Flowable <scp>fiber‐reinforced</scp> versus flowable <scp>bulk‐fill</scp> resin composites: Degree of conversion and microtensile bond strength to dentin in high <scp>C‐factor</scp> cavities
Youniss Saleh Harp, Marmar Montaser, Nadia Mohamed Zaghloul
Abstract
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 , 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 . 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 . 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.