Bactericidal effect of a Nd:YAG laser on <Emphasis Type="Italic">Enterococcus faecalis</Emphasis> at pulse durations of 15 and 25 ms in dentine depths of 500 and 1,000 μm

The success of endodontic treatment depends on the effective elimination of microorganisms from the root canal, and lasers provide more effective disinfection than conventional treatment using rinsing solutions. The objective of this in vitro study was to determine the bactericidal effect of laser irradiation in dentine of various depths at a wavelength of 1,064 nm and pulse durations of 15 and 25 ms. A total of 90 dentine slices were cut from bovine incisors and divided into two groups (45 slices each) of thickness 500 and 1,000 μm. All were inoculated with a suspension of Enterococcus faecalis (5.07×10⁹ bacteria/ml). Based on the clinically accepted dose (approximately 300 J/cm²), the following laser settings were chosen for this study: 1.75 W, 0.7 Hz for 4 s, three repetitions. The two groups were divided into two subgroups of 15 slices each to be irradiated with pulse durations of 15 and 25 ms. The remaining 15 slices per group were not irradiated to serve as a control. After irradiation, the colony-forming units (CFU) were counted and evaluated. To determine the bactericidal effect of irradiation with different pulse durations, the results in the different groups were compared statistically. For all irradiated subgroups a bactericidal effect was observed at pulse durations of 15 and 25 ms (p=0.0085 and p<0.0001). The corresponding average log kills were 0.29 (15 ms) and 0.52 (25 ms) for 500 μm and 0.15 and 0.3 for 1,000 μm, respectively. The results of this in vitro study showed that Nd:YAG laser irradiation with a pulse duration of 15 ms eliminated an average of 49% and 29% of E. faecalis at dentine depths of 500 μm and 1,000 μm, respectively, and irradiation with a pulse duration of 25 ms eliminated 70% (500 μm) and 50% (1,000 μm). However, these values are lower than those achieved with the established protocol using microsecond pulses.     

Influence of CO2 (10.6 μm) and Nd:YAG laser irradiation on the prevention of enamel caries around orthodontic brackets

Lasers in Medical Science - One possible undesirable consequence of orthodontic therapy is the development of incipient caries lesions of enamel around brackets. The aim of this study was to...     

Efficacy and safety of prostate vaporesection using a 120-W 2-μm continuous-wave Tm:YAG laser (RevoLix 2) in patients on continuous oral anticoagulant or antiplatelet therapy

The aim of our current study was to demonstrate the efficacy and safety of vaporesection using a 120-W Tm:YAG laser (Revolix Duo) in patients with BPH receiving systemic anticoagulation or antiplatelet therapy. Between April 2010 and November 2011, a total of 76 patients using oral antiplatelet or anticoagulant (OA) agents affected by LUTS for BPH were underwent thulium vaporesection of the prostate (ThuVARP) using a 120-W 2-μm CW Tm:YAG laser and evaluated at 3- and 6-month follow-up. Of these, in 41 patients (group A) was performed vaporesection while receiving OA therapy. In 35 patients (group B), OA agents were discontinued 10 days before surgery. There were no significant differences in average vaporesection times, catheterization time, or hospital stay. There was no significant change in serum sodium level before and immediately after vaporesection in either group. Significant improvements compared to baseline were observed at each postoperative assessment in both groups for Qmax, PVR, IPSS, and QoL. More specifically, the IPSS score improved from 21.7 at baseline to 5.2 at 6 months in group A and from 20.7 to 4.5 in group B. At 6 months, Qmax increased 226 and 190 % for the 2 groups, respectively. The PVR decreased from 119 at baseline to 11 mL at 6 months in group A and from 125 to 11 mL in group B. ThuVARP is a safe and efficient procedure for patients with BPH, refractory to pharmacotherapy, who require active antiplatelet or anticoagulant therapy.