exam revision Flashcards
1
Q
professional conduct?
A
behave prof, cosnent, confidentaility, rights of patients, continuing education
dedicated learning, respectful, patient need first, honest and integrity and emotional maturity and physical health
2
Q
labial?
A
lip
3
Q
lingual?
A
tongue
4
Q
FDI notation
upper right lateral incisors
A
federation dentaire international notation
12
5
Q
FDI lower left canines
A
33
6
Q
Palmer notation upper right lateral incisors
A
2
7
Q
minimal requirements of areas to be recorded in primary casts - max arch (5)
A
1 - residual ridge - inclduing full extent of tuberosities and hamular notch
2 - functional depth of labial and buccal sulci, including fraena and muscle attachments
3 - hard palate and junction with soft palate
4 - base parallel to occlusal plane
5 - sufficient bulk of strength and stability - 15mm base
8
Q
minimal requirements of areas to be recorded in primary casts - mand arch (5)
A
1 - residual ridge - inclduing full extent of retromolar pads
2 - functional depth of labial and buccal sulci, including fraena, muscle attachments and external oblique ridges
3 - lingual sulci, lingual fraenum, mylohyoid base and retro-mylohyoid areas
4 - base parallel to occlusal plane
5 - sufficient bulk of strength and stability - 15mm base
9
Q
special trays points (3)
- made from?
- constructed on__ and helps__
- resulting__ allows__
A
- made from acrylic (light or cold cured) or shellac (thermoplastic material)
- constructed on primary cast - helps adaptation of impression material and reduces amount required
- resulting master cast - well detailed and allows accurate construction of denture
10
Q
custom impression tray
- increases__
- prevents__
A
- increase impression accuracy by providing uniform thickness of impression material
- prevent distortion of impression by providing rigid tray
11
Q
closed or close fitting special tray
- what is it (3 points)
A
- no space between cast and special tray
- min block out undercuts (max - frenum, buccal surface of tuberosity, rigae, flabby portions of alveolar ridge)
- fine details capture with min spacing
12
Q
closed or close fitting special tray
- what types of material and eg?
- mucostatic or mucocompressive
A
- zinc oxide eugenol, light bodied elastomers (rigid, low viscosity materials)
- mucostatic
13
Q
spaced special tray
- description
- 3 materials and spacing?
A
- space between natural teeth and impression tray, spacing of wax:
- alginate (3mm)
- elastomeric impresison materials (1.5mm)
- impression plaster (1.5-2mm)
14
Q
spaced special tray
- what material can’t use and why
A
cannot use ZOE for dentate because it has huge undercuts
15
Q
spaced special tray
- mucostatic or mucocompressive
A
mucocompressive
16
Q
spaced special tray
- allows (3)?
A
- allows better flow and adaptation
- allows better handling of undercuts
- materials that require more space –> capture details without distortion
17
Q
mucostatic
- pressure?
- retention?
- stability?
- material
A
- no pressure
- min pressure (min displacement) to tissues and records resting shape
- better retention - denture –> closer adaptation to mucosa at rest
- instability of denture
- eg low viscosity alginates
18
Q
mucocompressive
- pressure?
- retention?
- stability?
- material
A
- applying pressure to mucosa, so shape of tissue under load is recordoed
- results wider distribution of load during function –> more stable denture (good for function) –> compensates for differing compressibility of denture bearing area reducing risk of fracture due to flexion
- retention compromised –> as soft tissues wish to return to original position at rest
- eg high viscosity alginates or elastomers
19
Q
impression materials - elastic/nonelastic according to-
A
ability of set material to be withdrawn over undercuts
20
Q
use of wax rims (4)
A
- registration –> try in
- teeth secured in wax
- try in stage
- prior to waxing down
21
Q
contour rims/wax registration rims
(7) purposes
A
1 - establish posterior extent of max denture
2 - establish aesthetic labial and buccal contours
3 - establish occlusal plane
4 - to mark/transfer midline, high lip line and cuspid to cuspid distance
5 - to mount max cast on articulator - relates to cranial landmarks
6 - to measure rest relations, resting vertical dimension (RVD)
7 - to register occlusion vertical dimension (OVD) and centric relation (CR)
22
Q
pound line - what is it
A
- lingual surface of lower posteriors situated between 2 lines projected from buccal and lingual aspect of retromolar pads to mesial aspect of canines
23
Q
pound line - importance? (2)
A
if teeth not within pound line, dentures become unstable and leads to movement or dislodgement
AND helps distribute occlusal forces evenly across denture base
24
Q
neutral zone - what is it
A
the potential space between lips and cheeks on one side and tongue on the other;
that area or position where forces between the tongue and cheek or lip are equal
25
neutral zone
- maintains
- allows (3)
maintain stability of denture and retention-
allows no cheek/tongue biting AND functionality and comfort
26
ideal registration rims (4)
1 dished out area anteirorly - allow room for lips
2 tapered posterior (max)
3 models parallel
4 allows for articulation
27
selection of tooth (4)
1 horizontal
2 biometric guidelines
3 interpupillary width - inter canine width (canine to canine)
4 interalar width = inter canine width (end canine to end canine)
28
size tooth check (2)
- line pass thru distal edhes of incisive papilla
- perpendicular to palatal midline intersects cusp tip of canine
29
face shape
square, tapering, ovoid
- relationship between face shape, arch shape and tooth shape
- square - suggested for males
- tapering - suggested for skinny
- ovoid - suggested for females
30
Gerber's 7 anatomic landmark guidelines
1. incisive papilla
- max anterior teeth lie facial to incisive papilla
- anterior arch form
2. distance - middle incisive papilla to labial surface of max central incisors = 8-10mm
3. labial surface of canine - 10.5mm from lateral aspect of anterior rugae
4. distance between tips of canine = width of base of nose
5. canines immediately inferior to side of nose
6. width of central incisor ~ width philtrum
7. 1st premolar appear at head of buccal corridor and behind canine buccal corridor - area between back of teeth and corner of lip
31
definitions of occlusion
- occlusion - any contact between incising or masticating surface of upper and lower teeth
XX
- occlusion - static relationship of teeth when in contact
- occlusal contact - any meeting or touching of tooth surface
- teeth make occlusal contact during parafunctional (abnormal ie bruxism) act of swallowing
- act or process of closure of being closed or shut off
32
definition of articulation (5)
- static and dynamic contact relationship between occlusal surfaces of teeth during function ie contact between teeth when mand moving
- when teeth kept tgt during this movement they are articulating and in presence of food, mastication take place
- articulation - can be non-functional as in bruxism or functional as during mastication
- relationship of cusps of teeth during jaw movement
- relationship of all components of masticatory system in normal function
33
centric relation of occlusion (CRO)/ centric relation (CR)
- relationship of bones of upper and lower jaws without tooth contact or with teeth only barely contacting before closing teeth into max intercuspation
34
centric occlusion (CO) (4)
- max intercuspation or contact attained between max and mand posterior teeth
- determined by way teeth fit tgt, not determined by muscle or bone
- fit tgt most tightly/best
- habitual occlusion/ natural bite
35
define terminal hinge axis (THA)
- axis of rotation of mand
36
define occlusal vertical dimension (OVD)
artbitrary space between upper and lower jaws upon closure, may decrease over time due to wear, shifting or damage to teeth
37
define resting vertical dimension (RVD)
position of mand at rest when patient sitting upright and condyles in unstrained position, jaw muscles relaxed
38
free way space (FWS)
define and formula
- vertical distance between occlusal surface max and mand when at rest and no tooth contact
FWS = OVD - RVD
39
lateral excursion
mand moves toward right/left side
40
working side
side which mand moves
41
balancing side
non working side
42
protrusion
mand move forward, from centric occlusion, only anterior teeth should touch
43
premature contact
define and results in (4)
if one tooth occludes slightly earlier than others, becomes interference and bears more force than others, resulting in:
- stress TMJ
- tooth becomes sensitie to percussion
- widening of PDL
- mobility
44
protrusion
when both external pterygoid muscles contract simulataneously and pull condyles with articular discs forwards onto articular eminencies
- condyles - translating
- mand forward
45
retrusion
mand back
46
eccentric mandibular movements define
movement away from center (lateral excursion)
47
during lateral movement of mand to left...right and left condyles...
during lateral movement of mand to left, right condyle, balancing condyle, moves down, forward and medially, left condyle, working side condyle, moves to less extent, slides outwards or slightly forwards or someto=imes backwards
48
bennett movement
define
working and non working condyle moves...
mm?
- bodily movement of mand
- lateral and spatial shifting of laterotrusion condyle (working side) in outward direction
- lateral movement of working condyle = 0.6-1.5mm (average-2mm)
- metrotrusion condyle (nonworking) moves more toward centre
49
bennett angle formed by...
condylar path of mediotrusion side and a line parallel to median plane during lateral movement
50
bennett angle varies and average (dentulous and edentulous)
varies - 10-20º
average - 15º
average dentulous - 15º
average edentulous - 20º
51
articulation (2)
process of...
done by...
- process of transferring records taken from wax registration rim and face bow to articulator
- done by mounting models to articulator using plaster or accessory items
52
dental articulators
- a mechanical instrument represents TMJ and jaw to which max and mand casts may be attached to stimulate some or all mand movements
53
Class III articulator
semi- adjustable types divided into arcon (artic and con) and non arcon
54
arcon class III articulator
- arcon maintains same arrangement as human skull - condylar mechanisms are attached to upper member while condyles attached to lower member
55
nonarcon class III articulator
has condylar guidance mechanisms in lower member of articulator and condyles - upper member
- unlike natural anatomy
56
average value articulation (7 points)
- average radius for hinge movement as casts are mounted according to Benwill's triangle
- intercondylar distance - consequently equal to distance from condyle to centre of lower central incisors (incisal point)
- 3 points - equilateral triangle - 10.16cm (4inches)
- inclination of condylar path - fixed value
- masticatory movements can only be carried out on average value basis
- average value inclination of condylar path eg 10º, 34-35º
- average value bennet angle eg 10º ,15º ,20º
57
facebow registration
- calliper like device
- used to record relationship of max arch to condyles (TMJ) point(s) and then transfer relationship to articulator
- purpose of facebow - transfer both esthetic and functional components from patient to articulator in efficient manner
- replicate centric, working and balancing and protrusive movements
- teeth - sensory organs - articulators - movement stimulators
- teeth masticate food and fine sensors which are permanently moving when laughing, speak or smile - important in movement and direction of mand and max, articulators must be equally accurate if they are to replicate movement of real patient
- facebow-reproduces angle and position
58
theories of occlusal function (3)
- mutually protected occlusion - canine and anterior guidance
- group function - Beyron and pankey-mann-schuyler (PMS)
- bilaterally balanced occlusion - Gysi's concept on balanced occlusion
59
canine guidance (5 points)
- mutually protected occlusion
- canine protected articulation
- vertical and horizontal overlap of canine teeth disengages posterior teeth in excursive movements of mand
- canines - the only teeth contacting lateral movement AND disoccludes posterior teeth lateral excursions - canine guidance
- most common in natural dentition
60
anterior guidance (5 points)
- mutually protected occlusion
- anterior protected occlusion/ posterior disocclusion
- occlusal scheme which anterior teeth protect posterior and vice versa during protrusive movement
- posterior teeth protect anterior teeth in max intercuspation
- most common in natural dentititon
61
group function
- __ occlusion
- define (2)
- effect -
- unilaterally balances occlusion
- multiple contact relations between max and mand teeth in lateral movements on working side
- simulataneous contact of numerous teeth acts as a group to distribute occlusal forces
- effect - distribute lateral forces to multiple teeth rather than single canine or other weakened anterior guiding teeth
- the more teeth that bears stress, less stress any one tooth must bear
62
bilateral balanced occlusion
- bilateral, simultaneous anterior and posterior occlusal contact of teeth in centric and eccentric positions
63
bilateral balanced occlusion advantages (7)
stability during mand movements
even force distribution
food for eccentric movements
aesthetics
better food epentration
anatomic position arranged in harmony with muscles of mastication
64
bilateral balanced occlusion disadvantages
very difficult and time consuming process
need precise technique
cuspal inclines tend to create greater lateral forces that can harm ridges
65
lingualised occlusion (3 points)
- one of bi-lateral balanced occlusion
- developed to maintain food penetration
- upper lingual cusp occludes with central fossae lower teeth
66
lingualised occlusion advantages (6)
better adpatation to different types of ridges
greater masticatory efficiency
eliminates lateral interferences
maintains aestehtics
maintains food penetration
bilateral balance possible
67
lingualised occlusion disadvantages (5)
less resistance of denture base rotation than balanced
may result in increased lateral forces
more wear
precise technique needed
68
monoplane occlusion principles (4)
0º incisal guidance
0º cusp height (angle)
flat occlusal angle
limited overbite/overjet
69
monoplane occlusion indications (6)
class II or III malocclusion
severe residual ridge resorption
excessive interarch distance
poor neuromuscular skills
poor patient adaptability
inconsistent bite - most common reason
70
monoplane occlusion advantages (9)
1 - used for patients with poor neuromuscular coordination
2 - less time set up
3 - more adaptable to unusual jaw relations
4 - can use in cross bite
5 - mand not locked in one position
6 - greater comfort and efficiency
7 - improve denture stability
8 - accommodates changes in horizontal and vertical relations
9 - relining and rebasing - easier
71
monoplane occlusion disadvantages (5)
1 - less efficient to masticate (poor food penetration
2 - aesthetically inferior
3 - clogging to occlusal surfaces
4 - difficult to establish balanced occlusion
5 - occlusal adjustments - more difficult
72
angle's classification
- define
- based on ...
- system of classifying relationship of upper teeth to lower
- based primarily on relationship of:
- permanent 1st molars to each other
and
- permanent canines to each other
73
angle's classification I
- define
- molar relation
- canine relation
- neutrocclusion (anteroposterior occlusal relations of teeth - normal)
- canine relation - max canine occludes with distal half of mand canine and mesial half of mand 1st premolar
- molar relation - MB cusp of max 1st molar in line with buccal groove of mand 1st molar
74
angle's classification II
- define
- molar relation
- canine relation
- division 1
- division 2
- distocclusion (mand is posterior to normal position, relative to max)
- canine relation - max canine occludes anteriorly (more forward) to distal half of mand canine and mesial half of meand first premolar
- molar relation - buccal groove of mand 1st molar distal to MB cusp of max 1st molar
- division 1 - overjet with proclined incisors (>2mm)
- division 2 - overbite with retrocliend incisors (>2mm)
75
angle's classification III
- define
- molar relation
- canine relation
- mesiocclusion
- canine relation - distal surface of mand canine is mesial to mesial surface of max canine by at least width of a premolar
- molar relation - buccal groove of mand 1 moalr is mesial to MB cusp of max 1st molar
76
occlusal contact determinants (5) - Hanau's quint
1. orientation of occlusal plane
2. condylar guidance
3. incisal guidance
4. cuspal angle
5. compensating curve
77
Hanau's quint for BBO - orientation of occlusal plane
average value articulators - preset distances between condylar components and incisal tips, orientation of occlusal plane - determined by clinician when trimming max wax registration rims
78
Hanau's quint for BBO - condylar guidance
- define (2)
- angles? (edentulous and dentate)
- condylar angles of average value articulators - preset, usually are 10-30º
- usually 10º - edentulous
- 30º - dentate
- fixed in patients' anatomy
- condylar path - route taken when condyles move downwards and forwards from glenoid fossae onto articular eminicies during protrusive and lateral movements
- condylar guidance angle - inclination of this path relative to axis orbital plane (Frankfurt plane)
79
Hanau's quint for BBO - incisal guidance
- define
- angle?
- commonly set arbitrarily at 10 or 15º
- angle to orbital axis plane (approx to Frankfurt plane) which incisal edges of lower incisors make with palatal surfaces of upper incisors when mand protruded with teeth in contact
80
Hanau's quint for BBO - cuspal angle
produced by manufacturer
81
Hanau's quint for BBO - compensating curve allows...
for balanced occlusion
82
curve of spee
anatomical line beginning at tip of canine and following buccal cusps ot premolar and molar when viewed buccally
83
curve of wilson
curve that follows cusp tips as seen from frontal view
84
spee + wilson =
(diameter)
curve of monson
- 4 inch (10cm) radius ball
85
importance of Hanau's quint (4)
- to achieve balanced occlusion (contacts)
- to mimic real human (teeth)
- stability of dentures - minimise tipping, dislodging
- allow/improve functionality of denture in mouth for patients
86
controlling factors of hanau's quint (3)
- cusp height (cusp angle) - tooth form
- steepness of compensating curve
- incisal guidance angle
(increase in one, increases others)
87
posterior palatal seal to enhance... and maintain... by compensating for... (4)
retention and maintain peripheral seal of max denture base by compensating for:
- polymerisation shrinkage
- minor denture bse functional movements
- improves retention (air tight_
- prevents food trap
88
Post DAM
what is it
- posterior extension of fill denture to accomplish a complete seal between denture and tissues
89
selective grinding technique - protrusive movement
nonfunctional cusps -
why dont want to trim functional cusps-
reduce-
non functional cusps:
- Buccal Upper (BU) – Lower Lingual (LL)
- Distal Upper (DU) – Mesial Lingual (ML)
- dont want to trim functional cusps (otherwise disturb BBO OVD, which increases freeway space - dont want)
- reduce Disto Lingual (DL) inclines of Mx buccal cusps.
- Reduce Mesio Buccal (MB) inclines of Md lingual cusps
90
selective grinding technique - laterotrusive movement (working side)
* Buccal Upper – Lower Lingual
* Reduce lingual inclines of buccal cusps of Mx teeth.
* Reduce buccal inclines of lingual cusps of Md teeth
91
selective grinding technique - medriotrusive movement (non working side)
* Max palatal cusp; reduce DistoBuccal inclines
* Mand buccal cusp; reduce MesioLingual incline
* NEVER GRIND BOTH CUSPS!
92
define porosity
Surface & subsurface voids will compromise physical, aesthetic & hygienic properties.
93
porosity 4 reasons
1. Porosity is more likely to occur in thicker portions
- Results from vaporisation of un-reacted monomer & low molecular weight polymers and will be seen randomly
- Raising the temperature too quickly – voids spherical.
2. Inadequate mixing of powder & liquid.
- Results in shrinkage & produces voids.
3. Inadequate pressure or insufficient material.
- Voids are irregular, not spherical & abundant...opaque.
4. Inclusion of air on mixing and pouring.
- Sizable voids, improved by careful mixing, spruing and venting
94
complications of pososity
not clinically accepted, traps food particles and bacterial leading to bacterial growth, gum diseases, health risks, weakens denture leading to prone to breaking
95
what is an immediate denture?
An immediate denture is a temporary, transient, or transitional denture which is entirely constructed prior to the extraction of teeth which it replaces AND is inserted immediately after the extraction of the teeth
96
immediate denture - Similar process to complete dentures, however,
need to work around existing teeth - impression, jaw relationship, setting teeth and removal of existing teeth
97
lab procedure - immediate denture
- the cast must be modified to represent the anticipated changes in contour that will occur with surgical removal of teeth.
- If the dental midline and the facial midline are not coincidental, it is imperative that the facial midline be established by removing the central incisor that is most closely approximated to the facial midline as the preliminary step in cast modification.
- The midline marked in pencil on cast.
- The posterior teeth will already have been arranged; consequently, the remaining teeth may be removed from the stone cast and the cast adjusted to simulate the soft and hard tissue contours that would be anticipated following removal of teeth
98
sequencing of removal
- adjacent teeth used as guide
- attention given to tooth - shape, angle, length, inclincation and direction
- alternating left and right
- L cen, R lat, L canine, R cent, L lat, R can
99
sequencing of removal of teeth - alternating left and right to: (2)
- maintain occlusion and symmetry
- preserving function
100
types of immediate denture
1. open faced denture where teeth are:
- gum fitted (1st preference)
- socketed (Only used when the teeth have been extracted because of periodontal disease resulting in alveolar bone loss)
2. fully flanged denture
3 part flanged denture (half flanged)
101
reline used to improve...
the fit of a denture, therefore it is the fitting (tissue) surface that is prepared and altered allowing for accurate adaptation to the changed surface
-Replacement of the fitting surface of a denture
102
rebasing -
what is it?
usually done when...
Replacing the entire denture base without altering the occlusal relations.
Rebasing is usually done when the denture teeth are in good condition in comparison to the denture base material. It is a process of retrofitting dentures by replacing the acrylic denture base with new acrylic, which provides a stable denture without replacing the denture teeth or changing the occlusal relations
103
indications for reline or rebase (4)
- immediate denture - 3-6 months after fabrication
- when residual alveolar ridges hae resorbed
- when patient cannot afford new denture
- when making new denture - too much stress to patient
104
reasons for relining (4)
*To improve retention (scuction) and stability (the fit).
*To improve appearance.
*To restore vertical dimension and equality of occlusal pressure.
*To reduce pain (comfort & function).
(*However, the mouth is constantly changing the alveolar process is naturally resorbing (shrinking) with the aging process. Once the denture becomes loose it can cause ulceration of the tissue surface)
105
types of reline -
- Hard or permanent relining
(Heat cured or self/cold cured)
- Soft relining
106
acrylic resins (4 points)
- Supplied in the form of a liquid & a powder.
- Liquid – Monomer (one Methyl Methacrylate; MMA).
- Powder – Polymer (many MMA, is monomer ground up into a powder, at a molecular level they are identical).
- Poly-methyl-methacrylate (PMMA)
107
Soft lining material
Used to...
activated by...
a disadvantage..
- Used to absorb the energy produced by masticatory impact.
- “Shock absorber” between occlusal surface and underlying oral tissue.
- May be heat or chemically activated.
Acrylic (Vertex soft) or Silicone (Molloplast B).
- Difficult to clean and prone to the buildup of microorganisms
108
techniques for reline and rebase
- plain line articulator
- Reline jig
- Denture flask
- They can be used to locate the denture in relation to the tissue surface
109
direct flask method
- Saves flasking job twice
- Lab putty not as accurate with OVD
110
Technical procedure of reline
(11)
1 Preserve the gingival roll of the impression when pouring up the model.
2 ‘Score’ model on the base.
3. Take a ‘key’ of the occlusal surface while the model is still in the impression. A key can be used on a reline jig or plain-line articulator.
4 model can be removed from the impression.
5 Clean up the denture and take note of the thickness of the impression material.
6 Replace the denture on the key (reline jig, articulator).
7 Check the amount of acrylic that can be removed or roughened...we only want to replace 5 mm of original acrylic.
8 Grind the fitting surface and peripheral boarders so the old acrylic will accept the new.
9 Clean the denture and place on ‘key’.
10 Process using a heat or cold cure process.
11 The denture is highly shined on completion...without disturbing the new fitting surface, teeth or of course the occlusal surface
111
types of reline (4)
- Fractures (hairline cracks)
- Replace Teeth/tooth (simple reattachment or replacement)
- Addition of Teeth to the current denture
- Add a clasp
112
dental implants
- a device that is used to replace the root portion of a missing tooth or missing teeth.
- Biocompatible screw-like titanium "fixture" that is surgically placed into the jawbone.
- used to support natural looking teeth and enable patients who are missing some or all of their natural teeth to smile, speak with confidence and chew their food more comfortably
113
Components of an implant restoration
- Screw retained implant restorations consist of three components
1 Implant fixture
2 Abutment
3 Restoration
- The abutment screw secures the abutment to the fixture
The prosthetic retention screw secures the prosthesis to the abutment
- Implant - replaces tooth root
- Crown - artificial replacement tooth
- Post (cylinder)
- Abutment (post extension)
114
overdenture define and 2 key factors
- complete or partial removable denture supported by retained roots or teeth to provide improved support, stability, and tactile and proprioceptive sensation and to reduce bone resorption
- Stability and retention are the key factors for using overdentures
