Influence of thickness and degree of opacity of lithium disilicate on the degree of conversion and bond strength of resin cements.

The aim of this study was to evaluate the influence of various opacities and thicknesses of lithium disilicate on the degree of conversion (DC) of two resin cements and on their bond strength (BS) to the ceramic. Two hundred and forty ceramic samples of lithium disilicate with high translucency (HT), low translucency (LT), and medium opacity (MO) were obtained from IPS e. max CAD in five different thicknesses. Light-cured and dual-cured resin cements were used for DC (n = 9) and BS (n = 8). Cement samples were light-cured under ceramic samples and analyzed using a Raman confocal spectrometer to determine the DC. For BS, resin cement cylinders were fabricated using ceramic samples which were thsen subjected to a microshear bond strength test. The mean values were provided for statistical analysis. The increase in thickness resulted in a decrease in DC for both cements under all experimental conditions, but only affected the BS of the light-cured cement for the MO ceramic. Comparing the opacities, the most translucent ceramics with particular thicknesses exhibited higher DC values than the less translucent ceramics. The LT and MO ceramics with certain thicknesses exhibited the highest BS values than the HT. The dual-cured cement generally showed highest values in both analyses than the light-cured cement. A thicker and more opaque ceramic material can reduce the DC of the cement. The BS decreases with the increasing thickness of the more-opaque ceramics.

Nanoencapsulated hypericin in P-123 associated with photodynamic therapy for the treatment of dermatophytosis.

The antifungal application of photodynamic therapy (PDT) has been widely explored. According to superficial nature of tinea capitis and the facility of application of light sources, the use of nanoencapsulated hypericin in P-123 associated with PDT (P123-Hy-PDT) has been a poweful tool to treat this pathology. Thus, the aim of this study was to evaluate the efficiency of P123-Hy-PDT against planktonic cells and in a murine model of dermatophytosis caused by Microsporum canis. In vitro antifungal susceptibility and in vivo efficiency tests were performed, including a skin toxicity assay, analysis of clinical signs by evaluating score, and photoacoustic spectroscopy. In addition, tissue analyses by histopathology and levels of pro-inflammatory cytokines, such as quantitative and qualitative antifungal assays, were employed. The in vitro assays demonstrated antifungal susceptibility with 6.25 and 12.5 µmol/L P123-Hy-PDI; these experiments are the first that have used this treatment of animals. P123-Hyp-mediated PDT showed neither skin nor biochemical alteration in vivo; it was safe for dermatophytosis treatment. Additionally, the treatment revealed rapid improvement in clinical signs at the site of infection after only three treatment sessions, with a clinical score confirmed by photoacoustic spectroscopy. The mycological reduction occurred after six treatment sessions, with a statistically significant decrease compared with untreated infected animals. These findings showed that P123-Hy-PDT restored tissue damage caused by infection, a phenomenon confirmed by histopathological analysis and proinflammatory cytokine levels. Our results reveal for the first time that P123-Hy-PDT is a promising treatment for tinea capitis and tinea corporis caused by M. canis, because it showed rapid clinical improvement and mycological reduction without causing toxicity.