Assessment of Chemical, Mechanical, and Microscopic Properties of Novel Self-Adhesive Dental Composites

To synthesize and characterize a novel self-adhesive bioactive and antibacterial dental composite with enhanced mechanical properties.All components were procured from Sigma Aldrich, United States. Commercially available Filtek Z250 and Nexcomp were used as control groups (C1 and C2, respectively). Four novel dental composite groups (C3, C4, C5, and C6) were prepared by mixing monomer solution and inorganic fillers (silica, chlorhexidine, MCPM, and β-TCP): in varying concentrations. The resulting dental composites were assessed for chemical, mechanical, and microscopic characterizations. Structural analysis and degree of conversion (DC) of prepared samples were evaluated with Fourier transform infrared spectroscopy (FTIR), while the microscopic interface was evaluated by scanning electron microscope (SEM). Mechanical characterizations included the biaxial flexural strength (BFS) test and the shear bond strength (SBS) test. The obtained data were then analyzed by SPSS version 21.0. Descriptive statistics were used to describe all the values for BFS, SBS, and DC. One-way analysis of variance and post hoc Tukey's test were used to compare the mean values. A <i>p</i>-value of less than 0.05 was considered statistically significant.FTIR results showed a major alteration in DC by calculating the differences in unpolymerized and polymerized aliphatic (1,638 cm^-1) and aromatic (1,608 cm^-1) peaks. It was reduced due to the increased quantity of fillers. Commercial composite showed the least DC value, whereas C3 showed higher DC as compared to other novel composites. For BFS, all the groups showed statistically significant differences except C4, whereas SBS results showed an insignificant difference among all the groups. SEM images of the dentin composite interface showed that C1 and C2 composites were not properly bonded to the dentin. The novel dental composite (C3, C4, C5, and C6) showed good bonding with the dentin.The novel C3 dental composite showed high DC and BFS, whereas C4 had higher SBS but lower than C2. Moreover, effective bonding was achieved with C3 novel composite. It is crucial to optimize the monomer-to-filler ratio for the development of durable bioactive self-adhesive composites with antibacterial property.