Midterm Exam Review Flashcards
1
Q
What is an Inlay?
A
-does not include any cusps
-involves the proximal surface and occlusal surface
-stronger than a resin/amalgam restoration
- can be made out of metal (gold or porcelain
-placed in posterior
2
Q
What is an Onlay?
A
- cusps are involved
-involves atleast one cusp, and most of the occlusal surface
-stonger than a resin/amalgam restoration - can be made out of metal (gold or porcelain)
-placed posterior
3
Q
What is the main difference between an Inlay and Onlay?
A
Inlay does not include any cusps
Onlay involves atleast one cusp and most of the occlusal surface
4
Q
What is a Veneer?
A
a thin shell of a tooth-coloured material. Used to improve esthetics due to chipping, excessive wear, heavy staining, close diastema spacing
5
Q
What are the 2 types of veneers available?
A
Direct veneer - created directly in the patient’s mouth by applying resin material to facial surface
Indirect Veneer - created in the dental laboratory on the basis of an impression taken of the prepared tooth. PORCELAIN material is used, NOT resin
6
Q
What is a Crown?
A
-indirect restorations that replace severe damaged tooth structure due to decay or fracture.
- often done after root canal treatment.
- cemented permanently into place and cannot be removed by the patient
-provides full coverage, adds strength to teeth
7
Q
What are the 3 types of crowns?
A
Full Crowns (completly covers tooth)
Three-quarter Crown
Porcelain Fused to Metal (PFM)
8
Q
When is a full crown used?
A
When a tooth has decay so severe, or a fracture that reconstruction can not be preforme dwith the use of a direct restoration
9
Q
What is a three-quarter crown?
A
Covers the anatomic crown of a tooth but facial or buccal portion is unchanged
10
Q
What is a PFM Crown?
A
- full metal crown with outer surfaces covered with a layer of procelain (for esthetic reasons) and inner layer covered with metal
-metal is added for strength and to prevent crown from fractures ue to heavy mastication
11
Q
What is a bridge?
A
- an indirect restoration that replace either one or multiple teeth that are missing within the same quad or sextant
-consists of a series of units joined together for greater strength
-cemented permanently into place and cannot be removed by patient
12
Q
What are the three components of a fixed bridge?
A
Unit
Pontic
Abutment
13
Q
What is the Unit of the bridge described by?
A
The unit of the bridge is described by the total number of teeth involved in the fabrication
14
Q
What is the Pontic of the bridge?
A
The missing tooth/artificial tooth is referred to as the Pontic
15
Q
What is the Abutment of a bridge?
A
The tooth anchoring the bridge is referred to as the abutment.
- tooth must be stable enough to withstand bridge forces
16
Q
How is the Abutment tooth prepared?
A
Outer layer of enamel will be removed, tooth will be reduced in size all circumference (all directions) by use of dental high-speed handpiece and bur.
17
Q
What is a cantilever bridge?
A
-does not have an abutment on one end
-various materials can be used including metal/gold porcelain
18
Q
What is a maryland bridge?
A
-consists of a pontic with wing like extensions from the mesial and distal sides on LINGUAL
-bonding of extensions to the lingual surfaces of the adjacent teeth supports the point.
-various materials can be used including metal, gold, or porcelain
19
Q
What is an implant supported indirect restoration?
A
refers to artificial “root” replaced with the titanium component.
-titanium is anchored surgically into the bone.
- incorporates principles from both fixed and removable prosthodontics in conjuction with the use of bone-anchored implants
20
Q
What are Endosteal implants?
A
- implant is surgically placed into the jawbone
-for one or more prosthetic teeth
-typically used for patients requiring a crown, bridge, or partial and full denture
21
Q
What is a Subperiosteal implant?
A
is a metal frame that is palced under the periosteum and on top of the bone
- NOT placed into the bone
- indicated for patients who do not have enough alveolar ridge remaining
22
Q
What is a Transosteal implant?
A
is inserted through the inferior border of the mandbile and into the edentulous area
- primarily used in patients with severely resorbed ridges
23
Q
This describes a stable tooth to support the bridge
A
Abutment
24
Q
This word is used when describing the number of teeth involved in the bridge
A
Unit
25
This restoration is offered to close the gap between the teeth - it calls itself the fifth wheel
cantilever
26
This restoration is offered to close the gap between the teeth
maryland
27
This describes a missing tooth within the bridge
pontic
28
This type of restoration is offered when cusps are involved
onlay
29
This type of restoration is offered when cusps are not involved
inlay
30
This tin shell of tooth-coloured material witll be placed on anterior teeth
veneer
31
when entire tooth is reduced in shape, dentist will call this restoration a ____
crown
32
Is an impression a negative or a positive reproduction?
An impression is a negative reproduction
33
Which of the three classifications of impressions is used for occlusal relationships?
The bite registration is used for occlusal relationships
34
Which type of impression tray covers half the arch?
A quadrant tray covers half the arch
35
Which type of tray allows impression material to lock on mechanically?
A perforated tray allows the impression material to lock on mechanically.
36
Which type of tray is designed to fit a specific patient.
A custom tray is designed to fit a specific patient
37
What is used to extend the length of a tray?
Utility wax is used to extend the length of a tray
38
What is the most widely used irreversible hydrocolloid for preliminary impressions?
Another name for irreversible hydrocolloid is alginate.
39
What is the organic substance within hydrocolloid materias?
The organic substance within hydrocolloid is alginate, which is derived from seaweed/
40
Why would you select a fast set alginate over a normal-set alginate?
You would select a fast-set alginate if the patient had a strong gag reflex.
41
What is the water-to-powder ratio for taking a maxillary impression?
The water-to-powder ratio for taking a maxillary impression is three scoops of powder to three measures of water.
42
Do you mix irreversible hydrocolloid on a paper pad or in a mixing bowl?
Irreversible hydrocolloid is mixed in a rubber mixing bowl.
43
Before an impression is taken with *reversible hydrocolloid, where is the material kept?
Before an impression is taken with reversible hydrocolloid, the material is kept in a conditioning bath.
44
Is an elastomeric material used for preliminary impressions or final impressions?
Elastomeric material is used for final impressions.
45
In which three forms are elastomeric materials supplied?
Elastomeric materials are supplied as light-bodied, regular, and heavy-bodied.
46
What technique is used to place light-bodied material placed around a prepared tooth?
A special syringe, or extruder, is used to place light-bodied material.
47
What impression material will the dentist first apply to a prepared tooth—the heavy-bodied or the light-bodied form?
The dentist first applies the light-bodied material to the teeth.
48
What system completes the mixing of final impression material for you?
An automix system completes the mixing of final impressions.
49
What is another term for polysulfide?
Another term for polysulfide is rubber base.
50
What type of tray is used when ZOE bite registration paste is applied?
A gauze bite tray is used when ZOE bite registration paste is applied.
51
Do you cool or warm the wax before placing the tray in the patient’s mouth for a bite registration?
You warm the wax to soften it before placement in the patient’s mouth.
52
A(n) __________ is a gel or sol substance with its particles suspended in a water-based medium.
colloid
53
_____ is the process of using the fingers to acheive a closer adaptation of the edges of an impression.
Border molding
54
A(n) ______ impression material has flexible properties and is made from rubber.
elastomeric
55
A foundation or main ingredient of a material is the _______.
base
56
To have something _______ is to have it aligned, such as the maxillary teeth centered over the mandibular teeth.
centric
57
______ is a gelatin-type material derived from seaweed found in reversible hydrocolloid material.
Agar
58
Irreversible Hydrocolloid vs. Reversible Hydrocolloid?
Reversible hydrocolloids change from a liquid to a gel-like consistency through physical means, while irreversible hydrocolloids change through a chemical reaction. Both are types of impression material used in dentistry.
59
___________ is the loss of water, which causes shrinkage
syneresis
60
______________ is a way of bringing a material to a desired temperature and consistency.
Tempering
61
_____ describes a property of fluids with a high resistance to flow.
viscosity
62
______ is the material of choice in dentistry for preliminary impressions.
Alginate
63
_______ is to transform a material from one physical state to another.
Hysteresis
64
A(n) ____________ is a reproduction of someone's bite with the use of wax or an elastomeric material.
Occlusal registration
65
A(n) ________ is a substance that modifies or increases the rate of chemical reaction.
catylyst
66
____ is the absorption of water, which causes an object to swell.
Imbibition
67
If a patient has periodontal disease, but good dental hygiene habits. Are they a canditate for prosthodontics?
NO, because of the patients periodontal disease
68
How many appointments are commonly required for a crown or bridge?
2 Appointments
69
What is the difference between an onlay & a three-quarter crown?
An onlay covers most of the occlusal and proximal surfaces (involves atleast 1 cusp)
A three quarter crown covers other surfaces such as the facial or buccal surface
70
How does a dentist convey to a dental laborartory technichian the type of crown or bridge theat they should be making?
Laboratory prescription
71
What type of indirect retoration is placed to improve the appearance of the facial surfaces of the teeth?
Veneers
72
An impression would be considered a ________.
negative reproduction
73
Of the 3 classifications of impressions, which of these could be an expanded function for the certified dental assistant?
Preliminary & Bite Registration
*not final!
74
Of the 3 classifications of impressions, which would be used by the dental lab tech for determining occlusal relationship?
Bite registration
75
Which type of stock tray would be selected and prepared to cover half of an arch?
Quadrant
76
Which type of impression tray allows the impression material to mechanically lock on?
Perforated
77
Which type of tray is constructed to fit the mouth of a specific patient?
Custom
78
_____ would be used to extend the length of a tray to accomodate third molars.
Utility wax
79
The organic substance of a hydrocolloid material is ______.
seaweed
80
Why would a fast-set alginate be indicated when taking a preliminary impression?
The patient has a strong gag reflex
81
The powder/water ratio for a maxillary preliminary impression is ___________.
3 scoops of powder to 3 measures of water
82
Hydro- means _______.
water
83
Irreversible hydrocolloid material is also referred to as _______.
alginate
84
Irreversible hydrocolloid material is mixed in/on a/an ____________.
mixing bowl
85
Where would a reversible hydrocolloid material be placed prior to taking the impression?
Conditioning bath
86
Elastomeric materials are intended for what type of impression?
Final & Bite Registrations
87
How is an elastomeric material supplied?
As a paste, putty or cartridge
88
Which viscosity of a final impression material is applied first to the prepared tooth or teeth?
Light body
89
Another name for polysulfide is ___________.
rubber base
90
How is the light-body impression material applied during the final impression procedure?
Extruder with tip
91
What additional method can be used to mix final impression material instead of an extruder?
Spatula and pad
92
_______________ is the material universally used for taking a bite registration.
Baseplate wax
93
What type of tray is most commony selected when zinc oxide-eugenol bite registration material is used?
Gauze
94
Baseplate wax is _____________ before being placed in the patient's mouth for a bite registration.
warmed
95
While the dentist is dispensing the syringe material around the prepared tooth, what should the dental assistant be doing during a final impression procedure?
Readying the tray with heavy-body material
96
A preliminary impression is ________ before being transported to the lab for pouring up.
rinsed, disenfected, wrapped in a moist paper towel, and placed in a precautionary bag
97
Where would the dental laboratory be located in a dental office?
The dental laboratory would be a separate space, away from the patient treatment areas.
98
What piece of equipment is used to grind away plaster or stone?
A model trimmer is used to grind away plaster and stone.
99
What piece of eqipment does the dentist use to determine centric relation on a diagnostic model?
A face bow is used to determine centric relation
100
What is the most common wax spatula size used in the laboratory?
The #7 wax spatula is used most often in the laboratory.
101
What is another term for a dental model?
Study cast
102
What dental materials are used to make dental models?
Gypsum products are used to make dental models
103
What are the three forms of gypsum?
The three forms of gypsum are model plaster, dental stone, and high-strength stone
104
What is the water to powder (g/ml) ratio of plaster?
100g of powder to 45-50 ml of water
105
When mixing gypsum materials, do you add the "powder to the water" or the "water to the powder"?
You add the powder to the water
106
What are gypsum materials mixed in ?
A specialized rubber bowl
107
What are the two parts of a dental model?
the anatomic parts and the art portions
108
When pouring an impression, where in the maxillary impression do you begin to place the gypsum material?
Near the most posterior tooth
109
How long should you wait before you separate the model from the impression?
45 - 60 minutes
110
Which of the two models (maxillary or mandibular) do you begin measuring and trimming first?
The maxillary model is measured and trimmed first
111
What area on the maxillary and mandibular model is trimmed different?
The anterior portion of the maxillary and mandibular model is trimmed differenlt
112
What should be placed between the maxillary and mandibular cast when trimming them together?
A wax bite should be placed between two models when trimming.
113
Of the 3 types of custom trays discussed, which technique uses a more hazardous material in the fabrication of the tray?
A more hazardous material is used in acrylic resin trays. The liquid monomer used in this tray is highly volatile.
114
Which type of custom tray is made for a vital bleaching procedure?
A vacuum-formed tray is made for a bleaching procedure.
115
Name two ways that acrylic resin can harden
Self-cure and light cure
116
Which type of material is used for a vacuum-formed custom tray?
Thermoplastic resin is used for a vacuum-formed tray
117
What is the purpose of a spacer?
A spacer is used to create room in a tray for the impression material.
118
How are the undercuts corrected on a model when a custom tray is prepared?
Undercuts are corrected by filling in with wax or molding material.
119
What type of wax could be used to form a wall around a preliminary impression when pouring it up?
Boxing wax is used to form a wall around a preliminary impression
120
To extend an impression tray, what type of wax?
Utility wax
121
What type of wax would you use to obtain a patient's bite impression?
Bite registration wax is used to obtain a patient's bite.
122
What is the most common wax used to create a pattern for an indirect restoration?
Inlay casting wax is most often used to create a pattern for an indirect restoration.
123
A dental material that is uniform in mixture and consistent throughout is said to be ________.
homogenous
124
A(n) ___________ is a dental lab machine used for cutting, grinding, and polishing dental appliances.
lathe
125
______ is a type of mineral used in the formation of plaster of paris and stone.
gypsum
126
A substance is said to be _____________ if it has an explosive property.
volatile
127
A _____________ is a compound of a gypsum product with two parts water to one part calcium sulfate.
dihydrate
128
If an object is resistant to change in width, height, and length it is said to be _______.
dimensionally stable
129
The ________ is a portion of an articulator used to transfer the relationship of the upper teeth and the temporomandibular joint to a cast.
Face Bow
130
A(n) ______ is a compound of many molecules.
polymer
131
______ is a chemical process in which crystals form into a structure.
crystalization
132
_____ is the removal of one-half part water to one-part calcium sulfate to form the powde product of gypsum.
hemihydrate
133
A __________ is a replica of the maxillary and mandibular arches fabricated from an impression.
model
134
________ refers to the structural portion of a dental model/cast.
anatomic portion
135
A(n) _________ is a dental laboratory device that stimulates the movement of the mandible and the TMJ when models of the dental arches are attached.
articulator
136
A(n) __________ is a molecule that when combined with others forms a polymer.
monomer
137
_____ is a mixture of gypsum and water to be used in the finishing of models.
slurry
138
Where would you commonly find the lab in a dental office?
Separate, but in proximity to the clinical operatory
139
Which specialty practice would have a more extensive laboratory set up?
fixed prosthodontics & orthodontics
140
An example of a contaminated item that could be found in the dental lab would be a(n) _____.
impression
141
Which piece of lab equipment would be used to grind away plaster or stone?
model trimmer
142
Which piece of lab equipment would the dentist use to determine centric relation from a diagnostic model?
face bow
143
The size of the wax spatula most commonly used in the laboratory is a _______
#7
144
Another name for a dental model is ___________
dental cast
145
What dental material is used in creating a dental model?
gypsum
146
Which type of gypsum is used to fabricate a replica for an inlay or crown?
die stone
147
The powder (g) / water (ml) ratio of model plaster for pouring a dental model is ...
30 g powder / 100 ml water
148
When a gypsum material is mixed, how is the powder and water incorporated?
Add the powder to the water.
149
Gypsum materials are mixed using a(n) __________.
spatula and rubber bowl
150
Which of the following terms are the description of the portions of a dental model?
Anatomic / Art
Base / Teeth
151
When pouring up an impression, where would you begin placing the gypsum material in a mandibular impression?
most posterior tooth
152
How long should you wait before you separate a model rom its impression?
45 to 60 minutes
153
Which model (maxillary or mandibular) should you begin trimming first?
maxillary
154
What is the one specific area of a dental model where the maxillary and mandibular models are trimmed differently?
anterior portion
155
What should be placed between the two models during trimming?
wax bite
156
Digital models and traditional plaster models have the same advantages listed below except:
Diagnosing and treatment planning **
Same advantages:
-unbreakble
-shows a 3-d image
-accuracy
157
Of the 3 types of custom trays discussed in the chapter, which technique uses a volatile hazardous material?
thermoplastic resin
158
What type of custom tray would be made for a vital bleaching procedure?
acrylic resin
159
What type of wax is used to form a barrier around a preliminary impression when it is poured up?
boxing wax
160
What is placed to prevent a tray from seating too deeply onto the arch or quadrant?
spacer stops
161
What is the purpose of placing the water before putting in the alginate powder in mixing bowl?
Adding the powder to the water ensures that the powder particles are wet evenly. IF mixed in the reverse, the chemical reaction will start early with some particles setting faster than others.
162
Is an impression a negative or a postive reproduction of the teeth?
Negative
163
What type of immpression is used to record occlusal relatinoship?
Bite registration
164
Which type of impresstion tray covers have the arch?
Quadrant tray
165
What is Tisodium phosphate role within irreversible hydrocolloid?
Slows down the reaction time for mixing
166
The purpsoe of tripple tray impression is too....?
Record: upper occlusion, lower occlusion and bite registration
167
Why Dental Models Are Required?
-Diagnostic cast/mouth guards/ whitening trays
-Custom Trays
-Provisional coverage
-Orhtodontic appliances
-Visual presentation of dental treatment
168
What is the Art porition of a dental model?
The base - on max and mand
169
What is the Anatomic Portion of a Dental Model?
Teeth, Oral Mucosa, and muscle attachments
170
What are Dental Models?
Three Dimensional reproductions of the teeth and the surrounding soft tissue. They are also referred to as study casts
171
What is the reason for ginvial cord placement?
To retract gingival tissue so you can see the margins of crown
172
This " ingredient" is added to alginate to prevent impression tearing apart by making the material stronger.
Potassium Alginate
173
This " ingredient" is added to alginate to form a gel like consistency when the material is set.
Calcium Sulfate
174
This " ingredient" is added to alginate to help you mix in 45 sec vs 10 sec, it slows down the reaction time for mixing.
Trisodium phosphate
175
This " ingredient" is added to alginate to make look alginate fuller/ denser in consistency.
Diatomaceious Earth
176
This " ingredient" is added to alginate to create bulk like appearance.
Zinc Oxide
177
Another word for AGAR is ____
Reversible Hydrocolloid
178
Another word for alginate is ____
Irreversible Hydrocolloid
179
When hydrocolloid is more liquid state it is referred to as:
Sol
180
You left alginate impression on the counter for a few days, alginate looks dry and did shrunk . What process appeared?
Syneresis
181
You left alginate impression on the counter, covered in water, wrapped in sealed plastic bag. It appears impression is twice a big now as it was before! What process appeared?
Imbibition
182
What do you call hydrocolloid in a rubbery or semi-hard state?
Gel
183
One of the reasons to take preliminary impressions is to create "precise" image of the tooth. True or False?
True
184
Preliminary impressions are used to make study models, whitening trays and sport guards. True or False?
True
185
Preliminary impression are used to make orthodontic appliances. True or False?
True
186
When setting up for an impression appointment, distilled water is required to mix the powder. True or False?
False
187
When choosing the correct tray for preliminary impressions, the following should be considered: presence of all teeth, size of the oral cavity, presence/absence of the mobile teeth, bony growth and height of the palate. True or False?
True
188
Utility wax is used to adapt an impression tray to accommodate anatomical variations such a high palate or bony growth ( tori). True or False?
True
189
Mixing alginate powder and water requires "feather like touch". True or False?
False
190
Taking occlusal bite impression by using dental wax is more accurate then using polyvinyl siloxane. True or False?
False
191
When charting entries for recording preliminary impressions, type and size of the tray used is written. True or False?
True
192
Impression trays should be disinfected one at the time. True or False?
False
193
What are Pre-Op instructions for preliminary impressions?
What to expect during impression recording: sensation, drooling
Identify approx. time impression stays in the mouth: as per manufacture instructions
Ask patient to follow directions closely during impression taking
Explain briefly purpose of tray size fitting
194
What are Post-Op Instructions for Preliminary impressions?
Instruct patient to rinse with water to remove any access alginate
Provide patient with tissue to clean impression debris from around the face
Use of floss by be required to remove alginate
Patient can eat and drink right away
195
What patient mangement techniques can you use while recording a prelim impression?
Ask patient to lift tongue when asked (during mandibular tray seating)
Ask patient to breathe to nose (during maxillary tray seating)
Ask patient to lean forward when advised
196
List 3 different methods of pouring preliminary impressions.
1. Double Pour
2. Boxing Method
3. Inverted Pour (what we do!)
197
What speed should be used for vibrating plate?
Turn dial to medium
198
Why do you need a tongue spacer for mandibular
To be able to separate tray from the stone
199
How long do I mix stone and water to pour anatomy portion?
Not long, just under 1 min. Mix should look thick like ice cream
200
Material with high amount of hemihydrate crystals will make the pour very strong. True or False?
True
201
Plaster products are typically classified based on their composition, with different types designed for specific uses like study models or casts. True or False?
True
202
When pouring gypsum anatomical part for study models, it's important to mix the plaster to a consistency that is thick enough to allow for adequate detail capture and to avoid runniness, which could cause air bubbles or incomplete impressions. True or False?
True
203
Once a gypsum cast is poured, it should be left to set for a period of time before separating it from the impression to ensure a strong, durable cast. True or False?
True
204
Evaluating a gypsum cast includes checking for defects like cracks or incomplete areas, which should be repaired before the cast is used for any further procedures. True or False?
True
205
For pouring study models and casts, it's crucial to have the proper armamentarium, including a mixing bowl, spatula, and rubber bowl for proper consistency. True or False?
True
206
Gypsum products should be stored in tightly sealed containers to prevent them from absorbing moisture from the air, which can interfere with their properties.
True
207
What material contains hemihydrate crystals.
Stone
208
Below types of gypsums:
Impression plaster (Type I), Model plaster ( Type II), Dental stone
(Type III) contain high amount of hemihydrate crystals. True or False?
False -
Type IV & V have higher amount of hemihydrate crystals
209
Can you explain the functions of trimming equipment?
Used to trim, & shape gypsum products such as stone or plaster.
210
What is one essential maintenance step for a model trimmer?
Water flow should be edquate to keep the abrasive wheel clean when in use.
Trimming wheel/disc may need to be sprayed and/or brushed to remove any built-up gypsum sludge
211
You are about the trim cast for a study model. What should you do to make your trimming easier?
It is recommended to soak the art portion (base) of the modle in a bowl of water for atleast 5 minutes. This will produce softer model/cast which will make trimming easier.
212
Why is "occlusal plane" important when trimming dental models?
When in occlusion, the bases of the models should be parallel to the occlusal plane
213
What personal protective equipment (PPE) should be worn when trimming models?
Safety glasses/sheilds, face mask, and lab coat
(NOT GLOVES)
214
What is one important factor to assess when evaluating an articulated study model?
Are the angle and length of each heel cuts equal on both sides of the model? Do they match the opposing model?
Did you accidentally remove any portion of tooth or any other anatomy?
215
What are the guidelines to trim anterior part for the maxillary model?
Trim Base
Trim Posterior borders
Trim the lateral sides
Trim heel cuts
Trim anterior borders (cut is angled from the right canine to left canine)
216
How are study models labeled?
Label both model/casts
include the month/day/ year impression was taken
include patients full name
write clearly and printed with permanent marker
217
Study models should be trimmed by following the sequence as this will produce symmetrical cast. List the order of trimming steps.
Do max first
Trim Base
Trim Posterior borders
Trim the lateral sides
Trim heel cuts
Trim anterior borders (cut is angled from the right canine to left canine)
218
List the steps for trimming the mandibular model/cast (done second)
-Occlude the mandibular model with the maxillary model, using the wax bite is recommended as wax will keep accurate occlusion during trimming
Trim base until it is even with the maxillary model
Trim lateral cuts
Trim heel cuts
Trim anterior borders (cut is angled from the right canine to the left canine) This part is trimmed by its self
219
Why would a dentist request study models?
Used to evaluate patient bite, shape of the teeth, and surrounding tissue.
220
What additional tools are available to help with diagnosis alongside study models?
Face bow and articulator
221
What are the types of impression materials available?
Preliminary - reversible (agar) & irreversible (alginate) hydrocolloid
Bite registration / occlusal - bite registration using wax or PVS (polyvinyl siloxane)
222
What type of impression trays are available?
full trays/ stock trays
kwik tray / sextant trays
triple tray for sextant or quadrant
223
To prevent impression material from peeling away from the tray during separation, what can be done?
Add adhesive to tray
Use perforated trays
224
Why are you looking into a mouth prior to taking an impression?
To access oral cavity health status
To determine tray sizes
225
Should the impression tray fit loose or tight?
Loose - we need space for impression material
Use bigger tray vs smaller
226
Upon reviewing CO you determined that patient has a moderate bony growth like tori present L-Q 3. To make the tray more comfortable during impression taking, what material should you use and why?
- add utililty wax to soften the tray rim
- wax is placed on lingual border of Q3
227
What chemical ingredient controls alginate setting time?
Trisodium phosphate - slows down the reaction time for mixing
Our current alginate does not have lots of it as we have under 45 secs to mix
228
What chemicl ingredient within the alginate makes the material thick?
Potassium Alginate
229
What chemical ingredient within the alginate prevents material from breaking apart when removing from the mouth?
Potassium titanum - provides strength
230
Due to patient having a strong gag reflex, what techniques should you use during appointment?
-breath through your nose, head forward, distraction, nitrous gas, drooling is normal
- do not mention gag reflex, no negative words
231
Explain the technique for placing impression material on a mandibular and maxillary impression tray.
Mandibular - load from lingual borders of the tray, place more anterior
Maxillary - load from back border of the tray, place more anterior
232
How should impression tray be seated: anterior to posterior or posteror to anterior and why?
Posterior to anterior (back to front) as this allows access material to move away not only from the gag reflex but also forms vestibular roll
233
Just seconds before seating maxillary tray in
your patients’ mouth, she grabs your hand and tells
you “STOP, I am not ready” What should you do?
Stop and reassure patient its going to be okay!
* you can always remix
* do not let patient remove tray when impression is
setting
234
Both impressions had been taken, what IPC steps
should be done prior pour and what office space will
be used to pour them?
2 methods available (with gloves or without 1 glove)
-rinse impression under cool tap water
-disinfect (follow manufacture instructions)
-rinse again under cool tap water
-follow manufactures instructions for each product
235
Impresson criteria for Study Models... what is a MUST?
-tray is seated fully (bone height is fully visible)
-proper extension over mandible retromolar area is present (distal of most posterior tooth recorded)
-Proper extension over maxillary tuberosity area is present (distal of most posterior tooth recorded)
-Sharp anatomical detail is present
-adequate tray size chosen
-tray is centered
-peripheral roll is present throughout
-no voids or tears interproximal
-alginate is smooth, not grainy
236
Dr. Lind asked you to fabricate a study models. What type of Stone Type will you
use ?
Type 1, 2 or 3.
1 and 2 may be white in appearance, less crystals and not as strong. Type 3 is yellow in color, more crystals = little more stronger)
237
What is Type 4 stone?
Die stone (not used by assistants, used by lab techs)
238
What is Type 5 Stone?
High strength stone (not used by assistants, used by lab techs)
239
Can you give more examples when study models
can be used?
Study models
whitening trays (base not needed)
Sports guard (1 upper impression only, thin base)
240
Which type of stone has an abundance of hemihydrate crystals?
die stone (type Iv)
high strength stone (type 5)
241
Lots of hemihydrate crystals will make the material weaker or stronger?
stronger
242
Little of hemihydrate crystals presence willl make material weaker or stronger?
Weaker
243
What are the 3 types of wax?
Occlusal / bite registration wax
Boxing wax - used with boxed pour method
Unity wax/used with impressions to extend or soften trays border
244
What is double pour method?
2 mixes are made
everything can be poured with this methodW
245
What is box and pour method?
- wax wall is made around the border
- one mix is made
-not used for study models, works for sports guards and whitening trays
246
What ist he inverted pour method?
1 mix is made, flipped into the base
-everything can be poured with this method
247
What does the anatomic portion include?
teeth, oral mucosa, and muscle attachments (2/3)
248
What type of wax is used to extend the impression tray or make it more comfortable?
Impression wax - utility
249
What does the prefix hydro mean?
Water
250
What type of impression tray covers half the arch?
quadrant tray
251
What other system completes the mixing of impression material for you?
Automix system
252
List the 5 kinds of gypsum products that are used in dentistry, and which one is the strongest?
Used by Dental Assistant:
Type I - Impression plaster
Type II - Dental Plaster
Type III - Dental stone
Used by Lab Tech:
Type IV - die stone
Type V - high-strength
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