Sessions 1-4 (Quiz One) Flashcards
1
Q
Define Fix Prosthodontics
A
The branch of prosthodontics concerned with the replacement and/or restoration of teeth by artificial substitutes that are not readily removed from the mouth.
2
Q
What is the masticatory system responsible for?
A
Chewing, speaking and swallowing
3
Q
What is the masticatory system made up of?
A
Bones, joints, ligaments, teeth and muscles
4
Q
What does the neurologic controlling system of the masticatory system do?
A
Regulates and coordinates all the structural components
5
Q
Define mutually protected occlusion
A
An occlusal scheme in which the posterior teeth prevent excessive contact of the anterior teeth in maximum intercuspation, and the anterior teeth disengage the posterior teeth in all mandibular excursive movements.
6
Q
Posterior teeth protect _____ teeth
A
Anterior teeth
7
Q
Anterior teeth protect _____ teeth
A
Posterior teeth
8
Q
How do posterior teeth protect anterior teeth?
A
Posterior teeth prevent excessive contact of the anterior teeth in maximum intercuspation
9
Q
Since the teeth are constantly receiving occlusal forces, what is put in place to help control these forces?
A
Periodontal ligament is present between the root of the tooth and the aveolar bone
10
Q
The periodontal ligament runs ____ from the cementum, extending ____ to attach in the alveolus
A
Obliquely; occlusally
11
Q
When force is applied to a tooth, what does the PDL do?
A
Support it
12
Q
What can osseous tissue not accept? What stimulates bone formation?
A
Cannot accept pressure.
Tension stimulates bone formation
13
Q
What does the PDL convert pressure into?
A
Able to convert a destructive force (pressure) into an acceptable force (tension)
14
Q
The PDL can be thought of as a ______ ____ ____ controlling the forces of occlusion on the bone.
A
Natural shock absorber
15
Q
Define axial loading
A
Process of directing occlusal forces through the long axis of the tooth
16
Q
Where should tooth contacts be located that are ideal for loading?
A
On either cusp tips or relatively flat surfaces that are perpendicular to the long axis of the tooth
17
Q
What flat surfaces are ideal for tooth contacts?
A
Crests of marginal ridges or the bottoms of fossae
18
Q
With ideal contacts, the forces will be directed through the __ ___ of the tooth
A
Long axis
19
Q
What are three ways posterior teeth protect anterior teeth?
A
Number of roots
Occlusal table
Orientation of teeth
20
Q
How does the body allow the PDL to accept damaging forces to the bone and reduce them?
A
With vertical loading to eliminate off-axis forces
21
Q
What should the tooth be contacted with so that the resultant force is directly vertically through its long axis and accepted by the PDL?
A
When the tooth is contacted on a cusp tip or a relatively flat surface such as the crest of a ridge or bottom of a fossa
22
Q
How does the number of roots help posterior teeth protect anterior teeth?
A
The increased root surface allows for greater dissipation of force through the PDL when loaded in the vertical direction.
23
Q
Describe how an occlusal table can help posterior teeth protect anterior teeth?
A
The wider occlusal table of posterior teeth is ideal for the absorption of transfer of force down to the root and underlying bone
24
Q
How is orientation of teeth different in posterior teeth compared to anterior teeth
A
Posterior teeth: oriented vertically -> force applied along long axis of tooth
Anterior teeth: Generally oriented off axis from each other
25
How can anterior teeth protect posterior teeth in movement?
Disengage posterior teeth in all mandibular excursive movements
26
Which tooth has the longest root?
Canines
27
Which tooth is best suited to accept horizontal forces that occur during eccentric movements?
The canines
28
What type of bone are canines surrounded by compared to posterior teeth? How does this help the canines?
Canines: Compact bone
Posterior teeth: Medullary bone
Helps canines tolerate forces better than medullary bone on posteriors
29
Describe the difference in muscle movement with canines compared to posterior teeth?
Fewer muscles are used when canines make contact during eccentric movement than when posterior teeth come in contact.
30
Lower levels of muscular activity decrease forces to the dental and joint structures, thus minimizing ______
Pathosis
31
What occurs when a tooth is contacted on an incline?
Resultant force is not directed through its long axis -> causes tipping
32
What percentage of the general population has bilateral canine guidance?
26%
33
What is the most favorable alternative to canine guidance?
Group function
34
What happens during group function?
Several of the teeth on the working side make contact during the laterotrusive movement
35
What teeth are part of the most desirable group function?
The canine, premolars and sometimes the mesiobuccal cusp of the first molar
36
Why are laterotrustive contacts that are more posterior than the mesial portion of the first molar not desirable?
Because of the increased force that can be created as the contact gets closer to the fulcrum (TMJ)
37
Why is group function more common among older people?
Most likely due to canine wear
38
When is group function considered acceptable?
When it does not show any signs and symptoms of occlusal trauma
39
What are three ways anterior teeth protect posterior teeth?
1. Longest root
2. Location
3. Muscles
40
What two movements do the central incisors separate the posterior teeth and canines?
1. Posterior teeth -> Protrusive movement
| 2. Canines -> Lateral movements
41
What feedback loops helps protect posterior teeth from being overloaded?
Proprioceptive feedback loop
42
Describe the teeth's position during protrusion
Anterior teeth separate posterior teeth
43
Describe teeth's position during lateral excursion
Canine separate the posterior teeth
44
Define optimum occlusion
Uniform contact of all teeth around the arch when the mandibular condylar processes are in their most superior position
45
Optimum occlusion: Stable posterior tooth contacts with _____ directly resultant forces
Vertically
46
Optimum occlusion: Centric relation with ____ intercuspation
Maximum
47
What should not be contacting in lateral or protrusive movements?
Posterior teeth
48
Define occlusal trauma
Trauma to the periodontium from functional or parafunctional forces causing damage to the attachment apparatus of the periodontium by exceeding its adaptive and reparative capacities
49
Describe primary occlusal trauma
Abnormal or excessive occlusal forces on teeth with normal periodontal support
50
Describe secondary occlusal trauma
Effects induced by normal occlusal force acting on teeth with decreased peridontal support
51
What are four signs and symptoms of occlusal trauma?
Pulpitis, mobility, fremitus, widened PDL
52
Average width of PDL
0.17 mm
53
Class One Tooth Mobility
>0.2 mm but < 1.00 mm
54
Class Two Tooth Mobility
> 1.00 mm
55
Class Three Tooth Mobility
>1.00 mm+ Axial Displacement
56
What three things can occur in primary occlusal trauma?
Loss of posterior support
Bone Level loss
Flaring of anterior teeth
57
How would you treat primary occlusal trauma?
Reduce forces
58
What is a classic example of primary occlusal trauma? How is it solved?
Patient has new restoration in hyperocclusion. Solution: Adjust tooth so that occlusal force is evenly distributed among all the teeth.
59
What occurs in primary occlusal trauma with many missing posterior teeth? Solution?
Leads to overloading of anterior teeth -> Restore posterior support by adding teeth to missing spaces
60
How could you treat secondary occlusal trauma?
Splint teeth
61
How can spliting teeth solve secondary occlusal trauma?
Share/distribute the force among the teeth-> can stabilize compromised teeth
62
What are the functional cups of the mandibular teeth?
Buccal cusps
63
The most mesial buccal cusp of the mandibular tooth occludes with what?
MMR of its corresponding maxillary tooth
64
The distal buccal cusp of the mandibular molar occludes with what?
Corresponding maxillary tooth
65
What are the functional cusps of the maxillary teeth?
Lingual cusps
66
The most distal lingual cusp of the maxillary tooth occludes with?
The DMR of the corresponding mandibular tooth
67
The mesial lingual cusp of the maxillary molar occludes with?
The central groove of the corresponding mandibular tooth
68
Describe Tripodized contacts
Three points of contact which function to stabilize the tooth
69
Where do Tripodized contacts occur? What do the function as well as?
Occur on a cusp incline.
| Function as well as holding cusps
70
Define Axial loading
Process of directing occlusal forces through the long axis of the tooth
71
Describe the first method of achieving axial loading.
Development of tooth contacts on cusp tips or relatively flat surfaces that are perpendicular to the long axis of the tooth.
72
Describe how axial loading is achieved through tripodization
Requires that each cusp contacting an opposing fossa can be develop to produce three contacts surrounding the actual cusp tip.
73
Describe incline contacts
Teeth that occlude on inclines without tripodized contacts.
74
Why are incline contacts not stable?
Because they can cause teeth to shift
75
What is the main goal of typodont adjustment
Develop a stable occlusal relationship between the upper and lower members
76
What are two types of rocking you don't want in Typodont adjustments?
Anteroposterior or mediolateral rock
77
Typodont Adjustment: How many bilateral posterior contacts do you want? How many premolar/molar?
Minimum of five bilateral posterior contacts
3 molar
2 premolar
78
Typodont Adjustment: How many anterior contacts do you want? How many canines/incisors?
Four
Canines bilaterally
2 Incisors
79
Typodont Adjustment: Canines should contact only in ______ movements
Laterotrustive
80
Typodont Adjustment: What types of movements should canines not contact during?
No laterotrusive or mediotrustive posterior movements
81
Typodont Adjustment: A minimum of ___ anterior contacts with incisors end to end in protrusive movement, no posterior contacts bilaterally in protrusion
2
82
When adjusting contacts, do not shorten ___ ____. Instead, deepen the corresponding ____
Functional cups; Fossa
83
When adjusting contacts, adjust a prematurity on a triangular or marginal ridge by adjusting the mesial and distal +++++
Slopes
84
When adjusting contacts, for anterior prematurities, adjust the lingual of _____ _____
Maxillary anteriors
85
When adjusting contacts, why do you not want to adjust the incisal edges of the mandibular anterior teeth?
Phonetics or incising ability may be affected when mandibular incisal edges are altered
86
When adjusting contacts, what should be done if both functional cusps are contacting each other?
You can choose either cusp incline to adjust
87
What are three reasons why a tooth needs a crow?
Tooth structure
Improve esthetics
Change contour
88
Why does loss of tooth structure need a crown?
Loss of tooth structure compromises its structural integrity, necessitating cuspal coverage for protection.
89
What are five things that can cause loss of tooth structure?
```
Caries
Attrition
Abrasion
Abfraction
Erosion
```
90
Define caries
Infectious microbiological disease of the teeth that results in localized dissolution and destruction of the calcified tissues
91
Define attrition
Act of wearing or grinding down by friction
92
Where does attrition occur? What is it limited to?
Mechanical wear resulting from mastication or parafunction.
| Limited to contacting surfaces of the teeth.
93
Attrition is grinding down by _______
Friction
94
Define abrasion
Wearing away of a substance through some unusual or abnormal mechanical process
95
What causes abrasion?
Caused by something other than mastication.
| Brushing, nail biting, chewing on a pencil
96
Abrasion is an ____ mechanical process
Unusual or abnormal mechanical process
97
Define abfraction
Pathologic loss of hard tooth substance caused by biomechanical loading forces
98
Abfraction is caused by ____ loading forces
Biomechanical
99
Define erosion
An eating away; type of ulceration
100
Erosion is a loss of tooth substance by _____ processes
Chemical
101
What does improving esthetics help with?
Addresses the patient's dissatisfaction with the color and contour of their teeth.
102
Define survey crown
Crown that supports a removable partial denture
103
Crown Prep: Grind tooth _______ and on top
Circumferentially
104
How to make a Crown Steps
```
Prep
Impression
Mount
Wax up
Investment
Casting
Porcelin
```
105
Crown Prep: Impression step
Make a mold of what the tooth looks like
106
Crown Prep: Mount step
Turn impression into stone and put it on an instrument that stimulates the movements of the mouth
107
Crown Prep: Wax Step
Add and carve wax until it looks like a tooth
108
Crown Prep: Investment Step
Pour investment around the wax pattern
109
Crown Prep: Casting Step
Burn off the wax and fill the space with metal
110
Crown Prep: Porcelain Step
Add porcelain to metal
111
Describe impression material
Polyvinyl siloxane is an elastomeric material that is hydrophobic by nature.
112
Why is Polyvinyl siloxane a good impression material?
Elastric recovery, surface detail and tear strength
113
Describe what Gypsum is
Dental stone
Type One -> Weakest
Type V -> Strongest
Expands upon setting
114
What are the three functions of a custom tray
Carry, confine, control
115
What does the use of a custom tray minimize?
Amount of impression material used
116
What is a light cured custom tray made out of?
Urethane dimethacrylate (UDMA)
117
What is a self cured custom tray made out of?
Poly methyl methacrylate (PMMA)
118
What are the two parts of liquid acrylic?
Monomer -> Methyl methacrylate
| Activator -> Tertiary amine
119
What are the two parts of powder acrylic?
Pre-polymerized pmma beads
| Initiator (Benzoyl peroxide)
120
What is the most common acrylic used in dentistry?
PMMA
121
What is used for dentures and temp crowns?
PMMA
122
PMMA ___ biocompatible
Is
123
Does PMMA shrink during polymerization process?
Yes
124
PMMA is ___thermic
Exothermic
125
What are Acrylic's five distinct stages?
Sandy, stringy, doughlike, rubbery/elastic, stiff
126
Acrylic Material: Sandy Stage
No interaction on molecular level.
| Beads are unaltered
127
Acrylic Material: Stringy stage
Monomer attacks polymer beads -> Polymer chains are formed -> increase viscosity
128
Acrylic Material: Doughlike stage
Increased number of polymer chains -> no longer tacky or sticky
Material should be inserted into mold cavity during latter phases of doughlike stage
129
Acrylic Material: Elastic stage
Monomer is dissipated by evaporation and by further penetration into remaining polymer beads
130
What is an advantage to using self-curing acrylic resin?
Resin provides strong and easily adaptable material to create a custom tray
131
What is a disadvantage to using self-curing acrylic resin?
Liquid monomer is very volatile and poses as a hazard
132
Define Chamfer
Gingival aspect meets the external axial surface at an obtuse angle
133
Define Shoulder
Gingival floor meets the external axial surfaces at a right angle
134
Why do you want to use a chamfer for metal and a shoulder for porcelain?
```
Can be used in non-esthetic areas
Chamfer is more conservative
Metal is stronger than porcelain
Marginal seal is better with metal
Porcelain is strongest under compression
Porcelain needs more reduction to hide the metal
```
135
Define Retention
Quality inherent in the dental prosthesis acting to resist forces of dislodgment parallel to the path of placement
136
Define Resistance
Features of a tooth prep that enhance the stability of a restoration and resist dislodgement along axis other than path of placement
137
Define total occlusal convergence
Angle, measured in degrees, formed between opposing axial walls when a tooth or teeth are prepared for crowns.
138
Define undercut
Any irregularity in the wall of a prepared tooth that prevents the withdrawal of seating of a wax pattern or casting
139
Define path of placement
Specific direction in which a prosthesis is placed on the tooth
140
Provisional Restoration: What are five biological requirements?
1. Protect pulp
2. Maintain periodontal health
3. Provide occlusal compatibility
4. Maintain tooth position
5. Protect against fracture
141
Provisional Restoration: What are three mechanical requirements?
1. Resist functional loads
2. Resist removal forces
3. Maintain inter-abutment alignment
142
Provisional Restoration: What are four esthetic requirements?
Easy to contour
Color compatibility
Translucency
Color stability
143
Describe Temp-Bond NE
Will not inhibit polymerization of permanent resin cements and acrylic temporaries
144
Bis-acryl Advantages
Low exothermic reaction
Low shrinkage
Ease of dispensing
Short setting time
145
Bis-acryl disadvantages
High cost
brittle
Dissimilar chemistry w/flowable composite
Thick oxygen inhibited layer
146
Why is SNAP (PEMA) acrylic better than PMMA?
Safer intraorally
Does not traumatize pulp
Less polymerization shrinkage
