DENTURE BASE RESINS

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					                                                                                                               Removable final objectives: 1
                                                      DENTURE BASE RESINS
What is resin?                                        A broad term used to describe natural or synthetic substances that form plastic
                                                      materials after polymerization. They are named according to their chemical
                                                      composition, physical structure, and means for activation of polymerization
What is acrylic resin?                                Any of a group of resins made by polymerizing esters of acrylic or
                                                      methylmethacrylate acids
What is polymerization?                               A series of chemical reactions by which a large number of low molecular weight
                                                      molecules (mers) react to form a single large molecule of high molecular weight
                                                      (polymer). Polymerization is never entirely complete, which means that a
                                                      processed denture base resin will always have some residual monomer
What is condensation polymerization?                  Not presently used much in dental restorations or prosthetic appliances. Ex: nylon,
                                                      polyurethane, polysulfide rubber base impression material
What is addition polymerization?                      The structure of the monomer is repeated many times in the polymer; proceeds
                                                      without forming any byproducts; can produce giant molecules of almost unlimited
                                                      size. Ex: vinyl acetate, polyvinyl chloride (PVC), acrylic resins: polymethyl
                                                      methacrylate, polyethyl methacrylate
What is activation of addition polymerization?        The chain reaction requires an initiator species with a “reactive center.”
                                                      Polymerization is dependent upon the formation of free radicals, a compound with
What is the initiator?                                an unpaired electron which makes the radical very reactive. Benzoyl peroxide is a
                                                      substance which decomposes at relatively low temperatures (50-100degrees C) to
                                                      release free radicals. Thus, benzoyl peroxide is a potent initiator of the
                                                      polymerization of polymethyl methacrylate resin
What are the four methods of activation of the        Heat, chemical, light, microwave
initiator?
What is the most common denture base resin?           Polymethyl methacrylate (PMMA). Transparent, may be tinted/colored to almost
How is the color? What is the strength?               any shade and degree of translucence. Color and optical properties are stable
                                                      under all normal conditions, strength is adequate and is processed with relative
                                                      ease
What are the components of the liquid and powder of   Monomer/liquid: methyl methacrylate, hydroquinone (.006% or less)—inhibitor
the denture base resin?                               added to prevent polymerization during storage. Glycol dimethacrylate (1-2%) a
                                                      cross linking agent which improves craze resistance. Polymer/powder:
                                                      polymethyl methacrylate beads, pigments, benzoyl peroxide—initiator for
                                                      polymerization, plasticizer—dibutyl phthalate. (May be in monomer or powder.
                                                      Increases solubility of the powder)
What is the polymer to monomer ratio when mixed?      3 to 1 by volume
When do you pack the resin into the mold?             When it is in the doughy stage, not tacky or sticky
What is a “trial closure” and what is it’s purpose?   “Trial packing” a preliminary closing of the processed flasks under pressure for the
                                                      purpose of eliminating excess material and ensuring that the mold is completely
                                                      filled
What are 2 polymerization cycles for heat activated   165˚ for 1.5 hours, then 212˚ for 30 min OR 165˚ for 9 hours. NO terminal boiling
denture base resin?
Tell me about the polymerization cycle for heat       When the temp of the dough rises above 60˚ C or 140˚ F, the molecules of benzoyl
activated denture base resins?                        peroxide decompose to form free radicals. Free radical reacts with monomer
                                                      molecule, and a new free radical is formed. The chain is propagated.
What reacts with the monomer? What kind of            Polymerization reaction is exothermic. The temp inside the mold can increase
reaction is polymerization?                           beyond the temp of the water bath. The effect of the temp rise above 100˚ C is to
                                                      produce porosity in the interior of the thick sections of the resin. The boiling point
What is the boiling point of the monomer?             of the monomer (100.8˚ C or 213.4˚F) is barely higher than that of water. Porosity
                                                      is not usually present on the surface of the resin, but is on the interior of the base
What happens with chemically activated denture        Polymerization may be completed at room temperature by adding a chemical
base acrylic resins?                                  activator instead of using heat or microwave energy to activate the benzoyl
                                                      peroxide. This is the fundamental difference between this and heat activated
What does the monomer contain?                        A tertiary amine (dimethyl-p-toluidine) which reacts with the benzoyl peroxide to
                                                      form free radicals
                                                                                                                    Removable final objectives: 2
The degree of polymerization is higher in which?          Heat activated
(heat or chemical)
Is the color better here?                                 Better with heat activated, with chem. It is inferior due to oxidation of the tertiary
                                                          amine (turns orange color)
What is polymerization shrinkage?                         Calculated volumetric shrinkage due to polymerization contraction (approx 8%)
                                                          contributes very little to the linear shrinkage that is observed with all denture base
                                                          resins
What should predict the linear shrinkage? How             Volumetric shrinkage calculations—2%. This amount does not occur. Thermal
much? Chief contributor?                                  shrinkage is the chief contributor.
What is the typical amt of linear shrinkage for denture   .2% to .69%
base resins?
Where is polymerization shrinkage of a maxillary          Palatal portion lifting away from the tissue and the posterior teeth (max and
denture?                                                  mandibular) are pulled closer to each other across the arch. The result is a slight
                                                          increase in OVD when dentures are processed by compression molding tech
What are the imp properties of denture base resins?       Porosity, water, absorption, and strength
What causes porosity?                                     Monomer boils, lack of homogeneity in dough, inadequate pressure during
                                                          polymerization, not enough resin in the mold
Why is water absorption important?                        PMMA absorbs water slowly over time, may take 17 days to become fully
                                                          saturated with water, store dentures in water when not in the mouth
What affects strength?                                    May be reduced by finishing of denture with abrasives and polishing agents. Heat
                                                          from polishing wheel may cause warpage of the denture, heat may cause partial
                                                          depolymerization and a decrease in strength and rigidity
How are resin denture teeth adhered to the denture        Chemically bonded. Conventional acrylic resin—crosslinked, dense, easily
resin base? Types?                                        adjusted. IPN acrylic resin—“interpenetrating polymer network” a highly
                                                          crosslinked copolymer linked into 3D network. These have basically the same
                                                          composition as the denture base
What are resilient liners? How are they put on            Elastomer polymers used to prevent chronic soreness from dentures and to
base? Useful lifetime? Types?                             preserve supporting structures. Are heat-processed to the hard denture base.
                                                          Useful life of months to a few years (2-5). Plasticized ethyl methacrylate, vinyl
                                                          resins, silicon rubbers, and polyurethanes
What are tissue conditioners?                             Highly plasticized acrylic resins, are temporary soft reliners—useful for only a
                                                          matter of a few days/weeks. A powder and a liquid. Powder=polyethyl
Useful life?                                              methacrylate and liquid=aromatic ester in ethanol or other alcohol. Undergo
Made of?                                                  viscous flow under load and change form with the changing contour of tissue to
Types?                                                    maintain good adaptation. Lose their plastic properties as they age (Coe comfort,
                                                          coe soft, lynal)
                                                            DENTURE INSERTION
What is the lab remount?                                  Reattach the casts to the mounting with compound, examine how much pin is
                                                          opened, decide if gross movement is present, decide how much pin closure can be
                                                          accomplished with occlusal adjustment at this stage. Judiciously adjust to
                                                          determined VDO (usually stop, when anterior teeth are about to come into contact
                                                          and pin is unlikely to return to zero or baseline); check for eccentric occlusal
                                                          contacts—and adjust only gross interferences—do NOT destroy anatomy
How should you go about doing occlusal                    Even contacts in MIP so remember the BULL rule—adjust B on the upper and L on
adjustments?                                              the lower (nonfunctional cusps on each), return to previous vertical dimension (or
                                                          close to it, do NOT grind until you see separation), if eccentric balance was desired
                                                          and prescribed, gross interferences are eliminated now
What needs to be done before you send them back           Make a facebow preservation record if not yet accomplished—set pin at ZERO,
to the lab to be finished?                                just as you would in making the facebow transfer, lightly apply petroleum jelly on
                                                          occlusal surfaces, close on platform, then separate and return to lab to break casts
                                                          off and polish
What happens to the cast when it is sent back?            It is destroyed to get the dentures off
What should you do prior to the insertion                 Inspect the finished dentures to determine that: polished surfaces are smooth and
appointment?                                              devoid of scratches, no imperfections on the tissue surfaces (no beads or nodules
                                                          of resin), and borders are round with no sharp angles in the border areas.
                                                                                                                 Removable final objectives: 3
When are your remount casts made?                     Prior to the appointment. The max remount cast should be correctly attached to
                                                      the articulator using the facebow preservation index and an accurate mandibular
                                                      remount cast is prepared for the patient remount
How do you do this?                                   Inspect intaglio surface first and eliminate sharp edges and spicules. Do NOT
                                                      polish the intaglio surface. Block out undercuts, pour/base with plaster, set, trim
                                                      and separate carefully, add notches, connect maxillary cast to articulator using
                                                      facebow preservation. REMEMBER—mand is mounted at the clinical remount
What should your pt do prior to this appointment?     Existing dentures should be left out of the mouth for 24 hours prior to the delivery
                                                      of the new dentures. This permits the oral tissues to return to a healthy,
                                                      undisplaced state as they were (hopefully) when the secondary impressions were
                                                      made
What happens once the patient arrives?                4 main areas: location and relief of pressure areas in tissue side of denture base,
                                                      id and reduction of overextended borders, refinement of the occlusion on an
                                                      articulator, and instructions to the patient on use, care, maintenance of dentures
What helps you check for pressure spots on the        PIP: pressure indicating paste—liquid carbon paper. Brush strokes/streaks, id of
intaglio surface?                                     pressure areas, contrast “wipe-off” (not true pressure areas—reevaluate in 24hrs
                                                      to be sure there is not discomfort from them), repeat, unilateral if necessary. If
                                                      pressure is confirmed then judicious adjustment or grinding
How should you insert the denture?                    Gently—do NOT snap it into place until the severe undercuts have been located
                                                      and removed
Where are frequent areas of border overextension?     Frenae, at db corners of the mandibular denture, any vestibular area where the
                                                      tissues were displaced by overextended impression trays or cold impression
                                                      compound at border molding stage
How do you test overextended borders?                 By slowly seating the denture. If you see premature contact with frenae or
                                                      vestibular tissue as the denture continues toward its final position, the border may
                                                      be overextended
What should you test once you have corrected the      The PPS, have pt close on cotton rolls and maintain pressure for 10 min. Then
overextended borders?                                 apply light to mod pressure to the lingual surface of the max anterior teeth. If seal
                                                      is inadequate the denture will dislodge. If questionable, check at 24 hr appt
What do you do after seating is confirmed?            All borders should have been adjusted, dentures retentive, stable, comfortable,
                                                      stabilize and make centric relation records, material of choice: AluWax, elastomer
                                                      (ex: regisil rigid) ensure NO contacts/perforation. Use record to mount mandibular
______ remount only compensates for                   Lab
polymerization shrinkage?
After they are remounted what do you do?              Finalize the occlusion—done on the articulator with verified mounting. Eliminate all
                                                      interference to closure in centric, to maximal intercuspation. No slide should be
                                                      detected, have even contacts in posterior teeth, eccentric movements, esp.
                                                      protrusive contacts, should be in harmony
What do you do at the actual insertion?               Ensure all areas are not interfering with function, evaluate esthetics, speech, minor
                                                      adjustments to border/frenal areas, smoothen/polish all areas adjusted, borders,
                                                      esp., must be smooth, post op instructions—almost as critical as everything else
                                                      you do
What should you reiterate to your patient?            No prosthesis is ever final, permanent. And that they need regular recall to id
                                                      need for future reline and oral exam for cancer surveillance
What will the patient need to do with their new       Learn how to eat, speak and function
dentures?
How will they need to train their tongue?     To rest on the floor of their mouth so that the tip of it only touches the lower front
                                              teeth. this will help keep the lower denture in place
                TISSUE CONDITIONERS, DENTURE CLEANERS, DENTURE ADHESIVES, METAL BASE DENTURES
What are tissue conditioners again?           Materials whose useful function is measure in days.

What do these allow?                                  Inflamed or distorted oral tissues resulting from ill-fitting dentures can be allowed to
                                                      return to “normal” by the use of tissue conditioners in the old denture. Attention
                                                      can then be turned toward remaking the denture
                                                                                                                     Removable final objectives: 4
How do you place this?                                     First you need to relieve 1-2mm on the intaglio surface with a large bur. Then you
                                                           place the gel in the denture and the denture in the pts mouth. Have the pt lightly
                                                           close to a very light contact, but don’t have them bite. The gel will flow to fill the
                                                           space between the denture base and the oral tissue.
What happens as the tissue conditioners age?               They lose their plastic properties (owing to the loss of ethanol, absorption of water,
                                                           and loss of plasticizer.) although the material remains fairly soft for about a week,
                                                           the effectiveness appears to greatly reduce after 72 hours.
What are some other uses of tissue conditioners?           Stabilize dentures or record bases. Functional impression material (pt wears the
                                                           denture with the impression material in it for 2-3hrs, then lab reline procedures are
                                                           initiated)
What are the types of denture cleaners?                    Dentifrices, proprietary denture cleaners, household cleansers, and immersion
                                                           type commercial denture cleaners.
What are the commercial immersion type made of?            Alkaline compounds, detergents, flavoring agents, and sodium perborate. When
                                                           dissolved in water, the perborate decomposes to liberate oxygen. The oxygen
How do they work?                                          bubbles supposedly mechanically loosen debris on the denture.
What are two brands of these?                              Efferdent tablet—sodium bicarb, sodium carbonate, citric acid; polident tablet—
                                                           potassium monopersulfate, sodium perborate monohydrate. . .
What are denture adhesives?                                Commercial mixtures of short acting and long acting polymers which take on
                                                           water, swell and become viscous (eliminating voids between denture base and the
                                                           soft tissues). Most are synthetic materials which hydrate in water and display
                                                           “quick onset ionic adherence” to both denture and mucous epithelium surfaces.
                                                           Eventually, all the polymers are washed out by saliva (hot liquids hasten this)
What are examples?                                         Fixodent and poli-grip
What are materials used for metal base dentures?           Gold, aluminum, base metal alloy, titanium (inexpensive, lightweight, strong, but
                                                           has casting difficulties)
What are indications for metal bases?                      When high degree of processing change is expected (deep palatal vault or
                                                           prominent residual ridges), maxillary denture opposing lower natural teeth where
                                                           repeated fractures of the max denture occur, maxillary denture opposing lower
                                                           natural dentition and limited interarch space exists, overdentures in which stresses
                                                           are concentrated over small areas of the denture
What are advantages?                                       More rigid, less base deformation during function, better thermal conductivitiy,
                                                           improved adaptation of the denture base, and improved speech because of
                                                           reduction of palatal bulk
What are disadvantages?                                    Lab costs are greater, difficult (!) to reline, reduced margin of error in
                                                           placing/correcting the pps
                                                            THE SINGLE DENTURE
What is the problem with the single denture?               Pt is usually younger than the completely edentulous pt and this is often their first
                                                           denture experience. They expect more from a denture than an experienced
                                                           wearer. The occlusal harmony is more difficult to achieve and there are limitation
                                                           to how much alteration of the natural teeth can be done.
What if occlusal harmony is not achieved?                  Retention and stability of the denture become a problem
What is the most common combination?                       Maxillary complete denture against mandibular natural teeth
What is the problem with mandibular denture and            The prognosis is bleak to dismal. The small denture-bearing area of the
max natural?                                               mandibular arch and the great occlusal forces of the natural max teeth often cause
                                                           rapid and severe resorption of the mandibular ridge.
If equilibration of the natural teeth is needed, when is   Prior to denture fabrication. Once the denture is completed, occlusal correction
it done?                                                   done on the natural teeth are often interpreted by the patient to be a mutilation of
                                                           his/her perfectly good natural teeth to fit a poorly made denture. If extensive they
                                                           may require PFMS
What is the combination syndrome?                          See with max CD is opposed by ant mand teeth only or opposed by a mand arch
                                                           of natural ant teeth plus a bilateral digital extension RPD which has not maintained
                                                           the posterior support (occlusal forces are concentrated in the ant region)
What are the five classic features of the combination      Severe max ant bone resorption, inflammatory papillary hyperplasia, downgrowth
syndrome?                                                  of max tuberosities, severe resorption of mand posterior alveolar ridges, and
                                                           supraeruption of mand anterior segment
                                                                                                                Removable final objectives: 5
What are the jaw relationships?                         The max edentulous arch resorbs vertically and posteriorly in the anterior and
                                                        vertically and medially in the posterior. This results in a smaller maxilla than
What does this cause?                                   mandible. This causes difficulty in placing the denture teeth in a position to allow
                                                        the denture-bearing area to be in line with the occlusal support. Posterior denture
What is sometimes done because of this?                 teeth are sometimes placed in crossbite with the lower teeth for this reason
What are the main concerns when contemplating           The occlusal plane, the interarch space, the stability of the denture foundation
fabricating a single denture to oppose nat dentition?   tissue, the jaw relationships, and any history of breaking of the previous denture
If restorations on the opposing arch are needed,        They should be done prior to fabricating the denture. If teeth are extruded beyond
when are they completed?                                the desired occlusal plane, they should be reduced, restored with crowns, or
                                                        removed prior to denture fabrication
What occlusal scheme should be used with a single       Most feel that bilateral balanced is the preferred for single dentures. Gliding
denture?                                                contacts of the posterior teeth in eccentric movements are believed to be beneficial
What else could work?                                   to help keep the max denture stable and retentive. This includes anatomic
                                                        balanced occlusion and lingualized balanced occlusion
How far back do you need opposing teeth if doing a      We want opposing teeth at least halfway back between the incisive papilla and the
single denture?                                         hamular notches to prevent anterior alveolar ridge loss. This usually means
What does this mean?                                    occlusion to the first molar area (premolar occlusion may be acceptable in the
                                                        dental or skeletal class II pt)
What are the problems/sequelae of the single            Wear of natural teeth—problem only if porcelain teeth are used in the denture,
denture?                                                wear of the resin teeth by the natural teeth, fracture of the denture base
What contributes to the fracture of the denture base?   Any history of bruxing with natural teeth may predispose the denture to bruxing
                                                        induced fracture (the pt will likely continue to clinch and brux with a denture);
                                                        heavy contact of anterior teeth; prominent max labial frenum which necessitates a
                                                        deep frenal notch in the denture (most common cause of fx in max CD)
What should you do if the denture base fx or is         Consider a labial frenectomy and/or a metal base for the denture
suspected to fx?
What are problems with mandibular single CD?            Prognosis is dismal, reduced quantity of support (12 cm2 in man vs 23cm2 in max
                                                        and vs 45 cm2 PDL space in each arch of natural teeth), residual ridge resorbs
                                                        rapidly from the impact of occlusal forces from the static max natural teeth
What needs to be considered?                            Implants, overdenture, processed resilent liner, or removing the max teeth and
                                                        fabricating 2 dentures
                                                            RELINES/REBASES
What is a reline?                                       A process whereby the intaglio surface of a denture or RPD is removed and
                                                        refitted to the tissue mucosa by use of a new impression in the prosthesis
What is a rebase?                                       The entire denture base (not just the intaglio surface) is replaced after making a
                                                        new impression in the prosthesis. The artificial teeth are preserved in the new
                                                        denture base
Why are these needed?                                   The oral enviorment is composed of living tissues which are ever chanign in
                                                        topography over time. The denture base loses its close adaptation to the
                                                        supporting tissues.
What do reline/rebases require?                         A meticulous technique and skill. Surprise to denture wears b/c of home
Why is this a surprise to pts?                          treatments, but these actually cause more rapid destruction of the residual ridge
What are indications for relines/rebases?               Simple looseness of the CD or immediate dentures at 4-6 months after insertion
What are contraindications to reline/rebases?           When an excessive amount of resorption has occurred (REMAKE), when abused
                                                        soft tissues are present (use conditioners first), TMJ problems (resolve that prob
What should you do in these situations?                 first), when the dentures have poor esthetics or unsatisfactory jaw relationships
                                                        (REMAKE), if the dentures create major speech/phonetic problems
Special consideration should be given to which areas    Is the OVD satisfactory? Do not reline to correct an inadequate OVD—REMAKE;
before committing to reline/rebase?                     does CO coincide with CR? Is discrepancy correctable? Is the pt’s appearance
                                                        acceptable? Size, shape, arrangement of teeth acceptable? Oral tissues healthy?
                                                        Extensions acceptable? IO space acceptable? Speech satisfactory? Undercuts?
What are the most common errors to avoid during         Do not allow the maxillary denture to shift forward during the impression making
reline?                                                 procedure. Do not increase the OVD. Ensure that a uniform thickness of
                                                        impression material is obtained (no pressure thin spots or thick areas), reline the
                                                        dentures one at a time—start with the least stable
                                                                                                                    Removable final objectives: 6
What causes the max to shift forward?                     Considerable hydraulic pressure builds up in the anterior region of the max
                                                          denture. This causes the denture to be displaced forward of its normal position,
How can you prevent this from happening?                  adversely affecting the flange thickness, lip support, tooth position and occlusion.
                                                          Prevent problems by adequate relief, venting, viscosity of imp material, etc.
                                                          perforate the labial and palatal portion of the denture base
How can you prevent increasing the OVD?                   Ensure that the denture base is fully seated. Perforate the palatal and labial
                                                          portions of the max denture base
When should you remake the dentures instead of            If denture bases are underextended, if the OVD is overclosed, if CO and CR are
doing relines/rebases?                                    not coincident
What are processed resilient liners?                      Heat processed to the hard denture base of the definitive prosethesis.
                                                          Resilience—energy absorbed owing to elastic deformation
What are indications for processed resilient liners?      Chronic sore ridges, post irradiation patients, xerostomia pts (denture wearing is
                                                          difficult for these pts), bruxing pts, acquired or congenital oral defects from trauma,
                                                          neoplasm, surgery, etc; man CD opposing max natural dentition
What are the usual groups of liners?                      Rubber, vinyl polymers, silicone elastomers, polyurethane elastomers
What is the usual length of wear?                         6 months to 5 years, with 3-4 years average. 5 yr success rate is good, but more
                                                          appt to observe, service, and replace the liner should be anticipated by the dentist
                                                          and the pt
What are used for intermediate and long term              Room temp vulcanizing (RVT) silicones. They don’t require investing the denture
resilient liners?                                         nor applying heat
                                                 POST INSERTION FOLLOW UP APPOINTMENT
What should you specifically mention at the post          The temporary nature of the prosthesis. All treatment in dentistry and medicine is
insertion appt?                                           temporary to varying degrees; oral hygiene; removal at night; and learning to eat—
                                                          diet selection at first, with gradual increases in consistency of food at a self
                                                          determined rate
The dx and tx of post insertion problems usually fall     Esthetics, phonetics, tissue irritations, and retention/stability problems. Treating
into 4 categories, what are they?                         these problems requires determining their causes
What is the best means for treatment of esthetics?        The best means of tx for esthetic concerns such as fullness under the nose,
                                                          inadequate lip support, too much tooth display or the “artificial look” of the denture
                                                          is prevention. Both the pt and the dentist should participate in achieving
                                                          acceptable esthetics before processing the dentures
How do you treat phonetics?                               Speech may be altered temporarily with a new prosthesis. Reading aloud each
                                                          day helps speed up the adjustment to the dentures. The adaptability of the tongue
                                                          is quite dramatic. If the speech difficulties do not disappear, reassessment should
                                                          be done of the proper placement of teeth in vertical, horizontal, and frontal planes
                                                          and reassessment of the thickness and contours of the palatal denture base
What are common phonetic problems?                        Sibilant sounds are distorted. Causes: improper ant tooth position or contour of
                                                          denture base on palate; fricative sounds distorted; contact and clicking of teeth
                                                          during s sounds—OVD is too great (interocclusal space is too small)
What if you whistle when saying s sounds? Lisp?           Anterior palate is too narrow; lisp—ant palate is too broad
If you try to say “f” and sounds like “V”? if you try and t-v maxillary incisors are too long (too far down)
say “v” and sounds like “f”?                              v-t maxillary incisors are too short (too far up)
What kinds of tissue irritations can there be?            Irritation on the crest of the ridge, irritation near the vestibules, irritation on the
                                                          anterior lingual slope or mand ridge or lateral slopes of man ridge, soreness at
                                                          frenum, soreness of tissue over the coronoid process, biting of cheeks, lips or
                                                          tongue; irritations on median palatal raphe
What should be done post op, prior to making              Ask the pt to indicate areas of soreness and when and where it occurs. Soreness
adjustments to tissue irritations?                        upon insertion/removal or soreness on biting.
If you have irritation on the crest of the ridge, what is Deflective occlusal contact. Correct with a remount and selective grinding.
the usual culprit?                                        Pressure from the denture base is corrected by dx with PIP and relieving it
Irritation in the vestibules is usually from?             Unpolished or poorly polished denture border, sharp, or overextended border
Irritation on ant L slope or lat slope of man ridge?      Occlusal disharmony (CO not coincident with CR) or pressure from base
What if soreness in area of coronoid process?             Too much thickness at DB corner of the max denture
When does soreness to swallowing occur?                   It often results from irritation in the mylohyoid region
                                                                                                                    Removable final objectives: 7
What if there is a burning or numb sensation in the       The mental foramen might be exposed
lower bicuspid region?
What if pt is biting cheeks, lips, tongue? How do you      Inadequate horizontal overlap of teeth, OVD is overclosed, inadequate space btwn
treat this?                                                denture bases in the posterior, incorrect location of plane of occlusion. Tx by
                                                           modifying or replacing/resetting some teeth
What if irritation is on the medial palatal raphe?         Insufficient relief of raphe area, anterior teeth contacting in CR. If appears 1-2
                                                           days after insertion, inadequate relief is possible.
What if the CD drops when pt smiles?                       Excess thickness on posterior border
What if the max CD drops when eating?                      Inadequate PPS
What causes the dentures to dislodge?                      Overextended borders, errors in occlusion, lack of room for the tongue, tongue
                                                           habits, incorrect border of L flange, incorrect external form of the denture base.
                                                           Max denture should stay in place without the use of the tongue to keep it there. if
                                                           the tongue must be used to keep it from falling the CD is too loose
What if it drops when laughing?                            Inadequate border extension (under or over)
What if the denture is initially retentive, but loosen     Errors of occlusion or character and flow of saliva; tx by remouting and
after worn for several hours?                              equilibrating. If saliva (which will decrease overtime) rinsing is helpful
With lack of retention, what areas should be               Occlusion, border seal, and contour of the denture base and borders. If the
evaluated?                                                 occlusion and border seal are adequate, the contour of the denture border should
                                                           be evaluated. The border should be convex and rounded. Thin or sharp borders
                                                           will contribute to the loss of border seal
What are possible causes for the loss of the               Occlusal disharmony, location of the teeth relative to the surrounding musculature,
mandibular denture?                                        contuour of the cameo surface of the denture, intaglio surface of denture: uniform
                                                           contact of denture with supporting tissues; retracted tongue position: may be
                                                           acquired early in life or caused by the denture if OP is too high, the arch is too
                                                           narrow, or the ant teeth are set too far lingually with no labial tilt
What if gagging occurs soon after?                         Suspect OVD is too far open, overexeteded posterior border of max denture,
                                                           posterior border too thick, mand distolingual flange is too thick
What if gagging starts 2 weeks to 2 months later?          Suspect malocclusion causing dentures to loosen, incomplete border extension
                                                           with loss of peripheral seal.
What if pt gets deafness or earache?                       Deaf—overclosed OVD; earache—OVD too far open
What happens if the tongue space is too small?             “dentures feel too big”, “feels like a mouth full,” or “difficult to speak or eat”
What is the neutral zone?                                  That area or position where the forces between the tongue and the cheeks or lips
                                                           are equal (neutralize each other)
                                                       IMMEDIATE COMPLETE DENTURES
What are immediate dentures?                               A CD or RPD fabricated for placement immediately following extractions
What are advantages of immediate CD?                       Prevent pt embarrassment—there is no period of complete edentulism; provides a
                                                           guide to optimal esthetics—artificial teeth can be placed where the natural teeth
                                                           were; denture acts as a bandage over the surgery sites—pt usually experiences
                                                           less pain; hastens pt adaptation to dentures (the completely edentulous pt will
                                                           learn new habits of speaking and eating that will be unlearn when CD are
                                                           delivered, this is avoided with immediate dentures)
What are disadvantages?                                    Inability to do a trial placement and ant evaluation before the dentures are
                                                           processed. (this is a critical pt when significant esthetic changes are being made.);
                                                           increased complexity of the clinical procedures (presence of natural teeth makes
                                                           the 2nd impression procedures and registering of jaw relationships more difficult;
                                                           increased denture maintenance—relines, adjustments, occ. Equilibrations while
                                                           healing; more visits=more tx costs
What are contraindications for immediate dentures?         Pts who have undergone irradiation therapy to head and neck, pts with systemic
                                                           condition which adversely affects blood clotting, wound healing, tissue
                                                           regeneration; aged or medically compromised pts who cannot tolerate multiple
                                                           extractions, malposed teeth/alveolar bone requiring extensive surgical correction;
                                                           psychological disorders; pts who do not want increased maintenance and expense
What are the clinical and lab procedures?                  Dx and tx planning; impressions; maxillo-mandibular relationship records; arrange
                                                           teeth/trim master cast; evaluate posterior trial denture; insertion/surgical
                                                           template/follow up
                                                                                                               Removable final objectives: 8
What do you do at diagnosis?                         Educate pt about their role (critical if pt has never worn a removable prosthetic),
                                                     evaluate tori, tuberosities or frenal attachments, preliminary casts
What kind of treatment plan is needed?               2 phase: phase 1: remove posterior teeth, retaining 1st premolar to preserve OVD
                                                     (if acceptable), surgical correction of posterior area—tuberosity reduction and/or
                                                     alveoloplasty, wait 6-8 weeks, begin fabrication of immediate denture. Phase 2:
                                                     extraction of anterior teeth, frenectomy, minor alveoloplasty if needed
What type of impressions can be done?                Custom impression try for secondary impression or combination impression tech
What do you do with custom tray tech?                Baseplate wax blockout (spacer) of remaining teeth; impression tray covers teeth
                                                     and edentulous areas; tray is border molded. Secondary impression made using
                                                     flexible impression material—NOTE: excessive size of tray may distort lips and
                                                     unattached mucosa and block out the embrasures with wax to prevent impression
                                                     from locking around remaining teeth
What is the combination tech?                        Fabricate custom tray to cover edentulous areas and palate. Border mold. Make
                                                     secondary impression of palate and posterior edentulous areas. Verify impression
                                                     is acceptable; place back in mouth and make another impression over custom tray
                                                     and remaining teeth (using irreversible hydrocolloid)
What is better about tooth selection?                It should be easier than with conventional CD d/t the existing teeth—remember to
                                                     set post teeth first with CID
What do you do at the posterior tryin?               Verify CR mounting; verify occlusal plane—are there modifications that need to be
                                                     made to the opposing arch; verify OVD; record landmarks on casts and pts
                                                     esthetic desires; allow pt to see articulator and comment
How do you arrange anterior teeth?                   Alternate teeth, start at midline and then place every other. May want pt to return
                                                     to look at them prior to seat and give post op instructions at this time
What is the surgical template for?                   Made if alveoloplasty is needed. Should be made by the lab at the wax elimination
                                                     stage. It is clear and rigid and used as a guide to ensure that alveoloplasty is done
                                                     adequately
What do you do at the placement appointment?         Evaluate occlusion, bilateral, simultaneous contact needed. Remount procedure is
                                                     delayed until swelling has subsided and pt is comfortable (5-10 days) unless gross
                                                     discrepancies are present
What are pt instructions?                            Do not remove the dentures until the 24 hr appt, may wear at night for 2-3 nights,
                                                     maybe a week. Warm salt rinses, avoid mouthwashes containing alcohol; expect
                                                     gradual loss of retention as ridges resorb, will need reline/rebase/remake in 4-6
                                                     months. Soft diet for awhile.
                                                 SEQUELAE OF DENTURE WEARING
What are problems associated with denture use?       Residual ridge resorption, traumatic ulcers, inflammatory papillary hyperplasia
                                                     (IPH), denture stomatitis, epulis fissuratum, and angular cheilitis
What is the major oral disease entity? Tell me about Residual ridge resorption. Progressive, irreversible loss of bone after tooth
it?                                                  extraction and placement of dentures. Adversely impacts support, stability, and
                                                     retention.
How do you minimize it?                              Denture bases cover maximum extent of basal seat (within physiologic limits) to
                                                     achieve “snowshoe” effect of max support; soft tissues recorded in their
                                                     undisplaced state to assure even contact with the tissue side of the denture and to
                                                     minimize the pressure to the underlying bone; overdentures—preserving tooth root
                                                     and PDL preserves surrounding bone; occlusal harmony—clinical remount;
                                                     dentures out at night and resilient liners, osseointegrated implants etc
When do you get ulcers? What causes them?            Common with new dentures; caused by friction from base against soft tissue. Not
What if at the crest of the ridge?                   limited to new dentures: alveolar resorption, denture base settling etc can cause
Vestibular areas?                                    too; crest of the ridge suspect occlusion; vestibular areas: suspect overextension
What is IPH?                                         A reactive tissue growth developing under a denture. Occurs on hard palate
                                                     (sometime the crest of the ridge) and is usually asymptomatic, red or pink nodules
                                                     on mucosa. Directly related to constant wear of ill-fitting denture and poor OH
What strains are often present?                      Candida
How do you treat?                                    Early lesions—leave denture out some, antifungals, improve OH.
                                                     Advanced lesions—surgery probably needed to remove the collagenized nodules
                                                     then tissue conditioners, leave dentures out, improve OH, reline/rebase/remake
                                                                                                                Removable final objectives: 9
What is denture stomatitis?                            Mucosa red, usually asymptomatic. Confined to denture bearing mucosa of a
                                                       maxillary removable prosthesis. Often associated with C. albicans. Not a true
Cause?                                                 infection (denture culture is positive mucosa is not). Uncertain cause: poor OH?,
                                                       24 hr wearing?
How do you treat?                                      Tissue rest, tissue conditioners, another prosthesis
What is denture sore mouth?                            The dx given when denture stomatitis is tx is not successful. Cause may be
                                                       metabolic, psychological or nutritional.
What is epulis fissuratum?                             Denture irritation hyperplasia, inflammatory fibrous hyperplasia. Clinically it is one
                                                       or more folds of hyperplastic tissue in the vestibule—usually the labial; forms as a
                                                       reaction to irritation from the flange of an ill-fitting denture, or a thin, sharp,
                                                       overextended flange. Anterior affected more than posterior
Which sex is this more common in and why?              Females: more older women wear dentures than men, women live longer, women
                                                       wear their dentures more frequently and for longer periods of time than men
How do you treat this?                                 Shorten/improve the denture border, tissue conditioners, etc. and see if epulis
                                                       fissuratum resolves or reduces. Surgery may be required, but beware of scar
                                                       band at vestibular depth which can compromise border seal.
                                                       Reline/rebase/remake denture
What is angular chelitis?                              Aka perleche—red, fissured irritations at the corners of the mouth. Reduced OVD
                                                       may give accentuated folds at corners of the mouth (saliva pools here). Areas
                                                       remain moist, favoring an infection of the yeast-like fungus candida albicans.
What else is considered to be a contributor to this?   Vitamin B2 deficiency. Can also see combination infection of C. albicans and staph
What is treatment?                                     aureus. Treat with antifungals (mycology cream)
Candida can be in most of these, why?                  Oral candida infections occur when host defenses are compromised by: local
                                                       factors—denture irritation, xerostomia; medications—antibiotics,
                                                       immunosuppressives; tx regimens—chemo, radiation; systemic disorders—
                                                       physical debilitation, malnutrition, endocrine/immune alterations (diabetes, anemia,
                                                       adrenal suppression
How do you treat candida?                              Remove the source and eliminate the infection from the tissue
How do you remove the source?                          Remove the prosthesis from the mouth more frequently and for longer periods of
                                                       time. Estimates as high as 70% of denture pts wear their prosthesis overnight,
                                                       contributing to increased tissue irritation and enhanced growth of candida
What is another method?                                To remove 1mm of the intaglio surface that has been penetrated by the fungus,
                                                       then reline with a soft liner which is changed frequently. MUST clean the surfaces
                                                       efficiently and often to prevent fungal growth
How do you eliminate the infection?                    Topical nystatin has been used effectively for 30 yrs. Topical applications rely on
                                                       contact with the lesion so use 4-5 applications per day and some formulations
                                                       contain sucrose and risk of caries with prolonged use in pts with some remaining
                                                       natural teeth

				
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