Physical n Chemical injuries of teeth Flashcards
- The smear layer consisting of components of enamel, dentin,
water and saliva can be beneficial to the cut surface of dentin by
one of the following actions
(a) Reducing permeability of enamel
(b) Increasing the caries resistance of enamel
(c) Increasing surface of contact between tooth structure and
restorative material
(d) Reducing permeability of dentin
(d) Presence of smear layer over the cut surface helps to reduce
the permeability of dentin by closing off the opening of the
dentinal tubules and prevents the exit of dentinal fluid.
- Lesion manifested as alteration in ground substance, fibrosis,
edema, odontoblastic disruption and reduced predentin
formation in pulp directly opposite the cavity site produced by
high speed instrumentation is called
(a) Smear layer
(b) Tertiary dentin
(c) Dead tracts
(d) Rebound response
(d) This response is supposed to be caused by waves of energy
transmitted to the pulp tissue by the pulpal walls.
- Which amongst the following reactions is not directly attributable
to restorative materials on tooth?
(a) Hypercementosis
(b) Pulpal necrosis
(c) Tertiary dentin formation
(d) Dead tracts formation
(a) Majority of the restorative materials exert their pulp irritant
action only after coming in close contact with pulpal
tissues. Materials with high irritant action are avoided
these days. Also with the use of cavity liners and varnishes,
the incidence of pulp irritation has drastically come down.
Hypercementosis is not a response associated with most
restorative materials
- Identify the incorrect statement regarding traumatic bone cyst.
(a) Most commonly occurs in mandible
(b) Appears as a well-defined, unilocular radiolucency
(c) It is lined by stratified squamous epithelium
(d) Thought to arise due to trauma, followed by degeneration
of clot.
(c) Traumatic cyst is classified as a pseudocyst, i.e. a cyst that
lacks an epithelial lining.
- Which one of the following lesions cannot be considered in the
differential diagnosis of focal osteoporotic bone marrow defect?
(a) Dentigerous cyst
(b) Odontogenic keratocyst
(c) Traumatic bone cyst
(d) Residual cyst
(a) A dentigerous cyst by definition, is attached to the neck of
the tooth, while other lesions including focal osteoporotic
bone marrow defect are not intimately associated with a
tooth.
- Apart from the base of socket, where else is new bone deposited
during extrusive movement of tooth?
(a) Outer surface of labial cortical plate
(b) Crest of alveolar socket
(c) Outer surface of lingual cortical plate
(d) Inner surface of lingual cortical plate
(b) The tissue changes produced by extrusive movements consist
of deposition of new bone spicules at the alveolar crest and
base of the alveolar socket with the spicules arranged in a
direction parallel to the direction of orthodontic force
- Which amongst the following is not directly attributable to
bruxism?
(a) Gingival recession
(b) Root resorption
(c) Severe tooth attrition
(d) Loosening of teeth
(b) Bruxism or night grinding is the habitual biting or grinding
of teeth during sleep or as an unconscious act even during
waking hours. Local, systemic, psychogenic as well as
occupational factors are recognized in the etiology. In
well-established cases, severe attrition, gingival recession,
drifting of teeth, facial pain, TMJ disturbances and
hypertrophy of masticatory muscles especially master have
been reported.
- Which one of the following is not a cause of tooth ankylosis?
(a) Periapical inflammation as a result of pulp infection
(b) Damage to PDL resulting from endodontic treatment
(c) Fracture of crown without pulp involvement
(d) Occlusal traumatism
(c) Ankylosis occurs when partial root resorption is followed by
repair with either cementum or bone that unites the root and
the surrounding alveolar bone. It is rarely seen in deciduous
teeth and is even rarer in permanent teeth. While occlusal
trauma, periapical inflammation and endodontic treatment
resulting in PDL damage can predispose to ankylosis, crown
fracture is not associated with tooth ankylosis.
- Fractures of teeth most commonly occur in
(a) Maxillary posterior teeth
(b) Maxillary anterior teeth
(c) Mandibular anterior teeth
(d) Mandibular posterior teeth
(b) Fracture of teeth is very common and can occur in a great
variety of setting, but the commonest is a sudden, severe
trauma like a blow, fall or other common incidents with
which children are usually involved. Expectedly, it is the
maxillary anterior teeth that are most prone to accidental
injuries
- Vitality of a tooth is most likely to be maintained if
(a) Crown is fractured without pulp involvement
(b) Crown is fractured with only a very thin layer of dentin
remaining
(c) Crown is fractured with pulp exposure
(d) Root is fractured with pulp involvement
(a) Except (a), in all other instances, the pulp is either vulnerable
or is exposed and irreversibly inflamed leading to its death
- Riga-Fede disease represents
(a) Recurrent aphthous ulcerations
(b) Traumatic ulcerations caused by erupting teeth during
nursing, in infants
(c) Herpetic ulcerations
(d) Linea alba
(b) Riga-Fede disease occurs in infants between one week
and one year of life. Lesions are observed usually on
anteroventral surface of tongue caused by contact of tongue
with erupting mandibular incisors.
- All of the following terms except ____ represent Epulis fissuratum.
(a) Denture injury tumor
(b) Denture epulis
(c) Inflammatory papillary hyperplasia
(d) Inflammatory fibrous hyperplasia
(c) Epulis fissuratum is one of the most common tissue
reactions to chronically ill-fitting denture. It is manifested as hyperplasia of tissue along the denture borders, characterized by development of elongated rolls of tissue
in the mucobuccal or mucolabial fold, area in which the
flange of a denture sits.
- Which amongst the following is not associated with occlusal
trauma?
(a) Attrition
(b) Faulty occlusion
(c) Bruxism
(d) Epulis fissuratum
(d) Physiologic tooth wear, drifting of teeth, high filling, faulty
occlusion, bruxism, improper orthodontic tooth movement
are all commonly associated with chronic occlusal
trauma.
- Blowing of compressed air into a root canal can result in
(a) Cervicofacial emphysema
(b) Anesthetic necrosis
(c) Pneumoparotid
(d) Motsus humanus
(a) Emphysema refers to swelling due to presence of air in
the interstices of connective tissue. This can occur due
blowing of air into root canal(s) or periodontal pocket,
spontaneously due to patient’s breathing action following
some surgical procedures, etc
- White or reddish, ulcerative or superficial erosions on marginal
and attached gingivae involving maxillary canine and premolars
is most likely to be
(a) Recurrent aphthous ulcers
(b) Herpetic gingivostomatitis
(c) Toothbrush trauma
(d) Epidermolysis bullosa
(c) Toothbrush trauma lesions can be very commonly mistaken
for vesiculobullous lesions or infective lesions if the history
is not elicited properly.
