Properties of a New Nanofiber Restorative Composite

Abstract

A new nanofiber-reinforced hybrid composite (NovaPro Fill, Nanova) was recently introduced with reportedly improved mechanical properties. The purpose of this study was to compare the properties (flexural strength/modulus, degree of conversion [DC], depth of cure, and polymerization shrinkage) of the nanofiber composite to those of traditional hybrid composites (Filtek Z250, 3M ESPE; Esthet-X HD, Dentsply). To determine flexural strength and modulus, composite was placed in a rectangular mold, light-cured, stored for 24 hours, and then fractured in a universal testing machine. For degree of conversion, composite was placed in a cylindrical mold, light-cured, and stored for 24 hours. Measurements were made at the top and bottom surfaces using Fourier Transform Infrared Spectroscopy. To determine depth of cure, composite was placed in a cylindrical mold and light-cured. Uncured composite was scraped until polymerized resin was reached. Remaining composite was measured and divided by two. Polymerization shrinkage was determined by placing the composite material on a pedestal in a video-imaging device while light-curing. Shrinkage was determined after 10 minutes. Data were analyzed with one-way analysis of variance and Tukey post hoc test per property (α=0.05). Compared to Filtek Z250, NovaPro Fill had significantly lower flexural strength and modulus, greater volumetric shrinkage, and similar depth of cure, but greater top and bottom DC. Compared to Esthet-X HD, NovaPro Fill had similar flexural strength, shrinkage, and top and bottom DC, but significantly greater depth of cure and flexural modulus.

Characterization of restorative short-fiber reinforced dental composites

“…Alert has fiber length in micrometer scale (20-60 µm) and diameter of 7 µm (Fig. 2), while NovaPro composites have fiber diameter in nanometer scale (50-200 nm) and length in range between 100 and 150 µm, which is well below the critical fiber length and desired aspect ratio 15,18) . This explained the difference in fracture toughness values between the commercial SFRCs.…”

“…A number of manufacturers have developed short fiberreinforced composites (SFRCs) which claimed to overcome the weakness of conventional PFC. Many recent studies in the literature have approached to find way to support the remaining tooth structure and improve the durability of the final composite restorations [13][14][15][16] . The attempt has been to use SFRC as dentine-replacing material (bulk base) or post-core foundation under surface layer of enamel-replacing material (PFC), i.e.…”

“…To the author's knowledge, until now they are a limited number of SFRCs available in the market. These SFRCs perhaps mimic structurally the fibrous structure of dentine and some of them are recommended to use as bulk base or core build-up materials in large cavities of either vital or non-vital posterior teeth [14][15][16][17][18][19] .…”

Effect of post-irradiation polymerization on selected mechanical properties of six direct resins

“…Kim et al 25) suggests that resin composites with round filler particles allow more filler loading and thus higher flexural strength values, which is noted in some of the flexural strength results of this study. While Esthet X HD is classified by the manufacturer as a Micro Matrix Restorative, its filler content of irregular barium borosilicate glasses ranging from 0.6 to 0.8 μm with 0.04 μm nanofillers has been suggested to be classified as a nano-hybrid 41,42) . SpectrumTPH3 is classified as a nanohybrid with borosilicate and barium silicate glasses that are less than one micron diameter and silicon dioxide spherical particles that are 10 to 20 nm in size.…”

24 hour polymerization shrinkage of resin composite core materials

“…Furthermore, this technique has not been frequently cited in the dental literature. As is the case with measurement of stresses due to polymerization, there are many additional methods of measuring polymerization shrinkage, including bonded disks 22–24 dilatometers, 25–29 strain gauges, 30,31 photoelastic deformation, 32,33 X‐ray microtomography, 8,34,35 displacement transducers, 32,36 gas pycnometer, 37 interferometry, 38 and video imaging 39–46 . As with stress measurement, there is no consensus on which method is most clinically relevant.…”