Shear Bond Strength and Color Stability of Novel Antibacterial Nanofilled Dental Adhesive Resins

Abstract

Experimental adhesives containing co-doped metaloxide nanoparticles were demonstrated to display strong and long-term antibacterial properties against Streptococcus mutans biofilms. The present study represents an effort to characterize the shear-bond strength (SBS) and color stability (CS) of these novel biomaterials. Experimental adhesives were obtained by dispersing nitrogen and fluorine co-doped titanium dioxide nanoparticles (NF_TiO2, 10%, 20% or 30%, v/v%) into OptiBond Solo Plus (OPTB). Dentin surfaces were wet-polished (600-Grit). Specimens (n = 5/group) of Tetric EvoCeram were fabricated and bonded using either OPTB or experimental (OPTB + NF_TiO2) adhesives. Specimens were stored in water (37 °C) for twenty-four hours (T1), three months (T2), and six months (T3). At T1, T2, or T3, specimens were removed from water storage and were tested for SBS. Disc-shaped specimens (n = 10/group; d = 6.0 mm, t = 0.5 mm) of adhesives investigated were fabricated and subjected to thermocycling (10,000 cycles, 5–55 °C, 15 s dwell time). Specimens’ colors were determined with a VITA EasyshadeÒ V spectrophotometer (after every 1000 cycles). SBS data was analyzed using two-way ANOVA and post-hoc Tukey tests, while CS data was analyzed using one-way ANOVA and post-hoc Tukey tests (α = 0.05). Mean values of SBS ranged from 16.39 ± 4.20 MPa (OPTB + 30%NF_TiO2) to 19.11 ± 1.11 MPa (OPTB), from 12.99 ± 2.53 MPa (OPTB + 30% NF_TiO2) to 14.87 ± 2.02 (OPTB) and from 11.37 ± 1.89 (OPTB + 20% NF_TiO2) to 14.19 ± 2.24 (OPTB) after twenty-four hours, three months, and six months of water storage, respectively. Experimental materials had SBS values that were comparable (p > 0.05) to those from OPTB independently of nanoparticle concentration or time-point considered. Experimental materials with higher NF_TiO2 concentrations had less intense color variations and were more color stable than OPTB even after 10,000 thermocycles. In combination, the results reported have demonstrated that experimental adhesives can establish strong and durable bonds to human dentin while displaying colors that are more stable, thereby suggesting that the antibacterial nanotechnology investigated can withstand the harsh conditions within the oral cavity without compromising the esthetic component of dental restorations.

Changes in physical properties of universal composites and CAD/CAM materials after bleaching and antioxidant applications: Scanning electron microscope and atomic force microscope evaluation

“…There is no direct indication in the application brochure of this device for its use in color measurement of resin‐based materials. However, when other studies in the literature investigating the color changes of resin‐based restorative materials were examined, it was seen that the measurements were made with the VITA Easyshade V (Floriani et al, 2022; Hong et al, 2022; Karakaya & Cengiz, 2017; Savic‐Stankovic et al, 2021). This device was preferred in our study to ensure that the results of our study were comparable.…”

Bioceramic micro-fillers reinforce antibiofilm and remineralization properties of clear aligner attachment materials

“…Thirty enamel samples were prepared as described in Section 2.1 with six samples for each group. The shear bond test was performed according to a previously published protocol ( Hong et al, 2022 ). Teeth samples were mounted in an acrylic mold (Ultradent Products, South Jordan, UT, United States) using self-curing resin (Epo Thin 2, Buehler, Lake Bluff, IL, United States), positioning the buccal surface for exposure.…”