Dentosphere : World of Dentistry

 # Gangrene due to known infectious agent is:  A. Wet gangrene B. Dry gangrene C. Pyoderma granulosum D. Fournier gangrene The correct answer is D. Fournier gangrene.  Fournier gangrene, a relatively rare form of necrotizing fasciitis, is a rapidly progressive disease that affects the deep and superficial tissues of the perineal, anal, scrotal, and genital regions. Named after Dr. Alfred Fournier, the French dermatology and venereal specialist, it was initially described in 1883 as necrotizing fasciitis of the external genitalia, perineal, and perianal region in five of Dr. Fournier’s patients. Also known as necrotizing fasciitis, the disease involves the rapid spread of severe inflammatory and infectious processes along fascial planes affecting adjacent soft tissue; therefore, the disease may initially go unnoticed or unrecognized as there may be minimal or no skin manifestations in its early stages. This disease process results from polymicrobial aerobic and anaerobic s...

 # Biosafety level 4 (BSL-4) pathogen is:  A. XDR strain of Mycobacterium tuberculosis B. SARS CoV-2 C. Ebola D. Measles The correct answer is C. Ebola. Biological Safety Levels (BSL) are a series of protections relegated to the activities that take place in particular biological labs. They are individual safeguards designed to protect laboratory personnel, as well as the surrounding environment and community. These levels, which are ranked from one to four, are selected based on the agents or organisms that are being researched or worked on in any given laboratory setting. For example, a basic lab setting specializing in the research of nonlethal agents that pose a minimal potential threat to lab workers and the environment are generally considered BSL-1—the lowest biosafety lab level. A specialized research laboratory that deals with potentially deadly infectious agents like Ebola would be designated as BSL-4—the highest and most stringent level. The Centers for Disease Cont...

 # Once bone is formed, it grows by:  A. Interstitial growth only B. Appositional growth only C. Both appositional and interstitial growth D. Degenerative changes into bony structures The correct answer is B. Appositional growth only. Which is growth by the addition of new layers on those previously formed. Bone formation begins in the embryo where mesenchymal cells differentiate into either fibrous membrane or cartilage.  This leads to two paths of bone development: 1. Intramembranous ossification is so called because it takes place in membranes of connective tissue. Osteoprogenitor cells in the membrane differentiate into osteoblasts: a collagen matrix is formed which undergoes ossification. Note: The maxilla and mandible as well as the cranial vault are forrmed this way. 2. Endochondral ossification is how the remainder of the skeleton forms and takes place within a hyaline cartilage model. Cartilage cells are replaced by bone cells (osteocytes replace chondrocytes), o...

 # The incisor overjet is increased for a  class II case that is undergoing treatment. The reason is:  A. Loss of anchorage B. Arch collapse C. Crowding in the lower arch D. None of the above The correct answer is A. Loss of anchorage. Following are the features of anchorage loss in class II cases: - Increase in overjet - Molar relation  becoming more class II - Normal canine relation without any change

 # Which of the following are typical and acceptable preventive and therapeutic measures for dealing with the periodontal problems during fixed appliance therapy?  A. Elimination of gingivitis prior to placing orthodontic appliances B. Home care instructions regarding the use of toothbrush and water pik during orthodontic treatment C. Megavitamin therapy D. Scaling and curettage immediately after appliance removal The correct answer is A. Elimination of gingivitis prior to placing orthodontic appliances. The mean value of visible plaque and visible inflammation showed significant increases during orthodontic treatment. Therefore, prior to orthodontic treatment, patients should have a high level of periodontal health and it should be maintained during the treatment period. Considering the relationship between orthodontic treatment and gingival health, patients, orthodontists and periodontists should cooperate during orthodontic treatment. Reference: Boke F, Gazioglu C...

 # FDA approved locally delivered minocycline for subgingival placement is marketed under trade name:  A. Periochip B. Atridox C. Arestin D. Elyzol The correct answer is C. Arestin. FDA has approved Arestin 2% Minocycline for subgingival placement as an adjunct to scaling and root planning. Periochip: Chlorhexidine chip placed in the pocket for local drug delivery.

 # The recommended concentration of acidulated phosphate (APF) fluoride gel is:  A. 2% B. 8% C. 1.23% D. 10% The correct answer is C. 1.23%. Brudevold's solution or APF solution is prepared by dissolving 20 gms of NaF in 1 Litre (2% NaF) of 0.1M phosphoric acid and to this 50% hydro fluoric acid is added to adjust the pH at 3.0 and fluoride ion concentration at 1.23% APF gel is prepared by adding gelling agents like methylcellulose and hydroxyl ethyl cellulose and the pH is adjusted between 4-5.