An Electronic Method for Measuring the Fit of Removable Partial Denture Frameworks to Dental Casts

Abstract

It is well established that the Removable Partial Denture (RPD) is an effective treatment prosthesis. The objectives of a successful RPD are: to preserve the health of remaining oral structure, restore function and restore esthetics. To achieve these objectives, an RPD framework must fit accurately to the supporting structures. This paper presents a method for measuring the gaps or spaces present between the RPD framework and supporting structures which will enable the dentist and the dental technician to evaluate the accuracy of fitting of the prosthesis before it is delivered to the patient. The method used in this research is based on the principle of electric capacitance and uses a specially designed prototype measurement system.

Comparison between digital superimposition and microcomputed tomography methods of fit assessment of removable partial denture frameworks

“…2,3,12,32 Therefore, the present study focused on the discrepancy between the occlusal rests and the respective rest seats. [9][10][11] In the present study, an impression of the gap between each occlusal rest and rest seat allowed an indirect quantitative assessment of the discrepancy. The impression material used was polyvinyl siloxane, a silicone elastomer material better than acrylic resin to reproduce details.…”

“…Assessment of fit is an essential step in controlling the quality of the framework production and ensuring the appropriate function of the prosthesis. 8,9 The fit is based on the intimate contact and residual discrepancies between the RPD framework and the supporting teeth. 12,45 Specifically, the design and fabrication standards of the RPD mean that stability and support of the framework are achieved when all rests are seated.…”

“…2 Thus, assessing frameworks in the dental laboratory could optimize clinical fit, decrease chair time, and ensure a successful prosthesis. 8,9 Different methods have been proposed to assess RPD fit based on the measurement of the discrepancy between the framework and the supporting structures. Visual inspection and pressing tests have been the most described methods, as they are rapid and straightforward to apply in the dental laboratory or clinically.…”

“…2,[12][13][14] Other proposed direct analog methods, such as measuring with a calibrated wire scale or optical microscope, use low-resolution power or may lead to structural damage. 9,[18][19][20][21][22][23] A more detailed and objective evaluation can be obtained with an impression of the discrepancy followed by its quantitative analog measurement with calipers, a profile projector, or optical microscopy. 24,25 These sensitive techniques can lead to errors because of the low dimension and resilience of the impression materials.…”

“…24,25 These sensitive techniques can lead to errors because of the low dimension and resilience of the impression materials. 8,9,12,[26][27][28][29][30][31][32][33] Digital techniques, such as digital microscopy, can identify errors imperceptible to the human eye and overcome the limitations of analog methods. 19,32,34 Furthermore, image capture digital techniques, such as microcomputed tomography (mCT), have been used as high-precision and high-resolution techniques in various fields of biomedical analysis.…”