Objective: To analyse microleakage in Class V cavity preparation with Er;Cr:YSGG at different parameters using a self-etching adhesive system. Background: Several studies reported microleakage around composite restorations when cavity preparation is done or treated by Er;Cr:YSGG laser. We want to compare different energy densities in order to obtain the best parameters, when using a self-etching adhesive system. Methods: A class V preparations was performed in 120 samples of human teeth were divided in 3 groups: (1) Preparation using the burr. (2) Er;Cr:YSGG laser preparation with high energy 4W, 30 Hz, 50% Water 50% Air and (3) Er;Cr:YSGG laser preparation lower energy 1.5 W, 30 Hz, 30% Water 30% Air. All the samples were restored with self-etching adhesive system and hybrid composite. Thermocycling (5000 cycles) and immersed in 0.5% fuchsin. The restorations were sectioned and evaluated the microleakage with a stereomicroscope. Results: Lower energy laser used for preparation showed significant differences in enamel and dentin. To group 3, the microleakage in the enamel was less, whilst the group 1, treated with the turbine, showed less microleakage at dentin level. Group 2 showed the highest microleakage at dentin/cement level. Conclusion: Burr preparation gives the lowest microleakage at cement/dentin level, whilst Er;Cr:YSGG laser at lower power has the low energy obtains lowest microleakage at enamel. On the contrary high-energy settings produce inferior results in terms of microleakage.
Objective: The function of granulosa cells is regulated by various hormones and growth factors. Our aim is to clarify the regulation of vascular endothelial growth factor (VEGF) production via mitogen-activated protein kinase (MAPK) induced by low level laser therapy (LLLT) in human granulosa cells. Methods: A human granulosa cell line, KGN cells, were cultured and incubated after LLLT (60mW, GaAlAs 830nm). The levels of VEGF in the culture media were determined by an enzyme-linked immunosorbent assay. The activation of MAP kinase in KGN cells was detected by western blot analysis. Results: VEGF production was significantly increased by LLLT in a time-dependent manner. MAP kinase activity was increased by LLLT. In addition it was enhanced by LLLT and follicle-stimulating hormone (FSH) stimulation. Conclusions: The results suggested that VEGF is induced by LLLT through mechanisms involving MAPK. The increase in VEGF may contribute to neovascularization, which in turn would promote various ovulation phenomena as well as follicular growth.
Background and Aims: The 830 nm GaAlAs diode laser has played an extremely active role in low level laser therapy (LLLT) since the early 1980’s. Recently, the author modified his original proximal priority laser technique (PPLT), and the current article set out to explain the improved approach and show scientific evidence for its efficacy. Laser Therapy System: The laser therapy system used was based on the GaAlAs diode (OhLase-3D1, JMLL, Japan), delivering 60 mW in continuous wave at a wavelength of 830 nm in the near infrared with a power density at the tip of the probe head of approximately 1.2 W/cm2. Proximal Priority Laser Technique: Under the author’s PPLT concept, the brain is the control center for the body so every other part of the body is distal to the head. The main blood supply to the head is through the carotid arteries, and the deep penetration of the 830 nm beam applied to the side of the neck can involve and photoactivate the external and internal carotids, increasing the blood supply to the brain and creating a systemic parasympathetic system-mediated wholebody effect. The author has added gentle neck-stretching, trunk-stretching and his distal tissue softening approaches concomitant with the irradiation which enhance treatment efficacy. Results: Real-time fine-plate thermography has revealed whole-body warming as a result of the PPLT, with applications including chronic pain attenuation, female infertility and functional training of paraplegic cerebral palsy patients. The warming effect had a latency from hours to days, increasing in intensity and latency with subsequent PPLT sessions. Both Doppler flowmetry and SPECT have shown increased cerebral and systemic blood flow following PPLT. Conclusions: PPLT is easy to deliver and offers tangible results in a large range of conditions, enhancing the efficacy of diode laser LLLT.
Background and aims: Laser acupuncture is a therapeutic medical method. Innovative basic research is necessary within this fascinating area of research. This publication focuses on visual evoked potentials (VEP) elucidated by non-invasive and partially non-perceptible laser stimulation. Materials (Subjects) and Methods: The first part of this study presents systematic VEP-monitoring in connection with laser acupuncture and manual needle acupuncture in 40 healthy volunteers. The second part deals with bilateral non-perceptible laser needle (658 nm, 40 mW, 500 μm, 1 Hz) irradiation of the Neiguan acupoint (PC6) in a 26-year-old female healthy volunteer using a new 32-channel evoked potential analysis technique. Results: We were not able to find significant changes in latency or amplitudes of VEPs during laser acupuncture within the first part of the study. However in the second part we report about human cerebral evoked potentials after non-perceptible laser stimulation. Conclusions: The findings indicate that exposure to laser needle stimulation with a frequency of 1 Hz can modulate the ascending reticular activating system. Further studies are necessary to confirm or refute the very interesting findings.
Background and aims: Oral mucositis (OM) is still a common and severe acute side-effect of many oncologic treatments, especially in patients treated for head and neck cancer. It may affect quality of life, require supportive care and impact treatment planning and its efficacy. Low-level laser therapy (LLLT) seems to promote pain relief and reduces OM incidence and its severity. It has been recommended for these patients as a treatment option but without any consensus in the LLLT procedure. New recommendations and perspectives for clinical trials will be discussed. Materials (Subjects) and Methods: Step by step, the efficacy of soft laser in the management of iatrogenic oral mucositis has been evaluated during the last two decades. Its effectiveness and level of recommendation got stronger with time. We will report and discuss some major results and the latest recommendations published on this topic. Results: The major clinical results have been reported and analysed last year in a first meta-analysis 1). 11 randomized placebo-controlled trials were selected with a total of 415 patients treated with chemotherapy and/or radiotherapy for head and neck cancer. The relative risk for developing OM was significantly reduced after LLLT but only for a dose between 1 to 6 Joules per point. Pain, severity and duration of OM grade ≥ 2 were also reduced without difference with placebo for possible side-effects. Nine years after the positive results published for patients treated by radiotherapy alone 2), a new French randomized, multicentric, phase III trial for patients treated with new standard treatment, using LLLT in accordance to recent recommendations is ongoing. Seven centers are specifically established for this trial which should include a hundred patients. Conclusions: The very encouraging results of LLLT in the prevention and treatment of OM in patients treated by chemotherapy or radiotherapy for advanced head and neck cancer could soon be proposed as a new standard of care, according to the multinational Association of Supportive care in Cancer (MASCC) criteria. Modern lasers are less time consuming and extraoral applicators for a possible use by trained paramedical staff could be helpful to complete clinician practice. A preventive dose of 2 J/cm2 and a curative dose of 4 J/cm2 if using a red wavelength lasers are now recommended.