The pulsed dye laser is the preferred laser for treating port wine stains. It is relatively effective with a low incidence of side effects. However, although considerable lightening of a port wine stain is likely to occur with treatment, complete clearance is achieved in the minority. There has been a number of therapeutic advances over the last few years in the laser treatment of port wine stains. These have come from modification of the original pulsed dye laser, use of other lasers and light sources and a greater understanding of laser - port wine interactions. All of these developments will be discussed in this review.

The aim of this study was to assess the feasibility of autoflorescence spectroscopy in the diagnosis of cervix maturity through cervical mucus florescence and foetal lung maturity through amniotic fluid fluorescence. LED and broadband Mercury light were used to induce fluorescence in cervical mucus and amniotic fluid respectively. Mature specimens compared to immature ones showed a significant decrease in cervical mucus fluorescence values measured at 420 nm (p = 0.0004) and in measured amniotic fluid fluorescence values at 410 nm (p = 0.0686). Probability-based classification algorithm was developed to identify samples 'maturity' through analysis of the fluorescence spectra. Employing fluorescence intensity at 420 nm for cervix maturity diagnosis rendered optimal sensitivity of 92.9%, specificity of 83.3% and area under the ROC curve of 91.1%.

Ninety three patients with obstructing tracheobronchial tumors were treated with Neodymium: Yttrium - Aluminum - Garnet (Nd:YAG) laser photocoagulation over a period of six years. There were sixty seven Males and 26 Females with a mean age of 44.3 years (range 6- 79 years). 21 benign and 72 malignant lesions were treated with a total 212 sessions of laser photocoagulation (mean 2.4 sessions). The anatomical distribution of lesions were as follows; larynx 9 (three benign and 6 malignant) trachea 39 (27 benign and 12 malignant) left main bronchus 27 (14 malignant) right main bronchus 24 (14 malignant) and vocal cords - 9 (three malignant). There were 21 patients with squamous cell carcinoma, two adenocarcinomas, one adenoid cystic carcinoma, 7 cases of locally infiltrating tumors from thyroid and esophagus, 6 cases of carcinoid tumor and 16 benign lesions. Twenty one patients had a tracheostomy tube in place when treatment was started. Eighteen of the 21 patients with tracheostomy were weaned off the tube in a mean of 5.5 days from the start of treatment. Lumen was restored in 31 (79.4%) patients. In the other eight (20.6%), lumen was achieved, but not sustained. Complications included bleeding in three cases which were managed conservatively, two cases of pneumothorax, and four cases of bronchospasm. There were six deaths during the follow up but none attributable to the procedure. Laser photocoagulation offered effective treatment in the majority of patients with obstructing tracheobronchial tumors, with acceptable morbidity.

Aim of the work was an investigation of ureter wall perforation possibility by various types of mid-infrared radiations (from 2.01 μm (Tm:YAG) up to 2.94 μm (Er:YAG)) and exploration of the interaction basic characteristic for ureter surface (epithelium) and its deep structures (mesenchym). From results follow that CTH:YAG, Er:YAG, and CTE:YAG laser radiations accomplish a good wall ureter perforation. A distinguished difference appeared in modifications of the ureter tissue - epithelium and mesenchym.

The KTP/532 laser dwells in the visible segment of the electromagnetic spectrum and does not need an aiming beam. This wavelength is preferentially absorbed by haemoglobin and therefore, the laser energy results in better coagulation. The laser beam is delivered through a quartz fibre in a hand held delivery with an adjoining suction channel for evacuation of smoke. The laser beam exists as a divergent beam with maximum energy at its exit and minimal as the beam diverges away from the tissue. Taking advantage of this characteristics, the surgeon changes the distance between the tissue and the fibre achieving cutting, vaporization and coagulation effect on the tissue. The tissue penetration of this wavelength is slightly more than CO2 and considerably less than Nd.Yag laser. This wavelength of KTP is widely used in rhinology to deal with various pathologies. It has a specific application in the field of Endoscopic Sinus Surgery especially revision cases.

The direct and secondary changes following diode laser irradiation of intervertebral discs were studied in rabbits. A quartz fiber was inserted into the discs, and laser irradiation was applied. Subsequently, the lumbar vertebrae were extracted en bloc, and subjected to sagittal magnetic resonance (MR) imaging and histologic examination immediately after irradiation, and 3, 12, and 24 weeks after irradiation. MR images showed low signal intensity of the intervertebral discs on T2-weighted images 3 weeks after irradiation, which remained unchanged to 24 weeks. Although the signal intensity of the adjacent vertebral bodies remained unchanged on T1-weighted images, the intensity was high on T2-weighted images 3 weeks after irradiation, but had reverted to normal or was low 12 to 24 weeks after irradiation. On histologic examination, the inner layer of the annulus fibrosus was seen to protrude into the void created by vaporization of the nucleus pulposus 3 weeks after irradiation. Multinuclear chondrocytes were observed, as if the disc was being reconstructed. Fibrous tissue in the epiphysis and metaphysis was observed soon after irradiation but decreased over time and was replaced by normal bone marrow.

Changes in discs after Er-Yag laser irradiation are scarcely reported. We made an experimental study using white rabbits and Er-Yag laser. Under general anesthesia, Er-Yag laser was irradiated into lumbar discs. Three or 8 weeks after irradiation, rabbits were sacrificed, and these discs were extracted. The quantitative analysis of the glycosaminoglycan content in the annulus fibrosus, and the incorporation of 35S-sulfate in chondroitin 4 sulfate were measured. The results showed, the increased incorporation of 35S-sulfate in chondroitin 4 sulfate and chondroitin 6 sulfates in groups of laser irradiation may indicate Er-Yag laser irradiation in nucleus pulposus, accelerated glycosaminoglycan production, in the annulus fibrosus. But no difference of unsaturated isomers of chondroitin 4 sulfate, and chondroitin 6 sulfate, and no difference of saturated isomer of keratan sulfate indicate, the influence of Er-Yag laser irradiation was not so high, as to bring the quantitative changes of matrix of annulus fibrosus in term of 8 weeks.

Multislice fluoro-CT allows 3 dimensional millimetric precision in needle guidance and placement. The main benefit of this technique is a volumetric approach with precise management of the patient's Z-axis. This allows performing fast procedures, low x-ray exposure of the patient, central needle positioning inside the disc, absence of radicular lesion, absence of technical failure of the procedure. It can be considered therefore as the safest technique to perform fast and efficient Percutaneous Laser Disc Decompression (PLDD).

Percutaneous Laser Disc Decompression (PLDD) is a minimal invasive and effective treatment for contained lumbar disc hernias with correspondent radicular pain. This prospective study evaluates clinical efficacy of patients treated with PLDD under CT-fluoroscopic guidance. An independent observer assessed clinical outcome in a series of 40 consecutive patients at a mean follow-up of 7.5 months after treatment. According to Mac Nab criteria, 80% of patients experienced a good response to PLDD, 12.5% a fair response and 7.5% a poor response. 37 patients (92.5%) were back at work after 3 weeks. This technique could represent an alternative and secure treatment to conventional surgery for contained disc hernias.

The aim of Percutaneous Laser Disc Decompression (PLDD) is to vaporize a small portion of the nucleus pulposus. Clinical efficacy of this technique is largely proven. However, time-evolution of intervertebral disc and its hernia after PLDD is not known. This study analyses changes in disc herniation and its native intervertebral disc at a mean follow-up of 7.5 months after PLDD in asymptomatic patients. Main observations at MRI are appearance of a high signal on T2WI in the hernia in 59%, shrinking of the hernia in 66% and overall stability of disc height.

No Abstract Available.

Pharmacological Laboratory of Vilnius University Medical Faculty explored pharmacological activity of two classes of chemical compounds on the rats and showed that these compounds are more effective than drugs from other classes with similar pharmacological activity. The purpose of our experiment was to know teratogenic effects of compounds with interesting pharmacological activity from both of these classes. Teratogenic effect was explored by traditional and new our methods. The results both of these methods were the same and showed that in the one hand our explored compounds have no teratogenic effect in the first generation of rats, in the other hand there were no difference in results using traditional or our method.

A comparison of laser tissue cutting on bovine muscle samples, by a CO₂-CW laser and by a short-pulse (1 ps) amplified Ti-ZAFFIRE laser, has been performed. The CO₂ laser application shows a large area of burned tissue, whose extension can be as large as 300-400 μm. The Ti-ZAFFIRE laser application shows a sharp cutting line, without burned tissue around. Numerical simulations of the temperature increasing using repetitive (1 kHz) short pulses reveal that after 1/10 sec of application of 0.5 W of average power, the local temperature has reached the evaporation value of about 300-350°C.

In this study the main interest was focused on the to investigation the photodynamic efficacy of hypericin, three other photosensitizers and 5 aminolevulinic acid-induced protopofirin IX in their ability to block the growth of rather aggressive tumor - Ehrlich ascite carcinoma in mice as well as Reh cells in humans (B-leukemia). Hypericin was found to exhibit the highest phototoxicity and antitumor activity in treating Ehrlich ascite carcinoma. The different photosensitizers were ranked as follows: Hypericin > hematoporphyrin dimethyl ether > Photofrin II > meso-tetra (para-sulfophenyl)porphin > 5-aminolevulinic acid. The most important is that just after Hyp-based photodynamic therapy 75% of mice survived a 4 month-period, and no recurrence of tumor within this period was detected in 25% of the treated mice. The clear cut correlation observed between intracellular dye concentration in the tumor cells and efficiency of photodynamic therapy, supports the idea that the intracellular accumulation of the photosensitizer is one of the most important factors in determining the benefit of photodynamic therapy. Hence, the accumulation of the photosensitizer in the tumor cells should be considered as one of the prognostic factors for the determination of the therapeutic outcome. Eventually, one of the most significant result is that hypericin is effective photosensitizer for human B-leukemia cells and induces apoptosis after photosensitization.

We have analysed an endometrial tissue fluorescence excitation spectra with a purpose to determine the characteristic wavelength of excitation for multiwavelength diagnostics of tissue. Fluorescence excitation-emission matrices from 200 to 500 nm excitation and 200 to 800 nm emission were measured as a supplementary data for previous measurements to unambiguously characterize biochemicals quantitatively in endometrial tissue.

Hydroxypyrimidine 5-fluorouracil (5-FU) belongs to the cytostatics group known as antimetabolites. The effect of UV irradiation on 5-FU was investigated by absorption and fluorescence spectroscopy. The study of the photosensitizer properties of 5-FU was made since their effects could be enhanced by exposure to UV radiation at different doses. Solutions 2.5x10^-4M in natural saline water (0.8% NaCl), irradiated with optical beams emitted by N₂ laser and UV Hg classic lamp, were used. The 5-FU was chosen due to its strong absorption along a large spectral range which makes possible the fluorescence excitation in UV. The absorption spectra exhibit bands between 250 - 450 nm. The emission fluorescence was measured in the 400-550 nm spectral range, with λ_ex=320 and 350 nm for samples irradiated with Hg lamp and with λ_ex=360 nm for samples irradiated with N₂ laser. The excitation fluorescence was measured in the spectral range 200-400 nm, with λ_em=440 nm for samples irradiated with N₂ laser. The spectra reveal a fluorescence enhancement with the exposure time, with a maximum at 3 min due to the transformation of 5-FU molecule into a fluorescent tautomeric form. The destruction more rapid than usual of the neovascularisation was observed for conjunctive of rabbit eyes, when they are impregnated with 5-FU solution and exposed to incoherent UV and visible light.

Further research in laser therapy has resulted in the introduction of sources such as LEDs, and filtered and unfiltered broadband thermal sources. While well-controlled studies and comparisons of these devices have not yet been done, such studies should include the same well-documented description of the sources and other parameters of the studies.

The paper presents the three most important subjects in medical applications of lasers; the laser-tissue interaction mechanism, the laser parameters, and the beam delivery system. For the first one, the thermal and non-thermal interactions and their role will be presented. The laser parameters, such as; wavelength, mode of operation (CW or pulsed), pulse duration and other relevant techniques will be highlighted and their matching to the specific application will be discussed. Finally, the transport of the laser beam to the targeted tissue through articulated arms and fiber optic cables will be compared and discussed. The optical processing of the beam, at the hand piece end, to focusing, collimating, defocusing and scanning will also be presented.

A reduced mortality due to hyperglycaemia was noted since the development of insulin treatment for type I diabetes and various oral hypoglycaemic agents for type II diabetes. Nevertheless the chronic metabolic disorder, Diabetes Mellitus, remains an important cause of morbidity and mortality due to a series of common secondary metabolic complications. Patients with diabetes have an increased tendency to develop infections of the skin. Healing of skin lesions in diabetics evolves often relatively slow and the lesions tend to be more severe than in non-diabetics. Endeavouring to accelerate the healing process of skin lesions in diabetic patients, this preliminary in vitro study investigates the efficacy of green Light Emitting Diode (LED) irradiation on fibroblast proliferation of cells in hyperglycaemic circumstances. In an attempt to imitate the diabetic environment, embryonic chicken fibroblasts were cultured in hyperglycaemic medium (30.000mg Glucose per litre Hanks Medium). LED irradiation was performed three consecutive days with a wavelength of 540 nm and a power output of 10 mW, at 0,6 cm distance from the fibroblasts. Each treatment lasted 3 minutes, resulting in a surface energy density of 0,2 J/cm². Statistical analysis revealed that LED irradiation at the applied parameters induced a higher rate of proliferation in hyperglycaemic circumstances after irradiation than in the same circumstances without irradiation. Regarding these results the effectiveness of green LED irradiation on cells in hyperglycaemic circumstances is proven. To ensure the effectiveness and to evaluate the value of LED irradiation in vivo, further research is required.

We report about the treatment of thermic lesions on children’s hands and face caused by household injuries with Low Level Laser therapy (wave length 810/670 nm, energy density 2 J/cm²). All of our patients (n = 16, median age 2 years) could be treated successfully, the treatment being easy applicable and non-invasive.

This work aims to verify the effect of laser of low potency to label red blood cells and plasmatic protein with ^99mTc in vitro. The experiments were carried out by incubating of anticoagulant whole blood. Differents doses of gallium arsenide laser with energy density of 3j/cm², 6j/cm², 9 j/cm², 18 j/cm² and 804nm wavelength was applied. A stannous chloride solution of 1,2μg/mL was added the incubation for 60 minutes. After this the ^99mTc was added and the incubation was continued for another 10 minutes. Those were centrifuged, precipitated with thrichoroacetic acid 5% and mensured in a counter. The results shows that there is a significant decrease in the fixation of ^99mTc in red blood cells when the concentration of 3j/ cm² and (from 93 to 32.2%) and in occurs an increase %ATI from 12 to 54,6% of plasma protein. The laser promote modification on some properties of the red blood cellular membrane, probably, due to the metabolization of cellular that could be capable to generation the active metabolites.

With the rapid development of tissue engineering and gene therapy, collagen-based biomaterials are frequently used as cell transplant devices; an example is tissue-engineered skin substitutes. In this study of low level laser therapy (LLLT) we determined the influence of the irradiation and treatment parameters on the proliferation rate of 3T3 mouse fibroblast cells cultured on collagen-glycosaminoglycan (GAG) lattices and Petri dishes for up to 4 and 7 days respectively. Helium-Neon (He-Ne) laser at 1 - 4 J/cm² was used to irradiate the cells. Using 5-carboxyfluorescein diacetate (CFDA) fluorescence, studies on the proliferation rate of irradiated cells before and after cell attachment, and on different treatment days were conducted. The viability of cells on collagen-GAG lattices were assessed using the MTT assay. It was found that in terms of cell proliferation, the cells irradiated at different fluences and treatment modes (at 3 J/cm²) showed no statistically significant difference from the control cells. Control cells on collagen-GAG lattices were found to be more viable than the irradiated cells. It was concluded that with existing experimental conditions, LLLT was found to have no statistically significant effect on the post-cell attachment proliferation and viability of 3T3 mouse fibroblast cells.

PLDD is neither conservative method or surgical one, but the results of PLDD are so excellent and the time of treatment is short. In 1999 we made a new fiber for PLDD, named Active Fiber. And we have experienced over 1600 cases with active fiber. The system controls the front irradiation of laser beam, and performs enhanced irradiation. Active fiber makes PLDD more safety than old fiber, easy to vaporize with minimum laser irradiation for hernia. The author will mention construction and principle of the active fiber, in addition, discuss the results of animal models and actual clinical cases.

The treatment of herniated disc disease (HNP) over the years involved different miniinvasive surgical options. The classical microsurgical approach has been substituted over the years both by endoscopic approach in which is possible to practice via endoscopy a laser thermo-discoplasty, both by percutaneous laser disc nucleoplasty. In the last ten years, the percutaneous laser disc nucleoplasty have been done worldwide in more than 40000 cases of HNP. Because water is the major component of the intervertebral disc, and in HNP pain is caused by the disc protrusion pressing against the nerve root, a 980 nm Diode laser introduced via a 22G needle under X-ray guidance and local anesthesia, vaporizes a small amount of nucleous polposus with a disc shrinkage and a relief of pressure on nerve root. Most patients get off the table pain free and are back to work in 5 to 7 days. Material and method: to date, 130 patients (155 cases) suffering for relevant symptoms therapy-resistant 6 months on average before consulting our department, have been treated. Eightyfour (72%) males and 46 (28%) females had a percutaneous laser disc nucleoplasty. The average age of patients operated was 48 years (22 - 69). The level of disc removal was L3/L4 in 12 cases, L4/L5 in 87 cases and L5/S1 in 56 cases. Two different levels were treated at the same time in 25 patients. Results: the success rate at a minimum follow-up of 6 months was 88% with a complication rate of 0.5%.

Despite the widespread use of lasers for hair removal there is little data published on the incidence of side effects from this treatment. We aimed to generate data on a large number of patients receiving laser hair removal to obtain an accurate assessment of the incidence and type of side effects resulting from treatment. A multicentre prospective study of patients attending for laser hair removal was conducted to determine incidence of side effects in relation to skin type and laser(s) used. Laser hair removal is associated with a low incidence of side effects which are self-limiting in the majority of cases. Highest incidence of side effects was seen in darker skinned patients treated with the long pulsed ruby laser. Laser hair removal is inherently safe. For darker Fitzpatrick skin types the long pulsed Nd:YAG laser is preferred to the ruby laser.

A medical practice by laser or IPL device means professional experience, reputation, strong economical investment, while a patient needs results for the bill he pays. In front of a publicity of non-invasive solutions for a broad base of clinical applications, the everyday practice offers embarrassing side effects about which it is better to prepare the users. Inefficiency, hypo-hyper-pigmentations, scars show that we need to have clear instructions and experienced studies, before emphasizing good results.

In recent years there has been intensive research in the field of non-ablative skin rejuvenation. This comes as a response to the desire for a simple method of treating rhytids caused by aging, UV exposure and acne scars. In numerous studies intense visible light pulsed systems (20-30J/cm²) are used. The mechanism of action was supposed to be a selective heat induced denaturalization of dermal collagen that leads to subsequent reactive synthesis. In this study we suggest a different mechanism for photorejuvenation based on light induced Reactive Oxygen Species (ROS) formation. We irradiated collagen in-vitro with a broad band of visible light, 400-800 nm, 12-22J/cm², and used the spin trapping coupled with electron paramagnetic resonance (EPR) spectroscopy to detect ROS. In vivo, we used dose 30 J in average (35 for acnis scars, 25 for wrinkles and redness). Irradiated collagen results in hydroxyl and methyl radicals formation. We propose, as a new concept, that visible light at the intensity used for skin rejuvenation, 20-30J/cm², produces high amounts of ROS which destroy old collagen fibers encouraging the formation of new ones. On the other hand at inner depths of the skin, where the light intensity is much weaker, low amounts of ROS are formed which are well known to stimulate fibroblast proliferation.

Blood Saving Campaign is a campaign to lessen the risk of intra- and post-operative blood transfusion by decreasing the amount of blood loss during surgery and at the same time will lessen the risk of transmission of blood born diseases. The blood saved can be used to treat those afflicted with diseases such as hemophilia and aplastic anemia where blood transfusion is imperative for the survival of the patient. At the 7th forum of WFSLMS held in Germany 2003, the steering committee has evolved to an organizing committee of WFSLMS. The aim of WFSLMS is to contribute to the health and welfare of mankind through the merit of minimum tissue damage and high efficacy of hemostasis in laser medicine. Therefore we also organized a Laser Blood Saving Campaign (Laser B-SAC) committee within WFSLMS at the same congress. The methods of laser blood saving are divided into 4 categories. 1. Surgical Laser Treatment (HLLT). 2. Non-surgical Laser Therapy (LLLT). 3. Laser Treatment with Newly Developed Laser Machines. 4. Laser Treatment with Newly Developed Techniques. I will mention on the History of B-SAC, Action Plan of B-SAC and so on.

Our purpose is to discuss treatment possibilities for macular degeneration and to show, which combination of diagnostic devices might lead to the best therapy.

Purpose of this course is to review the principles that guide the diagnosis and the classification of macular diseases, and the new options available for this purpose. Among new treatments modalities, photodynamic therapy (PDT) has been recently introduced in the clinical practice for treating subfoveal choroidal neovascularization (CNV). In age-related macular degeneration (AMD), eyes in which the classic CNV components covers at least 50% of the entire lesion, called predominantly classic lesions, benefit from a substantial reduction of the rate of moderate visual loss during the first year. Preliminary results in other types of CNV also indicate a possible efficacy. We will present the theoretical basis and mechanisms of action of PDT and then comment on the main results of the TAP study; the preliminary results available from the VIP will also be displayed. Numerous cases treated with PDT, one year after its introduction in the clinical practice, will be shown and discussed. The introduction of PDT has probably reduced the applicability of surgical techniques for treating CNV. Yet, surgeons are developing less invasive techniques to minimize the complications associated with membrane removal and the various types of translocation. This innovation will be illustrated, as well as the criteria for patients selection in the era of PDT.

The model of corneal biotissue layers and their values of optical parameters are presented. The model of the processes involved in laser thermal keratoplasty of eye biotissues is proposed, and the results of computer modeling are presented. Characteristics of optical and thermal processes and the influence of parameters of radiation and biotissues on the results of laser action are studied. The results of numerical simulations demonstrate the possibility of heating of the region in corneal stroma by a converging beam of laser radiation with a sufficient parameters.

Since the introduction of lasers to dentistry, dentists have been intrigued with the idea of placing laser energy into an infected root canal with the goal of removing the bacteria and infected tissue, and sterilizing the root canal system. This paper will discuss the bacterial origin of endodontic infections, and describe the use of the Er.YAG laser to remove bacteria, prepare the canal walls, and aid in the creation of a superior seal of the root canal system.

μThe study describes the preclinical experience with laser-activated bleaching agent for discolored teeth. Extracted human upper central incisors were selected, and in the bleaching experiment 35% hydrogen peroxide was used. Three various laser systems and halogen-light unit for activation of the bleaching agent were applied. They were Alexandrite laser (wavelength 750 nm and 375 nm - SHG), Nd:YAG laser (wavelength 1.064 m), and Er:YAG laser (wavelength 2.94 μm). The halogen-light unit was used in a standard regime. The enamel surface was analyzed in the scanning electron microscope. The method of chemical oxidation results in a 2-3 shade change in one treatment. The halogen-light units produced the same effect with shorter time of bleaching process (from 630 s to 300 s). The Alexandrite laser (750 nm) and bleaching agent helped to reach the desired color shade after a shorter time (400 s). Alexandrite laser (375 nm) and Nd:YAG laser had no effect on the longevity of the process of bleaching. Overheating of the chemical bleaching agent was visible after Er:YAG laser activation (195 s). Slight surface modification after bleaching process was detected in SEM.

Photodynamic therapy (PDT) is one of a novel modalities which has recently been exploited to eradicate various microorganisms. In our study we have evaluated bactericidal efficacy of PDT in the presence of 5-δ aminolaevulinic acid (ALA). Porphyromonas gingivalis were incubated with increasing concentration of ALA and subsequently irradiated by progressive light doses. Complete killing effect was obtained for bacteria irradiated with 25J/cm² in ALA solution final concentration of 1mM, 5mM, 10mM. Statistical analysis has revealed ALA concentration to be a major factor responsible for eradication of bacteria. The latter may be attributable to the known ALA dark toxicity.

Dental practice consists of a series of laboring procedures which demands the use of several types of equipment and materials. Usually patient’s fears brings additional burden to the Dentists. The use of Lasers for treating and diagnosis in Dentistry is quite new comparing to other medical areas. Initially Laser technology was used as an alternative method for treating dental caries in order to substitute the use of the drill. Lately surgical Lasers have shown themselves very useful for treating several pathologies and began to be used as a powerful tool on the treatment of several conditions affecting the maxillofacial complex and later on, the era of the use of Laser therapy began. The advent of the diode Lasers made possible the introduction of small units at the dental office and Laser therapy was used to improve healing and later included also caries diagnosis. This paper discuss the use of Laser therapy on Restorative Dentistry, Periodondology, Oral and Maxillofacial Surgery, Oral implantology and other. Clinical and laboratorial experience has demonstrated that Laser therapy does improve the healing of both mineralized and soft tissues, reduces pain and inflammation, and also reduces both cost and length of the dental treatment.

The use of the Carbon dioxide Laser to perform surgical procedures in the oral cavity has been described as a successful method for the treatment of several conditions affecting the maxillofacial region. Several benefits of the use of the CO₂ Laser have been reported and includes reduction of postoperative pain and edema, local hemosthasis, reduction of scaring and wound contraction and infection. The aim of this work is to present our clinical experience in performing several surgical procedures using the CO₂ Laser to treat soft tissue pathologies of both benign and malign origin as well as on performing pre-prosthetic surgery, apical surgery and on the treatment of pre-malignancies. Our experience demonstrate that the use of the Carbon dioxide Laser in treating oral soft-tissue pathology presents advantages over conventional techniques and local discomfort and pain are the most common complaints after Laser surgery. The Carbon dioxide Laser does not offer any enhanced cure-rate for oral pathology, but rather it is a precise means of removing soft tissue lesions with little upset afterwards.

Dissemination of blood into the dentinal tubules caused by pulp extirpation or traumatically induced internal pulp bleeding is a possible cause of discoloration of non-vital teeth. Discolored teeth, especially in the anterior region, can result in considerable cosmetic impairment. The whitening of these teeth is an alternative therapeutic method that is relatively non-invasive and conserves dental hard tissue. Recently, intracoronal bleaching of pulpless discolored teeth can be performed with the association of laser irradiation to hydrogen and carbamide peroxide and can even be accomplished in one session. This report shows a clinical case of an endodontically treated tooth submitted to bleaching using LED light and infrared LLLT therapy.

Teeth-bleaching is an initial phase in the reproduction of an aesthetic smile; thus, it is very important that the dentist knows how to diagnose the causes of color changes and indicate whitening before proposing dental treatment. Technological advances in teeth-whitening lead to the development of new techniques, improving comfort, security and decreasing time of execution: argon laser, diode Laser, LED whitening, xenon light whitening. The clearing agent used in all techniques, including home whitening, is hydrogen peroxide (H₂O₂) in different concentrations. In this study, the authors describe mechanisms of gel activation, the use of Laser and LED’s for teeth-bleaching, the importance of diagnosis and the comfort of the patient in in-office teeth-bleaching techniques.

Raman Spectroscopy was used to examine the distribution of the mineral and organic components in the human dentin before and after the chemical and thermal etching process. Polished dentin disks (n = 6/group) with 4mm thickness from twelve third molars were irradiated with Er:YAG laser. The dentin disks were prepared by polishing through a series of SiO₂ papers with water and cleaned by ultrasonic system. Four pretreatment were performed. The disks were etched with 37% phosphoric acid (group I), Er:YAG laser 80mJ, 3Hz, 30s. (group II), Er:YAG laser 120mJ, 3Hz, 30s. (group III) and Er:YAG laser 180mJ, 3Hz, 30s. (group IV). The Raman spectra obtained from normal and treated dentin were analyzed. Attention was paid to the mineral PO₄ (962 cm^-1), CO₃ (1073 cm^-1) and to the organic component (1453cm^-1). Raman spectroscopy showed that the mineral and organic dentin content were more affected in autoclaved teeth than in the specimens treated by Thymol. Peak area reduction in the specimens treated by Thymol in group I and II showed to be the most conservative procedures regarding to changes in organic and inorganic dentin components. Pulse energies of 120 and 180mJ showed to produce more reduction in the organic and inorganic content associated with more reduction in the peak areas at 960 and 1453cm^-1.

The author has, in the past, classified treatment methods for pain geometrically as point, line, two-dimensional, three-dimensional treatment and has used these over the years. However as a practitioner of western medicine, the author originally treated pain only directed at the painful site, and encountered cases where local treatment did not suffice. The author proved with SPECT and the Rand Phantom that treating the neck which is the midpoint of the brain, the center of the nervous system and the heart, the center of circulation, increased cerebral blood flow and also that laser emitted to neck will reach the spinal chord no matter from where on the neck the laser is emitted. From such research and 25 years of clinical experience, the author has created an anatomy based, systemic treatment method called the Proximal Priority Laser Therapy (PPLT) where not only the cerebral cortex, spinal chord and peripheral nerves are treated but also the tracts of blood vessels and lymph ducts are treated as well. Treatment method and cases are presented herein.

Low back pain, caused by lumbar disc herniation, is prevalently treated with a conservative approach. In this study we valued the efficacy of High Intensity Laser Therapy (HILT), compared with accepted therapies such as TENS and NSAIDs. Laser therapy obtained similar results in the short term, but better clinical effect over time than TENS and NSAIDs. In conclusion high intensity laser therapy appears to be a interesting new treatment, worthy of further research.

Objective: Low energy lasers are widely used to treat a variety of musculoskeletal conditions. The aim of this clinical study is to determine the action of the IR diode laser 904 nm pulsed on pain reduction therapy. Summary Background Data: With respect to pain, has been shown the Low power density laser increases the endorphin synthesis in the dorsal posterior horn of the spinal cord stopping the production of bradykinin and serotonin. Besides laser causes local vasodilatation of the capillaries and an improved circulation of drainage liquids in interstitial space causing an analgesic effect. Additionally, laser interferes in the cytochines (TNF-α, interleukin-1 and interleukin-6) that drive inflammation in the arthritis and are secreted from CD4 e T cells. Methods: Treatment was carried out on 555 cases and 525 patients (322 women and 203 men) in the period between 1987 and 2002. The patients, whose age ranged from 25 to 70, with a mean age of 45 years, were suffering from rheumatic, degenerative and traumatic pathologies. The majority of the patients had been seen by orthopaedists and rheumatologists and had undergone x-ray, ultrasound scanning, Tac, RM examination. All patients had received drug-based treatment and/or physiotherapy with poor results. Two thirds were experiencing acute symptomatic pain, while the others presented a chronic pathology with recurrent crises. We used a pulsed IR diode laser, GaAs 904 nm, maximum power 60 W, frequency impulse 1300 Hz, pulsed duration 200 nanoseconds; peak power per pulse 27W; maximal energy density: 9J/cm²; total number of Joules per treatment session: 10-75J/cm², chronic 12-90J/cm². Average number of applications: 12; maximum number of applications: 20. Results: In the evaluation of the results the following parameters have been considered: disappearance of spontaneous and induced pain (Likert scale, Rolland Morris disability scale, dynamometer). The pathologies treated were osteoarthritis in general, epicondylitis, tendonitis, periarthritis and neurutis, metacarpalgia, metatatarsalgia, Dupuytren's Disease. The summary of the results have been classified in very good = 44%, good = 52.8%, poor = 2.7%, nil = 0.36%, worse = 0%. Conclusions: Treatment with 904 nm IR diode laser interrupts the "circulus vitiosus" of the origin of the different pains (neuropathic, metabolic, traumatic, toxic, immune-mediated, ischaemic) and its development. LLLT brings a normal physiological condition back to the tissue, thus myofascial pain relief, decreases tension and substantially reduces the symptoms as well as improves the quality of life of the patients. More than that, we have discovered an acceleration of the healing process, early return to work and sport competition.

Crystals of Yttrium-Aluminum Garnet (YAG) doped with three-valence vanadium V₃₊ in tetrahedral position suggest e_cient passive absorber for lasers operating in range 1100 { 1400 nm. V₃₊:YAG is a hard and durable material which has good thermal conductivity, is chemically stable, and capable of being grown to very high quality. This solid state saturable absorber has high damage threshold and it can operate without optical degradation. The Q-switching and mode-locking has been obtained with a number of active media such as Nd:YAG, Nd:KGW, Nd:YVO₄ under ash-lamp and laser diode pumping in last ten years. We reported output improvement of the Nd:YAP (Yttrium-Aluminum Perovskite) ash-lamp pumped laser passively mode-locked with the V₃₊:YAG crystal. Laser has been operating at wavelength 1340 nm. Special _nishing of all surfaces was used to avoid operation at 1080 nm. Low-level transmission of V₃₊:YAG crystal was 28%. The optimal output coupler reectivity was 60%. With pumping energy 100 J stable generation of a single train of pulses was achieved with repetition rate 5 Hz. Length of the pulse train was 17 ns (FWHM); a single pulse was shorter than 1 ns. Energy at whole train of pulses 53mJ was obtained what corresponds to peak power 2MW.

In this study we evaluate the cytotoxicity of two photosensitisers with absorption peaks in the green and red part of the spectrum on animal cell lines. The cytotoxicity assessment was performed for a tumor cell line LSCC-SF-Mc29, obtained from a transplantable chicken hepatoma induced by the myelocytomatosis virus Mc29, a tumor line LSR-SF-SR, obtained from a transplantable sarcoma in rat induced by Rous sarcoma virus strain Schmidt-Ruppin and for normal mouse and bovine cell lines. Up to now the effect of the photodynamic therapy on virus-induced cancers has not been clarified. The cells were treated with 5,10,15,20 - tetra (4-sulfophenyl) porphyrin with main absorption peak at 519 nm and a dye activated with a red light. The cells were seeded in 96-well plates at 2 x 10⁴ cells/well. The cells were exposed to irradiation from a pulsed CuBr vapor laser at 510.6 nm and 578.2 nm and exposure rate 50 mW/cm², from an Ar-ion laser at 514 nm and 1 mW/cm² and to 655 nm-irradiation from a semiconductor laser at 10 mW/cm². The biological activity of the tested compounds was measured by the neutral red uptake cytotoxicity test. The light dose-response curves and light exposures that ensure 50% drop in the treated cells viability in comparison with the cells grown in non-modified medium were obtained for each cell line. The cytotoxic effect of both photosensitisers is most distinguished for the tumor line LSCC-SF-Mc29. The 2-4 times higher viability of the normal cell lines in comparison with the tumor lines is established. The bovine cell lines are more vulnerable than the mouse lines.

PDT has been a common treatment modality for cancer in the recent years. Compact non-coherent diode based light source has been investigated for their compatibility as a light source for treatments in vitro. The light emitting diode (LED) emitted a peak wave length of 400nm with a half-band width of 40nm. Cell proliferation as function of the LED exposure time was investigated as test for light source compatibility.