Influence of Core Build-Up Designs on Preventing Early Failure of Composite Resin Core in Molars Under Traction Forces: A Finite Element Analysis Study

Abstract

Objective The aim of this study was to investigate, analyze and compare the stress distribution and biomechanical displacement generated at the interface between composite resin core buildups and two retentive shoulder designs on molars subjected to traction forces, through the utilization of finite element analysis (FEA).Method Four nonlinear 3D virtual Models of the maxillary first molar with resin core buildups with and without pins supported by a retentive shoulder design were generated using SOLIDWORKS 2017Ⓡ. All four virtual Models; Model 1: Pin Retained Complete, Model 2: Non-Pin Retained Complete, Model 3: Pin Retained Partial and Model 4: Non-Pin Retained Partial were subjected to a traction force of 1000 N and analyzed for the mechanical behavior of composite resin core buildups in relation to the retentive shoulder design.Results The resin core buildups without pins, Model 2 (2.62 µ) and Model 4 (5.83 µ) exhibited comparable levels of resin core buildup maximum displacement when compared to the Models with pins, Model 1 (2.24 µ) and Model 3 (5.11 µ), respectively. Model 2 (45.2 MPa) exhibited lower stress distribution than Model 1 (89.8 MPa). Similarly, Model 4 (29.5 MPa) displayed lower stress distribution compared to Model 3 (38.8 MPa).Conclusion The comparison of two core buildup designs with and without pins through FEA revealed that retentive shoulder designs without pins provided similar retention and resistance form for composite resin buildups than those with pins.

Keywords

• Retentive shoulder design
• core build-up design
• early failure
• composite resin
• traction forces
• core buildups