RG Practice Exam Questions
what is the boiling point of water at sea level
100 degrees celcius
dentistry in the USA began to organize dental societies around the year
1840
in what year was the first commercial dental lab in the US established
1887
the melting temperature for pure gold is
1945 degrees
when was the CDT program instituted
1959
100degrees Celsius is equal to
212 degrees F
one inch equals
25.4mm
the maxillary 2nd molar develops from
4 lobes
approximately how many CDTs are there today?
4000-7000
The chemical symbol for gold is
Au
which Federal agency sets health and safety standards that apply to dental labs?
The Occupational Safety and Health Administration
class III occlusion occurs when
The mandibular arch or position of the mandibular arch is anterior to the maxillary arch
The system for measuring weight of precious metals and alloys is?
Troy
The certified dental technician program is administered by the
Trustees of the National Board of Certification (NBC)
when mixing acids for lab use, which sequence should be followed?
acid poured into water
when setting an anatomic or adjustable articulator, the position of the table depends upon the
amount of overjet or overbite
the expansion of casting investment materials increases as the
amount of water is decreased
tuberosity is
an eminence of bone at the end of the maxillary ridge
excess flow of solder may be confined by using
anti flux
what ingredient in an alloy may be hazardous to the technicians health if handled improperly?
beryllium
what adds hardness and gloss to dental waxes
carnauba
The prominence at the cervical 1/3 of the lingual surface of an anterior tooth is the
cingulum
Which of the following is a requirement for annual recertification of all active CDTs
continuing education
which metal, when contained in a dental alloy lowers the melting temperature of the alloy
copper
the ingredient in soluble impression plaster that makes it water soluble is
cornstarch
hydrocal is a type of
dental stone
what is the preferred term for the process of pickling
deoxidizing
the space between two teeth are called
diastema
one of the disadvantages of resin die materials is that they may
distort when heated
the space between the crests of the maxillary and mandibular ridges is the
freeway space
in malocclused cases, which of the following the the most important consideration: esthetics, cusp interdigitation, canine guidance, functional mastication
functional mastication
the ground terminal in any electrical equipment is always colored
green
in proper occlusion, cusps should
guide the direction of closure
heat treatment means
hardening or softening of any metal
A bridge to be soldered is invested in soldering investment to
hold the parts in position
the term overjet refers to the amount of
horizontal extension of the maxillary over the mandibular teeth
all of the following terms may describe the same surface of a tooth except: mesial, incisal, axial, proximal
incisal
reducing the amount of water when mixing investment will cause the resulting crown to be
loose
with which of the maxillary teeth does the mandibular second molar occlude
maxillary 1st and 2nd molar
baseplate wax is composed primarily of
paraffin
color is normally added to the methyl-methacrylate in the
polymer
The Federal Denture Act was enacted to
prevent "mail-order" dentures from being transported to or from unlicensed and/or unauthorized persons
which of the following is not a service of the NBC? continuing education, the recognized graduate program, news and technical publications, product testing
product testing
Which part of a flame will provide for the greatest heat and the least oxidation?
reducing zone
Alginate impressions are used primarily for
removable prothesis
lateral excursion is the
right and left movement of the mandibular arch
irregular mucous membrane found in the anterior 1/3 of the palate is called the
rugae
the most commonly used accelerator for the setting time of plaster is
salt
the bone surrounding natural dentition is
the alveolar bone
it is essential to use clean wax for any wax-up because
the debris in the wax can result in pits in the finished casting
the number 650 on a stick of solder indicates
the melting temperature
the two ridges that combine to form a transverse ridge are the
triangular
which type of gold would be used for most crown and bridge procedures
type III
For safety, tanks of compressed gas must be secured
upright
how often must a CDT apply for recertification
whenever his/her service is interrupted for more than one year