A longer gray scale of contrast can be accomplished through

# In radiography, a longer gray scale of contrast can be accomplished through:
A. Increasing the focal spot-skin distance
B. Increasing the kilovoltage
C. Decreasing the filtration
D. Increasing the milliamperage

The correct answer is B. Increasing the kilovoltage.

Longer gray scales of contrast can be
achieved by increasing the kilovoltage peak.

Increasing the kilovoltage causes the
radiographic image to have low contrast
and longer gray scales.

Low kilovoltage creates low energy x-rays
responsible for producing high contrast and
shorter gray scale.

# Which of the following MOST ACCURATELY describes osseointegrated dental implants?
A. They create a pseudo-periodontal ligament
B. They create a junctional epithelium with the surrounding tissue
C. They are attached directly to living bone as determined by analysis by radiographs and light microscopy
D. They possess a direct structural and functional connection with bone only at the radiographic level of detection

The correct answer is C. They are attached directly to living bone as determined by analysis by radiographs and light microscopy.

Osseointegrated implants are implants that
are able to create a direct interface with
bone cells after they grow and interlock,
without any interposing layer of soft tissue.
In the process of osseointegration, the bone
directly attaches to the implant material
because the titanium oxide fuses with the
surrounding bone.

In osseoinegration, no scar, fibrous or
connective tissues get in between the bone
and the implant material. osseointegration
can be verified through microscopic and
radiographic images as well as by tapping
the implant with a mirror and hearing a
sharp metallic ring (not a dull thud).

The use of titanium for osseointegration
was discovered by Per-Ingvar Branemark in 1952.

Most common reason for a crown not to fully seat upon delivery

# What is the most common reason for a crown not to fully seat upon delivery?
A. Excessive proximal contacts
B. Over extended margins
C. Undercuts on the axial surfaces of the prepared
tooth
D. Positives on the intaglio surface

The correct answer is A. Excessive proximal contacts. 

Excessive proximal contacts are sometimes accidentally made by dental technicians effort to prevent open contacts on their fabricated dental crown/ bridge.

The respective tooth preparations on the

die casts are sawed to separate each component and provide better visualization

of the prep. Dental technicians may accidentally scrape a portion of the contact

area of the adjacent teeth causing a future

excessive contact in the final crown restoration.

Excessive contacts can also be created

when wax patterns are not immediately

invested, causing dimensional changes in

the final restoration.

Which of the following organisms is an intracellular parasite

# Which of the following organisms is an intracellular parasite?
A. Nocardia asteroides
B. Coccidioides immitis
C. Histoplasma capsulatum
D. Aspergillus flavus
E. Cryptococcus neoformans

The correct answer is C. Histoplasma capsulatum.

Histoplasma capsulatum is a type of fungi
which is the main cause of histoplasmosis
infection. This is an intracelular parasite of
macrophages that commonly causes
fungal respiratory infection in the US.