Author(s): Juergen Waldschmidt; L. Stroedter; T. Doede; A. Kischkel
Vascular malformations of the gastrointestinal tract are rare phenomenon. They are generally manifested by upper or lower GI - bleeding and do not resolve spontaneously. Emergency intervention is necessary. This paper reports on 10 cases, treated in the Dept. of Pediatric surgery of the FU Berlin, recorded from 1981 to 1999. We use the Nd:YAG laser 1064 nm, Fibertom 5100, Dornier, Germany, with a 600nm barefiber. Reduction in size of the hemangiomas and stop of the GI-bleeding was achieved in all cases.
Author(s): U. Waldschmidt; Juergen Waldschmidt; D. Cholewa; L. Stroedter
Retroperitoneal Lymphangiomas are rare tumor-like lesions, predominantly found in the new-born period and pediatric age. They are always benign. About 1 percent of Lymphangiomas arise in the retroperitoneal space. Until now surgical excision was the only consistently effective method. Compete excision of the tumor is in more than a half of the cases not possible, and the rate of occurrences is about 50 percent. Because of this background new therapeutic methods were sought. In 1986 we have introduced the interstitial laser therapy in the treatment of the Lymphangiomas and treated more than 200 cases, 10 of them were located in the retroperitoneum. Technique and results are discussed.
The present prospective study aims at determining whether denervation of the zygapophysial joints can be rendered safer and more efficiently by combining modern imaging procedures with the laser technique.
Author(s): Daniel A. Cassuto; Deborah M. Ancona; Guglielmo Emanuelli
Facial telangiectasias are a common cause of cosmetic concern. Current treatment modalities present various effects and limits. The pulsed dye laser has been considered the golden standard in efficacy and safety. Unfortunately it causes postoperative intracutaneous hematomata that discourage many patients form undergoing this treatment. Several other vascular lasers are disadvantaged by the risk of hypopigmented and atrophic scars. We assessed a recent powerful version of the potassium titanyl phosphate 532 nm laser, that can deliver sufficient energy in single pulses lasting 10-50 msec. Collateral damage is reduced while the heating of the vessel is slow enough to avoid explosive photothermolysis with its associated purpura. Sixty-six patients with facial telangiectasias were treated. In 62/66 patients, we achieved a 75 percent-100 percent clearance of the lesions, while two treatments were needed to reach an acceptable clearance in the remaining 4/66 patients. The overall need for more sessions was well tolerated, because the acceptable postoperative appearance allowed patients to continue normal business and social activities between treatments. No permanent complications or undesired effects were noted. The KTP/532nm laser is also being tested in combined laser-sclerotherapy of fine leg capillary telangiectasias with encouraging results.
Author(s): V. A. Mikhailov; I. N. Denisov; George A. Frank; N. N. Voltchenko
Laser therapy with semiconductor laser was performed on 41 patients with 2nd-3rd stage breast cancer. LLLT was used before surgery and in postoperative during 2 years. LLLT decreased postoperative complications by 15.3 percent and decreased duration of limphorrhea. 86.9 percent of patients with 2nd stage breast cancer survived 10 years after LLLT treatment. For patients with III stage breast cancer treated by LLLT the rate was 83.3 percent. 82.6 percent of patients with 2nd stage treated by LLLT had no recurrences in 10 years period. 77.7 percent of patients with 3RD stage treated by LLLT had no recurrences for the same period of time.
In 1988 we started our investigation on the influence of low-level laser on oncologic patient. Now we have an experience of application of LLLT on more than 700 patients with the confirmed diagnosis of cancer at different stage. We used LLLT on 112 with stomach cancer 4th stage before and after operation and on patients without operating interference. LLLT investigations, with a wavelength of 890 nm, have shown that the laser therapy before operation is most effective. Laser therapy activates the immune system by increasing T-active rosette-formed cells and T-helpers and by decreasing T-suppressor cells. Application of LLLT decreases postoperative complications by 11.86 percent after palliative operations; by 9.63 percent after non-radical operations. It also promotes more rapid restorations of the motility and improves general status of patients by 58.69 percent. Investigations of low-level radiation have shown that the life-span of patients with 4th stage stomach cancer who were treated by laser therapy before surgery was increased by 2.03 percent; for those who were treated by LLLT after surgery it was increased by 1.81 times and by 3.03 times in those who took LLLT without surgery.
Transmyocardial laser revascularization was found to be a new way how to convey oxygen-rich blood directly from the left ventricular cavity to the myocardium. In our study, a comparison has been made of the interaction of mid-IR solid state laser radiation with a myocardium tissue. For this purpose, the CTH:YAG, Tm:YAG and Er:YAG laser systems were designed, constructed and used for the interaction experiments. Besides those mid-IR lasers, the commercially produced CO2 laser was used for the comparative study. The ablation coefficients were measured to be 0.029 mm/J for CTH:YAG laser radiation; 0.061 mm/J for Tm:YAG; 0.75 mm/J for CO2, and 10.5 mm/J for Er:YAG. From the histological examination follows that only the channels ablated by Er:YAG laser radiation are without any thermal damage of the surrounding tissue and with the minimal mechanical injury. As a conclusion - Er:YAG laser could be considered as a good candidate for the TMR besides CO2 laser.
Previous investigations of transmural capillary ingrowth into the inner surface of biosynthetic vascular prostheses through perforations created by an excimer laser have shown that spontaneous endothelialization of the protheses can be achieved. Disadvantages of the excimer laser are a large and non-circular beam profile and an inconvenient handling of the UV-radiation for medical applications. Therefore, a new commercial laser system, consisting of a mirror-dispersion- controlled Ti:S oscillator and a femtosecond multipass amplifier, which avoids these disadvantages was sued to perforate grafts made of a new biomedical. The laser-tissue interaction is based ona different mechanism due to the short pulsewidth high peak intensity and near IR wavelength. The very short pulsewidth reduces thermal damage of the tissue. The basic mechanism of the laser tissue interaction is not yet fully understood and still subject of investigations. Several biografts with 1 mm wall thickness have been used. The hole diameter could be varied between 50 and 200 micrometers and the distance between the holes was 4 mm. At laser intensities of approximately 20-30 TW/cm2 and a repetition rate of 1 kHz it took less than a second to drill a single hole. Subsequently to the perforation procedure, one perforated and one untreated biograft were implanted into the carotid arteries of several test sheep. It can be concluded that very intense near IR laser radiation is an ideal means for structuring biological tissue.
Hair regrowth is a common problem in our practice as well as a frequency complaint from our patients after treatment with pulsed light. In response to those complaints various parameters should be taken into account; among them one has to consider the necessary time for regeneration of pulled- out hair before treatment which varies according to the body area. Causes for real regrowth and apparent regrowth should be carefully evaluated and a balance between appropriate and excessive treatments should be made.
Lasers with a wavelength between 351-1064nm, preset fluence and pulse duration induce a selective thermolysis of tissue chromophores. Specific exogenous chromophores, such as indocyanine green, are used in ophthalmology, in photodynamic therapy, in welding, and more recently for epilation. The aim of our study was to assess the effectiveness of a wavelength of 808nm on tissues stained with different exogenous chromophores whose absorption curves we studied by spectrophotometer. Out of five chromophores, methylene blue proved to be effective at 808nm. We tested the diode laser 808nm, at focused powers of 1, 2, 3, 5, 7 W in cw, for 1, 2, 3, 5, 7, 10 sec on skin specimens stained with 1 percent methylene blue in a small- spot sequence. At low powers the destructive effect was highly concentrated, both in depth and laterally, while greater intensities result in marked destruction even after a short irradiation time. The use of exogeneous chromophores increases absorption and reduces laser energy transmission and scatter. This study confirms that the selectivity of 808nm lasers can be 'tricked' since thermolysis is confined to the stained areas and there is less risk of damaging surrounding areas in the event of abrupt movements by either the surgeon or the patient, especially in the case of emotionally unstable or very young patients.
Until now there is a lack of objective methods to evaluate the clinical efficacy of low level lasers (LLL). The reported results in this paper are showing that the cutaneous ultrasound could be a valuable method to be used in order to objectify the results obtained in low level laser therapy (LLLT). 52 patients with osteoarthritis were divided into three groups: Group A:19 patients treated with IR emitted laser diode, CW, 3mW power, 780 nm wavelengths. Group B: 18 patients treated with the same IR laser diode as above and He-Ne laser, CW, 2mW power. Group C: 14 patients exposed to placebo laser. To every patient was done cutaneous ultrasound before and after LLLT and we followed also the clinical evolution. The positive results meaning significant US favorable changes were found in 73.9 percent for group A and 77.7 percent for group B and 21.4 percent for PLACEBO group. We conclude that cutaneous ultrasound could be an objective method to appreciate the clinical efficacy of low power lasers.
Studies on beam power behavior in time and laser beam mode structures of laser diodes/LEDs used in low level laser therapy (LLLT) were performed. Two laser diodes with cw emission in red at 635nm, a cw laser diode emitting in IR at 904nm and 2 LEDs which emit radiation at 904nm, respectively 650nm were analyzed from the point of view of the beam power, 3D, 2D distributions and the variation of radiation intensity in time. A laser beam analyzers, model LBA-100 was used for laser beam profile studies. The time behaviors of the lasers/LEDs beams intensity were achieved with a LASERSTAR energy meter, OPHIR OPTRONICS. These studies are very useful for establishing the appropriate irradiation doses and procedure for LLLT.
The article aims to make a comparison, starting form a review of the available literature data, between the low level laser therapy and the light emitting diode therapy (LEDT) applied on human patients. The main conclusion is that too little research efforts have been devoted on the effects specific to LEDT. More than that, it is the authors opinion that every device claiming to heat has to prove the effectiveness in controlled studies.
Much more precise laser treatments are possible with application of new methods for measurements of selected parameters of tissues during a laser treatment. It enables us to eliminate large necrosis areas occurring near the regions exposed to laser radiation. An analysis of the chosen metrological problems arising during the trials of minimization of side effects of laser surgery was performed on the basis of phenomena of pulsed interactions of laser beam with biological tissues. The main problems dealt with determination of parameters of biological tissues being within the region of laser beam interaction, significant for a course of laser treatment and its duration, have been pointed out.
Author(s): Mihail-Lucian Pascu; Marin Ristici; E. Ristici; Madalina-Elena Tivarus
For the low power laser therapy, the experiments show that better results are obtained when the laser beam is an overlapping of two radiations: one in the visible region of the spectrum and the other in IR region. Also, some experiments show that for good results in biostimulation it is important to have a high coherence length of laser beam; this is not the case of the laser diodes The He-Ne laser has the best coherence, being able to generate laser radiations in visible and IR. It has tow strong laser lines: 633 nm and 1.15 micrometers . Although their gains are about the same, the available power of the red radiation is 3-4 times higher because of its larger width, when they oscillate separately. Using special dichroic mirrors for simultaneous reflection of the both liens, the laser beam will consist of the two radiations, each of them having good coherence . A 420 mm active length, 1.8 mm inner diameter He-Ne laser tube and a special designed resonator has been developed. The mirrors reflect both radiations as follows: one reflects 99.9 percent and the other, the output mirror, reflects 98 percent. There is a competition between them because these lines have a common lower level. The output power of the laser beam as 6 mW for 633 nm and 4 mW for 1.15 micrometers , respectively.
Author(s): A. Antipa; L. Trasa; Mihaela O. Pascu; Ruxandra Pascu
It is well known, in the low level laser therapy, that an important number of patients exhibit positive results at PLACEBO treatment. That is why we decided to analyze the psychological profile of 156 patients presented rheumatical diseases, divided into tow groups: laser group and PLACEBO group. We applied the Woodworth-Mathews test to all patients before the laser treatment. This is a test for identification of the abnormal tendencies in the normal human behavior. Finally, following the PLACEBO exposure, we noticed that the patients' emotional tendencies and psychological instability had a strong influence on the obtained good results. We conclude that the Woodworth- Mathews test is useful to anticipate the possible false/positive results in the real treatment. Nevertheless it may also be used from the psychological point of view.
5-Aminolevulinic acid (5-ALA) has been proven to induce selective accumulation of flourescent Protoporphyrin IX (PPIX) in many types of malignant tissue. According to the target to treatment different routes of topical and systemical application of 5-ALA can be chosen. They include techniques like inhalation, installation and rinsing. For fluorescence detection a lamp based system have been developed in the laser-Forschungslabor in Munich together with Storz company. By skillful balancing of excitation filter centered around 400 nm and the observation filter with transmission above 450 nm images with high color contrast can be obtained. The universal application of the D-LIGHT could be demonstrated in different clinical disciplines like urology, neurosurgery, ENT clinic, gynecology and others.
Author(s): Herbert G. Stepp; Reinhold Baumgartner; Ruth Knuechel; M. Kriegmair; H. G. Stepp; D. Zaak; Alfons G. Hofstetter
We report about the experience obtained in the fluorescence cystoscopic evaluation of 647 patients investigated since 1993. Of all histologically confirmed tumors, 32 percent would have been missed with conventional cystoscopy. Only 16 of 38 CIS were also detected under white light. In patients with entirely normal or unspecifically inflamed appearing mucosa, 44 otherwise invisible malignant lesions could be localized by fluorescence, 16 of them being present in patients with negative bladder washing cytology. The specificity of fluorescence cystoscopy is comparable to white light cystoscopy. A prospective multi-center study was conducted to show, whether a fluorescence controlled transurethral two weeks revealed residual tumor in 53 percent in the white light arm compared to 33 percent in the fluorescence arm. This difference was statistically significant. Of the 33 percent tumor in the fluorescence arm, most was gathered within the resection margins of the first resection, indicating an insufficiently deep resection rather than a failure in detecting the lesion.
Photodynamic therapy (PDT) involves the administration of a photosensitizing agent and its subsequent activation by light of the appropriate wavelength, resulting in destruction of cells containing the agent. PDT has been designed as a promising new modality in the treatment of various malignant and nonmalignant disease since the early 1980s. Recent chemical and physical developments have brought forth new methods of PDT. We provide an overview of photosensitizers, photobiology and photochemistry, and light sources available for PDT. Clinical and preclinical PDT studies are discussed.
The spectroscopic characterization of synthetic porphyrins such as TPP, TSPP, ZnTSPP, etc. is reported, namely: absorption and laser induced fluorescence spectra in different solvents. Results about the photo toxicity of such photosensitizers in 5 percent DMSO in ns NaCl 0.9 percent on rats are shown proving the good acceptance of the solutions by the rats organisms with immediate perspectives for application on human patients. The second main line of experiments was devoted to the measurements of the irreversible modifications induced in the cell structure of the brain malignant tumors - impregnated with photosensitizers solutions - by the nitrogen pulsed laser radiation. 'In vitro' samples of brain tumor tissue were prelevated and impregnated with photosensitizer solutions during 1 hour to 48 hours. The samples were treated and kept so that before and after exposures to the laser beams the modifications due to other factors than the laser irradiation be avoided or minimized. The exposures to laser radiation were made along time intervals form 3 minutes to more than 1 hour. Irreversible modifications at cellular level following the interaction of impregnated cells with laser radiation were evidenced by optical microscopy. Concluding remarks are made about further 'in vivo' application on human patients.
Author(s): W. L. Mang; K. Sawatzki; K. Plinkert; D. Rieger
In the past, treatment of facial wrinkles with the method of skin resurfacing, using the Ultra pulse CO2-laser, has gained in significance. However, the media, as well as fellow colleagues, often face the laser method too uncritically. To get good results, the applying surgeon not only has to dispose a well-founded physical basis-knowledge or dominate different methods, but primarily he has to give the indication correctly. Therefore - in our experience - in case of a wrinkle-depth more than one millimeter, the dermabrasion, the underpadding or the combination of underpadding and laser treatment are superior to the single laser dermabrasion. When the skin is flabby and hanging down, surgical procedures have to be applied. By the follow- up of 200 patients, the effectiveness and potential complications are shown. On one hand, histological investigations of human tissue, which was tread with the ultrapusle CO2-laser, should show which doses were necessary to generate a visible effect and on the other hand, should determine which doses cause damage in the tissue.
Today, laser resurfacing technique is codified. The purpose of our study is to reduce the post-intervention discomfort and the clinical signs. We tested a combination of pharmacological substances, applied as spray lotion and gel during and immediately after the intervention and the days after. We used this substances after laser resurfacing done with CO2 laser, Er:YAG laser and both. We noted a reduction statistically significant of the signs up described, with reduction of the recovery time. It is our opinion that this medical treatment must be done always, during and post laser resurfacing treatment.
Author(s): Leonardo Longo; A. L. Piccinetti; G. D. Monache; G. Botta; S. Mancini
The best treatment of these stretch mark is still unknown. Some authors proposed the treatment with flash-lamp-pumped dye laser 585 nm, with fluence over 8 J/cm2. Reviewing our experiences on no-surgical effects of lasers in the various phases of the wound healing, including the re- epithelization, we would like to apply the no-surgical laser therapy treating the stretch marks of breast, abdomen and lumbo-sacral region. The goal is to inhibit the fibrous tissue metabolism, encouraging the destruction of the collagen fibers with inflammatory mechanism, and increasing the reconstitution of the superficial dermis layers. We treated five cases of stretch marks in women 22-35 years old, since May 1999, with a cycle of applications of double lasers, 511 and 577 nm, with energy of 20 Joule for spot, respecting the maximum thermal relaxation times of the skin. We waited two weeks interval between the applications. Results obtained after five applications are very positive, and we are encouraged to continue this experimentation.
The author who is inventor of EasyPeel then Laserpeel wants to introduce new ways to choose the right indications for patients asking for cosmetic surgery. A lifting is as if you take a shirt and want to reduce its size cutting it. A resurfacing is as if you put a shirt and want to iron it. A peeling was as if you changed the color and grain of the shirt. Laserpeel is as if you iron the shirt treated with amidon, transform the second hand shirt as new, up to date on with glance effect sand give it then a stretching disco new wave effect. So, indications of facial lifting decrease at the same speed at the increase of indications of 'LASERPEEL'. Laser CO2 resurfacing should reborn because the post redness appearance decreases in intensity and duration due to LASERPEEL. LASERPEEL should be considered too as a preventive therapy coupled with preventive treatment resulting from longevity tests.
Author(s): Benedikt W. Sedlmaier; Sergije Jovanovic
Papillomas are the most common benign neoplasms of the larynx and trachea. There are two types with different biological behavior, both caused by the human papilloma virus: the form that usually manifest itself in adults as a solitary, rarely recurring lesion, whereas one form that manifests in children and adults. It involves multiple lesions with a tendency to spread and recur. There is still no alternative to repeated surgical removal of the papillomas. In a retrospective study the results of laser surgery are compared with the results of instrumental removal of papillomas. The larynges were treated with the CO2 laser applied via high-precision micromanipulators combined with different scanner systems. In cases where the disease has spread into the cervical trachea, the papilloma foci were exposed by special subglottoscopes prior to transglottic removal with the CO2 laser via the operating microscope. The Nd:YAG laser applied through a jet ventilation tracheoscope via optical fibers has proven useful for involvement of the intrathoracic trachea. The use of the laser has not reduce the recurrency rate but the rate of late complications such as anterior synechia. Furthermore in extensive disease laser therapy enables a controlled bloodless removal even in the thoracic trachea and bronchi.
Author(s): Peggy Voigt; Sergije Jovanovic; Benedikt W. Sedlmaier
Laser treatment of skin changes has become common practice in recent years. High absorption of the CO2 laser wavelength in water is responsible for its low penetration dpt in biological tissue. Shortening the tissue exposure time minimizes thermic side effects of laser radiation such as carbonization and coagulation. This can be achieved with scanner systems that move the focused laser beam over a defined area by microprocessor-controlled rapidly rotating mirrors. This enables controlled and reliable removal of certain dermal lesions, particularly hypertrophic scars, scars after common acne, wrinkles and rhinophyma. Laser ablation of rhinophyma is a stress-minimizing procedure for the surgeon and the patient, since it is nearly bloodless and can be performed under local anaesthesia. Cosmetically favorable reepithelization of the lasered surfaces is achieved within a very short period of time.
Author(s): Benedikt W. Sedlmaier; Antonio Jivanjee; Uwe Schoenfeld; Sergije Jovanovic
Tympanic ventilation is the treatment of choice for otitis media with effusion (OME). CO2 laser myringotomy has already proven its value and is finding increasing clinical application. The ventilation time in the middle ear is essentially determined by the size of the laser perforation. Perforations exceeding 2 mm in diameter enable tympanic ventilation for about three weeks and thus compete with the ventilation tube in the treatment of OME. IN a prospective study, laser myringotomy is performed in 84 children with OME with the new CO2 laser otoscope Otoscan. The closure time was 17 days in average for a preformation diameter of 2 mm. In the further clinical course, the ear-drums healed without atrophic scar formation. In an observation period of six month the recurrency rate of effusion was approximately 10 percent. Laser myringotomy seems to be an useful method in the operative therapy of secretory otitis media.
Author(s): Ronald Sroka; Andreas Leunig; P. Janda; P. Rosler; G. Grevers; Reinhold Baumgartner
Clinical studies were performed to assess the clinical outcome of laser assisted endonasal turbinate surgery in long-term. By means of a pulsed Ho:YAG laser emitting at (lambda) equals 2100nm 57 patients suffering form nasal obstruction due to allergic rhinitis and vasomotoric rhinitis were treated under local anesthesia. Furthermore 50 patients were treated by means of light of a diode laser. The light was fed into a fiber being introduced into a fiber guidance system which serves for suction of smoke and pyrolyse products. The distal part of this system could be bent in the range of -5 degrees up to 45 degrees due to the optical axes of the fiber. The study was conducted by a standardized questionnaire, photo documentation, allergy test, mucocilliar function test, rhinomanometry, radiology and histology. Within 2 weeks after laser treatment a significant improvement of nasal airflow correlating to the extent of the ablated turbinate tissue could be determined. This effect lasted up until 1 year post treatment resulting in an improved quality of life in more than 80 percent of the patients. Side effects like nasal dryness and pain were rare, no immediate complications were observed. The total treatment time took 3-8 minutes/turbinate and nasal packing was not necessary after the laser procedure. In conclusion laser treatment by means of the fiber guidance system can be performed as an outpatient procedure under local anesthesia with excellent ablation of soft tissue in a short treatment time with promising results. It will become a time and cost effective treatment modality in endonasal laser surgery.
A variety of surgical procedures has been introduced for the reduction of hyperplastic inferior nasal turbinates. We describe the results of the submucosal laser turbinotomy with the Nd:YAG laser in 15 patients as a new simple, effective and low-risk operation method, which leads to early subjective and objective improvement of nasal breathing.
Using a self-regulated power delivery system at low power rate in contact mode, the Nd:YAG-laser is a safe tool even in such delicate regions as the paranasal sinuses. patients profile from early ablation of local recurrences, before extensive revision surgery becomes inevitable.
The authors present their clinical experience regarding the possibilities of application of Nd:YAG and Ho:YAG lasers for the treatment of disorders in the are of the upper respiratory tract. The patients with symptoms of Obstructive Sleep Aphnoe Syndrom need a various operations techniques. Lasers techniques makes it possible to perform a number of procedures in local anesthesia which considerably improves the economic effectiveness of the treatment. The surgeries performed using laser beam enabled very good effect of treatment.
During more than 5 years Nd:YAG and Holmium laser has been used in our ENT Department for the treatment of varies pathological changes. Most of our cases were previously treated many times because of recurrences of the nasal polyps. As a rule the treatment was given in one to three sessions. Each patient was very closely monitored. The time period between the session was 2-4 weeks. The consequent application of laser was dependent on healing process. All adults' patients were treated in local anesthesia using 1,5 percent of Cocaine and 10 percent Xylocaine applied in a spray; no other anesthetics were needed, although in some patients 10 mg Valium was administered before first session of laser application. We do not observe a severe bleeding needed sponge or a nose package. Among advantages we have to concentrate on two: the recurrences of nasal polyps are definitely much rare and patient may appear at work at the same day.
Microscopic and endoscopic surgery are the current widely accepted state of the art for the treatment of chronic polypoid sinusitis. Postoperative recurrence of the disease is reported in 12-25 percent of the patients. Revision surgery mostly requires similar surgical techniques. Therefore, modifications of the primary micro surgical technique were worked out to allow wide endoscopic accessibility postoperatively. Nd:YAG laser surgical tools for the endoscopic application of laser fibers were developed for minimal invasive revision surgery. Applicators for proper fiber positioning within the paranasal sinuses were constructed. Meanwhile n equals 92 patients are treated over a period of two years. 90 percent of the patients with recurrence are free of symptoms and pathological findings for more than six months. Among two treated patients two developed hyposensitivity of the pterygopalatine nerve for two and six months respectively. No further complications were seen. The new endoscopic laser surgery of the paranasal sinuses reveals a reduction of sinus disease recurrence in 90 percent of the patients.
This study has been inspired by the European Medical Laser Association, and was conducted in cooperation with the ENT Department of the Jarov Policlinic and with the ENT Clinic of the Faculty Hospital FNKV Prague headed by associated professor A. Hahn, MD.
A major argument among the opponents of laser therapy has been the absence of scientific documentation. This was a valid position in the 80s and partly in the 90s. But today, is this still a sound argument. There are more than 2,000 published studies in the field, including meeting abstracts and anecdotal reports. The vast majority of these papers reports positive effects of LLLT in vitro and in vivo. It is fair to argue that negative results are less prone to be published, but certainly more than 80 percent of the published studies are positive. In the field of dentistry, for instance, the positive percentage is well above 90 percent. The present literature study will look at the heart of the positive documentation: the positive double blind studies. It may come as a surprise to many critics that there are more than 100 positive double blind studies in the field laser therapy. This is a god base for a further understanding of the effects of low level laser in the clinical setting. We must, however, be as critical as the sceptics themselves in order to obtain a constructive dialogue between 'attorneys' and sceptics. In this paper, a critical review of 100 positive double blind studies will be presented.
The relationship between dental plaque and gingivitis was verified. Nonspecific gingivitis is an inflammatory process, frequently caused by enzymes and toxins liberate by bacteria form dental plaque. Loose plaque has come under a great deal of investigation because of its role in attachment loss. The current methods used in the treatment of non specific gingivitis encompass the use of antibiotics and conventional surgical techniques. Treating gingivitis with laser energy may further reduce the gingival inflammation and decrease the wound healing time. The lack of correlation between the quantity of dental plaque and the intensity of gingivitis determined us to study the effect of Nd:YAG pulsed laser in reduction of gingival inflammation and wound healing. The aim of this work is to evaluate clinically the anti- inflammatory and wound healing effect of pulsed Nd:YAG laser and to compare the appearance and the levels of the bacteria in the supergingival and subgingival plaque in adolescents with tooth crowding after Nd:YAG laser. The experimental procedure consisted of a clinical and bacteriological study which was undertaken in 20 patients presenting moderate gingivitis. A group of 10 patients was the subject of a bacteriological study and the other group of 10 was used for clinical and histological examination. For each group the clinical criteria of evaluation were: the gingival index, papillary bleeding index, spontaneous aches. Each patient was tested before and after laser exposure or conventional therapy for bacteriological analyses. The results prove that early gingivitis exposure to laser registers a decrease of bacterial colony number and absence of loss of attachment as compared to the application of the conventional treatment. Clinical study has shown that the combination of scaling and root planning with laser therapy is enough to provide improvement in clinical indices and reduction in the number of bacterial colonies.
The purpose of this study was to observe the response of surrounding tissues on long-term presence of coated titanium implants under loading. The protective layer based on hydroxy apatite was created by the method of pulsed laser deposition with KrF excimer laser on the kernel from pure titanium. The coating thickness was about 1 m. Implants were inserted into the mandible of minipigs up extracted premolars. After 14 weeks of healing without loading the metal-ceramic crowns were cemented and implants were moved in to the occlusion. Six months after the crown application the experimental animals were sacrificed and from the bone blocks with implants were manufactured microscopic ground sections. The implant position in the bone were determined by radiovisography. The bone structure around the implants were viewed in the microscope using transmitted light. Observation after six months long functional loading acknowledged the presence of newly formed bone around all implants. In no samples were found any inflammatory or regressive changes. Osseointegration of both surface types was similar.
Author(s): Frederick M. Parkins; Thomas J. O'Toole; John M. Yancey
Previously herpes labialis and recurrent aphthous ulcers have not been successfully treated. A preliminary study with a pulsed Nd:YAG laser evaluated the results with a protocol of four minute non-contact exposures for both types of lesions. Most patients experienced relief of symptoms. The progress of herpes lesion was halted and aphthous lesions became desensitized.
Author(s): Wolf-Dieter Mueller; Christiane Schoepf; Klaus Ibendorf; Sigfried Rogaschewski; Klaus-Peter Lange
Laser welding of dental alloys is much more easy and faster than the soldering procedure of the same materials. Requirements for application of such junction are their stability and biocompatibility. Last is strong connected to the electrochemical, means corrosion, stability. Corrosion stability can be assessed by current (I) vs. potential (E) curves. The problem is the preparation of specimens and also the interpretation of the shape of I vs. E curves. The aim of this work is to demonstrate a new cell configuration for a fast and easy measurement routine. In this way it is possible to assess the electrochemical behavior direct and without preparation of separate specimens. The application of such system is possible in each technical lab and so it should be possible to reduce failures during the selection and combination of materials.
The aim of this study was to evaluate the different frequencies of low-level laser radiation on healing process after human molar extractions. Frequencies of 5 Hz, 292 Hz and 9000 Hz were used in experiments. Monitoring of secretory IgA and albumin level in saliva and changes in bone density were used as objective markers of biostimulatory effect. Subjective evaluation of therapy was observed using scale. Changes of sIgA, albumin levels and bone density were compared in group of 150 patients. Differences in levels of the saliva markers were found to be significant comparing irradiated and non-irradiated groups, as well as comparing groups irradiated by various modulatory frequencies. We observed significant differences between the increase of sIgA res. Albumin and subjective treatment feelings. Bone density after extraction and six-months after surgical treatment was examined using the dental digital radiovisiography. There were detected no significant differences between bone density in irradiated and non- irradiated groups perhaps due to our used therapy diagram.
Non-invasive laser therapy is currently frequently used in stomatological practice thanks to its analgesic, anti- inflammatory and biostimulating effects. Suitable indications and methodic procedures of treatment should be established to provide the relevant efficacy of the method. The work characteristics the efficacy of the treatment in selected indications with checking suitable physical parameters of laser radiation. The study was carried out on total of 382 patients divided into three groups depending on the method of the treatment. The treatment result were evaluated based on the above-mentioned effects expressed with the help of relevant coefficients. The result demonstrated the contribution of therapeutic laser to the treatment of herpetic affections, aphthae, erosions, decubiti on the mucous membrane, conditions after difficult extractions, papilitits, wounds after teeth resection, linqua geographica, scar and treatment aimed at reducing the dentin sensitivity.
Author(s): Manlio Curti M.D.; Valerie G. C. Zwilling; Marc Bolla
This study was conducted to compare and evaluate the structure and the micro hardness of FUJI II LC cured with Argon laser versus conventional vision light. The influence of Argon laser power for a constant curing time and the effects of aging in an humide environment on structure and the micro hardness are also investigated.
The aim of current multicenter clinical study was to assess the efficacy of low energy-level laser therapy (LLLT) in the treatment of soft tissue injuries compared to the placebo and classical phyiotherapeutic procedures. This clinical study was conducted in two centers located in Locarno, Switzerland and Opatija, Croatia. Two types of irradiation techniques were used: (1) direct, skin contact technique for treatment of trigger points where IR diode laser 830 nm continuous wave was applied; and (2) scanning technique for irradiation of larger surface area with use of Helium Neon laser 632.8 nm combined with IR diode laser 904 nm pulsed wave. Results were evaluated according to clinical parameters like: hematoma, swelling, heat, pan and loss of function. The findings were statistically analyzed via chi- square test. Results have demonstrated that the recovery process was accelerated in 85 percent of patients treated with LLLT compared to the control group of patients. The results and advantages obtained proved once again the efficacy of LLLT as a new and successful way to treat soft tissue injuries.
In the literature, the given parameters are seldom well enough specified. Because of that, it is not possible to repeat a study - even if the intensities to repeat it, it will always be a new and different one. The dose, for instance, is usually given as a single value and this is not unambiguous. As a matter of fact, no matter how a treatment is carried out, the dose is never a single constant factor. Our intensities is to shed some light on the complexity of the dose distribution in treated tissue and to give some recommendations in the specification of the dose in future reports on laser treatment.
Bronchial asthma is a common disease in both the pediatric and adult populations, characterized by wide variations over short periods of time in resistance to airflow in intrapulmonary airways. A primary goal in the use of low- level laser therapy (LLLT) was the safe, effective and rapid palliation of symptoms owing to tracheal or bronchial obstruction. We have investigated the effects of LLLT comparatively with other modality trials in children's asthma. In the study were included 98 patients aged 10-18 years diagnosed with moderate or severe asthma, in attack- free period. The patients were divided into 3 groups. Group 1 received only laser therapy using extra meridian acupuncture points and scanning technique. Group 2 was treated only with inhaled Serevent 2 X 25 micrometers , two times daily, 3 months. Group 3 was tread with Theophylline retard in dosage of 15-mg/kg/12 h, 3 months. At the end of treatment we remarked a noticeable improvement of the clinical, functional and immunological characteristics at 83 percent of patients in group 1, comparatively with only 70 percent (group 2) and 53 percent (group 3). The LLLT had a very good action on bronchial patency , displayed an immunocorrecting action and is recommended in attack-free periods at children.
Author(s): Laura Ailioaie; C. Ailioaie; Fl. Topoliceanu
Allergic rhinitis is the most common allergic disease affecting many people worldwide. Low level laser therapy (LLLT) was applied as monotherapy to 32 children, under placebo controlled conditions. There have been used two GaAlAs diode lasers. The density of energy and the frequency 2 sessions daily - were applied under a special experimental protocol of treatment, including endonasal regions treated with an optical fiber and the extrameridian acupuncture points for rhinitis, 10 days monthly, three months consecutively. The initial investigations with fiberoptic rhinoscope revealed a swollen, pale and edematous mucosa, with increased nasal sections, which may be watery to mucoid. At the end of LLLT, the symptoms of rhinitis like sneezing, nasal congestion, stuffy nose, mouth breathing, snoring - have disappeared and the aspect of nasal mucosa was normal. The results could be explained in the new scenario of self-organizing phenomena at membrane level. The physiological beneficial effects may be correlated and possibly explained by self-organizing paradigms. Our result warrant that LLL is a very good therapy modality for children suffering from allergic rhinitis.
Vaginitis is the most common female infectious disease. Females suffering from this disorder are annually increasing in number. There are a lot of modalities of treatment of vaginitis, but because of drug allergy and microbe's stability to drug the treatment of vaginitis is difficult. Our study compares the efficacy of laser-therapy with drug therapy in the treatment of non-specific vaginitis and vaginal candidiasis. Thirty women reci4eed the LLLT by local action with antiseptic liquid daily during ten days, 20 women received metronidazole and fluconozole and vaginal application of metronidazole. The results suggest that local laser-therapy is able to remove sights of vaginitis more efficiently and faster than drug therapy. Repair of normal vaginal microflora, which is the best indicator of recovery, was significantly at a faster rate in laser-therapy group. There were no report of adverse reaction with vaginal laser- therapy, whereas there were women on drug therapy who reported side effects. In conclusion, vaginal aser-therapy with antiseptic liquid is a suitable, effective, safe and chip alternative to drug therapy in the treatment of vaginitis.
Author(s): V. A. Mikhailov; O. A. Alexandrova; I. N. Denisov
Use of LLLT for 42 patients with an autoimmune thyroiditis has shown that the helper function of lymphocytes has decreased, the suppressive activity has increased, the quantity of B-lymphocytes has decreased and the immunoregulative index has been normalized. The effect of LLLT application was active about 4 months in 78 percent of the patients. Soft semiconductor laser was used. The radiation was in the IR range of spectrum, wavelength - 890 nm. The technique included cutaneous irradiation of the thymus projection zones, vascular junction and thyroid gland. The total doze was made 2.42 J/cm2.
Author(s): V. A. Derbenev; V. A. Mikhailov; I. N. Denisov
The purpose of this study was to compare the efficacy of the treatment of some pulmonary diseases with our without LLLT. 130 patients received LLLT and drug therapy, and 30 patients received only drug therapy. The obtained results on the use of LLLT show that the period of convalescence in patients with both pneumonia and exacerbation of chronic bronchitis was lower with 4-6 days compared with control group. 68 percent patients with chronic bronchitis have staunch remission more than three months. Patients with bronchial asthma reported the decreasing of both number of bronchospasms and doses of bronchodilators and glucocorticoids after LLLT. They have no exacerbation of asthma during 3-6 months; then these patients need the repetition of LLLT. In conclusion, LLLT is the suitable and effective complement to the treatment of pulmonary diseases.