Nanoparticle Augmentation of Adhesive Systems: Impact on Tensile Strength in Fiberglass Post Placement within Root Dentin.

BACKGROUND Modification of the glass fiber post (GFP) with titanium dioxide or silver particles can improve the durability and reliability of dental treatments for ensuring long-term success. This research assessed the tensile bond strength (TBS) of an adhesive system used for cementing GFPs into root dentin following the incorporation of nanoparticles of titanium dioxide (NTiO2) and silver (NAg). MATERIAL AND METHODS Sixty human maxillary canines were prepared to create a 10-mm intra-radicular space for post placement from the cementoenamel junction. The specimens were randomly allocated into 2 groups (a non-thermocycling group and a thermocycling group). Each group was divided into 3 subgroups (10 samples each) according to the adhesive system used (adhesive system devoid of any addition, adhesive system including 1% NAg, and adhesive system infused with 1% NTiO2). TBS tests were conducted and recorded in MPa using a Universal Testing Machine, with an axial load applied at a rate of 0.5 mm/min until failure. The TBS for both groups (non-thermocycling and thermocycling) was measured in megapascals (MPa), and the failure type was recorded. The data were statistically analyzed using one-way analysis of variance (ANOVA) and Tukey's test with P.

Microshear bond strength of Nano-Bond adhesive containing nanosized aluminum trioxide particles.

OBJECTIVES: The present study was conducted to evaluate the effect of nanosized aluminum trioxide (Al2O3) particles when added to the Nano-Bond adhesive system and its effect on the microshear bond strength of nanocomposite resin to dentin. MATERIALS AND METHODS: A newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. The occlusal surfaces of extracted human molar teeth were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. The adhesives were applied to the dentin surfaces according to manufacturers' instructions. The nanocomposite resin was then placed and light cured for 40 s. After immersion in water at 37°C for 24 h, the specimens were subjected to thermocycling before testing, and a microshear bond test was carried out. The recorded bond strengths (MPa) were collected, tabulated, and statistically analyzed. A one-way analysis of variance and Tukey's tests were used to test for significance between the means of the groups; statistical significance was assumed when the P ≤ 0.05. RESULTS: The mean microshear bond strength of the Nano-Bond adhesive system containing nanosized Al2O3 at a concentration of 2% was 23.15 MPa (Group B), which was significantly greater than that of the Nano-Bond adhesive system without additives (15.03 MPa, Group A). CONCLUSIONS: These results indicate that nanosized Al2O3 added to the Nano-Bond adhesive system at a concentration of 2% increases the microshear bond strength.