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All Ceramic Restorations

 # Which of the following is the BEST way to avoid porcelain failure in all-ceramic restorations?
A. Rounded angles of the preparation
B. Minimal occlusal forces
C. Porcelain is 3.5mm thick
D. Porcelain is not more than 0.5mm thick 




The correct answer is A. Rounded angles of the preparation.

All ceramic restorations should include rounded angles in the tooth preparation in order to reduce stress concentration along these areas. Sharp angles within tooth preparations are areas where stress is concentrated, and may cause fracturing.

Porcelain thickness is also an important factor in its fracture toughness. All porcelain crowns should have a minimum thickness of 1mm circumferentially and about 1.5mm along the occlusal/ incisal to
achieve strength (Not including the framework of the restoration).

Proper case selection and occlusal load analysis is also an important factor in preventing failure of an all ceramic restoration. 



Abutment teeth in a fixed partial denture

 # What is the primary reason why dentists splint adjacent abutment teeth in a fixed partial denture?
A. Improve spacing mesiodistally
B. Stabilize abutment teeth
C. Improve embrasure contours
D. Improve the distribution of the occlusal load 



The correct answer is D. Improve the distribution of the occlusal load 

Abutment teeth are included in fixed partial dentures to provide retention and help disperse the occlusal load placed on the restoration.

Abutment teeth provides support and stability to the pontic.

Abutment teeth allows better distribution of the occlusal forces acting on all teeth and pontic in the fixed partial denture.


Packing acrylic resin into the denture flasks

# After packing acrylic resin into the denture flasks, one should wait to cure the resin to:
A. Assure full flow of acrylic into the denture mold
B. Allow the monomer to reach all acrylic polymer
C. Allow for pressure to be equalized between the acrylic and flask
D. Make sure temperature equilibrium exists between the flask and acrylic 



The correct answer is D. Make sure temperature equilibrium exists between the flask and acrylic

Allowing the dental flask packed with acrylic to remain under the bench press until equilibrium in temperature is achieved will give enough time for the acrylic to achieve better monomer-polymer interaction and create stronger chemical bond.

The curing of resin should be uniformly completed to lessen any chances of distortion before and during the time the flask is immersed in a water bath.

 

Packing the acrylic during the rubbery stage

# When fabricating dentures, what would be the most likely outcome if the lab compressed/packed the acrylic during the rubbery stage?
A. Higher porosity than normal
B. A lot of extra resin being attached to the denture that will take a long time to trim
C. Incomplete picking up of anatomical details
D. The denture would have an increased VDO 



The correct answer is C. Incomplete picking up of anatomical details

Packing and compressing acrylic during denture fabrication should be done in its doughy stage.

The doughy stage is the ideal for packing acrylic resin because it is the moment when acrylic is most packable and workable.

The rubbery stage of acrylic denotes the start of the setting when heat is released from the setting acrylic.

Rubbery acrylic also has a tendency to revert back to its original position regardless of the forces applied to it during packing, resulting in incomplete packing.

VDO (Vertical Dimension of Occlusion) is synonymous with OVD (Occlusal Vertical Dimension) and is the relationship of the maxilla and mandible when the teeth are in maximum intercuspation. 
 

Excess height of the posterior palatal seal

 # Excess height of the posterior palatal seal of a complete maxillary denture will usually result in which of the following?
A. Gagging
B. Increased retention
C. A tingling or tickling sensation
D. Unseating of the denture



The correct answer is D. Unseating of the denture.

Over contouring or excessive beading of the posterior palatal seal causes too much pressure to be exerted on the palatal tissues resulting in the unseating of upper dentures.

The posterior palatal seal is typically placed approximately on the vibrating line between the hard and soft palate and provides a physiologically acceptable tissue pressure within the compressible portion of the soft palate to attain retention and peripheral seal.

Over extending the coverage of seal will cause gaggling and painful swallowing for the part of the patient. 

Flabby maxillary anterior ridge

# Which of the following is associated with a flabby maxillary anterior ridge under a complete denture?
A. Retained mandibular anterior teeth
B. A "V" shaped ridge
C. A "U" shaped ridge
D. A patient with Class Il occlusion
E. Osteoporosis 



The correct answer is A. Retained mandibular anterior teeth.

Combination syndrome is a condition that usually occurs when retained mandibular
anterior teeth opposes a maxillary complete denture.

In combination syndrome, the anterior aspect of upper maxillary ridge becomes highly resorbed and flabby due to the biting force against its natural tooth antagonist.

Since the occlusal force of a natural tooth is stronger than the force of a denture supported by an alveolar ridge, the area under pressure will exhibit higher resorption pattern than the rest of the denture.

Pterygomandibular raphe is a tendon between

# Pterygomandibular raphe is a tendon between which of the following muscles?
A. Masseter and medial pterygoid
B. Anterior belly of the digastric and Buccinator
C. Buccinator and Superior constrictor
D. Buccinator and Masseter


The correct answer is C. Buccinator and Superior constrictor.

Pterygomandibular raphe acts as a tendon between the buccinator and superior Constrictor muscle. It is a landmark used often for the identification of the pterygomandibular space for the administration of an inferior alveolar nerve block.

The injecting needle pierces the buccinator muscle to inject the local anesthetic solution in the pterygomandibular space.


 

Number of lobes in a tooth

 # The minimum number of lobes from which any tooth may develop is:
A. Two
B. Three
C. Four
D. Five




The correct answer is: C. Four.

Tooth development begins with increased cell activity in growth centers in the tooth germ. A growth center (lobe) is an area of the tooth germ where the cells are particularly active. These lobes are primary centers of calcification and are primary sections of formation in the development of the crown of a tooth. They are represented by a cusp on posterior teeth and mamelons and cingula on anterior teeth. They are always separated by developmental grooves, which are very prominent in the posterior teeth and form specific patterns. With anterior teeth, their presence is much less noticeable and these lobes are separated by what are known as developmental depressions.

Summary of number of lobes:
•All anterior teeth: three labial and one lingual (cingulum)
• Premolars: three buccal and one lingual.
Exception: The mandibular second premolar has three buccal and two lingual lobes.

• First molars (maxillary and mandibular): five lobes, represented by five cusps - one lobe for each cusp
•Second molars (maxillary and mandibular): four lobes, one for each cusp
• Third molars: at least four lobes. one for each cusp ***variations arc seen

Lethal dose of Fluoride

# The lethal dose of fluoride for a typical three-year-old child is approximately :
A. 100 mg
B. 200 mg
C. 350 mg
D. 500 mg
 

The correct answer is D. 500 mg.

The studies and surveys link fluorosis to three factors:
• Fluorosis is more common in geographic areas where the endemic levels of fluoride in the drinking water is higher than three parts per million
• Fluorosis is associated with fluoride supplementation at inappropriately high levels
• The use of fluoridated toothpaste has been implicated in fluorosis

In acute fluoride toxicity, the goal is to minimize the amount of fluoride absorbed. Therefore, syrup of ipecac is administered to induce vomiting. Calcium-binding products, such as milk or milk of magnesia, decrease the acidity of the stomach, forming insoluble complexes with the fluoride and thereby decrease its absorption. Note: Emergency Medical Service should be activated.

In acute fluoride toxicity, symptoms may appear within 30 minutes of ingestion and persist for up to 24 hours. Patients may experience some nausea, vomiting, diarrhea, and abdominal cramping. This may be due to the fact that 90-95% of ingested fluoride is absorbed through the stomach and small intestines. Fluorides are primarily eliminated from the body by way of the kidneys. However, the fluoride that does remain in the body is found mostly in skeletal tissue. In acute fluoride poisoning (which is rare), the most common causes of death are cardiac failure and respiratory paralysis. Fluoride toxicity shows up in the bones as osteosclerosis.

Important: The lethal dose of fluoride for a typical 3-year-old child is approximately 500 mg and would be proportionately less for a younger child and smaller child. To avoid the possibility of ingestion of large amounts of fluoride it is recommended that no more than 120 mg of supplemental fluoride be prescribed at any one time.

Note: If a six-year old child were receiving fluoridated water in the amount of 3 ppm, the result would most likely be fluorosis but not systemic toxicity. On the other hand, if a child in the same age range (6-7) were receiving 8 ppm of fluoridated water, there would be a good chance of systemic toxicity and moderate to severe fluorosis occurring.

Koplik's Spots are seen in

# "Koplik's spots" are associated with:
A. Smallpox (Variola)
B. German measles (Rubella)
C. Mumps
D. (Rubeola)


The correct answer is. D. Measles (Rubeola)

Before immunization, measles was very common during childhood so that 90% of the population had been infected by age 20.

Measles (also called Rubeola) is a highly contagious viral illness characterized by a fever, cough, and a spreading rash. It is caused by a paramyxovirus. The incubation period is 1 to 2 weeks before symptoms generally appear. The oral lesions are pathognomonic of this disease. These characteristic "Koplik's spots" usually occur on the buccal mucosa. They are 1-2 mm, yellow-white necrotic ulcers that are surrounded by a bright red margin.

Rubella (or German measles) is a fairly benign viral disease. The symptoms usually include
a red, bumpy rash, swollen lymph nodes (most often around the ears and neck), and a mild fever. Some people will feel a little achy. The virus can manifest in the oral cavity as small petechiae-like spots of the soft palate. The defects of congenital infection from an infected mother are more severe -enamel defects, hypoplasia, pitting, and abnormal tooth morphology.

Smallpox (Variola) is an acute viral disease, it manifests itself clinically by the occurrence of a high fever, nausea, vomiting, chills, and headache. The skin lesions begin as small macules and papules which first appear on the face, but rapidly spread to cover much of the body. Oral manifestations include ulceration of the oral mucosa and pharynx. In some cases, the tongue is swollen and painful, making swallowing difficult.

Mumps is an acute contagious viral infection characterized chiefly by unilateral or bilateral swelling of the salivary glands, usually the parotid (parotitis). Although it is usually a disease of childhood, mumps may also affect adults. The papilla of the opening of the parotid duct on the buccal mucosa is often puffy and reddened.

3M Ketac Molar Easymix Glass Ionomer Cement

 This particular brand of Glass Ionomer Cement Ketac Molar Easymix by 3M Germany was available in the dental clinic where I work. The powder felt like wheat flour and even after mixing repeatedly, I couldn't get the required consistency. I had used exactly one scoop of powder by the scoop provided by the manufacturer with one drop of liquid. Have you experienced the same problem? Or is this a great GIC product What about its clinical success? Please leave your honest feedback.



Seizure in the dental clinic

# Which of the following is true concerning a young epileptic who has a grand mal seizure in the dental office?
A. It is generally fatal
B. It is best treated by injecting insulin
C. They generally recover if restrained from self-injury and oxygen is maintained
D. It can be prevented with antibiotics



 The correct answer is C. They generally recover if restrained from self-injury and oxygen is maintained

Of the multiple types of seizures, the tonic-clonic (grand mal) type is the most frightening and the one that most often requires treatment. Grand mal seizures are manifested in four phases: the prodromal phase, the aura, the convulsive (ictal) phase, and the postictal phase.

The prodromal phase consists of subtle changes that may occur over minutes to hours. It is usually not clinically evident to the clinician or the patient. The aura is a neurologic experience that the patient goes through immediately prior to the seizure. It is specifically related to trigger areas of the brain in which seizure activity begins. It may consist of a taste, a smell, a hallucination, motor activity, or other symptoms. As the CNS discharge becomes generalized, the ictal phase begins. The patient loses consciousness, falls to the floor, and tonic, rigid skeletal muscle contraction ensues. This usually lasts 1 to 3 minutes.

As this phase ends, the muscles relax and movement stops. A significant degree of CNS depression is usually present during this postictal phase, and it may result in respiratory depression. Management of the seizure consists of gentle restraint and positioning of the patient in order to prevent self-injury, ensuring adequate ventilation, and supportive care, as indicated, in the postictal phase, especially airway management. Single seizures do not require drug therapy because they are self-limiting.

Important: Should the ictal phase last longer than 5 minutes or if seizures continue to develop with little time between them, a condition called status epilepticus has developed. This may be a life-threatening medical emergency. This condition is best treated with intravenous diazepam, and transport should be arranged to take the patient to the hospital.

Oral manifestation of Achondroplasia

 # An outstanding oral manifestation of achondroplasia is:
A. Rampant caries
B. Periodontal disease
C. Overcrowding of teeth
D. Supernumerary teeth



The correct answer is C. Overcrowding of teeth.

Achondroplasia is the most common form of short-limb dwarfism. It occurs in all races and with equal frequency in males and females. An individual with achondroplasia has a disproportionate short stature -- the head is large and the arms and legs are short when compared to the trunk length. Other signs are a prominent forehead and a depressed bridge of the nose. Many of these children die during the first year of life. Deficient growth in the cranial base is evident in many children that survive.

Important: The maxilla may be small with the resultant crowding of the teeth.

Note: A Class III malocclusion is very common.

Remember: The oral manifestations of the following disorders in children:

• Gigantism: enlarged tongue, mandibular prognathism, teeth are usually tipped to the buccal or lingual side, owing to enlargement of the tongue. Roots may be longer than normal.

• Pituitary dwarfism: the eruption rate and the shedding of the teeth are delayed, clinical crowns appear smaller as do the roots of the teeth, the dental arch as a whole is smaller causing malocclusion, and the mandible is underdeveloped.


Iron content in each ml of blood

 # Each milliliter of red cells contain how much elemental iron ?
A. 1 mg
B. 2 mg
C. 3 mg
D. 4 mg


The correct answer is A. 1 mg.

Each milliliter of red cells contains 1 mg of elemental iron.
Ref: Harrison’s 18th Ed. 845

Flexural strength

# The term "flexural strength" describes a material with the ability do which of the following?
A. Be visually detectable in radiographs
B. Sustain deformation without permanent change in
size or shape
C. Resist fracture during bending
D. Resist the propagation of a crack


The correct answer is C. Resist fracture during bending. 

Flexural strength is the ability of a material
to resist fracture while bending and is also
known as modulus of rupture, bend
strength, or fracture strength.

The transverse bending test is most
frequently employed to evaluate the flexural strength of a material using a 3-point flexural test technique.

The flexural strength gives the highest
stress experienced within the material at its
moment of rupture.

The significance of flexural strength is
commonly expressed in class V cervical
restorations.

Low tensile and high compressive strength

# A material with a low tensile strength and high compressive strength can be described as which of the following?
A. Ductile
B. Malleable
C. Resilient
D. Brittle
E. Tough


The correct answer is D. Brittle. 

Brittle materials can be hard solid materials
that can withstand heavy compression but
not tension.

Brittle materials exhibit low tensile strength and may fracture or break instead of being deformed when under tensile stress.

Ductile materials exhibit high tensile
strength and low compressive strength,
making them capable of being drawn into
wires.

Excessive segmentation of nucleus of neutrophils

# Excessive segmentation of nucleus of neutrophils is a manifestation of ?
A. Folate or vitamin B12 deficiency
B. Iron deficiency
C. Thalassemia
D. Repeated blood transfusion



The correct answer is: A. Folate or vitamin B12 deficiency.

Nucleus of neutrophils normally contains up to four segments. Excessive segmentation (>5
nuclear lobes) is seen in folate or vitamin B12 deficiency & congenital neutropenia syndrome of
warts, hypogammaglobulinemia, infections & myelokathexis (WHIM).

Ref: Harrison’s 18th Ed. 473

Contraindication for splenectomy

# Which out of the following is a contraindication for splenectomy ?
A. Iatrogenic splenic rupture
B. Thrombocytopenia
C. Presence of bone marrow failure
D. Hairy cell leukemia


The correct answer is C. Presence of bone marrow failure.

The only contraindication to splenectomy is the presence of marrow failure, in which the
enlarged spleen is the only source of hematopoietic tissue.

Ref: Harrison’s 18th Ed. 471

Weight of Normal Spleen

# Weight of a normal spleen is ?
A. < 150 grams
B. < 250 grams
C. < 350 grams
D. < 450 grams


The correct answer is B. < 250 grams.

Normal spleen weighs <250 grams.
Ref: Harrison’s 18th Ed. 468

Enlarged, grayish yellow or orange tonsils are pathognomic of

# Enlarged, grayish yellow or orange tonsils are pathognomic of ?
A. Waldenström’s macroglobulinemia
B. Polycythemia vera
C. Wolman disease
D. Tangier disease



The correct answer is D. Tangier Disease.

Tangier disease is associated with cholesterol accumulation in reticuloendothelial system with
hepatosplenomegaly & enlarged, grayish yellow or orange tonsils.

Ref: Harrison’s 18th Ed. 3154

Preauricular lymphadenopathy

# Preauricular lymphadenopathy accompanies which of the following?
A. Scalp infection
B. Ear infection
C. Conjunctival infections
D. Tooth infection




The correct answer is: C. Conjunctival infections.

Preauricular adenopathy accompanies conjunctival infections and cat-scratch disease.

Ref: Harrison’s 18th Ed. 466

Occipital lymphadenopathy

# Occipital lymphadenopathy accompanies which of the following ?
A. Scalp infection
B. Ear infection
C. Conjunctival infections
D. Tooth infection



The correct answer is : A. Scalp infection.

Occipital adenopathy often reflects infection of the scalp.
Ref: Harrison’s 18th Ed. 466

Platelet count rise at what time of menstrual cycle?

# During menstrual cycle, platelet count rise at what time ?
A. Following ovulation
B. At the onset of menses
C. After completion of menstrual flow
D. Before ovulation


The correct answer is A. Following ovulation.

Platelet count varies in menstrual cycle, rising following ovulation & falling at onset of menses.
Ref: Harrison’s 16th Ed. 673

Major risk factor for arterial thrombosis

# The major risk factor for arterial thrombosis is ?
A. Atherosclerosis
B. Hyperhomocysteinemia
C. Dysfibrinogenemia
D. Hormonal therapy


The correct answer is: A. Atherosclerosis. 

The major risk factor for arterial thrombosis is atherosclerosis. Risk factors for venous thrombosis
are immobility, surgery, underlying medical conditions, malignancy, hormonal therapy, obesity,
and genetic predispositions.

Epistaxis is the most common symptom in

# Epistaxis is the most common symptom in ?
A. Hemophilia A
B. Ehlers-Danlos syndrome
C. Hereditary hemorrhagic telangiectasia
D. Cushing’s syndrome


The correct answer is C. Hereditary hemorrhagic telangiectasia

Epistaxis is the most common symptom in hereditary hemorrhagic telangiectasia & in boys with Von Willebrand Disease.
Ref: Harrison’s 18th Ed. 460

Poikilocytosis

# Poikilocytosis is related to which feature of RBC ?
A. Size
B. Shape
C. Number
D. Colour


The correct answer is: B. Shape.

Variations in red cell shape is called poikilocytosis. Poikilocytosis suggests a defect in the
maturation of red cell precursors in bone marrow or fragmentation of circulating red cells.

Ref: Harrison’s 18th Ed. 450

Anisocytosis

# Anisocytosis is related to which feature of RBC ?
A. Size
B. Shape
C. Number
D. Colour


The correct answer is A. Size.
Variations in red cell size is called anisocytosis.

Ref: Harrison’s 18th Ed. 450

Palmar creases are lighter - Low Hemoglobin

# If palmar creases are lighter in color than surrounding skin, hemoglobin level is usually ?
A. < 10 g/dL
B. < 8 g/dL
C. < 6 g/dL
D. < 4 g/dL



The correct answer is B. < 8g/dL.

If the palmar creases are lighter in color than the surrounding skin with hyperextended hand,
the hemoglobin level is usually < 8 g/dL.  
Ref: Harrison’s 18th Ed. 449

Erythropoietin is produced by

# Erythropoietin is produced and released by ?
A. Glomerular capillaries
B. Proximal tubular cells
C. Peritubular capillary lining cells of kidney
D. All of the above


The correct answer is C. Peritubular capillary lining cells of kidney.

Physiologic regulator of RBC production, glycoprotein hormone EPO, is produced & released by
highly specialized epithelial-like peritubular capillary lining cells within kidney.

Ref: Harrison’s 18th Ed. 448

Role of Erythropoietin

# In the absence of erythropoietin (EPO), committed erythroid progenitor cells undergo ?
A. Stunted growth
B. Halting of growth
C. Programmed cell death (apoptosis)
D. Change to other series of hematopoietic cell


The correct answer is C. Programmed cell death (apoptosis).

For RBC production, EPO is the regulatory hormone. It is required for maintenance of committed
erythroid progenitor cells which undergoes programmed cell death (apoptosis) if EPO is absent.

Ref: Harrison’s 18th Ed. 448

Painful preauricular lymphadenopathy is a feature of

# Painful preauricular lymphadenopathy is a feature of ?
A. Cat-scratch disease
B. Tularemia
C. Tuberculosis
D. Syphilis


The correct answer is B. Tularemia.

Painful preauricular lymphadenopathy is unique to tularemia and distinguishes it from catscratch
disease, tuberculosis, sporotrichosis, and syphilis. 
Ref: Harrison’s 17th Ed. 978

Tularemia, also known as rabbit fever, is an infectious disease caused by the bacterium Francisella tularensis. Symptoms may include fever, skin ulcers, and enlarged lymph nodes. Occasionally, a form that results in pneumonia or a throat infection may occur.

The bacterium is typically spread by ticks, deer flies, or contact with infected animals. It may also be spread by drinking contaminated water or breathing in contaminated dust. It does not spread directly between people. Diagnosis is by blood tests or cultures of the infected site.

Multiple Choice Questions In Conservative Dentistry - Tooth Colored Restorations


# Restoration of angle fracture of anterior teeth can be done by:
A. Amalgam
B. Composite resin
C. Glass ionomer cement
D. All of the above

# Replanted avulsed tooth can be aesthetically stabilized by:
A. Occlusal splints
B. Composite resins
C. Arch bar
D. All of the above

# The main disadvantages of composites not being recommended for class II posterior restorations are:
A. Color matching is not good
B. Lacks sufficient strength
C. Occlusal wear
D. Frequent fractures at the isthmus

Not a contraindication to dental implant

# Which of the following conditions is not a contraindication to dental implant placement?
A. Diminished healing capacity of the patient's tissues
B. Current chemotherapy for the treatment of cancer
C. History of radiation therapy to the maxillofacial complex
D. Dysmorphophobia
E. Advanced patient age



Advanced patient age is not a contraindication to implant treatment. The ability of the
patient to withstand surgical treatment, etc. is a decision resting on the systemic health
of the patient.

Any condition that causes an impairment of the patient's ability to heal should be considered
as a contraindication to implant treatment. Serious psychiatric conditions such as psychoses should be considered a contraindication to implant treatment. Dysmorphophobia is an extremely irrational fear of being disfigured by treatment. Psychiatric complications can make the patient change his or her opinion about the acceptability of treatment which is difficult for the clinician to overcome.


Greatest esthetic challenge for the restorative dentist

# The greatest esthetic challenge for the restorative dentist occurs in the patient having a:
A. High smile line, thick periodontal biotype
B. Low smile line, thin periodontal biotype
C. Low smile line, thick periodontal biotype
D. High smile line, thin periodontal biotype



The correct answer is D. High Smile line, thin periodontal biotype

A low smile line indicates that the patient does not lift the lip upwards when smiling to
the extent that the gingival-restorative interface can be seen by the observer. Consequently,
esthetic compromises may be more acceptable to the patient because they are not routinely
visible. A thick periodontal biotype indicates that the patient has thicker, denser gingiva with a less pronounced scallop. This type of tissue is more resistant to the recession caused by restorative procedures and materials, a lower chance of "show-through" of the implant or abutment, and a lower chance of loss of the papillae adjacent to the implant.

Shade selection for composite restoration

# Shade selection for composite restoration in anterior teeth should be done:
 A. After end of etching
 B. After prolonged drying
 C. Before prolonged drying
 D. After applying bonding agent


The correct answer is C. Before prolonged drying.

For shade selection, the teeth should be moist and should not be dehydrated. A dehydrated tooth gives a whiter appearance due to scattering and reflection of light. Bleaching procedures if any should be done before shade selection.

Permanent dentition stage normally begins with:

# The permanent dentition stage normally begins with which of the following?
A. Exfoliation of the primary mandibular central incisor
B. Exfoliation of the primary maxillary 2nd molar
C. Eruption of the permanent mandibular 1st molar
D. Eruption of the permanent maxillary 1st molar
E. Exfoliation of the primary mandibular 1st molar


The correct answer is B. Exfoliation of the primary maxillary 2nd molar. 

The permanent dentition stage does not
begin until the final primary tooth is
exfoliated.

The term "'mixed dentition" describes the
time between the eruption of the permanent 1st molars until the exfoliation of the last primary tooth.

Patients who retain primary teeth don't
leave the mixed dentition stage until the
primary teeth are lost.

Primary dentition: 6 months- 6 years
Mixed dentition: 6 years- 12 years
Permanent dentition: 12 years +

Most effective topical anesthetic

# Which of the following is most effective as a topical anesthetic?
A. Lidocaine
B. Bupivacaine
C. Procaine
D. Prilocaine
E. Articane


The correct answer is A. Lidocaine.


Lidocaine is proven to be an effective
topical anesthetic drug that can effectively
numb the mucosal surfaces the oral cavity.

It is a strong anesthetic drug usually
delivered in gel, liquid, lotion, spray or
cream form.

Lidocaine topical anesthetic can penetrate
approximately 2-3mm deep into the
mucosal layer when applied properly.

Impurity found in nitrous oxide

# The impurity that is theoretically found in nitrous oxide that is considered slightly toxic is:
A. Methane
B. Cyclohexane
C. Ethylene oxide
D. Nitric oxide


The correct answer is D. Nitric oxide.

Nitrous oxide is a gas that creates
analgesia and dissociated anesthesia and
is commonly used in dentistry.

Nitrous oxide was first used by Horace
Wells for his own tooth extraction by his
assistant.

Nitrous oxide is used in general anesthesia
to enhance the effect of other drugs being
administered by allowing the concentration
of other drugs to be decreased without
decreasing their effect.

When nitrous oxide reacts with oxygen and
is converted into nitric oxide, causing
vasodilation.

Causes of Dark appearance of radiograph

# After processing a film, you notice that it appears too dark. What is the most likely cause of this problem?
A. Inadequate development time
B. Developer solution too cool
C. Depleted developer solution
D. Excessive developing time




The correct answer is D. Excessive developing time.

The causes underlying dark appearance of a radiograph are:
- Excessive developing time
- Developer solution too hot
- Inaccurate timer or thermometer
- concentrated developer solution

Solutions for the dark appearance of radiograph
- Chcck development time.
- Check developer temperature.
- Replace faulty timer or thermometer.
- Replenish developer with fresh solutions as needed.

Coronoid process of the mandible often appears in periapical x-rays of:

# The image of the coronoid process of the mandible often appears in periapical x-rays of:
A. The incisor region of the mandible
B. The molar region of the mandible
C. The incisor region of the maxilla
D. The molar region of the maxilla



The correct answer is D. The molar region of the maxilla.

As the mouth is opened, the coronoid process moves forward, and therefore it comes into  view
most often when the mouth is opened to its fullest extent at the time the exposure is made.
It is evidenced by a tapered or triangular radiopacity, which may be seen below, or in some instances superimposed on the molar teeth and maxilla.

The coronoid process appears as a triangular-shaped radiopacity.

Contraindication of Pulpotomy

# Pulpotomies are CONTRAINDICATED on primary molars with which of the following?
A. Radiographic evidence of deep caries approximating the pulp chamber
B. Radiographic evidence of internal resorption
C. Sensitivity to sweets
D. Exposure of the pulp during caries excavation


The correct answer is B. Radiographic evidence of internal resorption.

Root canal therapy is indicated to treat
cases involving internal resorption.

When a carious lesion approximates or
extends into the pulp chamber of a
deciduous tooth, removal of coronal pulp is
performed to prevent the spread of the
infection into the radicular pulp.

Pulpotomies are performed on deciduous
teeth to prevent premature tooth loss and
potential loss of space.

Careful clinical and radiographic
assessment along with the child's medical
and dental history are necessary before
performing a pulpotomy.

Pulpotomy is contraindicated where there is:
- Internal resorption (root canal therapy
indicated)
- Perforation of pulp chamber floor
- Over 2 root resorption
- Cellulitis
- Localized abscess
- Draining sinus
- Inability to isolate the tooth
- Inability to properly restore tooth after the
procedure

Severe pain of dentoalveolar abscess

#Sudden relief of severe pain associated with a dentoalveolar abscess can be explained by which of the following?
A. Neutralizing effect of tissue enzymes
B. Walling-off of the infection by the body
C. Rupture of the abscess from the periosteum into the soft tissue
D. Neurotoxic effects of bacterial toxins anesthetize the nocioceptors


The correct answer is C. Rupture of the abscess from the periosteum into the soft tissue.

Dentoalveolar abscesses are an accumulation of pus within the teeth, gums,
and supporting alveolar bone.

The accumulation of pus within the
dentoalveolar abscess creates hydrostatic
pressure, resulting in the sensation of a
severe pain.

Dentoalveolar abscesses are treated
through root canal treatment and possibly
incision and drainage depending upon case
severity.

Drainage of the lesion releases the pressure
caused by the suppuration and results in a
sudden relief of pain is experienced by the
patient.

The major symptom of dentoalveolar
abscess is a severe, intense, and throbbing
pain which worsens with the passage of
time.

Dentoalveolar abscesses can be partially
diagnosed by noting the presence of a
periapical radiolucency.


Cementoblastoma is more often seen

# The cementoblastoma is more often seen:
A. In the mandible than in the maxilla, and more often posterior than in the anterior regions
B. In the mandible than in the maxilla, and more often anterior than in the posterior regions
C. In the maxilla than in the mandible, and more often posterior than in the anterior regions
D. In the maxilla than in the mandible, and more often anterior than in the posterior regions


The correct answer is A. In the mandible than in the maxilla, and more often posterior than in the anterior regions

The cementoblastoma, also known as the true cementoma, is a rare benign neoplasm of cementoblast origin. It occurs predominantly in the second and third decades, typically before 25 years of age. It is more often seen in the mandible than in the maxilla and more often posterior than in the anterior regions. It is intimately associated with the root of a tooth, and the tooth remains vital. It may cause cortical expansion and, occasionally, lowgrade intermittent pain. Radiographically, this is a well-circumscribed radiopaque lesion that replaces the root of the tooth. It is usually surrounded by a radiolucent ring. Because of the intimate association of this lesion with the tooth root, this lesion cannot be removed without sacrificing the tooth. There is no recurrence.

Note: To distinguish this lesion from condensing osteitis - in condensing osteitis, you can distinguish
the root outline.

Odontogenic keratocyst (OKC) is derived from:

# The odontogenic keratocyst (OKC) is derived from:
A. Hertwig's epithelial root sheath
B. The reduced enamel epithelium
C. Remnants of the dental lamina
D. A pre-existing osteoma


The correct answer is: B. Reduced enamel epithelium.

Keratocysts differ from other odontogenic cysts in their microscopic appearance and clinical behavior.

They may resemble periodontal, primordial, or follicular cysts. Usually, they cannot be distinguished
radiographically. 

Clinical features:
• Wide age range. peak occurrence in 2nd and 3rd decades
• Lesions found in children are often reflective of multiple odontogenic keratocysts as a component
of the nevoid basal cell carcinoma syndrome
• More common in males than females
• The chief site of involvement is the mandible, in approximately a 2 to 1 ratio
• In the mandible. most occur within the posterior portion of the body and ramus region
• Typically asymptomatic

Radiographic features:
• Well-demarcated area of radiolucency with a scalloped, radiopaque margin
• Unilocular or multilocular

Microscopicall y:
• The lining epithelium is thin and parakeratinized.
• The basal layer is palisaded with prominent, polarized, and intensely staining nuclei of uniform
diameter
• The lumen may contain large amounts of keratin debris or clear fluid similar to serum transudate
• The parakeratotic type fonns 85 to 95% of all odontogenic keratocysts; the balance is made
up of the orthokeratinized variant.

Most common cause of xerostomia is:

# The most common cause of xerostomia is:
A. Hereditary
B. Medications
C. Tooth decay
D. Mouth breathing



The correct answer is B. Medications.

Xerostomia (dry mouth) is not a disease, however, it can be a symptom of certain diseases. Many times xerostomia is caused by failure of the salivary glands to function normally, but the sensation can also occur in people with normal salivary g lands. Xerostomia can cause health problems by a ffecting nutrition, as well as psychological heal th. At its most extreme, it can lead to rampant tooth decay and periodontal disease.

Perhaps the most prevalent cause of xerostomia is medica tion. The main culprits are antihistamines, antidepressants, anticholinergics (e.g .. atropine and scopolamine) , anorexiants, antihypertensive, antipsychotics {e.g. , chlorpromazine and prochlorperazine), anti-Parkinson agents, diuretics and sedatives.

The most common disease causing xerostomia is Sjogren's syndrome (SS), a chronic inflammatory autoimmune disease that occurs predominantly in postmenopausal women.

Sarcoidosis and amyloidosis are other chronic inflammatory diseases that cause xerostomia.

Other systemic diseases that can cause xerostomia include rheumatoid arthritis, systemic lupus erythema tosus, and scleroderma. 

Remember: Xerostomia is the most common toxicity associated with radiation therapy to the head and neck.
 

Ludwig's angina involves infection of:

# Ludwig's angina is a severe and spreading infection that involves the:
A. Submental and sublingual spaces only
B. Submandibular, submental, and sublingual spaces unilaterally
C. Submandibular and sublingual spaces only
D. Submandibular, submental, and sublingual spaces bilaterally


The correct answer is: D. Submandibular, submental, and sublingual spaces bilaterally

Ludwig's angina often results from an odontogenic infection. As a result, the bacteriology of theses infections generally involves oral flora, particularly anaerobes. Other recognized etiologies of Ludwig's angina include poor oral hygiene, IV drug abuse, trauma, and tonsillitis.

It is characterized by:
• Rapid onset
• The three facial spaces are involved bilaterally
• Board-like swelling of floor of the mouth and no fluctuance is present
• Typical "open-mouthed" appearance
• Elevation of the tongue
• Drooling. trismus, and fever
• Difficulty eating, swallowing, breathing
• Tachycardia, increased respiration rate
• Can lead to glottal edema; asphyxiation

Airway management, massive antibiotic coverage (IV), and surgical incision and drainage are the mainstays of treatment.

Very important: The most serious complication of Ludwig's angina is edema of the glottis (which is a slit-like opening between the true vocal cords).

Epithelioid cells and giant cells are derived from

# Epithelioid cells and giant cells are derived from macrophages and are important in the development of:
A. Initial inflammation
B. Granulomatous inflammation
C. Acute inflammation
D. Subacute inflammation


The correct answer is B. Granulomatous inflammation.

Granulomatous inflammation is a subtype of chronic inflammation and is characterized by granulomas, which are nodular collections of specialized macrophages referred to as epithelioid cells. A rim of lymphocytes usually surrounds granulomas. Granulomas are produced by multinucleated giant cells (Langerhans giant cells and foreign body giant cells). All the other cell types characteristic of chronic inflammation, including plasma cells, eosinophils, and fibroblasts, may also be associated with granulomas.

Note: Granulomatous inflammation is characteristically associated with areas of caseous necrosis produced by infectious agents, particularly Mycobacterium tuberculosis.

• Tuberculosis: caused by the inhalation of Mycobacte1ium tuberculosis. Oral non-healing chronic ulcers follow lung infection. Important: Characterized by caseating granulomas with multinucleated giant cells (Langerhans giant cells and foreign body giant cells).

Etiologic agents associated with granulomatous inflammation:
• Infectious agents
- TB and leprosy, which are mycobacterial diseases
- Fungal infections (blastomycosis, histoplasmosis, and coccidioidomycosis)
- Spirochetes (Treponema pallidum, which causes syphilis)
- Cat scratch disease (caused by an unnamed gram-negative organism)

• Foreign material (e.g., suture or talc)
• Sarcoidosis (unknown etiology; it is non-necrotizing)
• Crohn's disease (it is non-caseating)

Hepatitis found only in patients with acute or chronic episodes of Hepatitis B

# Which type of Hepatitis is found only in patients with acute or chronic episodes of Hepatitis B?
A. Hepatitis C
B. Hepatitis D
C. Hepatitis E
D. Hepatitis A



The correct answer is B. Hepatitis D, this virus causes "serum" or long-incubation hepatitis

The Hepatitis B virus (HBV) is a double-stranded DNA virus with worldwide distribution, transmitted by parenteral and sexual contact. Risk factors include multiple sexual partners, intravenous drug abuse, and receipt of blood products. Its incubation period is 40 to 100 days, and it can be recovered from all body fluids, most importantly, blood, breast milk, and amniotic fluid. The signs and symptoms are similar to hepatitis A (leve1; abdominal pain, nausea, etc.) but there is a longer incubation period (6-8 weeks). The symptoms are slower in developing but are of a longer duration. Most patients recover fully, however, some develop chronic liver disease.

Previously, viral hepatitis that was not caused by the type A or type B virus was called "non-A, non-B hepatitis." Recently three more viruses have been identified that cause some of these non-A, non-B infections.

These new viruses include:

• Hepatitis C: is a serum hepatitis that is caused by a virus antigenically different from Hepatitis viruses A and B. Most cases of post-transfusion hepatitides are of this type. It is usually much milder than A or B but is otherwise clinically indistinguishable from them. There is a higher incidence of chronic disease (chronic hepatitis), cirrhosis, and hepatocellular carcinoma. Note: Hepatitis C is now the most common reason for liver transplantation in the U.S.

• Hepatitis D: is found only in patients with acute or chronic episodes of Hepatitis B, and it makes the Hepatitis B infection more severe. Drug addicts are at relatively high risk.

• Hepatitis E: is transmitted enterically, much like Hepatitis A. It causes occasional epidemics similar to those caused by Hepatitis A. So far these epidemics have occurred only in underdeveloped countries.

Disease associated with a decreased incidence of dental caries

# Which of the following diseases is associated with a decrease in caries?
A. Sjogren's syndrome
B. Cystic fibrosis
C. Cerebral palsy
D. Down syndrome


The correct answer is B. Cystic fibrosis.

** Important: There is a significantly reduced caries rate in patients with cystic fibrosis. This is probably the result of alterations in saliva and the long-term use of antibiotics. Cystic fibrosis is a congenital metabolic disorder that causes the exocrine glands (which are glands that secrete fluids into a duct) to produce abnormal secretions, resulting in several symptoms, the most important of which affect the digestive tract and the lungs. In some glands, such as the pancreas and those in the intestines, the secretions are thick or solid {an excessively viscous mucous) and may block the gland completely. The mucous producing glands in the airways of the lungs produce abnormal secretions that clog the airways and allow bacteria to multiply. The sweat glands secrete fluids that have high sodium and chloride content. Note: The staining of the teeth is most likely due to the fact
that patients with cystic fibrosis are usually subjected to large amounts of tetracyclines during childhood.

Symptoms of CF include:
• Poor growth despite a good appetite
• Malabsorption and foul, bulky stools: steatorrhea
• Chronic bronchitis (COPD) with cough
• Recurrent pneumonia: respiratory infections
• Clubbing of fingers and toes
• Barrel-chested appearance 

Severe hypothyroidism in a child

# Severe hypothyroidism in a child is called:
A. Dwarfism
B. Myxedema
C. Cretinism
D. Acromegaly


The correct answer is C. Cretinism.

Hypothyroidism refers to a condition in which the amount of thyroid hormone in the body is below normal. This is the most common form of thyroid function abnormality and is far more common than hyperthyroidism. This condition is considerably more common in women than in men. The most common cause of hypothyroidism is Hashimoto's thyroiditis.

The second most common cause is the treatment of hyperthyroidism. Hypothyroidism is characterized by the puffiness of the face and eyelids and swelling of the tongue and larynx. The skin becomes dry and rough and the hair becomes sparse. The individual has a low basal-metabolic rate and a low body temperature. The affected individuals also have poor muscle tone, low strength and get tired very easily. Mentally they are very sluggish. The treatment of hypothyroidism is straight forward and consists of administering thyroid hormone (thyroxin).

Severe hypothyroidism in a child is called cretinism. Due to a lack of thyroid hormone, there is a retardation of growth and abnormal development of bones. Mental retardation is caused by the improper development of the CNS. If this condition is recognized early, it can be markedly improved with the use of thyroid hormones. Note: Extreme hypothyroidism in adults is called myxedema.
Note: Dental findings in a child with hypothyroidism include an underdeveloped mandible with an overdeveloped maxilla, enlarged tongue which may lead to malocclusion, delayed eruption of teeth, and deciduous teeth being retained longer.

Treatment of Parathyroid hormone deficiency

# A deficiency of parathyroid hormone can be treated with:
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K


The correct answer is C. Vitamin D.

Hypoparathyroidism is a rare disorder associated with insufficient production of parathyroid hormone, the inability to make a usable form of parathyroid hormone or the inability of kidneys and bones to respond to parathyroid hormone production.

Hypoparathyroidism can result from congenital disorders, iatrogenic causes (e.g., drugs, removal of the parathyroid glands during thyroid or parathyroid swge1y. radiation), infiltration of the parathyroid glands (e.g., metastatic carcinoma. Wilson disease, sarcoid), suppression of parathyroid function, HIV/AIDS, or idiopathic mechanisms.

Hypocalcemia is the most important consequence of hypoparathyroidism. Symptoms occur when ionized calcium level drops to less than 2.5-3 mg/1 00 mL. The clinical manifestation is tetany. A positive Chvostek's sign (twitching of the facial muscles when tapped on the facial nerve near the parotid gland) is characteristic of hypoparathyroidism.

Important: The dental manifestations of hypoparathyroidism (i.e., delayed eruption. enamel hypoplasia and blunted root apices) may be prevented by early treatment with vitamin D.

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