Dentosphere : World of Dentistry

# Granulation tissue is replaced by connective tissue in: A. 7 days B. 14 days C. 21 days D. 1 month # In guided tissue regeneration technique for root coverage, the titanium reinforced membrane was used to create space beneath the membrane by: A. Tinti and Vincenzi B. Pini Prato and Tonetti C. Ramjford and Nissle D. Widman and Cohen

# Primary immunoglobulin secreted or activated after vaccination: A. IgM B. IgA C. IgG D. IgE The primary immunoglobulin secreted or activated after vaccination is: C. IgG Explanation: IgG is the most abundant antibody in blood and extracellular fluid, making up ~75% of serum immunoglobulins. It is the key effector of the secondary immune response (activated after initial exposure or vaccination). IgM is produced first during the primary immune response but is short-lived. Vaccination typically aims to induce long-term immunity via IgG. IgA is important for mucosal immunity (e.g., respiratory/gut lining) but is not the dominant systemic response to vaccines. IgE is associated with allergies/parasitic infections and plays no significant role in vaccine-induced immunity.

# According to Clark’s rule for localization of object, if tube is shifted mesially to original angulation: A. Buccal objects move mesially B. Lingual objects move mesially C. Both buccal and lingual objects move distally D. Both buccal and lingual objects move mesially Correct answer: B. Lingual objects move mesially According to Clark’s rule (also known as the SLOB rule—Same Lingual, Opposite Buccal) for object localization in dental radiography, when the X-ray tube is shifted mesially while maintaining the original angulation: Buccal objects (those closer to the cheek) move in the opposite direction of the tube shift, so they move distally. Lingual objects (those closer to the tongue) move in the same direction as the tube shift, so they move mesially. Given the options: A. Buccal objects move mesially: Incorrect, as buccal objects move distally. B. Lingual objects move mesially: Correct, as lingual objects follow the tube shift direction. C. Both buccal and lingual objects move dis...

# All of the following are the features of dysplasia EXCEPT:  A. Enlarged nuclei and cells B. Increased nuclear to cytoplasmic ratio C. Hypochromatic nuclei D. Pleomorphic nuclei and cells The correct answer is C. Hypochromatic nuclei. Explanation: Dysplasia is characterized by abnormal cellular changes, including enlarged nuclei and cells, increased nuclear to cytoplasmic ratio, and pleomorphic nuclei and cells (variation in size and shape). These are all hallmark features of dysplasia. However, hypochromatic nuclei (nuclei with reduced staining, appearing pale) are not typically associated with dysplasia. Instead, dysplastic cells often have hyperchromatic nuclei (darkly staining due to increased DNA content), which is a key feature of the condition.

# Renin secretion is stimulated by all EXCEPT: A. Cardiac failure B. Low Na+ in proximal tubule C. Sympathetic stimulation D. High Na+ in proximal tubule The correct answer is D. High Na+ in proximal tubule. Explanation: Renin secretion, primarily by the juxtaglomerular cells in the kidneys, is stimulated by factors that signal a need to increase blood pressure or sodium retention. These include: A. Cardiac failure: Reduced cardiac output lowers renal perfusion, stimulating renin release to activate the renin-angiotensin-aldosterone system (RAAS) to restore blood pressure. B. Low Na+ in proximal tubule: Detected by the macula densa, low sodium levels signal reduced filtrate delivery, triggering renin secretion to promote sodium reabsorption and increase blood volume. C. Sympathetic stimulation: Activation of the sympathetic nervous system, via beta-adrenergic receptors, directly stimulates renin release to address stress or low blood pressure. D. High Na+ in proximal tubule, however, d...

 # As no dental biomaterial is absolutely free from the potential risk of adverse reactions, the testing of biocompatibility is related to: A. Risk factors B. Risk assessment C. Risk markers D. Risk predictors The correct answer is B. Risk assessment. Explanation: Biocompatibility testing for dental biomaterials focuses on evaluating the potential for adverse biological reactions, such as toxicity or irritation, when the material interacts with the body. This process is a key component of risk assessment, which involves systematically identifying, analyzing, and evaluating risks to ensure the material is safe for use. By assessing these risks, manufacturers and clinicians can minimize potential harm to patients.

 # Traumatic injury of a nerve causing paresthesia is: A. Neuropraxia B. Neurotmesis C. Axonotmesis D. Toxolysis The correct answer is A. Neuropraxia . Explanation : Neuropraxia is the mildest form of traumatic nerve injury, involving a temporary conduction block due to compression or mild trauma. It often causes paresthesia (tingling or numbness) without significant structural damage to the nerve. Recovery is usually complete within days to weeks. Neurotmesis is the most severe nerve injury, involving complete nerve transection with disruption of the nerve and its sheath, leading to permanent loss of function unless surgically repaired. Paresthesia may occur, but it’s not the primary feature. Axonotmesis involves damage to the axons but preservation of the nerve’s connective tissue. It causes more severe symptoms than neuropraxia, with longer recovery times (weeks to months), and paresthesia may be present but is less characteristic. Toxolysis is not a standard term in ...