Stress analysis in oral obturator prostheses over parallel and tilted implants: photoelastic imaging

Aldiéris Alves Pesqueira,Adhara Smith Nobrega,Marcela Filié Haddad,Agda Marobo Andreotti,Daniela Micheline Dos Santos,Marcelo Coelho Goiato,Amália Moreno

doi:10.1117/1.jbo.18.10.106009

Aldiéris Alves Pesqueira, Adhara Smith Nobrega + Show 5 more

Open Access

https://doi.org/10.1117/1.jbo.18.10.106009

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Abstract

This study aimed to evaluate the stress distribution through the photoelastic method in implant-retained palatal obturators prostheses. Two photoelastic models with bucco-sinusal communication were fabricated, one model without implants and another with two parallel implants and one tilted in the molar region. A conventional obturator prosthesis and five implant-retained obturators dentures with different attachment systems were fabricated: OR, three individualized O-rings; BC, bar clip; BOC, implants splinted by bars associated with two O-rings positioned at the center of the bar; OD, implants splinted by bars associated with two O-rings positioned in distal cantilever; and BOD, implants splinted by bars with clips associated with two O-rings positioned in distal cantilever. Each assembly (model/attachment system/prosthesis) was positioned in a circular polariscope and a load of 100 N was applied on each implant. The results were obtained by observing the photographic record of the tensions in the photoelastic models resulting from the application of load. It can be observed that a larger amount of stress fringes on BC system. It was concluded that the attachment system has a direct influence on the stress distribution of implant-retained obturator prostheses, with the three individualized O-rings exhibiting the lowest stress values, and tilted implants presented a biomechanical behavior similar to parallel implants.

Highlights

The installation of implants with distal inclination in areas of greater bone density, as in the region of first molars, has been an alternative for atrophic ridges of maxilectomized patients to improve the geometrical arrangement of the assembly prosthesis/implant
Thereby, this study aimed to evaluate the stress distribution through the photoelastic method in implant-retained palatal obturators over two parallel implants and one tilted using different attachment systems and conventional obturator
One mucous-supported obturator prosthesis and four implantretained obturator prosthesis using different attachment systems: OR, three individualized O-rings; BC, bar clip; BOC, implants splinted by bars associated with two O-rings positioned at the center of the bar; OD, implants splinted by bars associated with two O-rings positioned in distal cantilever; and BOD, implants splinted by bars with clips associated with two O-rings positioned in distal cantilever

Summary

Introduction

The installation of implants with distal inclination in areas of greater bone density, as in the region of first molars, has been an alternative for atrophic ridges of maxilectomized patients to improve the geometrical arrangement of the assembly prosthesis/implant. Without this technique, these regions would receive shorter implants or would require bone graft, increasing the complexity, time and cost of the treatment.[1,2,3]. Thereby, this study aimed to evaluate the stress distribution through the photoelastic method in implant-retained palatal obturators over two parallel implants and one tilted using different attachment systems and conventional obturator The dental literature has shown many studies that approach the distribution of forces in order to collect better background information for planning of overdentures.[4,5,7,8,9,12] A photoelasticity method through images has been widely applied in dentistry and allows a direct observation of stress distribution on structures, based on the ability of certain transparent materials to display color standards named isochromatic fringes when they are loaded and observed through a polarized light.[4,5,7,13]

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