Dentosphere : World of Dentistry

 # A minor connector contacting the axial surface of an abutment should not be located on a: A. Flat surface B. Concavo-convex surface C. Convex surface D. Concave surface The correct answer is C. Convex surface. Minor connector contacting the axial surface of an abutment should not be located on a convex surface. Instead, it should be located in an embrasure.  CLICK HERE FOR MORE MCQs

 # The first step in surveying the cast for RPD is:  A. Establishment of guiding plane B. Establishments of undercuts for retention C. Establishment of tooth contour for esthetics D. Establishment of interferences for major connector The correct answer is A. Establishment of guiding plane. The step by step procedures in surveying are: - Guiding planes - Retentive areas - Interferences - Esthetics CLICK HERE FOR MORE MCQs

 # A wrought wire clasp is considered most effective in Kennedy Class:  A. III cases for periodontally weakened abutment teeth B. I cases for periodontally weakened abutment teeth C. II cases for the non edentulous side D. IV cases with periodontally weakened teeth The correct answer is B. I cases for periodontally weakened abutment teeth. The wrought wire clasp is generally considered to flex and be kinder to the abutment tooth periodontally although it engages the undercuts about two to three times greater than a cast clasp.  CLICK HERE FOR MORE MCQs

 # Cotton wool appearance is seen in: A. Paget’s disease B. Osteomyelitis C. Fibrous dysplasia D. Achondroplasia The correct answer is A. Paget's disease. The radiographic appearance of chronic diffuse sclerosing osteomyelitis is, as the name suggests, that of a diffuse patchy, sclerosis of bone often described as ‘cotton-wool’ appearance. This radiopaque lesion may be extensive and is sometimes bilateral. In occasional cases, there is bilateral involvement of both the maxilla and the mandible in the same patient. Because of the diffuse nature of the disease, the border between the sclerosis and the normal bone is often indistinct. The pattern may actually mimic Paget’s disease of bone or cemento-osseous dysplasia. Reference: Shafer's  CLICK HERE FOR MORE MCQs

 # Pathological calcification is seen in: A. Scleroderma B. Lichen planus C. Dystrophic epidermolysis bullosa D. Lupus erythematosus The correct answer is A. Scleroderma. Pathologic calcification is a common process in a wide variety of disease states; it implies the abnormal deposition of calcium salts, together with smaller amounts of iron, magnesium, and other minerals. When the deposition occurs in dead or dying tissues, it is called dystrophic calcification; it occurs in the absence of derangements in calcium metabolism (i.e., with normal serum levels of calcium). In contrast, the deposition of calcium salts in normal tissues is known as metastatic calcification and is almost always secondary to some derangement in calcium metabolism (hypercalcemia). Of note, while hypercalcemia is not a prerequisite for dystrophic calcification, it can exacerbate it. Systemic sclerosis can be classified into two groups on the basis of its clinical course: • Diffuse scleroderma, characterized ...

 # Non disjunction of chromosome occurs in which stage? A. Prophase B. Metaphase C. Anaphase D. Telophase The correct answer is C. Anaphase. Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division (mitosis/meiosis). There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate during meiosis II, and failure of sister chromatids to separate during mitosis. Meiosis II Ovulated eggs become arrested in metaphase II until fertilization triggers the second meiotic division. Similar to the segregation events of mitosis, the pairs of sister chromatids resulting from the separation of bivalents in meiosis I are further separated in anaphase of meiosis II. In oocytes, one sister chromatid is segregated into the second polar body, while the other stays inside the egg. During spermatogenesis, each meiotic division is symmetric such that each p...

 # Mediators of inflammation are all EXCEPT: A. TNF B. IFN C. PG D. Myeloperoxidase The correct answer is D. Myeloperoxidase. Myeloperoxidase is not an inflammatory mediator. It is an enzyme in neutrophils that convert Cl-, I- and SCN- ions to corresponding acids -HOCl etc. These acids are potent oxidants and help in destroying the invading organisms.  CLICK HERE FOR MORE MCQs