Physicochemical properties of experimental self-adhesive resins containing 45S5 bioglass

Abstract

Objective

To evaluate the physicochemical properties of self-adhesive resin composites containing tailored 45S5 bioglass (BAG).

Materials and methods

Three experimental composite resins were formulated, comprising 20 wt% Bis-GMA, 10 wt% TEGDMA, 0.5 wt% camphorquinone, 1 wt% tertiary amine, and 55 wt% silanized barium particles. The groups were divided according to BAG and the type of resin, adhesive or self-adhesive: 1) CONT: without BAG and MDP; 2) 45S5: containing 15 wt% BAG (AD); 3) MDP + 45S5: containing 15 wt% BAG and 3 wt% 10-MDP- self-adhesive. The adhesive utilized Primer&Bond Universal, while the self-adhesive resin no prior treatment. The microtensile bond strength (μTBS) was measured at 24 h and after one year (n = 5). Failure analysis was conducted using a stereomicroscope. Flexural strength (FS) and elastic modulus (EM) was evaluated using bar-shaped samples after 24 h (n = 12). Disc-shaped samples were prepared for water sorption (WSp) and solubility (WSl) by ISO 4049 (n = 12). The degree of conversion after 24 h (DC, n = 3) and remineralization assessments were conducted via FTIR (n = 5). Statistical analysis was performed using ANOVA followed by Tukey's test (p < 0.05).

Results

No significant differences in DC were observed among the groups (p = 0.519). The incorporation of BAG resulted in a significant reduction in FS values, with CONT showing 45.01 MPa and 45S5 23.55 MPa. For MS, CONT (791.34 MPa) and 45S5 (623.44 MPa) showed higher values (p = 0.133). This was accompanied by an increase in WS and SL, measured at 69.08 mg/mm³ and 14.67 mg/mm³, respectively, compared to CONT and MDP +45S5 (p = 0.982). Regarding remineralization, the MDP +45S5 group exhibited a notable increase in hydroxyapatite phosphate peaks at 970 and 1030 cm⁻¹. At 24 h, no significant differences were detected in μTBS among the experimental resins (p < 0.05). Following aging, CONT (18.8 MPa) and 45S5 (17.20 MPa) displayed significantly higher μTBS values, predominantly characterized by mixed failure modes.

Conclusion

The experimental self-adhesive resin containing MDP and 45S5 exhibited satisfactory physicochemical properties, suggesting its potential as a remineralizing material.