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. 2018 Jun 7;6(6):1111-1119.
doi: 10.3889/oamjms.2018.226. eCollection 2018 Jun 20.

Comparative Study Clarifying the Most Suitable Material to Be Used as Partial Denture Clasps

Sherif Aly Sadek  1 , Wessam Mohamed Dehis  2 , Hala Hassan  3
Affiliations

Comparative Study Clarifying the Most Suitable Material to Be Used as Partial Denture Clasps

Sherif Aly Sadek et al. Open Access Maced J Med Sci. .

Abstract

Background: Removable partial denture's clasp is of particular importance as it affects the denture longevity during the function. The key of successful clasp selection is to select a direct retainer that will control tipping and torquing forces on the abutment teeth, provide retention against reasonable dislodging forces and are compatible with both tooth and tissue contour and the aesthetic desire of the patient. In this consideration, different materials employed for the clasp construction were compared mechanically.

Aim: This study aims to compare the most usable esthetic clasps mechanically to clarify the most suitable material to be used as partial denture clasps.

Methods: Evaluation of surface roughness, retention and deformation has been investigated utilising different in-vitro methods. All these techniques provide valuable information regarding the mechanical properties of the materials tested. However, none of the in-vitro techniques can expose the tested materials to conditions similar to that of the oral environment (in-vivo) such as pH value and temperature variations.

Results: Most commonly, RPD clasps are fabricated from the same alloy of the metal framework, as cobalt-chromium (CoCr) alloy although it is unaesthetic. Other methods consumed to avoid such esthetic mystery have included coating retainers with tooth-coloured resin or introduction of esthetic materials as Thermoplastic Acetal, Versacryl, and Thermopress.

Conclusion: It has been concluded that the non-metal Acetal resin retainer reveals superior mechanical properties.

Keywords: Clasps; Cobalt Chromium (CoCr); Deformation; Direct Retainer; Mechanical properties; Removable Partial Denture (RPD); Retention; Roughness; Thermoplastic Acetal; Thermopress; Versacryl.

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Figures

Figure 1
Figure 1
Model of surveyed metal teeth
Figure 2
Figure 2
The Specimens; A-Thermopress clasps; B-Metal clasps; C-Acetal clasps; D-Versacryl clasps
Figure 3
Figure 3
The testing machine with one of the specimens
Figure 4
Figure 4
Picture under the electron microscope form the metal specimen
Figure 5
Figure 5
Histogram showing the mean Roughness (Ra) for different tested Materials
Figure 6
Figure 6
Histogram showing the mean Retention for different tested Materials
Figure 7
Figure 7
Histogram showing the mean Deformation for different tested Materials
Figure 8
Figure 8
Scattered plot for the Correlation between Retention and Deformation
See this image and copyright information in PMC

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