| The success of the RPD is largely dependent on ______, which requires good understanding of_______ of supporting structure in addition to understanding the ______ of different impression materials | accuracy of impression; anatomical landmarks and physiology; properties and manipulation |
| When evaluating impression materials, 3 components are key to success | 1) to capture accurate and precise details 2) must be strong at the time of removal from the mouth to prevent tearing 3) appropriate material selection |
| Materials used in making final impressions in RPD:can also be used for RPD impressions and especially for secondary corrected or altered cast impressions. | Mercaptan Rubber-base Impression Materials |
| Mercaptan Rubber-base Impression Materials: To be accurate, the impression must have a uniform thickness that does not exceed _______--. | 3 mm (1/8 inch) |
| Materials used in making final impressions in RPD:Requires the use of a carefully made impression tray. | Mercaptan Rubber-base Impression Materials |
| Materials used in making final impressions in RPD:Demonstrated good accuracy in clinical evaluations and are thixotropic, which provides good surface detail and makes them useful as a border molding material. | Polyether Impression Materials |
| Materials used in making final impressions in RPD:Not compatible with the addition reaction silicone impression materials. | Polyether Impression Materials |
| Materials used in making final impressions in RPD:Hydrophilic, and have low to moderate tear strength and much shorter working and setting times, which can limit the usefulness of the material | Polyether Impression Materials |
| Materials used in making final impressions in RPD:more accurate and easier to use than the other elastic impression materials. | Silicone Impression Materials |
| Materials used in making final impressions in RPD:Have a pleasant odor, moderately high tear strength, and excellent recovery from deformation | Silicone Impression Materials |
| Materials used in making final impressions in RPD:Hydrophobic and can be disinfected in any of the disinfecting solutions with no alteration in accuracy | Silicone Impression Materials |
| Silicone Impression Materials:Ideally should be poured within ___. | 1 hour |
| Materials used in making final impressions in RPD:was once the only material available for RPD impressions, but now elastic materials have completely replaced the impression plasters in this phase of prosthetic dentistry; over 200 years | Plaster of Paris |
| Materials used in making final impressions in RPD:Usually some form of a zinc oxide-eugenol combination; Metallic oxide pastes are manufactured with a wide variation of consistencies and setting characteristics. | Metallic Oxide Paste |
| Materials used in making final impressions in RPD:Not used as primary impression materials and should never be used for impressions that include remaining natural teeth | Metallic Oxide Paste |
| Materials used in making final impressions in RPD:Can be used as secondary impression materials for complete dentures and for extension base edentulous ridge areas of RPD if a custom impression tray has been properly designed and attached to the removable partial denture framework. | Metallic Oxide Paste |
| Materials used in making final impressions in RPD:among the oldest impression materials used in prosthetic dentistry like the plaster of paris | Modeling Plastic |
| Materials used in making final impressions in RPD:most often used for border correction (border molding) of custom impression trays for Kennedy Class I and Class II removable partial denture bases | Modeling Plastic |
| Materials used in making final impressions in RPD(Modeling Plastic):most commonly used modeling plastic for corrected impressions of extension base areas, softens at about 132° F. | TYPE I: red (red-brown) material (cake form) |
| Materials used in making final impressions in RPD(Modeling Plastic):lowest fusing of the modeling plastics | green material |
| Materials used in making final impressions in RPD(Modeling Plastic):have a higher and broader working range than do the cakes of like color so they may be flamed without harming the material | red and gray sticks |
| Materials used in making final impressions in RPD:More commonly known as mouth-temperature waxes | Impression waxes & Natural resins |
| Materials used in making final impressions in RPD:may also be used to correct the borders of impressions made of more rigid materials, thereby establishing optimum contact at the border of the denture. | Impression waxes & Natural resins |
| what type of stone is used for making the fabrication of master cast | abrasive-resistant type IV stone |
| base of the cast should be ____ mm at its thinnest portion and should be extended beyond the borders of the impression so that buccal, labial, and lingual borders will be recorded correctly in the finished cast | 16 to 18 |
| Trim the excess from the sides of the cast. Wrap the impression and cast in a wet paper towel, or place it in a ___, until the initial set of the stone has taken place | humidor |
| After the cast and impression have been in the humid atmosphere for __ minutes, separate the impression from the cast. ___ minutes is sufficient for initial setting. Any stone that interferes with separation from the tray must be trimmed away with a knife | 30 |
| Do you need to place markings on your master cast and what are those markings, if ever? | yes |
| Markings on the Master Cast | Location of retentive arm for a c-clasp, Location of retentive arm for a bar clasp, Parallel projections on the axial surfaces of the cast, Beading, Location of rests, Location of finishing lines, Location of tissue stop, Height of contour on the teeth and soft tissue created during the survey of the cast |
| adjacent the occlusal rest that allows use of undercut adjacent to edentulous space. | retentive area |
| The clasps are drawn in reference to the ___ cast. | primary |
| Parallel projections on the axial surfaces of the cast is recorded using | tripoding technique |
| it is done by drawing parallel projections on the axial surfaces of the cast. These lines should be parallel to the path of insertion and should be drawn on three sides of the cast | tripoding technique |
| Scoring a cast with a sharp instrument or Bur in any desire | Beading |
| It is used to denote the scribing of a shallow groove on the maxillary master cast outlining the palatal major connector exclusive of rugae areas. | Beading |
| Beading is readily accomplished with a ____ | cleoid carver. |
| nothing but a depression created along the borders of the framework drawn on the cast so that the resultant framework will have an elevation at its borders | Beading |
| beading is only done on what arch | maxillary |
| purpose of beading | to get a good seal. |
| To prevent the denture base from moving cervically and impinging gingival tissue. | Location of rests |
| The location of ____ minimizes the bulk of resin attaching the artificial teeth. | finishing lines |
| palatal contours are restored, enhancing speech and contributing to a natural feeling of a patient. | finishing lines |
| integral parts of minor connectors designed for retention of acrylic-resin bases; Prevents distortion at free end during hydraulic pressure of processing. | tissue stop |
| It serves as a guide for a potential undercut and if feasible, can be used for designing the retentive components of an RPD. | Height of contour |
| Objectives of surveying the master cast: give 1 | To select the most suitable path of placement by following mouth preparations that satisfy the requirements of guiding planes, retention, noninterference, and esthetics |
| Flexibility of clasp depends on many of the following factors | a) the alloy used for the clasp, b) the design and type of clasp, c) whether its form is round or half round, d) whether it is of cast or wrought material, and e) the length of the clasp arm from its point of origin to its termmal end. |
| Retention of clasp depends on | a) the flexibility of the clasp arm, b) the magnitude of the tooth undercut, and c) the depth the clasp terminal is placed into this undercut. |
| undesireable undercut areas are eliminated by | blockout |
| The partial denture must be designed so that | 1) it will not stress abutment teeth beyond their physiologic tolerance, 2) it can be easily placed and removed by the patient, 3) it will be retained against reasonable dislodging forces, and 4) it will not create an unfavorable appearance. It is necessary that the diagnostic cast be surveyed with these principles in mind. Xlouth preparation should therefore be planned in accordance with certain factors that will influence the path of placement and removal. |
| Surveying the master cast: The master cast must be surveyed as a new cast, but the prepared _________surfaces will indicate the correct anteroposterior tilt | proximal guiding plane |
| Surveying the master cast: The ___ will be the position that provides equal retentive areas on all principal abutments in relation to the planned clasp design. | lateral tilt |
| After the path of placement and the location of undercut areas have been established on the master cast, any undercut areas that will be crossed by rigid parts of the denture must be eliminated by ____ | blockout. |
| It is the process by which the undesirable undercuts on the master cast are eliminated using wax. Since the undercuts are filled with wax, the refractory cast duplicated from the master cast will not have these undercuts | Blocking out the Master cast |
| Blockout - includes not only the areas crossed by the denture framework during seating and removal but also: | 1) areas not involved that are blocked out for convenience; 2) ledges on which clasp patterns are to be placed; 3) relief beneath connectors to avoid tissue impingement; and 4) relief to provide for attachment of the denture base to the framework. |
| may be used satisfactorily as a blockout material. It is easily applied and is easily trimmed with the surveyor blade. | Hard inlay wax |
| TYPES OF BLOCKOUT:proximal tooth surfaces to be used as guiding planes & below height of contour. | Paralleled blockout |
| TYPES OF BLOCKOUT:This blockout should be parallel to the path of insertion and removal. Parallel blockout extends from the survey line to the gingiva | Paralleled blockout |
| TYPES OF BLOCKOUT:is used on buccal or lingual surfaces to facilitate accurate placement of plastic or wax patterns for clasp arms | Shaped blockout or ledging |
| TYPES OF BLOCKOUT:The blockout wax may be placed in the undercut and trimmed flush with the survey line using the wax trimmer; may be done only in the area of the tip of the clasp; this is the most desirable method. | Shaped blockout or ledging |
| TYPES OF BLOCKOUT:It permits more flexibility in the waxing procedure, and, if the refractory cast is well made, there is no difficulty in placing the bracing portion of the clasp | Shaped blockout or ledging |
| TYPES OF BLOCKOUT:The blockout wax is not trimmed to flush with the tooth surface. This blockout will be reproduced as a ledge in the refractory cast duplicated from the master cast. This ledge guides the fabrication of the wax pattern for the retentive arm | Shaped blockout or ledging |
| TYPES OF BLOCKOUT:labial surfaces & labial undercuts not involved in RPD design | Arbitrary blockout |
| TYPES OF BLOCKOUT:used in less critical areas to prevent the encroachment of metal on the soft tissues and to critical withdrawal of the blocked out cast from the duplicating material. | Arbitrary blockout |
| TYPES OF BLOCKOUT:It is used for all gingival crevices, spaces between the teeth when they are not in the design, for soft tissue undercuts below areas involved in the design of the framework, and in the tooth or tissue undercuts not involved in the design but that would complicate the duplication procedure. | Arbitrary blockout |
| TYPES OF BLOCKOUT:It is termed _____ blockout because the surface of the block out wax need not be parallel to the path of insertion. | Arbitrary |
| TYPES OF BLOCKOUT:"The procedure of placing a sheet of - wax in strategic areas on the master cast to be duplicated so that a refractory cast can be made". | Relief |
| TYPES OF BLOCKOUT:to provide space between certain components of the framework and the adjacent oral structures such as the minor connector to which the denture base will be attached | Relief |
| TYPES OF BLOCKOUT:Used to create a space between the framework and the cast or soft tissue | Relief |
| TYPES OF BLOCKOUT:- Also used beneath framework extensions, in edentulous area to provide for attachment of denture bases, and to form internal finish lines | Relief |
| TYPES OF BLOCKOUT:Usually used beneath lingual bars and in other area where major connectors will contact thin soft tissue such as maxillary and mandibular tori. | Relief |
| Dimension of relief | 1-1.5 mm |
| Conveying the outline of the proposed prosthesis from the diagnostic cast to the master cast— | Design transfer |
| the process of accurately reproducing a cast | Duplication |
| cast made of materials that will withstand high temperatures without disintegrating, and when used in partial denture casting techniques, has expansion to compensate for metal shrinkage | Refractory cast |
| what is the first step in fabrication of refractory cast | The master cast should be soaked in slurry water for atleast 5 minutes before duplication |
| Fabrication of Refractory Cast:The soaked cast is positioned on the base of the duplicating flask such that there is at least ___ clearance all around the cast. | I/4 inch |
| Fabrication of Refractory Cast: Mix the alginate to a ____ consistency, about 3x the water you normally use. | runny |
| Properties: - rapid setting time - good flow characteristics - minimal expansion - easy to mix and manipulate - can be used for diagnostic and working cast | Plaster of Paris |
| Plaster of Paris type | type 1 |
| Plaster of Paris: Mixing time | 10-30 seconds |
| Plaster of Paris: working time | 5-10 mins |
| Plaster of Paris: setting time | 20-30 mins |
| Metallic Oxide Paste:mixing time | 30-45 seconds |
| Metallic Oxide Paste: setting time | 3-5 seconds |
| Properties - Rigid - Low viscosity - Good surface details in thin section - Dimensionally stable - Compatible with gypsum products | Metallic Oxide Paste |
| extension base edentulous ridge areas of a removable partial denture | Metallic Oxide Paste |
| used as an impression material for relining distal extension denture bases | Metallic Oxide Paste |
| All metallic oxide pastes have one thing in common with plaster of Paris impression materials | setting time during which they should not be disturbed |
| are those that become plastic at higher temperatures and resumes their original form when cooled. (they become hard) | Thermoplastic Material |
| used for making accurate transfers of abutment castings or copings in the fabrication of fixed restorations and internal attachment dentures and for making rigid indexes and matrices for various purposes in prosthetic dentistry | Plaster of Paris |
| Indications:- Preliminary Impressions (because of its rigidity) - Custom Tray Fabrication - Diagnostic Models | Plaster of Paris |
| MODELING PLASTIC: ___being an indication of the temperature range at which the material is plastic and workable | color |
| Materials used in making final impressions in RPD(Modeling Plastic): preferred by some dentists for border molding because of its contrasting color | gray material |
| Indications: - record edentulous ridges in removable partial denture (use modeling plastic as a secondary material to record edentulous ridges in removable partial denture fabrication | Modeling Plastics |
| Indications:For border correction (border molding | Modeling Plastics |
| Indications:Edentulous arch impressions for complete denture fabrication | Modeling Plastics |
| Indications:- A single prepared tooth impression (copper tube impression). | Modeling Plastics |
| Impression waxes and Natural Resin: - Also referred to as _____. | mouth-temperature waxes |
| probably the first impression material used in dentistry | Impression waxes and Natural Resin |
| Based on the dental industry’s evolution, _______, a German dentist to the King of Prussia, developed one of the first-known techniques to take a dental impression using sealing wax | Dr. Philip Pfaff |
| It is described as a rigid, muco-static, hydrophobic, reversible impression material that is set by physical change on applying heat, it softens when heated, and on cooling it hardens (thermoplastic material). | Impression waxes and Natural Resin: |
| Types of Mouth-Temperature Waxes:developed for use in recording the functional or supporting form of an edentulous ridge. | Iowa wax |
| Types of Mouth-Temperature Waxes:may be used either as a secondary impression material or as an impression material for relining. | Iowa wax |
| Types of Mouth-Temperature Waxes:may be used to correct the borders of impressions made of more rigid materials | Iowa wax |
| Korecta wax:Reinforcement | Type I |
| Korecta wax:Rebasing for use with type III & IV | Type II |
| Korecta wax: Minor tray for correction | Type III |
| OTHER TYPES OF IMPRESSION WAXES | HP physiological paste, adaptol |
| Melting Point: - Some waxes begin to melt at __ degrees Celsius. Other melt above 40 degrees Celsius. | 37 |
| are fluid at higher temperatures and gel on reduction in temperature, are used primarily as impression materials for fixed restorations. | Reversible hydrocolloids |
| organic hydrophilic colloid extracted from certain types of seaweed (kelp plant). | Agar |
| Widely used at present for cast duplication; For full mouth impression without deep undercuts | Reversible hydrocolloids |
| Working Time: Clinically, the normal time setting required by reversible hydrocolloid impression materials is | 7-15 minutes |
| Agar hydrocolloid requires special equipment called the ______. This conditioning unit is a thermostatically controlled unit having 3 compartments namely: boiling compartment, storing compartment and tempering/conditioning compartment | hydrocolloid conditioning unit |
| are used for making diagnostic casts, orthodontic treatment casts, and master casts for removable partial denture procedures. | Irreversible hydrocolloids (alginate) |
| can be used to create study casts, preliminary impressions, provisional crown or bridge impressions, opposing arch impressions, and fabricate orthodontic casts, sports mouth guards, occlusal splints, and bleaching trays | Irreversible hydrocolloids (alginate) |
| Normal set alginate- working time of ____ and a setting time of up to _____ after mixing. | 2 minutes; 4 minutes |
| Fast set alginate- working time of ___ and a setting time of _____ | 1 minute; 1 to 2 minutes |
| Mercaptan rubber-base impression materials - commonly known as ____ | Thiokol |
| are elastomeric impression materials used in dentistry. They belong to the category of rubber-based impression materials and are known for their flexibility and accuracy in capturing fine details. (Polysulfide) | Mercaptan rubber-base impression materials |
| Mercaptan rubber-base impression materials: working time of various products varies between _____, and the setting time varies between _____ | 3 and 9 minutes; 6 and 13 minutes |
| are commonly used in dentistry for making accurate impressions of oral tissues. It is ideal in fixed restorations such as crowns and bridges. | Silicone impression materials |
| Possible Causes of Inaccurate and/or Weak Cast:Use of non-rigid impression tray; Partial dislodgement from tray | Distortion of Hydrocolloid Impression |
| Possible Causes of Inaccurate and/or Weak Cast:Shrinkage due to evaporation of moisture from the material | Distortion of Hydrocolloid Impression |
| Possible Causes of Inaccurate and/or Weak Cast:Expansion (imbibition) or absorption of water when impression is stored in water or in a very wet paper towel | Distortion of Hydrocolloid Impression |
| Possible Causes of Inaccurate and/or Weak Cast:Attempt to pour cast with stone that has begun to set | Distortion of Hydrocolloid Impression |
| Possible Causes of Inaccurate and/or Weak Cast:- will result in a weak cast - the WP ratio determines the physical and chemical properties of gypsum - increased W/P ratio increases setting | Improper water-powder ratio |
| Possible Causes of Inaccurate and/or Weak Cast:may result in weak and/or chalky cast - the longer and more rapidly mixed = shorter setting time | Improper mixing |
| Possible Causes of Inaccurate and/or Weak Cast:insufficient vibration thus creation air bubbles that create holes in the cast | Trapped air |
| Possible Causes of Inaccurate and/or Weak Cast:related to the manner of mixing and crystallization that occur during setting | SOFT OR CHALKY CAST |
| Possible Causes of Inaccurate and/or Weak Cast:results in breakage | PREMATURE SEPARATION OF CAST FROM IMPRESSION |
| Possible Causes of Inaccurate and/or Weak Cast:will most likely make the handler exert too much force during removal causing breakage or distortion | FAILURE TO SEPARATE CAST FROM IMPRESSION FOR AN EXTENDED PERIOD |
| used for trimming the wax. | Surveyor blade |
| used for slightly heating the blade. | Alcohol torch |
| used for areas that are to be blocked for convenience. These areas include the labial surfaces and labial undercuts not involved in the denture design and the sublingual and distolingual areas beyond the limits of the denture design. These areas do not require the use of the surveyor. | Hard baseplate wax or oil-base modeling clay(artist’s modeling clay) |
| TRUE OR FALSE: Relief is ordinarily not used beneath palatal major connectors, as it is with mandibular lingual bar connectors, except when maxillary tori cannot be circumvented or when resistive median palatal raphe are encountered. | TRUE |
| The purpose of relieving the master cast with wax is to provide ___between the certain components of the framework and the adjacent oral structures. | space |
