Denture Midterm Flashcards
What is the most desirable arch form for dentures?
Square arch; tapering is least desirable
Which arch size has the smallest margin for error
during impression making: large or small?
Small
What determines the amount of denture bearing area for
support of complete or tooth-tissue supported RPD?
Edentulous ridge width
What does edentulous ridge height provide?
Vertical walls that help the complete denture resist
movement horizontally
Is edentulous ridge height as important for horizontal
stability in RPD’s as it is in dentures?
No, RPD has framework to aide in resistance of
horizontal displacemen
What should be done to the pour up of an impression
of a tall, thin edentulous ridge before removing it from
the custom tray?
Soak in hot water to soften wax and undercut
blockout to decrease risk of breaking cast removmign
the impression
In determining the radiographic ridge height, the value of B determined by what?
The inferior border of mandible to crest of edentulous ridge
In determining the radiographic ridge height, what is the value of A determined by?
The inferior border of mandible to top of the mental foramen
What is the formula for calculating the percent bone remaining from the above two variables?
(B/3A)x100
If teeth are in the mandible, what are the variables and the formula for determining the percent bone remaining in areas adjacent to natural teeth?
R=root apex to crest of alveolar bone
C=root apex to CEJ
(R/C)x100
What are 4 categories of edentulous ridge shape?
U-shaped
V-shaped
Bulbous
Flat
What is another classification that is reserved for the mandibular posterior ridge?
Concave
What area of the mandible is the theoretical primary denture bearing area for a mandibular complete denture?
Buccal shelf
When classifying the height of muscle attachment and frena attachment versus the edentulous ridge, what does a high versus low attachment delineate?
“High” indicates the muscle or frena moves within 1-2mm of the crest of the edentulous ridge
“Low” indicates the muscle or frena moves 5mm or
greater from the crest of the edentulous ridge
What is indicated if the crest of the edentulous ridge moves with the normal movements of the vestibule?
Surgery: vestibuloplasty, ridge augmentation, mucosal or skin graft
Which side of the mandibular denture base length is particularly critical to the success of the mandibular denture?
Lingual border
Which ridge has more denture bearing area?
Maxillary
Why is the ideal palatal vault form for a maxillary complete denture flat with moderate depth, fairly tall edentulous ridges with parallel sides, broad flat crest, and fairly steeply inclined rugae?
Vault shape gives max area perpendicular to occlusal forces for dissipation
Ridge height prohibits horizontal denture movement
Why is a deep palatal vault favorable for denture retention but difficult to obtain an accurate impression and cast?
Easy to trap air during impression
Why is an impression of the palate of inherently decreased accuracy?
Because material shrinks toward its bulk (i.e.toward the tray and away from palate as it sets)
What are 4 reasons complete dentures are beaded so they will contact the palate?
- Inaccurate impression because material shrinks toward its bulk
- Material falls away from palate due to gravity
- Dental stone slumps away from palate if the impression is poured and immediately inverted onto a base
- Plastic based distorts when removed from cast due to
strains from polymerization
A soft palate that flexes downward at an angle of 0-30 deg is what class?
Class I
A soft palate that flexes downward at an angle of30-60 deg is what class?
Class II
A soft palate that flexes downward at an angle of 60-90 deg is what class?
Class III
What is the term for the junction of the movable and non-movable
tissues in the posterior of the palate (NOT the junction of the hard and soft palate)?
Vibrating line
Over which palate, hard or soft, is the vibrating line always located?
Always over hard palate
The vibrating line is most often located anterior to what palatal landmarks?
Fovea
If the vibrating line is posterior to a line connecting the most distal part of the tuberosities, the soft palate form is what class?
Class I (corresponds to soft palate flex Class I (0-30 deg))
If the vibrating line is on the line that connects the distal most part of the tuberosities, the soft palate form is what class?
Class II (corresponds to soft palate flex Class II (30-60deg))
If the vibrating line is anterior to the line connecting the distal most part of the tuberosities, the soft palate form is what class?
Class III (corresponds to soft palate flex class III (60-90))
This line limits the area of the palate that can be covered by the denture, thereby limiting the amount of support that can be obtained from the palate?
Vibrating line
Which removable prostheses can be designed to rotate around an existing tori: complete denture or RPD?
Complete. RPD has to go parallel to long axis ofremaining teeth
Should tori still be removed if currently they do not interfere with anything?
Removal can be justified as a contingency plan because later removal as the RPD adds more teeth or the RPD is
replaced by a complete denture, the patient may be too old or in too poor health to undergo reduction surgery
What is the space required between the maxillary tuberosity and the mandibular retromolar pad area for one denture base and what is the breakdown?
4 mm
2mm for one denture base
2mm space between the base and the opposing ridge
What is the space required between the maxillary tuberosity and the mandibular retromolar pad area for a maxillary and mandibular denture base?
6mm
2mm maxillary denture base
2mm mandibular denture base2mm space between
What are 3 ways to gain space between the maxillary tuberosity and the mandibular retromolar pad?
- Surgery to create sufficient space (best option)
- Increase VDO
- Stop denture base short (not viable)
How much of the maxillary tuberosity must the maxillary denture base cover?
Entire maxillary tuberosity
How much of the mandibular retromolar pad area must be covered by the denture base?
¼ of retromolar pad
Why must denture base cover at least ¼ of mandibular retromolar pad area?
Prevent vertical bone resorption at distal end mandibular denture
Why must denture base cover at least ¼ of mandibular retromolar pad area?
Prevent vertical bone resorption at distal end mandibular denture
What is done to create space between the maxillary tuberosity and the coronoid process of the mandible if there is insufficient space?
Horizontal maxillary tuberosity reduction surgery
Mucosa on the edentulous ridge is considered firmly attached if it moves less than __ mm in any direction
1mm
Mucosa on the edentulous ridge is considered very displaceable if it moves more than how many mm in any direction?
3mm
Will the displaceability of edentulous ridge mucosa be uniform?
No, can have local or generalized displaceable areas
What is the optimal thickness of firmly attached mucosa for denture support?
2-4mm thickness
What are 2 reasons for 2-4 mm thickness of firmly attached mucosa on the edentulous ridge?
- Cover sharp areas of bone
2. Help dissipate applied forces
What are 3 causes of displaceable soft tissue over the edentulous ridge?
- Inadequate soft tissue removal during tooth extraction
- Replacement of resorbed cone with fibrous connective tissue
- Genetically thick submucosa
Is white mucosa considered healthy or unhealthy?
Unhealthy
How long should dentures be out of mouth daily to keep mucosa healthy?
8 hrs
How long should dentures be out of mouth before making impressions for new dentures or before the delivery of new dentures?
48 hrs or more
What are 2 things linked to extended denture wear or ill-fitting dentures?
- Inflammatory papillary hyperplasia
2. Epulis fissuratum
Surgical removal of inflammatory papillary hyperplasia to a cleansable height is indicated if the IPH does not
reduce to a sufficient height of how many mm?
<1½ mm
What are 2 concurrent treatments for Epulis fissuratum?
- Correcting border length and base fit
2. Surgical excision of hyperplastic tissue
Which area is critical to the retention and stability of the mandibular complete denture and is estimated by placing a dental mirror into the space, asking the patient to swallow, then observing the amount of the mirror pushed out of the space during the swallowing motion?
Retromylohyoid space/lateral throat form
Which retromylohyoid space/lateral throat form does not displace dental mirror at all during swallowing and is most suited for retention and stability of the mandibular denture base?
Class I
A thin film of this saliva type is sticky like denture adhesive and will aide retention, but it does not dilute chemicals so plaque accumulation and calculus formation is increased?
Thick, mucosey, or ropey saliva
Should existing TMJ issues be communicated to the patient even if there is no treatment for them and why?
Yes, may blame pre-existing condition on the new denture
Does having the patient hold the tip of the tongue against the soft palate as the mandible is hinged predictably result in closure around the transverse horizontal axis?
No
What is the imaginary line around which the mandible may rotate through the sagittal plane?
Transverse horizontal axis
The patient’s ability to hinge is important for making centric jaw relation records. What is the use of the centric jaw relation record?
To mount the mandibular cast to the maxillary cast
What is the position in which the tongue fills the space between the teeth or the edentulous ridge when the mouth is slightly open and the tip of the tongue rests gently against the lingual alveolus of the edentulous ridge (found in 75% of the population)?
Normal tongue position
A person with (pick one: a normal tongue position OR a retruded tongue position) will likely have a poor experience with a mandibular denture due to constant loss of border seal?
Retruded tongue position
What border molding will not be done if the patient lacks the ability to make tongue movement?
Lingual border molding movements on the mandibular custom tray
Chewing where on the denture promotes denture stability?
Anteroposterior center of the denture bearing area
How should complete denture patients chew their food?
- Do not incise as it will displace maxillary denture
- Cut up food
- Chew bilaterally simultaneously with a vertical chewing stroke around the transverse horizontal axis
Can border molding of the buccal vestibules still be accomplished if a person is unable to make movements of their lips and cheeks?
Yes, dentist will have to do it for them
What is the impairment of the power of voluntary muscle movement resulting in fragmentary or incomplete movement such as quivering or shaking of facial tissues?
Dykinesia
What is the term for a patient repeatedly pursing lips, sticking tongue between their teeth, excessive swallowing, non-
purposeful movements of the mandible or tongue, clenching, grinding, bruxing, clicking their dentures together, lifting mandibular denture up with their tongue?
Adverse habits
What are the 6 arch shapes?
- Square
- Tapering
- Ovoid
- Square tapering
- Tapering ovoid
- Square ovoid
How far are custom tray borders to be from the vestibule?
2-3mm
How long should patient have their current dentures out prior to the border molding/impression appointment?
48 hours
Will the current dentures feel tight or loose after the patient has left them out for 48 hrs?
Initially loose
How much space should there be between the sides of a stock impression tray and the edentulous ridge?
5mm
What should be done if wax is used to modify any part of the stock tray before taking the alginate impression?
Paint wax with alginate adhesive
The manual says what impression should be done first?
Mandibular
How should an irreversible hydrocolloid impression be stored before pouring up?
100% humidity container (zip lock)
What stone is the initial irreversible hydrocolloid impression poured in?
Type III dental stone (yellow)
What does the red line indicate on the initial casts when planning the custom tray?
Estimated border extension of the denture
What does the blue line indicate on the initial casts when planning the custom tray?
Border extension of the custom tray
How far should the blue line be from the red line on the initial cast when planning the custom tray?
2-3mm
The maxillary custom tray posterior border should be in what relation to the estimated vibrating line?
At or slightly anterior to the vibrating line
Should the mandibular custom tray be short of or cover the restromolar pads?
Cover the retromolar pads
Maxillary custom tray should have what path or placement: anterior or vertical?
Anterior
Mandibular custom try should have what path of placement: anterior or vertical?
Vertical
What is the process of determining the length and contour of the vestibular tissues before and / or wen making an impreeion (accopmlished by having the patient make functional movements and the dentist manipulating the patient’s tissues)?
Border molding
What must you have knowledge of in order to bordermold?
How denture border appear
What should be verified when the custom trays are tried in the patient’s mouth before border molding?
- Border are 2-3mm short of muscle and frena attachments
- Maxillary posterior covers tuberosities and extends to vibrating line
- Mandibular posterior border covers at least 1/2 of retromolar pad
What is the heat for the water bath?
140 degrees F
What should the compound for border molding be formed to?
Slightly longer and thicker than anticipated border
What is the purpose of the hot water bath?
Temper the hot wax
Should the compound be kept in the tissue surface of the custom tray?
No. Trim out to reveal the inside edge of the tray border
What is looked for when inspecting the compound after the border molding?
That there was sufficient height (203mm) of compound that vestibular muscles could have shaped the border
What are 2 things that could interfere with insufficient height of compound to allow border molding?
- Insufficient height of compound initially.
- Compound wiped off during seating of the tray
- Tray border too long
Compound in the tissue surface of the tray will displace the tray inferiorly and change all the borders slightly, unless what?
Unless soft tissue of the palate was displaced superiorly by the compound
When does the esthetics of the denture begin?
At border molding and impression
Should a border seal be created during the border molding process?
Yes
Where will the maxillary custom tray border molding be thickest?
Lateral in the molar area
What is the desired shape of the compound in cross-sectional view after border molding?
Tear drop
What are the 2 purposes of placing 3-5 holes with a #8 round bur in a border-molded maxillary custom tray before making the master cast impression?
Allow escape of trapped air
What must be done with the border molded custom tray before placing the master cast impression material in it?
Paint with an adhesive specific to the impression material
What impression material do we use for master cast impressions?
Polysulfide rubber base
How should the patient be positioned for impression-making?
- Jaw to be impressed parallel to the floor
2. Jaw at the level of the operator’s elbow
What are 2 things to prepare the patients oral environment for the master cast impression?
- Have the patient rinse with dilute mouthwash to decrease saliva
- Dry maxiilla and mandible with gauze
Are the diameters of the polysulfide rubber base material the same?
No
How is the base and the caralyst dispensed to ensure equal amounts?
Dispense equal lengths
How long does a polysulfide rubber base material take to mix and how will you know when it is mixed?
1-1.5 minutes
Will have a uniform color
What spatula is used to load the custom tray with the impression material: a diamond-shaped spatula or a cement spatula?
Cement spatula
The custom tray should be loaded with what thickness and to what extent with polysulfide rubber base impression material?
Thin layer throughout tissue surface and over the tray borders
How long should loading the tray take?
1/2 to 1 minute
The polysulfide rubber base material will reach initial set in how many minutes?
5 minutes
The setting time for the polysulfide impression material is how many minutes from initiating the mix?
10 minutes
How can the visualized vibrating line that is marked with an indelible marker on the palate be transferred to the impression?
- Replace impression
2. Valsalva to transfer the ink onto the impression
What can be used to correct small voids in non-critical areas of the master cast impression?
Iowa wax
How far below the master impression borders and how wide should the beading wax or the plaster mix be placed in preparation for the master cast pour up?
3mm below the peripheral roll
The height from the highest part of the tissue surface of the master cast impression to the top of the boxing wax for the master cast pour up?
8-10 mm for the beading wax method
13mm for the plaster method
The land area of the master cast should be how many mm wide initially?
5mm
After boxing the 1:1 mounting plaster, flour pumice mixture that the master cast impression is se in, what is applied to the exposed areas of the 1:1 mis to keep the dental stone from bonding with it?
Petroleum jelly
Which impression requires more stone: maxillary or mandibular?
- Mandibular (250g)
2. Maxillary (200g)
The trimmed land area of the master cast should be what dimensions?
3-4mm and beveled 10 degrees toward the facial
What is the vestibular depth dimensions of the master cast?
2-3mm
The base of the master cast should be how thick from the base to the bottom of the buccal vestibule in the maxillary or the base to the flat tongue area in the mandible?
8-10mm
The posterior of the mandibular record base should cover how much of the retromolar pad area and should not extend into what area?
Cover at least 1/2 of the retromolar pad
Should not extend into deep retromylohyoid undercut
The maxillary occlusal rim should be how wide buccolingually in the posterior?
8-10mm
Maxillary occlusal rim should be how far anterior from the posterior border of the maxillary record base?
15mm
Maxillary occlusal rim should be how wide faciolingually in the anterior?
1-2mm
Maxillary occlusal rim should be how tall in the posterior measuring from the depth of the buccal vestibule to the top of the occlusal rim?
18mm
MAxillary occlusal rim should be how tall in the anterior measuring from the depth of the facial vestibule to the incisal edge of the occlusal rim?
24mm
With the maxillary record base in the patient, what should be seen beneath the patient’s nose in profile?
Concavity = nasolabial sulcus
What is the starting point for the length of the occlusal rim below the patient’s resting lip to miic the length of the central incisor?
1mm inferior
What is the average distance from the facial vestibule to the inferior border of the occlusal rim that is adjusted to have 1m showing below the patient’s relaxed lip?
24mm
What can be done to test the length of the adjusted maxillary occlusal rim?
Have the patient say F and V to ensure lower lip brushes against the incisal edge of the occlusion rim
F and V sounds are called what type of sounds?
Labiodentals
What is the Fox Plane used for?
Check hieight and angulation of the posterior occlusion rim
The Fox Plane should be higher in what region?
Higher in mandibular region than incisors
The denture manual says the Fox plane resting against a properly contoued maxillary occlusal rim should be parallel to what line?
Camper’s Line (from inferior border of the ala of the nose to the superior border of the tragus of the ear)
What is the term for the vertical dimension of the face when the teeth are in occlusion?
Vertical dimension of occlusion
What is the term for the vertical dimension of the face when the mandible is in the “rest position” (closing muscles relaxed)?
Vertical dimension of rest
What is the term for the space between the teeth at VDR, also called freeway space?
Interocclusal clearance
Interocclusal clearance should be ___mm?
2-4 mm in the premolar region
The difference between VDO and VDR is what?
The interocclusal clearance, 2-4mm in the premolar region
What is the term for the space between the mandibular incisal edges and the maxillary anterior teeth when the patient is pronouncing the sibilant sounds (s,z,sh,zh,chi,j)?
Closest Speaking Space
The closest speaking space should be how much?
1mm or less
What should there be when a patient closes from VDR to VDO?
Some mandibular closure
What is the tentative centric jaw relation record is made based off what movement of the mandible: hinge or translation?
Hinge with the condyles in CR
What are indications that tentative centric jaw relation record is acceptable when it is hand articulated?
- No contact between record bases
- No rock in the record bases
- Position of record base is stable
Any tooth mold that is ____ the width indicated by the Truyte Tooth indicator is a potentially acceptable tooth mold for the patient?
+ or - 0.5
Which is more important from the Trubyte tooth indicator: the length or width?
Width
What did House’s research show about the length of the natural tooth versus that indicated by the biometeric ratio?
Length of natural usually less than that indicated by biometric ratio
A maxillary central incisor should be similar to what when held upside down?
To width, length, and outline form of patient’s face
A complete denture occlusal scheme indicated for no vertical overlap (no overbite) and 3mm or less horizontal overlap (overjet)?
Any occlusal scheme
What is a complete denture occlusal scheme indicated for no vertical overall (no overbite), and 3-5mm horizontal overlap (overjet)?
Any EXCEPT monoplane
What is a complete denture occlusal scheme indicated for no vertical overlap (overbite) and more than 5mm horizontal overlap (overjet)?
Balanced occlusion with flat teeth
What is complete denture tooth type is indicated in the maxillary denture for esthetics?
Cusped denture teeth
What is a complete denture occlusal scheme indicated when there is a discrepancy between the posterior maxillary and mandibular ridge widths?
Flat teeth
What is the simplest complete denture occlusal scheme and recommended when there is no vertical overlap (overbite) and little horizontal overlap (overjet)?
Monoplane occlusion (the flat teeth set flat)
When mounting the mandibular master cast to the articulator using the tentative centric jaw relation what should be done to the articulator index pin?
Open 1-2mm to account for CR record thickness
After the mandibular is mounted and the centric jaw relation is removed what is done and recorded?
Loosen the index pin until the maxillary and mandibular rims contact and record where that VDO is based on + or - from the 0 mark on the pin
What is used to determine a rough guide to the canine placement of denture teeth?
Line perpendicular to palatal suture through the incisive papilla onto the edentulous ridge
What wax is used to attach denture teeth to the record base?
Set up wax
What is mechanically desirable for mandibular posterior denture teeth arrangement?
Arrange over center of the ridge
Can a monoplane occlusion be arranged for the wax try-in even if another occlusal scheme is to be used for the denture?
Yes, easier to develop and can verify VD, CR mounting, esthetics, phonetics
What is a consideration for the initial alginate impression?
Use a bit less water to make thicker since you don’t have teeth to get around
What are 4 goals in complete denture construction?
- Esthetics
- Comfort
- Function
- Preserve remaining tissue
What is a major class of drugs prescribed to the elderly, who make up 10% of the population, but consume 25% of medications in the US?
Heart medications
What are 3 factors that interfere with normal function of removable prosthetsis?
- Xerostomia
- Impaired wound healing (pressure spots under denture)
- Frequent fungal infections
What are 4 psychological assessments of the patient?
- Philosophical
- Indifferent
- Exacting
- Hysterical
What is the psychological patient type that has had no previous denture experience?
Philosophical
What is the psychological patient type that does not feel the need for teeth and will most likely need education?
Indifferent
What are 2 psychological patient types that can be expected to have poor adaptation to dentures?
- Exacting
2. Hysterical
What are 3 objectives for a complete denture that begins with preliminary impression?
- Retention
- Stability
- Support
Is the hard palate epithelium keratinized or non-keratinized?
Keratinized
The masseter muscle only affects what part of which denture?
Distobuccal flange of the mandibular denture
What is another indicator, beyond being rolled, that the compound made tissue contact during the border molding?
Surface is smooth and shiny
What is the only border molding that cannot be done operator-assisted (the dentist manipulating the tissues to mold the border of the custom tray compound)?
Lingual
What are the times for the COE-Flex polysulfide rubber base impression material?
Working time 4 minutes
Curing time 8-10 minutes
What is the objective of beading and boxing the master cast impression?
Preserve and protect the borders by producing a protective ledge around the cast
What is the only place where tissue does not hang over and aide in holding the denture in, and is the reason it is given a posterior palatal seal?
Maxillary denture posterior
What are 3 functions of posterior palatal seal?
- Compensates for lack of soft tissue drape
- Compensates for linear shrinkage of denture base acrylic during processing
- Maintains tissue contact during functional movement of denture
What are 6 factors of retention?
- Adhesion
- Cohesion
- Interfacial surface tension
- Capillary attraction
- Atmosphere
- Oral and facial musculature
The masticatory mucosa covers what areas?
Residual ridge and hard palate
The dorsal surface of the tongue is covered by what mucosa?
Mucous membranes
The dorsal surface of the tongue is covered by what mucosa?
Specialized
Besides the mandible, what other bone do the muscles of the floor of the mouth (mylohyoid, genioglossus, and geniohyoid) connect to?
Hyoid
Is COE-Flex Polysulfide rubber base impression material low viscosity or high viscosity?
Low viscosity
What are 3 objectives of boxing a master cast?
- Produce a container
- Produce accurate cast of predetermined thickness
- Produce a dense accurate cast using gravity
Will the record base be a part of the final denture?
No
What is holding the jaw in place at VDR?
Muscles
Is a slide between CR to CO acceptable in the denture patient as it would be in the denture patient?
No
Do teeth have anything to do with a facebow?
No
What are 3 points of reference for a facebow?
2 posterior (the approximate hinge axis) 1 anterior (measured or parallel to infraorbital notch)
What is the purpose of the facebow?
To mount the maxillary cast on the articulator to mimc its relation in the patient to the patient’s hinge axis
What are 4 objectives of the maxillary occlusal rim?
- Establish proper lip support
- Establish proper tooth position
- Establish maxillary midline
- Establish anterior portion of occlusal plane
Our facebow is what style?
Caliper (opens/closes to different widths) Remote mount (only need the bitefork)
How can a long term denture wearer have a decreased VDO?
- Acrylic denture tooth wear
- Resorption of maxilla up and back
- Resorption of mandible down and forward
Why must the CR record be completely in the recording material?
To ensure the record base will not displace tissues
How is the tentative CR record verified once it has been mounted?
Make 2nd CR record and make sure when it is placed on the mounted master casts and the articulator closes that the condylar balls remain against the back of their housing
What increases the chance of success for dentures?
When the patient is involved in the production of the denture
According to Dr House, what is the width of the maxillary central incisor equal to?
1/16 of the bizygomatic width
Why do we use monoplane teeth?
Allows more stable occlusion so wherever the patient bites, due to their lack of proprioception, they will occlude on a flat table
What is a mechanical devide which represents the temporomandibular joints and jaw members to which maxillary and mandibular casts may be attached?
Articulator
Tooth shade is based on what premise?
Harmonious relationship between color or patient’s teeth and patient’s complexion
What is the tooth mold selection system we use?
Trubyte
There is a harmonious relationship between what tooth and what view of the face?
Inverted outline form of maxillary central incisor and patient’s facial shape
How many years will it take an acrylic tooth to wear to reverse curve?
5-7 years
What type of denture teeth have cuspal inclination of 30 degrees or more?
Anatomic teeth
What type of denture teeth have shallow cusps and less steep inclined planes than those of the 30 degree cusp type?
Semianatomic teeth
What type of denture teeth with occlusal form have no resemblance to anatomic teeth and offer occlusion without intercuspation?
Nonanatomic teeth
