Dentures Flashcards
Neurocentric
Position: closest to the tongue as possible
Proportion: reduce Occlusal table by 40%
Pitch: parallel between ridges
Form: non-anatomic
Number: reduce posterior teeth from 8 to 6
Devan
Neil’s Lateral Throat form
Class I: 8-12mm of extension below the mylohyoid ridge (long, wide flange)
Class II: 4-6mm of extension below the mylohyoid ridge
Class III: 2-3mm of extension below the mylohyoid ridge; RARE
Kelly Combination syndrome
Papillary Hyperplasia
Max ant ridge resorption
Extrusion of mand ant teeth
Downgrowth of tuburosities
Resorption of mand post ridge
House palatal throat form
Class I: 5-12 mm post from hard palate
Class II: 3-5 mm post to hard palate
Class III: anterior to hard palate
The area in the mouth where the force of the tongue pushing out is neutralized by the forces of the cheeks and lips pressing inward so that normal muscle activity retains dentures rather than dislodges them.
Neutral Zone
Berersin Scheiser
Dentogentics
Frush and Fisher
Sex
Age
Personality
Balancing ramps
Nepola and Sears
PDI for edentulism
1) residual bone height
2) residual bone morphology
3) muscle attachments
4) maxillo-mandibular relationship
Pear shaped pad
Cradock
-6 factors of retention
adhesion: the physical attraction of unlike molecules
-cohesion: the physical attraction between like molecules
-interfacial surface tension: resistance to separation by the film of liquid between
the denture base and the supporting tissues (combines cohesion and adhesion).
-mechanical locking into undercuts
-peripheral seal and atmospheric pressure: *the most important factor
-orofacial musculature: correct position of denture teeth must be in the neutral zone
The quality of a prosthesis to resist displacement by functional horizontal or rotational stress. THIS IS THE MOST IMPT FACTOR. Occlusion that is not balanced in excursive movements will create instability of the denture, loss of retention and eventually frustration to the patient.
Stability
The quality inherent in the prosthesis that resists dislodgement along the path of insertion
Retention
6 purposes of posterior palatal seal
1. retention of max denture
2. firm contact with the palatal tissue reduces the gag reflex
3. it reduces food accumulation
4. the pressure on the tissue makes the distal border of the denture less noticeable to the dorsum of the tongue.
5. it compensates for dimensional change
6. the thickened area provides added strength across the denture
the arbitrary terminal hinge axis: measured out from the posterior margin of the tragus of the ear – 13mm on a line between the tragus of the ear and the outer canthus of the eye.
Beyrons point
Hanau’s formula
L = H/8 + 12
-H is the horizontal condylar inclination established by the protrusive record
-L is the lateral condylar inclination
Theilman’s formula
K(balance) = IG x CG / CH x OP x CC
Foundation area on which a dental prosthesis rests
Denture support
5 ways to improve denture support
1. surgical removal of pendulous tissue
2. use of tissue conditioning materials
3. surgical reduction of sharp/bony ridges
4. surgical enlargement of ridge
5. implants
6 advantages of a anatomic teeth
-1. Can establish mechanical and physiologic occlusion.
-2. Penetrates food more easily.
-3. Articulate in harmony with TMJ and masticatory muscles.
-4. Resists rotation of denture base through interdigitation with cusps.
-5. Better esthetics.
-6. Less trauma to underlying tissues.
What is Frenum composed of?
Non keratinized, unattached alveolar mucosa with an underlying fibrous attachment to bone. 35% of max frenum have small striated muscle; Gartner, 1991
Muscles of Mastication
●Temporalis
Origin: lateral surface of the skull (temporal fossa)
Insertion: Coronoid process, anterior border of ramus
Action: elevates mandible, posterior part retrudes jaw
●Masseter
Origin: zygomatic arch (process)
Insertion: lateral surface of ramus, coronoid process
Action: elevates mandible
●Medial Pterygoid
Origin: medial surface of lat pterygoid plate, pyramidal process of palatine and tuberosity
Insertion: medial surface of ramus
Action: elevated mandible
●Lateral Pterygoid:
Origin: lateral surface of lateral pterygoid plate
Insertion: neck of condyle and Disc and capsule of TMJ
Action: depresses, protrudes, moves mandible side to side
What is in retromolar pad?
•glandular tissue
•loose areolar tissue
•pterygomandibular raphe
Superior pharyngeal constrictor
Buccinator
•Tendon of the Temporalis
•Most impt: cortical bone underlying these structures
How long leave denture out?
48-72 hours
How to balance monoplane setup
Balancing ramp
Nepola and Sears
PDI Classification for edentulism
1) residual bone height
2) residual none morphology
3) muscle attachments
4) maxillo-mandibular relationship
How to mark PPS
Empirical method; visually marked the vibrating line (ah technique) with Thompson indicator stick which transfer mark to record base. Adjusted the record base to this line and transferred to master cast
Landmarks for setting teeth and occusal plane
Esthetics; parallel to the inter-pupilary line and ala tragus line
Neutral zone impression: Fish; Beresin, Scheiser; ant corresponds to the modiolus Mandibular first molar is 2/3 way up the retro-molar pad
What are some reasons for porosity in processing?
If rate of reaction is too high you will get porosity; heat slow
What is Passavants pad
A prominence on the posterior wall of the naso-pharynx formed by contraction of the superior constrictor of the pharynx during swallowing.
Wax Classification
Baseplate: Type I, soft; Type II, medium; Type III hard (75% Parafin)
Casting: Type I direct(medium hard), Type II indirect(soft)
Modeling plastic: Type I stick, Type II cake
What is compound wax
“modeling plastic”
Low thermal conductivity: it requires time for cooling to prevent distortion ADA Spec #3: Type I, stick; Type II, cake
Compound specifications
Flow at 98.6 F is >6%
Thermal Contraction is .3%
Softening temperature:
Green, 123F
Red, 132F
Green stick compound makeup
Rosin
Copal resin
Carnauba(filler)
Talc
Rouge(color)
Stearic Acid(fat
Ways to evaluation vertical dimension
Physiologic rest
Phonetics
Pre-treatment records
Closing forces
Ceph
Esthetics
Tactile
Swallowing
Wear
Closest speaking space clearance
Class I: 2-3mm
Class II: 3-6mm
Class III: 1mm
Frankfort horizontal plane
Lowest point on orbit to Highest point on external auditory meatus
Porion to orbitale
Why use blue mousse
Initially dead soft
Fast set
Sets rigid
Dimensionally stable
Unaffected y disinfectants
Can be trimmed
What are the four methods of obtaining CR
1) Static Recordings; Direct interocclusal records
2) Graphic recordings; started with Balkwill but Gysi first to record mandibular movement and
CR, pantograph, coble balancer (Hardy and Pleasure)
3) Functional Records: myomonitor, swallowing with compound cones, stereograph (TMJ-
articulator- Swanson and Swif); chew-in Myers
4) Cephlometrics- Atwood
What are 4 ways of guiding patient?
1) swallowing (.4mm error); Shannahan (static)
2) chin point guidance (.14 error); Gnathology (static)
3) chin point w/ ant jig (.07 error); Lucia (static)
4) bimanual manipulation (.05 error); Dawson (static
Define CR
A maxillomandibualr relationship in which the condyles articulate with the thinnest avascualr portion of the disc with the complex in an anterior superior relationship against the articular eminance
What bacteria are in caries
Strep mutans (8 serotypes): found in everyone; probably responsible for onset
Lactobacilli: probably responsible for progression of cavitated lesions
Strep has ability to adhere to tooth structure, and form sticky matrix
Fluoride level
Optimal in water 1ppm
>10 cause fluorosis
Saliva quantity
1000-1500 ml/day
Parotid - 26% - serous
Submandibular - 69%- mixed
Sublingual & palatine - 5% - mucous
Facial forms for denture teeth
Williams classification
Square
Tapering
Ovoid
Dentogenics
Frush & Fisher
Sex
Personality
Age
Muscles of masseteric notch
Buccinator and masseter
How to treat Candida Albicans
Nystatin rinse 5ml qid 10 days
Ketoconazole 200-400mg daily 1-4 weeks
Treatment for patients with xerostomia
Sialogogue therapy
Pilocaprine 5mg qid
Acrylic powder
Polymer-PMMA
Initiator - benzoyl Peroxide (decomposes after 60 degrees Celsius)
Pigments - mercuric sulfide, ferric oxide, carbon black
Dyes - leach out by oral fluids
Opacifiers - zinc or titanium oxide
Plasticizers - dibutyl phthalate
Acrylic liquid
Monomer - MMA
Inhibitor - hydroquinone; prevents premature polymerization
Accelerator - tertiary amine; dimethyl-para-toludine; used in auto polymerization to initiate peroxide decomposition
Plasticizer - dibutyl phthalate- creates plasticity
Cross linking - glycol dimethacylate - resists cracking and crazing
Steps of acrylic
Initiation: formation of free radicals; heat/amine +peroxide = free radicals
Propagation: free radical + monomer = growing polymer chain
Termination: hydroquinone + free radical = polymer chain
What is triad
Urethane dimethacrylate
initiated by light (400-500 nm) and camphoriquinone
3% shrinkage
What are high impact resins reinforced with?
Butadiene styrene rubber
Initial PMMA shrinkage
Volumetric 21%
Linear 7%
Pre-polymerized shrinkage
Volumetric 6%
Linear .5%
Types of Shrinkage
1) thermal- due to different CTE of stone and resin
2) polymerization Shrinkage- due to covalent bonds which occupy less vol than unbound mole.
Dentate vs. edentulous bite force
Dentate 200psi
Edentulous 50psi
Earl Pound concept for maxillary central incisor
The central incisor length = the face length / 16
the angle formed between the saggital plane and the average path of the advancing non-working side as viewed in the horizontal plane during lateral mandibular movements.
Bennett Angle
Fisher’s angle
The angle formed by the intersection of the protrusive and non-working side condylar paths as viewed in the saggital plane when recording of mandibular movement is made by using a device located lateral to the TMJ.
a plane that passes through the inferior border of the mandible.
Mandiblar plane
The space that occurs between opposing posterior teeth during mandibular protrusion.
Christensen phenomenon
Decrease percent of complete edentulism by 2050
2.6%
Decrease in edentulism but increase in population
3 Indications for pre-prosthetic tori removal
A torus that extends beyond the posterior palatal seal area
A torus with overlying traumatized tissue/mucosa
A torus that interferes with function (speech and deglutition)
Contra-indication- tori fills more than half the palate
Advatanges of lingualized occlusion
Reduces lateral forces on the denture bearing tissues
Vertical forces are centered upon the mandibular residual ridges
This scheme yields cross-arch, but not cross-tooth, balance
During protrusion of the mandible, what are the actions of the superior and inferior heads of the lateral pterygoid muscles?
Superior head relaxes
Inferior head contracts
What is the primary function of the superior head of the lateral pterygoid muscle?
Positioning the articular disk during closure.
Types of Osteoporosis
Type I: primary—makes up the vast majority of cases—post-menoposal –loss of estrogen resulting in increased bone turnover, with predominant loss of travecular bone
Type II secondary—senile osteoporosis—gradual age-related bone loss found in both sexes caused by systemic senescense—induced by loss of stem-cell precursors, with predominant loss of cortical bone
Type III Osteogenesis Imperfecta—due to genetic mutation, affecting 6/100,000 people (eight known types of OI)
Type IV Idiopathic juvenile osteoporosis—no known cause, and usually has onset just before puberty
What are the types of oropharyngeal candidiasis
Acute pseudomembranous candidiasis
Acute atrophic candidiasis
Chronic atrophic candidiasis
Chronic hyperplastic candidiasis
Angular chelitis
Median rhomboid glossitis
Sleep hypopnea index
STOP BANG
Mild: 5-15 events/hour
Moderate: 15-30 events per hour
Severe: > 30 events/hour
Tongue size
Male
Neck circumference
Tallgren average bone loss over 25 years
Maxilla .05 per year
Mandible .2 per year
Average thickness of periosteum
.375mm
TNM classification
T=primary tumor size
N=node size
M=presence of metastatic sites
What does face bow record?
records the spatial relationship of the maxillary arch to the hinge axis
What etiologic factors are associated with denture stomatitis
Poor denture hygiene
Continual and nighttime wearing of dentures
Accumulation of denture microbiota
Ill-fitting dentures
Which oral microbes are responsible for denture stomatitis
Candida albicans
Candida tropicalis
Candida glabrata
Candida pseudotropicalis
Candida guillierimondii
Candida krusei
What are the effective doses of radiation for the following dental radiograph
Cephalogram = 10 uSv
Panoramic = 14.2-24.3 uSv
Full-mouth series = 13 – 100 uSv
CBCT = 19-1073 uSv (depends on machine)
The triangle formed by lines drawn between the mandibular incisors and right and left condyles
Bonwill triangle
4 inches
The angle formed by the imaginary plane of the Bonwill triangle and the mandibular occlusal plane (described by the incisors and disto-buccal cusps of the mand 2nd molars).
Balkwil angle
Composition of dental plaque
70% bacteria
30% intracellular matrix consisting of carbohydrates, proteins, calcium ions, and phosphate ions
Landmarks for Campers plane
Inferior border of the right or left ala of the nose and the superior border of the tragus of the ears.
Objectives of complete denture final impression
Preservation of hard and soft tissues—pressure in the impression technique is reflected in the denture base and can result in soft tissue damage and bone resorption
Support–maximum coverage of the appropriate denture bearing areas—the “snowshoe” effect
Stability—close adaptation to the underlying mucosa is important in reducing horizontal movement of the dentures
Esthetics—border thickness should be varied to restore facial contour and proper lip support
Retention—atmospheric pressure, adhesion, cohesion (depends on peripheral seal), mechanical engagement of undercuts, muscle control
Denture impression philosophies
Muco-compressive
Muco-static
Selective pressure
Functional
Thermoplastic modeling compound heat temp
Red 132-133
Gray 128-130
Green 122-124
the composition of Dentsply IPN 3D denture teeth?
Urethane methacrylate
3,3,5, trimethyl cyclohexanol-Alkyl methacrylate
Ethylene Glycol Alkyl di-methacrylate
Phosphorolated bisphenol A urethane di-methacrylate oligomer
Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide
Carbon black
Titanium Dioxide
Butylated hydroxytoluene
physical and mechanical properties of Dentsply IPN 3D denture teeth?
Wear resistance (Volume loss): 0.09 mg/400,000 cycles (ISO = > 65 MPa)
Flexural strength (130 MPa). (ISO = > 2000 MPa)
Compressive strength = 145 MPa (ISO = > 110 MPa)
Hardness: 0.41 GPa
Elastic modulus: 5.51 GPa
classification of denture base materials?
a. Type 1—heat curing polymers—polymerization temp >60o C
b. Type 2—self curing polymers—polymerization temp <60o C
c. Type 3—thermoplastic materials—polymers moldable when heated
d. Type 4—light cured materials—cured by UV or visible light
e. Type 5—microwave materials—heat cured polymers cured with microwaves
What is Ivobase
Combines benefits of heat cured and self-cured polymers.
Requires polymerization temp of only 40o C.
Benefits of Ivobase
a. Thermal loss much lower
b. Increases in VDO are virtually eliminated—little to no post-processing polymerization adjustments required
c. Fracture toughness equivalent to heat-cured polymers
d. Low residual monomer content
e. Overall curing time is 35 min (Ivobase hybrid), 50 minutes for IvoBase hi impact)
f. Cooling time is 15 minutes
What are the stages of polymerization following correct mixing of PMMA materials?
a. Sandy—little polymerization, grainy in appearance
b. Stringy-monomer molecules attack and dissolve PMMA particles, and disperse polymer changes in the liquid phase; larger PMMA particles unfold and enhance viscosity. Stage is characterized by sticky strings upon touching or stretching.
c. Doughy: characterized by lack of stringiness and stickiness—this is the suitable stage for packing into a flask.
d. Rubbery stage—further conversion of monomers into polymers, and evaporation of residual monomer. Rubbery appearance of the matrix (rebounds after releasing from compressive or tensile stresses)
e. Stiff stage: continued polymerization and evaporation—results in hardening and reinforcement of mechanical properties. PMMA becomes dry, stiff, and resistant to plastic deformation.
What is the significance of residual monomer content?
May have a sensitizing effect on patients.
What types of fibers may be used to enhance the PMMA base materials physical properties?
a. Carbon
b. Kevlar (aramid)
c. Nylon
d. Polyethelene and polypropylene
e. Glass
What are prosthetic denture teeth made of?
PMMA, composite resin, or porcelain
Muscles of soft palate
Palatoglossus
Palatopharyngeus
Tensor veil palatini
Lavator veil palatini
Musculus uvulae
Contents of retromolar pad
Glandular tissue
Loose areolar tissue
Tendon of temporalis
Pterygomandibular raphe
Underlying cortical bone
Contents of retromylohyoid fossa
Medial - mylohyoid
Posteromedial- palatoglossus
Posterolateral -superior constrictor
Distal - styloglossus
Floor of the mouth
Mylohyoid
Genioglossus
Geniohyoid
7 Muscles of modiolous
Buccinator
Obicularis oris
Risorius
Zygomaticus major
Zygomaticus minor
Levator anguli oris
Depressor anguli oris
Saliva composition
Ptyalin(salivary amylase)-serous
Mucins-mucous
Bactericidal: Thiocyanate ions, proteolytic enzymes, protein antibodies
Wolfs law
A bone will develop the structure most suited to resist the forces acting on it
Mucosa in mouth
Superior to inferior:
Mucous membrane-mucosa-submucosa(vessels and nerves)-periosteum-bone
Masticatory Mucosa-submucosa has base of fibrous CT and covering of keratinized CT
Gingiva and palatine raphe have no submucosa
Lining Mucosa-nonkeratinized
Specialized Mucosa-dorsum of tongue, has taste buds
What’s in hamular notch
Junction of maxillary tuberosity and hamular processes of medial pterygoid plate
Origin of pterygomandibular raphe
Tendon of tensor veil palatini
Innervation of tongue
Anterior 2/3: lingual nerve
Posterior 1/3: glossopharyngeal
Taste: chorda tympani (branch of facial)
Motor: hypoglossal
Protrudes tongue: genioglossus
Blood supply: lingual artery
Ligaments that attach to mandible
Collateral
Origin: Medial and lateral poles of disc
Insertion: Medial and lateral poles of condyles
Function: Restrict movement of disc away from condyle
Capsular
Origin: superiorly to temporal bone
Insertion: inferiorly to neck of condyle
Function: resists medial, lateral, inferior forces that tend to dislocate articular surfaces It encompasses entire TMJ, is well innervated and gives proprioceptive feedback
Temporomandibular
Outer oblique portion
Origin: articular tubercle(outer surface) and zygomatic process Insertion: Condylar neck(outer surface)
Function: Permits rotation but limits it also (not >15mm)
Inner Horizontal portion
Origin: articular tubercle (outer surface) and zygomatic process
Insertion: lateral pole of condyle and posterior part of articular disc
Function: limits posterior movement, provides bracing for lateral and retruding movements
Sphenomandibular ligament
Origin: spine of the sphenoid bone
Insertion: lingual
Function: no limiting effects on mandibular movement
Stylomandibular ligament
Origin: styloid process
Insertion: angle and posterior border of mandible
Function: Limits excess protrusion of the mandible
Action of levator veli palatini
elevates soft palate, brings lat pharyngeal wall medially
Action of uvulus
Thickens and lengthens soft palate
Action of superior constrictor
Brings post pharyngeal wall anteriorly
has intact structures but has inability to perform closure (neurological)
palatal pharyngeal incompetency
Palate does not have intact structures
palatal pharyngeal insufficiency
Innervation of speech
V: muscles of soft palate (trigeminal)
VII:muscles of periphery of mouth (facial)
IX: pharyngeal muscles (glossopharyngeal)
X: pharyngeal muscles, laryngeal muscles, soft palate (vagus)
What is the physiology of speaking?(Martone)
Three Physiologic Valves
•True vocal folds of the larynx
•Palatalpharyngeal region: nasal, oral and laryngeal pharynx
•Mouth
What is the physiology of gagging?
Afferent to medulla oblongata: V, IX, X; general innervates fauces, base of tongue, palate, uvula, and posterior pharyngeal wall(common trigger points)
Efferent: V,VII,X,XII, pharyngeal plexus(IX,X,XI), various sympathetic and parasympathetic nerves
Causes of gagging
Systemic, Psychological, Physiological, Iatrogenic(overextended, too thick, highly polished, inadequate postdam)
Reason to use fully adjustable articulator
Anterior/posterior control
Centric stop
Anatomical accuracy
Celenza classification
Class I: simple holding
Class II: vertical and horizontal movement, but not related to TMJ
A: motion unrelated to pt
B: motion based on theories
C: motion based on patient
Class III: condylar pathways using average anatomic values
A: static protrusive records
B: accepts lateral records
Class IV: 3-D registrations
A: paths formed by patient (TMJ)
B: paths from settings and inserts (D5A)
Who developed first facebow
Snow
Arcon vs. non arcon
Arcon is where is condylar elements are on the lower member and semi adjustable has condylar pathways based on scientific averages
Non arcon condylar element is on the upper member, you can get a 8 degree difference in the arc of closure if you increase the pin opening or from you CR records
What is average intercondylar distance
110mm
Mandibular movement averages
Horizontal Condy Inclination
IMLT
Progressive
Curve of eminentia
Intercondyler distance
Bennett
Horizontal Condy Inclination 37 degrees
IMLT .75mm
Progressive 7.5mm
Curve of eminentia 3/4 inches
Intercondyler distance 110mm
Bennett 16 degrees
Hanau Quint
Condylar Inclination
Incisal Guidance
Compensating Curve
Cusp Height
Plane of Occlusion
Jaw movement measurements
Hinge
Max opening
Excursive
Hinge: 20mm
Max opening: 40-60mm
Excursive: 8-10mm
Bodily shift in the mandible in the direction of the working side
Laterotrusion
Long centric
The anterior teeth should immediately disclude the posterior teeth but at a controlled angulation so that you don’t lock the patient in. The patient must have an unimpeded path to centric relation. PMS
Detrusion, surtrusion, retrusion definitions
Laterodetrusion: lat and down on working side
Laterosurtrusion: lat and up on working side; greatest effect since it brings arches closer together
Lateroretrusion: lat and back on working side
What systemic conditions affect the basal seat/denture prognosis
Osteoporosis
Xerostomia
Mucosal disorders
Burning tongue
Dermatalogic disorders
Radiation Therapy
Chemotherapy
Soft liner vs. tissue conditioner
Tissue conditioner- less viscous – more flow, change and adaptation to the tissues, flow easily and have a low viscosity; Coe-soft.
Soft liners – more viscous; Coe comfort
What are soft liners made of?
Soft Liners are plasticized acrylic resins, either PMMA or PEMA and the liquid plasticizer dibutly- phthalate. The large plasticizer minimizes entanglement of polymer chains, thereby permitting chains to slip past each other to allow a rubbery-like state. The liquids do not contain acrylic monomers only to be used short term. Plasticizers leach out over time and the material becomes more rigid. Biggest issue is the inability to thoroughly clean the surfaces, hence candida albicans is a major issue.
What is the REALEF Effect?
The resilience and like effect was described by Hanau and is used to describe the fact that the soft tissue under the denture base has movement so it compensates for any limitations of the articulator.
Discuss mucostatic impression?
Henry Page; soft tissue should be in unstrained postion for impressions; relies on interfacial surface tension for retention; disregards cohesion (like) and adhesion (unlike)
Resulting denture is almost flangeless and will not be very retentive
Discuss selective pressure technique?
Peripheral tissue s are slightly displaced to increase retention
You displace the tissues just enough to get retention but not to loose stability This method uses adhesion, cohesion and surface tension
Border molding maxilla
Anterior: lip is elevated and extended outward, downward, and inwar.(orbicularis oris fibers run horizontal –only indirect effect); no muscles in labial vestibule
Buccal Frenum: Cheek is elevated and pulled outward, downward and inward; also it is moved forward and backward to simulate movement of both the orbicularis oris and the buccinators; the levator anguli oris is under the buccal frenum
Posterolateral: rub with hand, open wide, move jaw side to side; pterygomandibular raphe (buccinators/sup constrictor) and coronoid process, and also medial pterygoid when patient open up wide
Border molding mandible
Labial flange: lift the lower lip outward, upward and inward ; mentalis and orbicularis oris Buccal Frenum:
Cheek is lifted outward, upward, and inward, backward and forward to simulate frenum movement; depressor anguli oris is under buccal frenum
Posteriorly: cheek is pulled buccally to ensure that tissue is not trapped, then the cheek is moved upward and inward.
Anterior Lingual Flange length(PM TO PM): Ask patient to protrude the tongue activates the genioglossus, raises sublingual fold
Anterior lingual flange thickness: push the tongue against the front part of the palate
Posterior edge of posterior lingual flanges: when tongue is pushed against the front part of palate it activates mylohyoid AND the superior constrictor which supports the retromylohyoid curtain) Inferior edge of both posterior lingual flanges: are border molded by touching tongue out and then into the opposite cheek; floor of retromyhoid region is the palatoglossus
Distal of retromolar pad and masseteric notch:
Open wide caused pterygomandibular raphe to be brought forward, thrust tongue out and then close the mouth. The downward pressure on the mandible activates the elevators of the mandible thus the masseter pushes on the buccinator marking the masseteric groove and medial pterygoids push against the retromylohyoid curtains distal end of the lingual flange.
Stress bearing areas maxilla
Primary stress bearing areas: hard palate lateral to median raphe
In some patients the maxillary ridge crest is considered a primary stress bearing area and in other patients it is considered a secondary stress bearing area (Jacobsen & Krol)
Stress bearing areas mandible
Primary stress bearing areas: buccal shelf and pear shaped pad
Secondary stress bearing areas: residual ridges
House Personality classification
Hysterical-most difficult, poor prognosis
Indifferent
Philosophical
Exacting
Cross tooth cross arch advantages
Zarb - Boucher text
-Better aesthetics
-Ease of penetration of food
-Stablility during swallowing and parafunctional movements Introduced by Gysi 1927
Occlusal spectrum
Parr and Loft 1982
Anatomic
Semi Anatomic
Lingualized
NonAnatomic
Neutrocentric – NonBalanced (DeVann)
What factors affect denture Stability? (Jacobsen and Krol)
Tissue surfaces (lingual flange, residual ridges shape and contour)
●Polished surfaces (muscles must not be interfered with by denture base and the muscles may help seat and stablilize denture base. Note: Fish though that polished surfaces were the most impt factor in stability
●Occlusal surfaces: Free of interferences
What factors affect denture Support?(Jacobsen and Krol)
Extension to maximum surface area and border extensions. Note: Tissues that resist resorption and vertical displacement have more pressure under function.
Maxilla shapes
Flat, round, u shaped, v shaped
Wright classification tongue position
Class 1 normal
Class 2 normal but broad and flat
Class 3 retruded
House tongue size classification
Class 1 normal
Class 2 teeth absent long enough for tongue to flatten
Class 3 excessively large
Why choose Stratos 300?
Fulfills Celenza class IIIB semi adjustable
Control of horizontal condylar inclination and Bennett angle
6 Advantages of Stratos 300
Wide posterior view
Centric latch to only allow hinge movement in CR
Curved condylar path (12.5)
Ability to incorporate protrusive and lateral check bite records
Incisal table with a fixed pin
Arcon articulator with condylar element on lower member following pt arc of closure
Adjustable elements of Stratos 300
Bennett angle 0-30
IMLT 0-1.5mm
Protrusive advance 0-4mm
Retrusive advance 0-2mm
Stratos based on 4 main geometric conditions
Campers plane
Balkwil, angle
Bonwill triangle
Monsoon template
How did you program articulator for HCI and laterotrusion
HCI - protrusive check bite
Laterotrusion - Hanau formula or lateral check bite
Process denture base materials
Ivobase
Ivocap
Press pack (lucitone 199)
3 ways to determine PPS
Functional - Iowa wax
Semi functional - border model
Arbitrary- 1-2,m beyond vibrating line
Shapes of PPS
Butterfly
Bead
Butterfly with roll
Double bead
Denture adhesive categories
Adhesives - methyl-cellulose
Anti-microbial agents - sodium tetraborate
Others - wetting agents
Specs for microstone
ISO Type 3
Brand:Premium dental stone
40ml/140g water to powder
5-7min working time 15 min set time
0.12% expansion
Compressive strength (MPA) after 1 hr 31 after 48 hr 59
Specs for mounting plaster
ISO type 1
Brand: “low expansion fast setting plaster”
63ml/100g water powder
60-90s working time 3 mins setting time
.09% expansion
Compressive strength (MPA) 1 hr 4 after 48 hrs 12
What does UTS stand for
Universal transferbow system
Anatomic structures for s curve
Mylohyoid, palatoglossus, superior constrictor
What impression philosophy did you use and why
Selective pressure- putting selective pressure on primary denture bearing areas
Why do teeth stay balanced in mouth
Realeff and denture movement
What limitations to my articulator
Cannot adjust intercondylar distance
What error comes from arbitrary facebow
Not accurately find hinge access
.2mm error - Weinberg
Gypsum formula
Ca sulfate hemihydrate + water = calcium sulfate dehydrate + heat
The process of heating gypsum to drive off part of crystallization to form hemihydrate
Calcination
Gypsum classifications
Type I Impression Plaster - 15% exp
Type II Model Plaster - .30% exp
Type III Dental Stone - .20% exp
Type IV Improved stone - .10 exp
Type V High Strength, Exp - .30 exp
Alginate composition
Potassium alginate
Calcium sulfate dehydrate
K Phosphate
Na Phosphate
Diatemaceous Earth
Glycols
PVS composition
Base: dimethyl siloxane with silane groups
Fillers such as copper carbonate which control consistency
Accelerator: vinyl terminated siloxane Chloroplatinic acid
