This in vitro study aimed to evaluate the effect of different bonding strategies on the micro-shear bond strength (μSBS) of luting agents to CAD–CAM composites. Surface scanning electron microscopy (SEM) and spectroscopy by energy-dispersive X-ray spectroscopy (EDS) were performed to analyze the surfaces of the composite before and after bonding treatment. Three CAD–CAM composites were evaluated: Lava Ultimate restorative (LU), Brava Blocks (BR), and Vita Enamic (VE). The LU and BR surfaces were sandblasted using aluminum oxide, while the VE surfaces were etched using a 5% hydrofluoric acid gel according to the manufacturers’ recommendations. All surfaces were subjected to the following bonding strategies (n = 15): adhesive with silane and MDP (ScotchBond Universal, 3M Oral Care, St Paul, MI, USA); adhesive with MDP (Ambar Universal, FGM, Joinville, Brazil); adhesive without silane or MDP (Prime&Bond Elect, Dentsply Sirona, Charlotte, NC, USA), pure silane without MDP (Angelus, Londrina, Brazil), and pure silane with MDP (Monobond N, Ivoclar Vivadent, Schaan, Liechtenstei). Afterwards, tygons were filled with RelyX Ultimate (3M Oral Care), AllCem (FGM), or Enforce (Dentsply Sirona), which were light-cured and subjected to the μSBS test. Data were analyzed using two-way ANOVA and Bonferroni’s post hoc test (α = 0.05). Additional blocks (n = 15) were subjected to scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) before and after the surface treatment. The μSBS values on VE surfaces were higher than those observed on LU and BR surfaces (p < 0.001). Silane without MDP (Allcem) promoted the highest μSBS values, while silane with MDP (RelyX Ultimate) provided the highest values among all bonding strategies (p < 0.001). Enforce promoted no significant difference in μSBS values. SEM and EDS analyses detected noticeable changes to the surface morphology and composition after the surface treatment. The effectiveness of the bonding strategy may vary according not only to the CAD–CAM composite but also to resin cement/bonding agent/silane used.

Oral administration of antifungal drugs can lead to subtherapeutic concentrations. The polymeric microparticles of nystatin can be effective against Candida albicans growth. The purpose was to develop and characterize six polymeric microparticles formulations, to increase drug solubility and antifungal effect. Microparticles were obtained using Eudragit L100® (E), Gantrez MS955® (G) or the combination of both polymers. Pure drug or polymers, drug free microparticles, and physical mixtures were also tested. The shape and particle size were analyzed by scanning electron microscopy. Yields were calculated as % of initial mass. The compatibility of nystatin and polymers was evaluated through Fourier transformed infrared spectroscopy, X-ray diffraction, differential scanning calorimetry and thermogravimetry. The antimicrobial effect of microparticles against C. albicans was tested by agar diffusion. Analyzes of physical and chemical characterization data suggest that the drug was incorporated into the polymers, and were effective against fungal growth, in vitro. Considering the low solubility and bioavailability of the drug, this technology has brought promising results of a cheap and accessible drug, like nystatin, for the treatment of recurrent fungal diseases, and have potential applicability in the development of mucoadhesive systems to treat oral candidiasis.