Clinical laser treatment of toenail onychomycoses.

Onychomycoses are fungal infections of the fingernails or toenails having a prevalence of 3% among adults and accounts for 50% of nail infections. It is caused by dermatophytes, non-dermatophyte filamentous fungi, and yeasts. Compressions and microtraumas significantly contribute to onychomycosis. Laser and photodynamic therapies are being proposed to treat onychomycosis. Laser light (1064 nm) was used to treat onychomycosis in 156 affected toenails. Patients were clinically followed up for 9 months after treatment. Microbiological detection of fungal presence in lesions was accomplished. A total of 116 samples allowed the isolation of at least a fungus. Most of nails were affected in more than two thirds surface (some of them in the full surface). In 85% of cases, after 18 months of the onset of treatment, culture turned negative. After 3 months months, only five patients were completely symptom-free with negative culture. In 25 patients, only after 6 months, the absence of symptoms was achieved and the cultures negativized; in 29 patients, 9 months were required. No noticeable adverse effects were reported. This study reinforces previous works suggesting the applicability of laser therapies to treat toenail onychomycosis.

Determination of the spatiotemporal dependence of Pseudomonas aeruginosa biofilm viability after treatment with NLC-colistin.

The emergence of colistin-resistant Pseudomonas aeruginosa in cystic fibrosis (CF) patients, particularly after long-term inhalation treatments, has been recently reported. Nanoen-capsulation may enable preparations to overcome the limitations of conventional pharmaceutical forms. We have determined the time-dependent viability of P. aeruginosa biofilms treated with both free and nanoencapsulated colistin. We also examined the relationship between the optimal anti-biofilm activity of nanostructured lipid carrier (NLC)-colistin and the structural organization of the biofilm itself. The results showed the more rapid killing of P. aeruginosa bacterial biofilms by NLC-colistin than by free colistin. However, the two formulations did not differ in terms of the final percentages of living and dead cells, which were higher in the inner than in the outer layers of the treated biofilms. The effective anti-biofilm activity of NLC-colistin and its faster killing effect recommend further studies of its use over free colistin in the treatment of P. aeruginosa infections in CF patients.

Atomic force microscopy visualization of injuries in Enterococcus faecalis surface caused by Er, Cr: YSGG and diode lasers

AIM: To visualize by Atomic Force Microscopy the alterations induced on Enterococcus. faecalis surface after treatment with 2 types of laser: Erbium chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser and Diode laser. MATERIAL AND METHODS: Bacterial suspensions from overnight cultures of E. faecalis were irradiated during 30 seconds with the laser-lights at 1 W and 2 W of power, leaving one untreated sample as control. Surface alterations on treated E. faecalis were visualized by Atomic Force Microscopy (AFM) and its surface roughness determined. RESULTS: AFM imaging showed that at high potency of laser both cell morphology and surface roughness resulted altered, and that several cell lysis signs were easily visualized. Surface roughness clearly increase after the treatment with Er,Cr:YSGG at 2W of power, while the other treatments gave similar values of surface roughness. The effect of lasers on bacterial surfaces visualized by AFM revealed drastic alterations. CONCLUSIONS: AFM is a good tool to evaluate surface injuries after laser treatment; and could constitute a measure of antimicrobial effect that can complete data obtained by determination of microbial viability

Bactericidal activity of erbium, chromium:yttrium-scandium-gallium-garnet laser in root canals.

The aim of this study was to investigate the effectiveness of the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser by measuring its bactericidal effect inside root canals experimentally colonized with Enterococcus faecalis. We also determined the optimal conditions for the Er,Cr:YSGG laser to achieve the maximal bactericidal effect. An Er,Cr:YSGG Waterlase laser was used, and its antimicrobial effect was compared with that of sodium hypochlorite (NaOCl) at various concentrations as widely used in clinics. This laser emits photons at a wavelength of 2.78 microm. It is a pulsed laser operating at 20 Hz (20 pulses/s). Significant differences between measurements in the different groups (P < 0.05) were observed, depending on time and power used. The use of NaOCl 5% was the most effective procedure, with NaOCl 0.5% being the least effective; however, laser treatment was as effective as NaOCl 5% when applied at 2 W for 60 s.