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.