the following statements regarding cholesterol crystals is accurate? a. They may induce granulomatous lesions.
b. They are potentially associated with nonresolving apical periodontitis. c. They are difficult for macrophages and multinucleated giant cells to remove. d. All of the above statements are accurate.
14. Which of the following statements regarding periapical actinomycosis is accurate?
a. It is caused by gram-negative organisms exhibiting branching filaments that end in clubs or hyphae.
b. It is a fungal disease characterized by filamentous colonies called sulphur granules.
c. It is most commonly an endodontic infection resulting from dental caries. d. All of the above statements are accurate.
15. Extraradicular infections are not found in which of the following? a. Solid, apical granulomas
b. Periapical-pocket cysts with cavities open to the root canal c. Periapical actinomycosis
d. Acute, apical periodontitis