Three steps are involved in making a denture framework by using relief, blockout ledges, and ready-made pattern forms | master cast with relief and blockout, complete wax pattern, finished casting returned to master cast |
It is essential to the dentist to understand the ____- involved. This enables them to design the RPD ____________ that communicates the desired design and authorizes its ______the quality of the framework | laboratory procedures; framework, complete a laboratory work authorization; fabrication, and evaluate |
_____of the key features required in a completed removable partial denture framework ensure the patient of a chance to ____ with the finished product | Understanding and evaluation; function comfortably |
Preformed plastic patterns- made of ____; they tend to stretch on removal from their backing. Therefore, care must be exercised when one is removing patterns | soft plastic material |
Preformed plastic patterns - Their use generally requires that ___ be applied first to the investment cast at their area of placement | tacky fluid |
Freehand waxing, Prepares wax patterns for metallic framework, Bulk form for sprue & vent sprue | RPD CASTING WAX |
SHEET CASTING WAX: For making pattern of a maxillary major connector, Can also be used in providing the “plate” of a mandibular linguoplate (22-24- gauge sheet wax | Smooth Casting Wax |
SHEET CASTING WAX: It is used for bases of upper partial dentures, Internal finish line | Stippled Casting Wax |
PRE-FORMED CASTING WAX: Minimizes modelling time for retention of maxillary partial denture with large saddles | Wax Border Strips with Retentions |
PRE-FORMED CASTING WAX:can be easily shaped as needed because the size can be varied by trimming the tips of the retentions | Wax Border Strips with Retentions |
PRE-FORMED CASTING WAX:used in providing a secure attachment of a plastic saddle to the mandibular partial denture | Wax Retentions for Mandibular Partial Denture Frame |
Wax Grid Retentions for Maxillary Partial Denture Frame: Large grid retention size | 60 x 42mm |
Wax Grid Retentions for Maxillary Partial Denture Frame: diagnonal grid retentions size | 75 x 150mm |
Wax Grid Retentions for Maxillary Partial Denture Frame: grid retentions with holes size | 70 x 70 mm |
Wax Grid Retentions for Maxillary Partial Denture Frame: high level of security in the connection between the resin and the partial denture plate | Large Wax grid retentions |
Wax Grid Retentions for Maxillary Partial Denture Frame:offer a very high degree of security in connecting the resin and the dentures. | Wax diagonal grid retentions |
Wax Grid Retentions for Maxillary Partial Denture Frame: can be used as retentions for partial maxillary dentures and as a reinforcement | Wax grid retentions with holes |
For premolars and molars- provides a firm grip as well as giving the partial denture the necessary stability. It helps to decrease the time for remodeling and wax shapes can be customized by shortening or lengthening them | Wax Clasp Profiles |
WAX PROFILE STICKS:It provides high internal stability and protection against unintentional deformation and constriction. | Wax Profiles Assortment |
WAX PROFILE STICKS:For customized shaping of the sublingual bar, Freehand waxing | Wax Profiles Assortment |
WAX PROFILE STICKS:for customized shaping of the sublingual bar | Anatomical Wax Bar Profiles for Lower Jaw Partial Denture Frame |
METHODS OF WAXING:A slow method of waxing; No control of uniformity | freehand |
METHODS OF WAXING:Faster than freehand, More control of uniformity than freehand, Do not compress patterns with much pressure or the pattern will distort | wax patterns |
METHODS OF WAXING: Excellent and fast method of waxing | plastic patterns |
METHODS OF WAXING: Combines the best qualities of freehand, wax patterns and plastic patterns | combination |
Aids in casting the RPD by acting as an auxiliary channel for metal flow | beading/ bead line |
Creates a seal in the mouth by displacing soft tissue | beading/ bead line |
Use ___ gauge round wax for all finish linep | 18 |
Position lingual to internal lines approximately ____ | 1 - 1.5 mm |
lingual plating should be no more than __ mm thick | 1 |
what wax to use on outer borders | 12-gauge 1/2 round |
what wax to use on cross struts | 12-gauge 1/2 round |
Cut shoulder of clasp at a __ degree angle | 45 |
what method of waxing is used to make rest and minor connectors | freehand |
Occlusal __ should be slightly concave to prevent interference with the opposing cusp | rest |
Minor connector should be approximately ___ thick or as thick as shoulder of clasp | 1 mm |
Junction of minor connector and rest should form a __ degree angle | 90 |
what wax is used on major connector for mandibular | 6-gauge 1/2 pear pattern |
MN WAX UP: Cut ends of major connector at __ degree angle | 45 |
use __-gauge round wax for all finish lines | 18 |
if external finish line is placed directly over the internal finish line, it will cause ___ between the retention grid and the major connector | weak junction |
opening that leads from the crucible to the cavity in which the framework is to be cast. | sprue channel |
have the purpose of leading the molten metal from the crucible into the mold cavity | Sprues |
have the further purpose of providing a reservoir of molten metal from which the casting may draw during solidification, thus preventing porosity caused by shrinkage | Sprues |
Sprues should be large enough that the molten metal in them will not solidify until after the metal in the casting proper has frozen (______ is usually used for multiple spruing of removable partial denture castings). | 8- to 12-gauge round wax |
Sprues should lead into the mold cavity as directly as possible and still permit a configuration that will induce a minimal amount of _____ in the stream of molten metal | turbulence |
Sprues should leave the ___ from a common point and be attached to the wax pattern at its bulkier sections, that is, no ____ of casting should intervene between two bulky, unsprued portions | crucible; thin sections |
For a maxillary framework, multiple ___ sprues or a single main sprue located posteriorly can be used. When a single main sprue is used, additional sprues can feed critical regions for casting completeness | 8-gauge |
Mandibular cast framework with sprue intact, showing three ___ sprues attached to the lingual bar. If one is concerned about completely filling distal extension base minor connectors, ____ sprues can be attached to the minor connector | 8-gauge; 12-gauge |
Two basic types of sprues are used:use of 8- to 12-gauge round wax shapes for main sprues and 12- to 18-gauge round wax shapes for auxiliary sprues | MULTIPLE |
Two basic types of sprues are used:limited to those maxillary frameworks in which—because of the presence of a palatal plate—it is impossible to locate multiple sprues centrally. | SINGLE |
Some important points to remember in multiple spruing are as follows: Use a few sprues of _____ rather than several _____. | large diameter; smaller sprues |
Some important points to remember in multiple spruing are as follows: Keep all sprues as ______ as possible | short and direct |
Some important points to remember in multiple spruing are as follows: Avoid ____ in direction; avoid ____ junctions as much as possible | abrupt changes; T-shaped |
Some important points to remember in multiple spruing are as follows: Reinforce all junctions with _____ to prevent constrictions in the sprue channel and to prevent ____sections of investment that might break away and be carried into the casting | additional wax; V-shaped |
The investment for a removable partial denture casting consists of two parts | The investment cast on which the pattern is formed; The outer investment surrounding the cast and pattern |
The investment must conform accurately to the _____ and must preserve the ______ as a cavity after the pattern itself has been eliminated through _______ | shape of the pattern; configuration of the pattern; vaporization and oxidation |
The technique for applying the outer investment is usually referred to as ________. The cast on which the pattern is formed is part of the investment also. | investing the pattern |
aka Wax elimination | BURNOUT |
The burnout operation served three purposes | Drives off moisture in the mold; Vaporizes and thus eliminates the pattern, leaving a cavity in the mold; Expands the mold to compensate for contraction of the metal on cooling |
contains the written directions for laboratory procedures to be performed for fabrication of dental restorations. | work authorization |
they provide a means for increased professional quality assurance and satisfaction in a removable partial denture service | work authorization |
similar to granting power of attorney. It grants authority for others to act on the dentist’s behalf and specifically prescribes what is authorized; effective channels of communication. | work authorization |
Information contained in a work authorization | 1. The Name and Address of The Dental Laboratory; 2. The Name and Address of The Dentist Who Initiates The Work Authorization; 3. The Identification of The Patient; 4. The Date of Work Authorization; 5. The Desired Completion Date of The Request; 6. Specific Instructions; 7. The Signature of The Dentist; And 8. The Registered License Number of The Dentist |
The following four important functions are performed by a work authorization | 1.It furnishes definite instructions for laboratory procedures to be accomplished and implies an expectation of a level of acceptable quality for the services rendered.
2.It provides a means of protecting the public from the il- legal practice of dentistry.
3.It is a protective legal document for both the dentist and the dental laboratory technician.
4.It completely delineates the responsibilities of the dentist and the dental laboratory technician. |
Work Authorization - Characteristics | 1.A work authorization must be legible, clear, concise, and readily understood.
2.It is sound practice to provide the dental laboratory technician with adequate written instructions for each laboratory service required in the fabrication of a restoration
3.No single work authorization form is adequate to furnish detailed instructions for accomplishing the laboratory phases in the fabrication of removable partial dentures, crowns, and fixed partial dentures, or complete dentures, or for accomplishing orthodontic laboratory procedures. |
Work Authorization - Legal Aspects | ●Made in duplicate
●Retain a copy for a specified period from the date of work authorization
●To substantiate or refute claims and counterclaims that concern the illegal practice of dentistry
●To aid in the settlement of misunderstandings between a dentist and a dental laboratory technician |
Modeling frames for lower jaw removable partial denture framework | Wax Retentions for Lower jaw Partial Denture Frame |
General request is prefaced by ____ and the specific instructions are ended with _____ | “please”; “thank you” |
Work Authorization - Delineation of Responsibilities | ● The dentist is responsible for all the phases of removable partial denture service
● Dentists should refrain from imposing responsibilities on auxiliary personnel that legally and morally
belong to the dentist.
● A good dental laboratory technician is a valuable team member.
● Team Collaboration and Dentist's Role
● Dentists may delegate the laboratory phase but should fulfill the moral obligation to supervise and
direct technical phases. |