Three-dimensional finite element analysis of resin-dentin interfaces bonded with total etching and self-etching systems under static tensile load

Abstract

Objective To analyze the effect of total etching and self-etching adhesive systems on resin-dentin interfaces and stress distribution under static tensile loading in order to understand the function of 2 interfaces under static loading. Methods Two idealized micro-scaled three-dimensional finite element models were constructed according to the micromorphological characteristics of the total etching and self-etching adhesive system bonded dentin interfaces. The stress distribution of the 2 interfaces was analyzed under a static tensile load of 20 MPa, as well as stress concentration factors of each structural components were calculated. Results The structural components of both bonded interfaces were subjected to tensile stress under static tensile loading, as the stress was concentrated predominantly at the junctions of different structural components. The highest stress concentration factor was found in the partially demineralized dentin in the total etching bonded interface (2.91), and the factor was 2.52 in the intact dentin in the self-etching bonded interface. The stress was lower in the self-etching bonded interface than the total etching bonded interface (50.32 vs 58.27 MPa). Conclusion Based on the 2 micro-scaled interfacial models constructed in this study, the mechanical stability of self-etching bonded interface is much better than that of the total etching bonded interface.

Keywords

• dentin adhesion
• interface
• finite element analysis
• static loading
• stress concentration factor