Flowable fiber‐reinforced versus flowable bulk‐fill resin composites: Degree of conversion and microtensile bond strength to dentin in high C‐factor cavities

Abstract

Objectives To compare flowable fiber‐reinforced and flowable bulk‐fill resin composites regarding their degree of conversion (DC) and microtensile bond strength (μTBS) to dentin in high C‐factor class I cavities. Materials and Methods One flowable fiber‐reinforced (EverX Flow, GC) and two flowable bulk‐fill composites (SDR, Dentsply, and Tetric N‐flow Bulk fill, Ivoclar Vivadent) were tested. Regarding DC, 10 cylindrical‐shaped specimens were prepared from each material (N = 30), measured using Fourier‐Transform Infrared Spectroscopy (FTIR). Regarding µTBS, class I cavities (4.5 × 4.5 × 3) were prepared on flat dentin surfaces of 30 molars, divided into three equal groups, restored with the three restorative materials, thermocycled, sectioned to create 1 mm × 1 mm cross‐sectional beams, then tested using a universal testing machine. Failure mode was assessed using a stereomicroscope. Two‐way ANOVA and Tukey's HSD post‐hoc tests were used in DC, while One‐way ANOVA was used for µTBS. Results The used materials showed statistically significant differences in DC with the fiber‐reinforced composite having the highest value. No statistically significant differences were found between the materials regarding their µTBS. Conclusions Flowable fiber‐reinforced composite provided the most DC performance compared to the flowable bulk‐fill composites. The three used restorative materials provided comparable bonding ability to dentin in high C‐factor cavities. Clinical Significance Flowable fiber‐reinforced resin composite is preferred as a dentin‐replacement material in high‐stress bearing areas. However, both flowable fiber‐reinforced and bulk‐fill resin composites are equally effective in bonding to dentin in high C‐factor cavities.

Mechanical and Ballistic Properties of Epoxy Composites Reinforced with Babassu Fibers (Attalea speciosa)

“…This means that, within the context of the study, these means do not differ in a statistically significant way. This identification of equal means reinforces the understanding that certain conditions or treatments have similar impacts, as evidenced by the statistical analysis [31,[37][38][39].…”

Effect of Dimethyl Sulfoxide Primer on Microtensile Bond Strength and Micromorphological Pattern of HEMA-free Universal Adhesive to Dry/Wet Dentin After Thermomechanical Aging

“…As a versatile and reliable testing method, the μTBS test was used to evaluate the durability of dentin-resin bonds under different conditions. As the bond strength of resin composites to dentin that is above or close to the pulp is around 30-40% of that to peripheral dentin, peripheral beams were excluded, and central beams were selected for more standardization and to decrease regional and tooth variabilities ( 21 ). According to the results of the present study, the null hypotheses regarding the bond strength were accepted since the main effects and interactions between the tested variables had no significant effect on dentin µTBS.…”

Effect of shelf-storage temperature on degree of conversion and microhardness of composite restorative materials

“…Composite specimens were kept in a dry dark condition for 24 h after light curing before testing to prohibit any light passage to the made samples [ 39 ]. As well, to reach the maximum DC as considerable increase in DC takes place even after the removal of the light curing source, lasting up to 24 h after polymerization [ 40 ]. To control the parameters which may inadvertently affect the final results, all tested specimens were submitted to a standardized fabrication technique, light-curing intensity, light-exposure time, and curing distance between the specimen’s surface and the light curing device’s tip.…”