Photoelastic Analysis of Biomechanical Behavior of Single and Multiple Fixed Partial Prostheses With Different Prosthetic Connections

Abstract

The aim of this study was to evaluate the stress distribution on external hexagon, internal hexagon, and Morse taper implant in single and 3-unit implant-supported fixed partial prostheses (FPPs) using photoelasticity. Six models were fabricated with the photoelastic resin PL-2: 3 models for the 3-unit implant-supported FPP with implants of 4.0 × 10.0 mm in the region of the second premolar and molar including 1 model for each type of implant connection, and 3 models for the single prosthesis for each implant type. The prostheses fabrication was standardized. A circular polariscope was used, and axial and oblique (45 degrees) loads of 100 N were applied in a universal testing machine. The results were photographed and analyzed qualitatively. The internal hexagon implant exhibited better stress distribution and lower intensity of fringes followed by the external hexagon and Morse taper implants for the models with the 3-unit prostheses. For the single implants, the Morse taper implant presented better stress distribution, followed by the internal and external hexagon implants. The oblique loading increased the number of photoelastic fringes in all models. It was concluded that the internal hexagon implant exhibited better biomechanical behavior for the 3-unit implant-supported FPP, whereas the Morse taper implant was more favorable for the single implant-supported prosthesis. The oblique loading increased the stress in all models.

Analysis of the biomechanical behavior of short implants: The photo-elasticity method

“…In the qualitative and quantitative analyses of models B and C, regarding the question of loading, it can be observed that the oblique loading also showed a greater number of strains. This is in agreement with the literature [7,9,11,19,20] with respect to the harmful effect on the peri-implant tissue and the large part of the masticatory forces that behave like oblique forces.…”

“…With regard to the qualitative analysis of stress magnitude, the fringe order (N) and the direction of the propagation of stress were observed, as proposed in the literature [10,11] and suggested by Caputo & Standlee [12].…”

Main Predictors of Bone Crest Preservation With the Use of the Switching Platform.

“…[14,20,46]. This fact is evidenced, especially, in the alteration of the height of the bone crest, as a consequence of the concentration of tension in the cervical region of the implant [21].…”

Photoelastic analysis of stresses transmitted by complete dentures lined with hard or soft liners

“…However, visual analysis of the stresses has been enough to establish the desired comparison, as observed in previous works [26][27][28]. Thus, the following methodological aspects were considered in the current study: (1) The observation of the stress was qualitative, and the photoelastic analysis was done in only one model per each group [25,27], and (2) As the observation was to verify the qualitative behavior of stresses, the statistical analysis is unnecessary by obvious reasons.…”