Influence of substrate design for in vitro mechanical testing

Abstract

BackgroundThe goal of this study was to evaluate the influence of dental substrate simulator material, and the presence of root and periodontal ligament on the stress distribution in an adhesively-cemented monolithic crown.Material and MethodsFive (5) 3D models according to the substrate simulator material and shape were modeled with CAD software for conducting non-linear finite element analysis (FEA): Tooth with and without periodontal ligament - subgroup “pl” (groups Tooth+pl and Tooth-pl), machined tooth in epoxy-resin with and without pulp chamber - subgroup “pc” (ER+pc and ER-pc) and simplified epoxy-resin substrate without pulp chamber and roots (SiER). Next, adhesively-cemented monolithic crowns in zirconia reinforced lithium silicate were modeled over each substrate. The solids were then imported in STEP format to the analysis software and the contact between teeth and cylinder was considered perfectly bonded; whereas, the contacts involving the resin cement were considered as non-separated. The materials were considered isotropic, linearly elastic, and homogeneous. An axial load (600 N) was applied to the occlusal surface and results of maximum principal stress (MPa) on the restoration were required.ResultsFEA revealed that all evaluated subtracts showed the crown intaglio surface as the most stressed region. The average stress and stress peaks were similar for restorations cemented onto Tooth+pl, Tooth-pl and ER+pc substrates, but, 13% higher in comparison to ER-pc and SiER substrates.ConclusionsSimplified substrates can be used to evaluate posterior full crown behavior without periodontal ligaments and roots, since the rigidity of the specimen is taken into account. Key words:Finite element analysis, axial loading, computed assisted numerical analisys, monolithic crowns,methodological study.

The impact of restorative material and ceramic thickness on CAD\CAM endocrowns

“…Although a periodontal ligament layer was not simulated, some studies have reported that this is not necessary (1,52). Other studies made representative anatomical teeth specimens lacking this dental tissue (3,26,41).…”

Influence of Cement Thickness on the Polymerization Shrinkage Stress of Adhesively Cemented Composite Inlays: Photoelastic and Finite Element Analysis

“…The cavity configuration, quality of the substrate and the type of bonding can compensate the generated stresses in this region [51]. Regarding dental pulp, according to the literature, studies that used synthetic substrates to replace human teeth in laboratory tests do not report the presence or absence of the pulp chamber space and there are also no studies that assess the influence of the pulp chamber space on compressive forces in indirect restorations [52,53]. If the resistance capacity of the cavity walls is not sufficient to com-pensate generated stresses, it may result in de-bonding at the cement-restoration and/or cement-substrate interface.…”

Tooth Mobility Reproduction in Dental Material Research: A Scoping Review

“…Hence, the PDL simulator is necessary in all laboratory models replicating an increase in tooth mobility when testing dental materials on traumatology or periodontology. An exception of PDL simulation can be taken into consideration when investigating mechanical properties of an experimented tooth with fiber post [38] or posterior full crowns behavior [39]. It was reported in their results that there were no significant differences in groups with and without PDL simulation.…”