Comparative analysis of stress distribution in different prosthetic solutions for Kennedy class I bilateral posterior edentulous arches

Abstract

One of greatest challenges of dentists is the rehabilitation of free-end Kennedy class I and class II patients due to the improper occurrence of stress around the supporting structures of conventional removable dentures during mastication. This work aimed to compare the stress distribution in different prosthetic solutions. For this analysis, four photoelastic models (PM) were produced simulating a Kennedy class I arch with the remaining teeth 34 through 44. In all models, teeth 33, 34, 43, and 44 received metal crowns. In addition to the crowns, the A model (PMA) received a conventional removable partial denture (RPD), the B model (PMB) received a RPD associated with a semi-rigid attachment, the C model (PMC) received a RPD associated with a rigid attachment, and the D model (PMD) received a RPD associated with implant and rigid attachment. Evenly distributed loads were applied on the last artificial tooth of the prostheses. Based on the results of the distributed load, the conventional prosthesis presented the best results for all regions (averages ranging from 25.70 to 17.80), followed by the prosthesis associated with the implant, the prosthesis associated with the rigid attachment, and lastly, the prosthesis associated with the semi-rigid attachment. The same result can be observed in the localized load, where the conventional prosthesis presented superior results in all regions (averages ranging from 47.35 to 8.30), followed by the prosthesis associated with the implant, the prosthesis associated with the rigid attachment and, with the prosthesis associated with the semi-rigid attachment. Based on the data obtained, it may be concluded that the conventional RPD presented a balanced stress distribution in the three regions analyzed, and when associated with the semi-rigid attachment, it presented a more favorable behavior than that associated with the rigid attachment.