Maximum fracture load and stress concentration in resin-bonded fixed partial dentures of indirect composite resin reinforced by silica-nylon mesh

Abstract

Objectives: This study aimed to evaluate the maximum fracture load using a silica-nylon reinforcement system on resin-bonded fixed partial dentures (RBFPD) made of indirect composite resin. Methods: An in vitro test simulated an anterior (A) and posterior (P) three-element RBFPD. Thus, 80 specimens were made in 8 experimental groups (n = 10). The groups were divided according to the silica-nylon reinforcement presence (R) and aging (C). The aging process was performed through mechanical cycling for 106 cycles at 4 Hz. The samples were tested by maximum fracture load in a universal testing machine with a 1000 Kgf load cell and analyzed by Stereomicroscope and Scanning Electron Microscopy (SEM). Statistical analysis consisted of analysis of variance (two-way ANOVA) and Tukey test 5%. An in silico study was performed by Finite Element Analysis (FEA), in which the abutment teeth and the prostheses were scanned and transferred to CAD Rhinoceros (version 4.0SR8; McNeel North America, Seattle, WA) for 3D modeling. The analysis test was performed in computer aided engineering software (ANSYS 19.3, Canonsburg, PA, USA). Results: The maximum fracture load results (N) were A=163.55; AC=184.48; AR=198.81; ARC=192.24; P=539.99; PC=359.61; PR=541.74 and PRC=608.74. The Maximum Principal Stress results obtained in the FEA were (MPa): A=53.24/122.40; AR=55.07/117.70; P=33.28/36.18 and PR=28.06/42.87. Significance. It was concluded that the presence of the silica-nylon mesh increased the maximum fracture load of the RBFPD without increasing the stress concentration, regardless of the prosthesis design.