Influence of Filler Loading on the Mechanical Properties of Flowable Resin Composites

Abstract

The aim of this study was to evaluate the correlation between the percent of inorganic filler by weight (wt. %) and by volume (vol. %) of 11 flowable resin composites (FRCs) and their mechanical properties. To establish the correlation, the quantity of inorganic filler was determined by combustion and shape/size analyzed by SEM images. The compressive strength (CS), flexural strength (FS), and flexural modulus (FM) were determined. The CS values were between 182.87-310.38 MPa, the FS values ranged between 59.59 and 96.95 MPa, and the FM values were between 2.34 and 6.23 GPa. The percentage of inorganic filler registered values situated between 52.25 and 69.64 wt. % and 35.35 and 53.50 vol. %. There was a very good correlation between CS, FS, and FM vs. the inorganic filler by wt. % and vol. %. (R2 = 0.8899–0.9483). The highest regression was obtained for the FM values vs. vol. %. SEM images of the tested FRCs showed hybrid inorganic filler for Filtek Supreme XT (A3) and StarFlow (A2) and a homogeneous type of inorganic filler for the other investigated materials. All of the FS values were above 50 MPa, the ISO 4049/2019 limit for FRCs.

Printable and Machinable Dental Restorative Composites for CAD/CAM Application—Comparison of Mechanical Properties, Fractographic, Texture and Fractal Dimension Analysis

“…Despite the differences in the structure of materials, a high positive correlation (R = 0.822) was observed between the filler content (by volume) and the microhardness. A similar relationship was observed by Ling et al [ 39 ], Chung (R = 0.89) [ 40 ] and Mirica et al [ 44 ]. The hardness of the material can also be related to the abrasion and materials with low hardness may be more susceptible to wear [ 46 ].…”

Dimensional stability of short fibre reinforced flowable dental composites

“…A higher weight fraction of glass filler particles would result in higher light scatter causing a decrease in total energy received and thus causing insufficient polymerisation of the monomer. In this study, the individual particle volumes of filler, 50AR and 70AR fibres were 0.14, 4909.00 and 6872.00 mm 3 , respectively. Hence, the number of particles was reduced by replacing 5 wt% fillers with 5 wt% long fibres and additionally the glass fibres transmit light through its length in different directions when randomly oriented, causing higher light penetration through the thickness, resulting in a degree of conversion, and curing depth.…”

Rheological and Mechanical Properties of Resin-Based Materials Applied in Dental Restorations

“…Filler is an important factor that can significantly affect the mechanical strength of composite materials [ 4 ]. In another study by Mirica et al [ 71 ], it was reported that the flexural strength can be improved to 60–90 MPa with the addition of around 50% appropriate fillers. At the same study [ 71 ], the prepared flowable composite had compressive strength of 182–310 MPa and flexural modules of 2.34–6.32 GPa, which was higher than those of the conventional flowable composites owing to the selection of functional fillers.…”