Denture Manual 81- (Heat vs Chemical Cure) Flashcards
Heat-activated resin composition (pg 87)
- Powder (2 components)
- Liquid (3 components)
- PMMA
- Benzoyl peroxide (initiator)
- Unpolymerized MMA (monomer)
- Glycol dimethacrylate (cross-linking agent)
- Hydroquinone (inhibitor)
What is the initiator for both heat resins? (pg 87)
Benzoyl peroxide
What is the cross-linking agent for heat-activated resins?
Glycol dimethacrylate
What does hydroquinone do? (pg 87)
Inhibitor
- Prevents polymerization of the monomer liquid during storage
What is the activator for heat-activated resin denture bases? (pg 88)
What is the activator for chemically-activated resin denture bases?
Heat (165 F or 70 C degrees for 8 hours or longer)
Dimethyl-para-toluidine (tertiary amide)
How does heat actually “activate” the process of heat-activated resin denture bases? At what temperature does this start? (pg 88)
Heat decomposes the benzoyl peroxide into a free radical to start the polymerization
Starts at 140°F / 60°C degrees, but you do the entire reaction at 165° F degrees
High impact strength resins are reinforced with what? (pg 88)
Give one example of this resin
Rubber (butadiene-styrene rubber particles are grafted to the methyl methacrylate to bond to the acrylic matrix)
Lucitone 199
What are the two recommended polymerization cycles for heat-activated resin (i.e. Lucitone 199)? (pg 88)
Long cure: 164° F for 9 hours, then 1/2 hour in boiling water, then bench cool 1/2 hour, then cool water for 15 minutes
Short cure: 164° F for 1.5 hours, then boiling water (212°) F for thirty minutes, then bench cure 1/2 hour, then cool water 15 minutes
Chemically-activated resin composition (pg 89)
- Powder
- Liquid
- PMMA
- Benzoyl peroxide (initiator)
- Unpolymerized MMA (monomer)
- Glycol dimethacrylate (cross-linking agent)
- Hydroquinone (initiator)
- Dimethyl-para-toluidine (activator)
Chemically-activated resin’s
- Advantages
- Disadvantages (3)
Advantage: Faster working time
Disadvantages: (Diewitt’s note: I think these are before Ivobase was introduced)
- Chemical cure has more residual monomer (irritates the tissue
- Decreased strength
- Less color stability
Light-activated resin composition
- Two major constituents
- Three minor constituents
- UDMA (urethane dimethacrylate - the resin matrix)
- Inorganic filler particles (quartz)
- Coupling agents (bonds filler particles to the resin matrix
- “Activator-initiator” system (UV light - activator) and (champhoroquinone-initiator)
- Optical modifiers (color - metal oxides)
At what temperature does acrylic monomer boil? How about water? (pg 92)
What does boiled acrylic monomer lead to?
Is this a major concern for thin or bulky areas of the denture?
213.4 degrees F for acrylic, compared to 212 degrees F for water
This leads to porosities in the denture base
Trick question - It is a major concern for both areas since the reaction is exothermic. For thick areas, this may lead to porosities. For thin areas, this may lead to incomplete curing.
Who developed the BULL rule? (pg 98)
Schuyler
Combination case syndrome AKA Kelly’s Syndrome (9) (pg 105)
- Papillary hyperplasia
- Anterior maxillary ridge resorption
- Extrusion of lower anterior teeth
- Downgrowth of maxillary tuberosity and pneumatization of maxillary sinus
- Posterior mandibular ridge resorption
- Loss of OVD
- Anterior repositioning of mandible and TMJ remodeling
- Occlusal plane discrepancies
- Epulis fissuratum
Which authors advocated for the use of gold occlusals?
Koehne and Morrow 1970
Advantages of immediate dentures (8)
- Bleeding, pain, and swelling reduced
- Patient is not without teeth during healing period
- Cooperation and emotional attitude of patient is improved
- Patient adapts to the presence of immediate dentures more quickly
- Individuals appear to function in speech, deglutition, mastication, and respiration sooner
- Esthetics, speech, and tooth arrangements are obtained by comparison to natural teeth
- Locations of occlusal plane and VDO are more easily ascertained
- Immediate dentures contour bone
Disadvantages of immediate dentures (5)
- Loss of proprioception
- Psychologically devastating
- Loss of function/efficiency
- Technically difficult
- No esthetic try-in appointment
Contraindications of immediate dentures (4)
- Patients with debilitating diseases
- Patients for whom multiple extractions might be unwise
- Emotionally disturbed individuals
- Indifferent or unappreciated patients
Cause/treatment if generalized sore spots at ridges (3 causes) (pg 133)
Cause -> Treatment
- Malocclusion -> Patient remount
- Excessive OVD -> remount to lower OVD or make new CD’s
- Inaccurate denture base -> Reline, rebase, or new CD’s
Cause/treatment if sore mouth (3 causes) (pg 133)
Cause: systemic / alcoholism / psychological
Treatment: Rule out dental origin and refer accordingly
Cause/treatment for immediate gagging (3) (pg 134)
Cause -> Treatment
- Border overextended, underextended, too thick -> Reduce or add to border
- Excessive OVD -> remount, adjust to lower OVD or remake RCD
- Overextended mandibular flange -> disclosing wax, reduce, and polish
Cause/treatment for delayed gagging (4) (pg 134)
- Inadequate PPS -> Reestablish, process, remount & polish
- Malocclusion -> Patient remount
- Poor retention -> Reline & remount
- Alcoholism -> Refer
Cause/treatment of burning sensation at localized areas
Cause: Pressure on nerve anatomy (such as anterior palatine foramen, mental foramen, or posterior palatine foramen)
Treatment: PIP & relieve
Cause/treatment of generalized burning sensitive (2) (pg 134)
Cause -> Treatment
- Denture base allergy -> : If completely cured denture base then refer out to allergy clinic for verification
- Ill-fitting dentures -> Reline, rebase, or remake
Cause/treatment of burning tongue (4)
Causes: Systemic problem, vitamin deficiency, endocrine, psychological
Treatment: Refer to confirm
Cause/treatment of trouble swallowing (2)
- Mand posterior lingual flange or max posterior border overextended/too thick -> Reduce or thin
- Excessive OVD -> Remount & adjust for lower OVD / make new CD’s
Cause for clicking of denture during speech
Excessive OVD or poor retention
Cause/treatment of clicking of denture during swallowing or at termination of speech (2)
- Mandibular CD overextended in retromolar pad areas -> Adjust, but make sure the retromolar pad is covered
- Porcelain teeth -> Replace with resin teeth
Cause/treatment of whistling (2) (pg 136)
- Palate too narrow -> Make palatogram (PIP) and grind to widen
- Maxillary premolars too far medially -> Reset teeth
Cause/treatment of S sounding like Sh (2) (pg 136)
Bonus question - What kind of “sounds” are these?
- Anterior palate too broad -> Add wax/rugae and process
- Incorrect closet speaking space (ala Pound) -> Reset max/mand anterior teeth
Bonus: Sibilant sound (pg 56)
Cause/treatment of T sounding like Th (2)
Bonus question - What kind of “sounds are these”
- Inadequate interocclusal distance -> Remount & reduce OVD or make new CD’s
- Maxillary teeth too far lingual -> Reset the teeth
Bonus: Linguodental (pg 56)
Cause/treatment of poor F and V sounds
Bonus: What are these sounds called?
- Maxillary anterior teeth positioned incorrectly -> Reset the teeth
Bonus: Labiodental (pg 56)
Initiator
- Heat cured
- Light cured
- Benzoyl peroxide
2. Camphoroquinone
Cross linking agent
- Which is it?
- How much?
- What does cross linking agent mean?
- Glycol dimethacrylate
- 1 to 2%
- Induces cross linking of polymer chains to increase molecular weight and thus the physical properties such as resistance to deformation
Activator
- Heat cured
- Chemical cured
- Light cured
- Heat
- Tertiary amine (dimethyl-para-toludine)
- Visible light
Inhibitor?
Hydroquinone
Powder of heat cured acrylic
- Contains what polymer
- Also contains what initiator?
- Poly(methyl)-methacrylate
2. Benzoyl peroxide