|Year : 2008 | Volume
| Issue : 4 | Page : 192-194
A systematic method for designing removable partial denture framework
Department of Prosthodontics, Isfahan University of Medical Sciences, Isfahan, Iran
|Date of Web Publication||7-Apr-2009|
Department of Prosthodontics, Member of Torabi-Nejad Research Center, Isfahan University of Medical Sciences, Hezar-Jarib Ave. Isfahan
Source of Support: None, Conflict of Interest: None
Designing a removable partial denture framework can be complicated for students and dentists. This article suggests a simple and systematic method for the process. In this method, the designing sequence outlines (1) rests, (2) minor connectors and proximal plates, (3) retentive meshwork, (4) major connector, (5) direct retainers, and (6) indirect retainers, respectively.
Keywords: Design, framework, removable partial denture
|How to cite this article:|
Mosharraf R. A systematic method for designing removable partial denture framework. J Indian Prosthodont Soc 2008;8:192-4
| Introduction|| |
When planning treatment for partially edentulous patients, the dentist is confronted with myriad combinations of edentulous spaces and remaining teeth,  so designing a removable partial denture (RPD) framework might be complicated for students and dentists.  This problem seems to arise not so much from a lack of understanding of basic concepts, but from the lack of a start point and a systematic sequence of designing. ,
This article suggests a simple and systematic method for designing an RPD framework.
- Survey the diagnostic cast in a classical manner. 
- Outline the supporting rests based on these rules:
- The position of rest seats is most often dictated by the classification. For Class III and IV arches, the quadrilateral configuration is indicated. The tripod clasping is used for Class II arches. For a Class I arch, a bilateral configuration is required. 
- In the tooth supported edentulous spaces, the rests should be placed next to the edentulous spaces  [Figure 1].
- In the distal extension areas, the rest seats must be located far from the edentulous ridge (e.g. RPI design)  [Figure 1].
- Outline the proximal plates and minor connectors based on these rules:
- All the rests next to the tooth-supported areas must be connected to proximal plates  [Figure 2].
- In the distal extension areas, the proximal plates are not connected to the rests. Mesial rest must be connected to a minor connector.
- Outline the retention mesh for the denture base resin considering these rules:
- In the tooth-supported areas, metal bases should be used [Figure 3]. However, in long span areas, unhealing extraction sites and severe resorption of residual ridge, using acrylic resin bases is necessary.
- In the maxillary distal extension base, the retentive meshwork must be extended to hamular notch [Figure 3]; but in the mandible, these elements should cover only two-thirds of ridge length. 
- Outline the major connector on the cast. The type of major connector is selected based on the support and rigidity needed for preservation of tissues, and anatomic limitations  [Figure 4].
- Outline the direct retainers considering these rules:
- In tooth supported edentulous spaces, the type of clasp selected is not critical. Tooth and tissue contours and esthetics should be considered, then the simplest possible clasp selected.
NOTE: In the case of mesial abutment of the modification area of a Class II mod 1 situation, wrought wire should be used in a mesiobuccal undercut and half-T or I-bar clasp must be used in a distobuccal undercut , [Figure 5].
- In the abutment tooth next to the distal extension area:
- If a distobuccal undercut is present, the vertical projection retentive clasp is preferred. 
- If a mesiobuccal undercut is present, a wrought wire clasp should be indicated  [Figure 5].
- Each retentive element must be opposed by a reciprocal or bracing element. Lingual plating may be substituted. 
- Outline the indirect retainers as far anterior to the fulcrum line as possible.  In some instances, the primary rest (draw in step 2) might act as an indirect retainer, too [Figure 6].
| Discussion|| |
The procedure described for designing a diagnostic cast is applicable to each dental arch. It is presented in a sequential and systematic manner and is not complex.
| Conclusion|| |
This simple and systematic designing procedure consists of six major steps, that must be remembered and followed in this manner: (1) rests, (2) minor connectors and proximal plates, (3) retentive meshwork, (4) major connector, (5) direct retainers, and (6) indirect retainers.
In each step, there are 2-3 rules that must be considered.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]